wy RAR AERIAL e ea yy acne islet yes BO 2 C " vet ni mena a iariart eh vena Vreans SON vay 4 y hates Wa utaronaie he Vey tony . faaly vubalo ob Ady vinivtnsstyn we carte alah Hh eae Win wn b rae te Durer) oy atti May yuh leethsy hae tly ay a nT n Oa htitatysiy th QSh te yey Vali TUN ately Lnsetntaatecm a: aace Or eRe ELPA? Natya vita RMON CINE nT SN eiata te nlath ttn ih TORMENT is aia ive . nha WAS EASE A Ornay gala eet tgh Wri ‘ vst Al RU USN Whe a ae \ Vive WAY SRI Si Ra agate wit " rx Vi A ate gate catvabinacanrealy h BERS CHEN Bae “a eaaytien the LAr Nha MATTEO en Y SACHA aA ec TUS ERG eaesl Deneroan i LEN hint sy iy aes Hy a oa yy Jiavala ly atncas ue a en ee bia s. ee tr eG RE MAnCar AML NH RMT REEL) ea eee ta SAE Alat ta Ny case angle AN hota nate at aad tatat uated lists ait ata Gata ae BUOOOS een Athiataretahicnea tic aty es stats a feth SHDN ie whee eee * hy SoA NERA Na gy AINA Ara) sl (esata) irnato Senta ouror : athe CNN FOR Rare OHS ‘ate telnet menses STA nls iy nth a rteata a! ain nent? ate stiithtaspar ae Pi avec bs tras Hiiee ty Jas tain oy fe pan Ati omearaas in veda he RO eat DOUG Lc het) ra te vatae dade st aur Ae STROVE EOIN SUVA Ua Riala"uvss en ak wn tela wa yet 4 Conner cn on itis OMA TET ESE Writ bh ‘ay ee Th Aes ae AA hana » CONT RENE a TE) TUN teal aan Salt keg ONS 8 EMS NN ABE A NSMAD A Tag on Ay Bia maraymte A bes Norse CRT Ee OT ta CCITT r ota ree E ny Veni nina mte bys Mp a hy hem Ma twa Ae ae ea em HA vlgee is ae viene Sie Vheathreteens a Nica rar sre me PETENCRLILY) Simcn ashe ma joe yea Nal Tate iain sah hoa ae saint no Jercgye yy wok Te ae TOO anata rane vhs Shai tin BS Vee an Ne ANS aT ea aling Wy utimeyae Ake eM phase Ae tee Wa Re hase Ariba it . “ i Pietro anise Snes ta ene ea Oke NARs TiAsaet cal eae shi ninim A pelaretee aN inontocy terested Pree sek nese zai srt Bch Cy Peteeoipetiar tt beh et sa TeEh OU fia « ss ta NS Dynes A ptete ve seyeit a: nota wew tates i Sbas cLee hs ph CiANEEY de { ra hot Reva gy! aor one ; (A Begone ee aaa ape tae * y Sine Nyaa ee EN eee veld slataetvean reloeg PML As eet Niue eer stipe vias Bahenihien iis Writs’ gra (este ego) a (Vuk gee ety ates " te rs : Raa Bate ae Peseta ete to" it ae pds SA Rd 2 whol WevVeswwwetenrets wWwatiwevwv:” Se ee oan FS A es eee te ee a eee ee z Be es tS Bae hilt < = E = W]y,: = z 5 = 5 o =a 2 Oo x o NY xr - O ea x wn ee WN Da Bo An a 7 fo) se ASD oO 35, : vw Oo a oO = 2 . = NS = E Qvyy 2 = 2 : = = “E Se z = ? SMITHSONIAN INSTITUTION NOILNLILSNI_ NVINOSHLIWNS S3IYVYGIT LIBRARIES SMITHSONIAN INSTITUTIO n S ” = MY S n S Ww WwW a ry) = a z 3 4 = a Ps = = = 3 K = = = = 5 a. > YS 5 > WS \ = 2 = = = > = == wn m a m n = 7) 4 z w z w z Hes z SMITHSONIAN INSTITUTION NOILNLILSNI NVINOSHLINS S3IYVYEIT LIBRARIES SMITHSONIAN _ 2 z x = = g z Ko z z = => SS OS fe Z af fe = = = 5 Oo WS Ss T | Soe Le, e) LOD fy 9 QR : xc (eo) z 2K 3 fH ? 3 Yds 2 We 2 2 =, 2 Uy, = S Gy = WY 2 : > = es li = = s = ay eS = z = 2 7) 2 ” bees a s NVINOSHLIWS’ S31uvuaIT LIBRARIES SMITHSONIAN _INSTITUTION NOILNLILSNI NVINOSHLINS S3IYVYST- > ” 2 re z “ S o Ww wW WW Ww al = 4 so) et oy é gi ey 4 = = cx = °* Gip s = = = SWS = > = > = Vi, ae = 2 WN E 2 = “2 = - & $yve - - =. RS SS - = i = 2 ae = a NS z m = m — ” — ” _- w = ” F EONOSHLINS 54 1uvud iy LISR&R | ES SMITHSONIAN INSTITUTION NOILMLILSNI_ NVINOSHLINS S31uV ual } : 2 My 5 ie to: _— S = yy he, 5 NN z 5 \, = Wy, 5 z = SMI fi = XN? Zr WWs HY = i} = Zy ee FE RNS Zz i= Ny 2,0 fo § S = = = a. > =s >" = > no z 7A) < ” a z o a SMITHSONIAN INSTITUTION NOILNLILSNI_NVINOSHLINS S31YVYAIT_ LIBRARIES SMITHSONIAN _INSTITUTIO wn = ” = 7) = a ee = bhi, A at =f = = oa’ 7 = fea) — ao = oo = = ro) = ° “SS = fo) = ro) ai Zz =i = - = = =z { I” NVINOSHLINS S3INVYUGIT LIBRARIES SMITHSONIAN INSTITUTION NOILNLILSNI NVINOSHLINS S31uvuagl) iS oe z = = am S G : z = eK ss S) Oo Oo oO = ’ fe) = KS = = = =) E oa = a We By = =e = a > Was = - > rai > = > > 7 SN — a S a i a _ = he = =e on = a m Se D Ce al o = oD 4 Je S SMITHSONIAN INSTITUTION NOILONLILSNI NVINOSHLINS S3SI1YVYEIT LIBRARIES SMITHSONIAN ” z= re a) z ” z ee n z = < @. = = = ee OS =< = = SAS =) z a ce NS = > ae oO Nw SS x oO ey ODO NWS. & sa 0g fo) a 7) INS as nw a a } a . ‘ a 2 n> z2 =‘ S 3 E z iE \. 2 = > t > > > s z = eS ra = a 8 = J Saiuvugi1a LIBRARIES SMITHSONIAN _ INSTITUTION NOILNLILSNI NVINOSHLINS S31uvugt = n” = w = ip) = = ve) 2 lw 2 lu 2 a He 77) =~ n ~ bee Avot je wo Ko & E oc “ a. % py = fo 4 gn. . < ivf. < = A < c = eS Cc (= o a GY; a o a PS = we ed a = Aas aN Lm) OUT Re ROAM A TUCO TEU LIEU dt ts FCN SLE SL a et So SAAD HI IB A Dhl ah EL dah Da aa rma ee ms (Tn uk a z a" z WY, < z YY, = = < x 2 : = @y 2 1 YfYy,% 3 A S S = 847 fY) = Zi ee is Z = - 2 Aen z 2 Bone ie 5 ILSNI_NVINOSHIINS, S3INVYEIT LIBRARIES SMITHSONIAN INSTITUTION | NOILOLILSNI_NVINOSHLIWS S31 UV! ae w ee Ww = lu a rm 4 = 4 = 2 a a a e ee c = oe < E = = S [ea] = oO. = faa] ro} (a6) fe) MS = fo) = fo) = S = ma — za J 4 a) a) RIES SMITHSONIAN INSTITUTION NOILLILSNI NVINOSHLINS S31 uvuai7 LIBRARIES _ iy za (ra = Toa Zz ins S) “0 o S NE S) = S) aa (es 3 aad s WG = = = a >. =) Wie SS =) > ‘ > =e = iS Pas INS E Ss = 0 a ea D = 5 TE = oD = Zz o zZ o pies D Zz a JLSNI_NVINOSHLINS SA1YVUAIT LIBRARIES, SMITHSONIAN | INSTITUTION, NROUAUA UMASS ISS Sa) eel z = Ee «FE SS 8 z 2 vz a wf fg a NS S SS z 5 2 Dy a o whi“ 2) NS ey n a a a o he pt 8 Gy = NY 2 z Z = 8 Gy - = ie eee Uae oh Se Sai RIES SMITHSONIAN INSTITUTION NOILNLILSNI_NVINOSHLIWS Sa1uvuat_ SMITHSONIAN _ INSTITUT hf Zz 2 2 2 w : 7 & HOH Ws 7) = we nO = f 4 4 = 4 8 \SS _ = = tty A fey cal ee # = = = QS Z = ‘ PUP = ce yf = = Sas ASS oe 5 a Gy Ss oO ey, — = ny = Ve EN = = 2 ee 2 Zines 2 JLSNI"NVINOSHLIWS (S31YVUGIT LIBRARIES SMITHSONIAN INSTITUTION | NOILALILSNI_NVINOSHLIWS {Salada — > - 5 ie : Oo fu Oo yy — ro) _— fo) \ = = L o = o ‘ = = We 5 5 — GY > = 2 We 5 NS O= z E GY“ = 2 XW = = AYE = Ef eo KE ps AQ m Ww Z m g m 2 m S\ wn = w = = = RIES SMITHSONIAN INSTITUTION NOILALILSNI _NVINOSHLIWS S31yvuat7_ | BRARIES SMITHSONIAN INSTITUT za * : y * = ara = < = = > Sa = DS . > 2 JISNI_NVINOSHLINS °S3 1YVYEIT_LIBRARIES SMITHSONIAN INSTITUTION MOTOS _ AUG NOSES luv Zz ai 2 i j Zz Ww = Ww (2) ae 7) = WME: (wr) sx e ox = 5 : zi « ¥%,: z = Nye S 7 bs Saf P = 2 5 a MF fer S ee 2 NO" 5 re) 2 rs} a” S a S) ~S\ = Zz a Zz a = aH Zz = SMITHSONIAN INSTITUTION NOILNLILSNI NVINOSHLINS Saluvugia_LIBRARIES_ SMITHSONIAN s 5 i 2 7 x z Si & = ‘ ce ann fe) o i) “Oo fm io) roa ios] ENG — = Soe a = WE 2 = a euZ Ly, > = > CE > > ee > — Uy 2 = 2 = a = 2 2 3 i» 2 a OE i es LILSNI NVINOSHLINS S3INVYGIT LIBRARIES SMITHSONIAN INSTITUTION, NOILMLILSN! NVINOSHLINS Saluwe Z z ES ~ < = al z P weet s \ : YO: =] ASS, 5 z BM 5 A SS = SA x= 35 bho UY 2 BGI BNR 8 Sas bbe yy = 2 “Wy © » 2 2 2 Gy = > = % > > G > wn Zz, 7) 3 Zz Zz ZZ SMITHSONIAN _ INSTITU ARIES SMITHSONIAN. INSTITUTION NOILNLILSNI NVINOSHLINS Saluvaugi7_L!BRARIES BRARIES SMITHSONIAN IBRARIES SMITHSONIAN BRARIES IINLILSNI OILNLILSNI OILNLILSN B RAR IES Ws ASS NSS IINLILSNI —” Sept. 1983 ATOLL RESEARCH BULLETIN Pans ie Bae a eT en ASTHENOSPHERE HOTSPOT Figure 5. Inferred interaction of the lithosphere with a mid-plate hot-spot. From the ridge to the hot-spot the lithosphere thickens and subsides by cooling. At the hot-spot, extra heat drives the isotherms upwards, thins the lithosphere and causes uplift. Beyond the hot-spot, the lithosphere cools rapidly because it is thin and thus subsides as younger lithosphere at the same depth, rather than as normal lithosphere of the same age (dashed line). After Detrick and Crough (1978, Fig. 4). It is obvious that if the Pacific plate is being forced north-west to be subducted below the edge of Asia there must be considerable compressional forces acting close to the subduction zone. Hanks (1971) reports strong horizontal compressional stresses seaward of the Kurile trench. Watts and Talwani (1974) call the positive gravity anomalies seaward of many trenches "outer gravity highs" and indicate that they correlate well with regional rises of up to a few hundred meters. Pacific plate margins showing slight upwarps before final subduction include areas along the Kurile, Bonin, Japan and Philippine trenches. The outer gravity highs seaward of the southern Bonin and Mariana trenches also correlate with regional topographic rises but they can be explained without inferring horizontal compressional stresses (Watts and Talwani, 1974). Topographic rises are not present along all subduction zones. In the discussion of island forms close to subduction zones the presence or absence of these topographic rises must be considered. 12 Melting anomalies and volcanic activity All Pacific plate island types require an original volcanic base. It is easy to envisage magmatic outpouring forming volcanic islands close to spreading centres that then drift away from these ridges as the plate cools and moves into deeper water. But how do we account for volcanic islands such as Hawaii which are both young and distant from the East Pacific Rise? A number of explanations have been proposed to explain this phenomenon of mid-oceanic plate volcanic activity which is not directly attributible to spreading centres along mid-oceanic ridges. They include the 1) hot-spot theory, 2) gravitational anchors, 3) asthenospheric bumps, and 4) slip-strike motion theory. The term "hot- spot" is frequently used to describe the phenomenon of magma discharge that forms line island-seamount chains on oceanic plates. Because the term hot-spot is also often used in the more specific sense as a theory to explain the origin of these island-seamounts, the term "melting anomaly" (Shaw and Jackson, 1973) will frequently be used to encompass all theories on their origin. The "hot-spot" theory depends upon the principle of a thermal plume originating at a fixed spot beneath the surface of the oceanic plate in the asthenosphere (Wilson, 1963; Morgan, 1965, 1972a,b). Essentially a convection cell mechanism is operative. This in turn causes weakness in the 100 km thick lithesphere and outpourings of magma occur over the plume. Magma discharges from a series of closely spaced point source vents that coalesce into a single vent as eruptions progress in time (Jackson & Shaw, 1975). As the ocean plate moves across this fixed hot-spot a series of volcanic seamounts results. It is most likely, however, that volcanism is not as precise as this ideal description infers, nor is it necessary that magmatic outpourings be aligned perpendicular to the East Pacific Rise spreading centre (Moberly and Larson, 1975). Shaw and Jackson (1973) proposed that volcanic activity at the south-eastern end of the Austral, Tuamotu and Hawaiian Chains is not the result of fortuitous location of thermal plumes but rather is a consequence of shear melting caused by plate motion. Once such melting begins a dense residuum is formed and sinks. This downwelling ultimately forms "gravitational anchors" that stabilize the anomalies and cause inflow of fresh parent materials into the source area for the basalts. Such gravitational anchors, they feel, provide a much more sensitive inertial guidance system for positioning of melting anomalies. Menard (1973) noted the close relationship between asthenospheric bumps and the actively growing end of volcanic chains on the Pacific Plate. He concluded that melting anomalies are located on the "updraft" sides of positive gravity or depth anomalies and are being overridden by moving plates. It is quite possible that this "warping" of the lithospheric plate determines the location of the melting anomaly, which, according to Menard (1973) would be the result of a thermal plume. Because of the importance of asthenospheric bumps in epeirogenic uplift resulting in raised island forms they will be discussed more fully in the next section. Handschumaker (1973) suggested that the Emperor Seamounts may have 3} been formed as a result of extrusion induced by strike-slip motion. Jackson and Shaw (1975), however, found that there is no evidence that any significant intraplate finite strain has been imposed on the lithosphere in the region of linear chains, so this theory is considered unlikely to explain the linear seamount chain phenomenon. Melting anomalies may therefore result from a number of possible mechanisms. The very fact that they do occur, however, produces the seamount-island chains on which atoll development depends. They also help account for the renewed crustal cooling-subsidence phase needed for atoll development (Fig. 5). It should be stressed that not all melting anomalies give rise to atolls, however. No atolls are found in waters where either cold or the simple absence of certain reef species prevent reef development as in the Marquesas, or where certain seamounts never reach the ocean surface. Kidd et al. (1973) indicated that there are as many as 150 terrestrial plumes giving rise to melting anomalies so oceanic seamounts are not the exception. While evidence indicates that melting anomalies are relatively stationary as in the Hawaiian Emperor Chain (Jackson et al., 1980), it is also possible that some are less fixed, particularly where they abut other continental plates and are subject to forces not directly attributable to their own lithospheric plate motion. Asthenospheric bumps Menard (1973) was perhaps the first to fully appreciate the relationship between the emergence of Pacific islands and broad low "bumps" on the ocean floor. Because he attributed these bumps to an asthenospheric surface which is not exactly level, he called them "asthenospheric bumps". In actuality they appear as low bumps up to several hundred metres in vertical elevation and 1,000-3,000 km in width on the surface of the ocean plate and are detected as positive gravity anomalies. As the plate moves over these asthenospheric bumps the general tendency for the lithosphere to deepen due to cooling (Le Pichon et al., 1973) is temporarily counteracted. Any islands or atolls on the upslope side begin to rise out of the water instead of subsiding in the expected way (Fig. 6). Ocean, Nauru and Marcus islands are good examples of the effects of asthenospheric bump uplift on islands (McNutt and Menard, 1978). Asthenospheric bumps are located in many parts of the Pacific. Care must be taken in evaluating their overall significance however. While it is tempting to associate all seamounts and islands riding over one asthenospheric bump with one melting anomaly, it may be that peaks produced by another melting anomaly nearer the East Pacific Rise have simply advanced to this new bump-melting anomaly area (Rotondo et al., 1981). In this way the idealized sequence of atoll formation may appear confused as high islands from the nearby melting anomaly may be associated with atolls from another but distant melting anomaly. Isostatic subsidence and lithospheric loading Darwin's original atoll development model infers isostatic subsidence 14 LEACHING & SOLUTION A pomp ne ie a ASTHENOSPHERIC BUMP Kilometres a= 1 oa Figure 6. Idealized history of an atoll emerging-subsiding as it passes over an asthenospheric bump. After Menard (1973). due to the islands own mass. Although some atolls have been subsiding for more than 50 ml years and have undergone subsidence exceeding 1,000 m it is very unlikely that isostasy alone could occur over such long periods of time. McNutt and Menard (1978) suggest that lithospheric loading by a new volcanic island produces a response over geologic time scales of 100,000 years or more, while Watts and Cochrane (1974) state that after only a few million years of loading isostatic adjustments approach zero and that the ocean plate then seems capable of supporting seamount chains for periods of tens of millions of years. Isostatic subsidence, for newly formed volcanic islands and submerged seamounts is very real, however, and immediately gives rise to a '"moat-arch" development (McNutt and Menard, 1978, 1979; Jarrard and Turner, 1979). Depression of the lithosphere by a new volcanic mass is variously described as crustal loading or lithospheric loading, and a crustal moat develops peripheral to the seamount. This moat may fill rapidly with sediments and not appear on bathymetric maps. Beyond the outer edge of the moat, flexuring develops an arch which experiences uplift in the order of tens of metres. If there are islands at various distances from this new loading mass those within the developing moat will experience gradual subsidence, while those on the developing arch will be slowly elevated. McNutt and Menard (1978) argue that the uplift of Atui, Mitiara, Mauke and Mangaia atolls in the Cook Islands result from lithospheric loading by three nearby volcanoes. Jarrard and Turner (1979), while agreeing with this conclusion, disagree as to the exact amount of resultant elevational change. When magmatic outpourings cease above a melting anomaly and the volcanic island "drifts'' away isostatic subsidence will soon cease. Likewise any island over which it had an influence would continue to move into deeper waters due to non-isostatic crustal cooling-ocean deepening. This picture can be confused in practice, however, if a new seamount again develops before other islands have had the opportunity to move beyond any new moat-arch development. Likewise, atolls drifting tS past a hot-spot seamount system not associated with its own igneous pedestal development could undergo subsidence or uplift depending on their proximity to the new crustal loading. McNutt and Menard (1978) consider this latter mechanism explains the emergence of some Tuamotu atolls following recent moat-arch development in the Tahiti area. In our consideration of island types on the Pacific plate isostasy by itself seems of minor short term influence in causing volcanic islands to subside. Unless a volcanic island ceased growth at, or just above, sea level an atoll could hardly result from isostatic causes alone. Isostasy can clearly have a major influence on other island types, however, causing increased but modest subsidence rates for existing atolls within the new moat and emergence of atolls or volcanic islands on the arch. Beyond the arch little or no isostatic influences will be felt and Watts and Cochrane (1974) consider that the 400 m thick carbonate cap on Midway could not be due to this influence. CASE STUDIES ON SPECIFIC ISLAND CHAINS A number of island groups are examined to show how the various island types within them correspond to the tectonic, volcanic and reef growing conditions known to be operating on the Pacific plate. Three island groups in the North Pacific were examined using information from the literature and extracting bathymetric data from maps produced by the Scripps Institution of Oceanography (Chase et al., 1970). These island groups are the Hawaiian, Marshall-Gilbert and Caroline. The Tuamotu and Society Island groups in the southern hemisphere were also examined with bathymetric data coming from a bathymetric map of the Pacific produced by the Academy of Sciences (1964). Hawaiian-Emperor Chain This chain was selected because not only is it the most intensively researched group but because it is also the best example of a continuous line island group that runs from warm reef-promoting waters to cooler reef-inhibiting waters. The Hawaiian-Emperor chain lies entirely within the North Pacific and constitutes the Hawaiian Islands, the atolls and shoals of the Midway group, and the seamounts and guyots of the Milwaukee- Emperor chains (Fig. 7). This volcanic (basaltic) ridge runs from the Island of Hawaii, a total of 6,340 km to the Kamchatka Trench. Figure 7 depicts the peaks and corresponding ocean floor depths from a point south-east of Hawaii to the Kamchatka Peninsula. Data was taken from bathymetric maps prepared by Chase et al. (1970) which use 200 fathom depth intervals. In order to determine ocean floor depths and the heights of peaks with respect to sea level and the ocean floor, a line was plotted from a point south-east of Hawaii through the major peaks to the Kamchatka Trench (see Fig. 2 for profile route). Sampling points were placed at regular intervals along this line and data on the elevations and depths between the closest volcanic islands, atolls or submerged seamounts were recorded for each point. In all there were 132 points along the 6,/00 km transect and using this data a profile of the more prominent peaks was produced (Fig. 7). 16 S8ijQW Ul UON|DAS w gozr\ | 9506 vem) new MSS) NBL v *Z ean3Tq ees e4nod e{tjoad 10g GL61T ‘OpucjoYyY wWotF peTJTpow) uteyD AorTedug-uettemey ey} FO eT[TJoIg 40014 NV3I90 W4IDVd \ Ly J \ z ie ~ 620) luncweas owns Junowees NWUEN WIVH LNNOWIVIS WON 39018 WIV AVH */ 2ansty iNe Ae LW w S6Iz lunoweas 1y2ua1 0009 9 ooos & ooor =: OOOE 5s oooz & oool 3 @Ae] Des ooo! 2 000z < oo0e = ooor 5 oo0s > 3 8 17 To obtain data on sea floor depths four lines were drawn parallel to the central ridge line at three and six centimetres to either side. Ocean depths were recorded exactly on these parallel lines at right angles to the 132 points on the central ridge line. The ocean floor profile in Figure 7 is the average of these four depths for each of the 132 profile positions. It should be noted, however, that this ocean floor curve is not coincident with the surface of the lithospheric plate. Since the Pacific plate was formed at the East Pacific Rise, thin layers of sediment as well as outpourings of magma associated with the Hawaiian melting anomaly have been superimposed on it to varying degrees. Despite the visible bumps that result from these magmatic ourpourings, the bumps are actually locked onto the plate as it moves into deeper water due to lithospheric cooling with age (Le Pichon et al., 1973). Minor asthenospheric bumps would be independent of these outpourings and could well cause the "bobbing" motion described by Menard (1973), but they could not be detected simply by examining bathymetric maps. An examination of these profiles shows a number of interesting characteristics. Following the peak-curve from the Island of Hawaii north-west, it can be seen that the average high island elevation drops off rapidly due to the longer exposure to subaerial erosion (Fig. 7). There is no reason why these islands should appear to be reduced in elevation in a linear way because the original islands were never all at the same elevation to begin with (MacDonald and Abbott, 1970). The majority of these high islands, however, did exceed 1,000 m before cessation of volcanic activity, and heavy orographic precipitation combined with high temperatures and easily weathered besalts gives rise to rapid chemical weathering (Scott and Street, 1976). This subaerial erosion, together with coastal erosion, combine to rapidly reduce the elevation of islands, and this trend does appear in the profile. The findings of Moore (1970) concerning isostatic readjustment of the Pacific Plate to the additional load of a new volcanic island must also be considered here because they indicate that isostatic subsidence is not as significant as originally suggested by the Darwinian subsidence model. According to Moore (1970) the absolute subsidence of the still- active Island of Hawaii is 4.4 mm per year. This agrees well with Apple and MacDonald (1966) who estimated that the west coast of Hawaii is subsiding at 3 mm per year. Moore also indicated that Maui (0.8-1.3 my, McDougall, 1964) is subsiding only 1.7 mm per year, Oahu (2.2-3.4 my) is stable, and Kauai (3.8-5.6 my) is actually rising. There is of course the real possibility that the Hawaiian chain in general will experience subsidence as it moves north-west because it will be descending the now cooling flank of a rise created over the Hawaiian hot-spot (Fig. 5). This cooling is similar to that near the mid-oceanic ridge and for the Hawaiian Islands would appear as in Figure 8. The true picture is somewhat confused near the hot-spot because of the current moat-arch development around Hawaii and the residual effects of Maui which must combine to give rise to the isostatic subsidence-emergence noted by Moore (1970) above. Oahu clearly does have a raised reef probably resulting from the arch produced by the combined masses of Maui and the earlier development of Hawaii. Now that Hawaii has become so massive 18 Oahu has stopped rising possibly because the Hawaii moat has now radiated outwards to bring Oahu into its flanks. The emergent island of Kauai continues to rise, however,’ as it may now have been fully overtaken by the Hawaii arch. The most northerly islands in the Hawaiian chain with visible basaltic rock, Necker, La Perouse Rock and Gardner Pinnacles, are all reduced to less than 90 m above sea level. It is unlikely that all of this reduction results from subaerial and marine erosion alone. Each of these islands is surrounded by extensive flat reef-shoals and all indications are that they have undergone gradual submergence (Menard, 1973). Between Gardner Pinnacles and Kure Atoll, island and ocean floor subsidence is clearly indicated (Fig. 7). North of Kure only one seamount, between Jingu and Kaumu seamounts at 35°N, 172-E, is within 60 m of sea level. Apart from this peak, which must have been a Pleistocene island, there are no peaks north of Kure that could have been above sea level in recent times. This peak is no doubt a submerged atoll which experienced difficulties in producing reef growth sufficient to keep it at wave level as it continued to move into cooler waters. Karst formation on this eustatic low-sea level island during the Pleistocene would have encouraged this submergence relative to present sea level. North of 35°N, WP peaks deepen in a relatively linear fashion, and parallel deepening of the ocean bottom occurs. Close to the Kamchatka Trench, seamount elevations are variable, the ocean floor receives greater thicknesses of continental sediments and there appears to be minor buckling associated with bending of the Pacific Plate as subduction begins. This buckling effect is confirmed by Watts and Talwani (1974) but it will only have the effect of modestly raising deeply submerged seamounts close to the trench. Irregularities are to be expected, however, as most seamounts never reached sea level even when they were first formed, and at their present great depths it is difficult to differentiate between a seamount that never reached the ocean surface, and a guyot which may have been truncated at sea level and subsequently subsided. The term guyot must be treated with caution here because not all flat topped seamounts (i.e. guyots) are considered EAST PACIFIC RISE HAWAII KANMU | SUIKO | MeWI Figure 8. Subsidence after reheating at Hawaiian hot-spot. Hawaii depicted at the depth of normal 25 my lithosphere. Dashed line is expected subsidence without reheating. Modified from Crough (1978, Fig. 16). 19 to have been planated at sea level. Recent corings on Ojin, Nintoku, Yomei and Suiko seamounts in the Emperor Seamount Chain (Jackson et al., 1980) confirm that these guyots were in fact volcanic islands before subsidence allowed them to pick up carbonate caps. Borings on Suiko (Fig. 7) hit a "Paleocene shallow-water reef or bank assemblage of carbonate sand and sandy mud with algal nodules, from 52.5 to 163.5 meters. Basalt directly underlies the shallow-water limestone'! (Jackson et al., 1980:11). Paleomagnetic measurements indicate that Suiko was formed at approximately 25°N latitude at a time when carbonate deposition (and possibly discontinuous reef formation) was occurring in water somewhat cooler than around the present-day Hawaii. The paucity of coral material on seamounts in the northern Emperor Chain is in marked contrast to seamounts at the bend of the Hawaiian-Emperor Chain (see A4 on Fig. 2) where corals are more abundant (Jackson et al., 1980). It appears then that a southward movement of the Hawaiian hot-spot into warmer waters accounts for the earlier development of bryozoan-algal caps (without coral) to the present day coral-algal caps. Figure 8 suggests that given time present day Hawaiian atolls will indeed become truly submerged atolls just as this appears to have already happened to Darwin Guyot in the Mid-Pacific Seamounts to the West (Ladd et al., 1974). This guyot has subsided to a depth of 690 fathoms but has preserved intact the atoll annular ring and ten-fathom deep lagoon. On the basis of the above analysis a schematic representation of what may well have happened to the Hawaiin-Emperor seamount chain over the last 70 my is presented (Fig. 9). While this figure clearly generalizes the actual profile given in Figure 7 it does exhibit a remarkable approximation to the known facts and tectonic possibilities. It should be noted that not only does Figure 9 account for many of the island types illustrated in Figure 3, but it indicates four distinct island-seamount zones or "phases". It should also be noted that but for the fact that many of the Emperor Seamounts were formed in poor reef- growing waters, submerged atolls would extend all the way to Kamchatka. Marshall-Gilbert Chain These islands differ quite markedly from the Hawaiian-Emperor chain. They are in fact much more scattered and do not represent a characteristic line island group. The chain also lacks almost-atolls and high volcanic islands at its south-eastern end. Likewise there is no clear indication that the chain continues north-west, as does the Emperor Chain, to be subducted into a trench. Figure 10 is based on a composite profile of the scattered atolls, shoals and seamounts of the Marshalls, and therefore differs from the single profile-transect method used in Figure 7, for the Hawaiian chain (bathymetric data from Chase et al., 1970). Because of the difficulty in interpretation of seamounts north of the Marshalls it was difficult to decide exactly the path taken or to be taken, by the most northerly seamounts in the chain. As a result two profiles are drawn. Both begin on the equator (Bl on Fig. 10) and move north-northwest to Wake (B2 and B3). Then one continues in the same direction to B4 in the deep ocean north of the Mapmaker Seamounts. It is possible that the numerous 20 ZONE 4 ZONE 3 ZONE 2 ZONE! , Subduction in Reef coral growth | Fringing reefs | Subaerial erosion | Kamchatka Trench ceases in cold water | become Atolls | ang fringing reefs Thick lens of Atolls carried under to | | continental margin | form Guyots-guyots to | sediments North have non-atoll | carbonate caps only | 19°N,155°W olcanic chain 54°N 163°E Kspine Te slope of pec aC 28 N c sea level asthenospheric bump and moat anomaly KAMCHATKA ASTHENOSPHERE a. Hawaii b. Kauai c. Gardner Pinnacles d. Midway Atoll e SuikoSeamount f. Seamount 53°N,165°E Figure 9. Schematic representation of the major physical factors influencing the Hawaiian-Emperor Seamount Chain (modified from Scott et al-, 1976): seamounts to the west and northwest may be part of the Marshall chain so another profile continues from B3 through Marcus Island to B5 at the Bonin Trench. For both profiles the generalized ocean floor depth increases towards the northwest. The members of the Gilbert group shown on the profile are of a line island type, but appear to be separated from the Marshalls both visibly and bathymetrically. The numerous atolls of the Marshalls are scattered in two general lines running SSE to NNW and are associated with numerous seamounts (not shown in Fig. 10). North of Taongi Atoll none of the Marshall Seamounts appear to have reached sea level. From the bathymetric map Wake Atoll would appear to result from a different melting anomaly than that which produced the main Marshall cluster. Marcus Island and the shoal just beside the Bonin trench represent isolated peaks, but it is more likely they were previously shallow drowned atolls. Marcus is now rising over an asthenospheric bump and is now a raised atoll (McNutt and Menard, 1978). The shoal close to the Bonin trench may have been elevated close to sea level by the outer gravity high produced just before subduction. In the case of the Marshalls, which must represent a senile volcanic chain produced by a long-inoperative hot-spot, the gradual movement into deep water combines with subaerial erosion to leave only atolls. Drillings on Bikini and Eniwetok (Ladd, 1973) at the northern end of the Marshall Chain hit basalt at depths exceeding 1,220 m, and shallow water fossils taken just above the basalt basement are about 55 my old. It is therefore quite probable that the parent volcanoes on which these atolls developed were formed just south of the equator in shallower water. They then collected these vast thicknesses of carbonate deposits on their slow 21 “uTeYyDO PUeTS] sUTTOIeD oYyQ SUOTe seTTjorg °{[T eanstyg 000‘01 000'01 = 0008 0008 & 2B + > ss 5 0009 en ate spurs o 9p uu, Guy" 2004 UEEDD 0009 = = Git: ae a Se SS en ee ree aN ee ooor 3 a ooor ne a 2 0002 a 000z 2 [842°] bes sj dojabuig VION = £7] “Vv eBN Vv AN} Gri Vv moun | Vv umuon | “y olnuoweny | i 3 w €ZI a a min | 12027 bes edeuod w us u oeseu +y yidune: Wha) e vy luy WOMEN Videos] ait ‘ie hm jana kes ! aan veuleg eae yueg ujy6ne73W SONVISI INITONVI *suTeyo pueT[st AISGTIO-T Te ysaey ou suoTe SOT tT sJoag “OL aINnst gy 000’01 000'01 5) 0008 0008 o ‘S i) o teh = 0009 0009 = S 5 5 0007 oo0r 5 a o = = % 0002 0002 3 ns Oe rAAADA WANE SEAN SELES Rais V, euriew | ‘VULYEW = :U0g | Vv nwen | “VW OOM, “vy !Buoe, “VW OYEAA “| snouew Ww OF! | ‘y Bueiqy ‘vunier = “y ulajefemey vy is | ewifeyey hy eynuey N,O ‘4.¢Sl N. 22 ‘3 ,cbb ——"S! 1438119 — ———— SONVISI TIVHSUVW SLNNOWVIS “SI NINOS ig ‘qq WINVANdVN "q sq Jad journey northward. Such thicknesses are greatly in excess of those in the northern end of the Hawaiian Chain and reflect the truly equatorial location of their parent melting anomaly. In the Hawaiian Islands great thicknesses of carbonate are inhibited by a much shorter passage through reef-promoting waters between the time their basalt cores are reduced to sea level and the time atolls suffer demise north of 30°N in cooler waters. Caroline Islands The Carolines run west-northwest from Kusaie to the Mariana Trench (Fig. 11). Like the Hawaiian-Emperor Chain there are volcanic islands to the south-east and atolls to the west. Unlike the Hawaiian Chain, however, the almost-atoll form is also present, and the complete chain lies within warm tropical waters conducive to reef growth. The presence of almost-atolls as well as young volcanic islands and atolls make the Caroline Chain one of the more typical line island chains insofar as island form is concerned. A composite profile based on data taken from bathymetric maps compiled by Chase et al. (1970) is shown in Figure 1l. As is the case with the Marshall profile in Figure 10 the western end of the chain appears as a confused pattern on the bathymetric maps, thus this portion of the profile follows two separate paths (see Fig. 2 for profile routes). Figure 1l also shows two profiles for the ocean floor, one along the southern side of the chain and one along the northern. They are separated because it is considered that to average these depths would be misleading. This discrepancy may arise because the southern side of the atoll portion of the chain on the Pacific plate appears to be under considerable stress from the north-eastern advance of the Bismark portion of the Australia plate and the Eauripik-New Guinea Rise. Long east-west trenches just south of Woleai Atoll tend to support this conclusion. Thus, depths to the south of the chain are not considered to be reliable indicators of Pacific plate deepening as it approaches the Mariana Trench. It is also possible that the melting anomaly which gave rise to these islands has been forced to migrate east as the Australia plate slowly moves north-east. This hypothesis might help explain the more east-west orientation of the Carolines that supposedly lies on a rigid lithospheric plate with a northwest movement and on which most line islands trend northwest. While deformation of the Pacific plate similar to that found by Rea (1970) north of the Hawaiian Ridge may account for some of this east-west trend it is unlikely to account for such a marked departure from the normal line-island trend. Despite these problems the Caroline Islands reflect the classical Darwinian atoll formation sequence when superimposed on a plate moving into deeper waters. It differs from the Hawaiian-Emperor chain sequence, however, in that atolls do not appear to die off except where subduction causes rapid subsidence into the Mariana Trench. Some circumstantial evidence also suggests that as the Carolines move towards the west they enter deeper water. While there is no reason to assume that newly-formed 23 islands have always been of the same size, the hypothesis presented here would require gradual reduction in area at sea level if they were moving into deeper water. Wiens (1962) indicated that the average dimensions of the 15 westernmost sea-level atolls is 12.2 x 5.6 km, while the average for those 17 to the east (in relatively shallower water) is 16.8 x 9.6 km. Tuamotu and Society Islands There is a total of 72 atolls in the Tuamotu Islands (Fig. 12). At the southeastern end of the chain is a near-atoll, Mangareva, an old volcano in a similar stage to Truk in the Carolines. Mangareva consists of a dozen small embayed islands and stacks in a lagoon surrounded by a well-developed barrier reef some 41 km in diameter. Pitcairn, a relatively young volcanic island, lies 450 km to the southeast of Mangareva. If Pitcairn was actually produced by the same melting anomaly responsible for the Tuamotu Archipelago proper, then the Tuamotu Chain cannot yet be considered a totally senile volcanic chain. In the area of the Tuamotu Islands there is no doubt as to the actual deepening of the ocean floor as it moves northwest towards the equator. These islands are relatively close to the East Pacific Rise where lithospheric cooling causes most rapid increases in depth (Heezen et al., 1973), and as they move into successively more suitable reef growing conditions atoll development conditions are optimal. The large number and close spacing of the Tuamotu atolls is also indicative of their origin in shallower waters close to the East Pacific Rise. On average more of the newly formed seamounts would have reached sea level here simply because of the shallower water. Because of their ideal position south of the equator it is probable that many of the larger atolls in the Tuamotu group will survive for many millions of years during their slow passage through warm equatorial waters. It is possible, however, that some of the smaller atolls will suffer demise even in equatorial waters because as island bases move into deeper water the top of their carbonate peaks will become so narrow that they will no longer support any island form whatsoever. Data for the Tuamoto Archipelago profile given in Figure 12, as well as for the Society Islands (Fig. 13), were extracted from Russian bathymetric maps of the Pacific (1:40,000,000) giving depths in 500 m intervals (Academy of Sciences, 1964). Although it does not show up well on a profile of this scale (Fig. 12) some of the atolls at the north-western end of the Tuamotus are raised. While there is some disagreement as to the absolute uplift involved there is general consensus that the uplift of Matahira, Tikehau, Makatea, Niau and Anoa is due to arch flexuring following recent crustal loading by Tahiti and Mahetia to the west-south-west in the Society Islands (McNutt and Menard, 1978, 1979; Jarrard and Turner, 1979). ‘ The Society Islands (Fig. 13) appear more like the Hawaiian than the Tuamotu except that they do not continue as seamounts to the north- west as do the Hawaiian. The Society group are probably much younger than the major portion of the Tuamotus because of their short length and lack of subaerial erosion. They exhibit all the characteristics of a 24 $O1jOW Ul UO|DAG|Z g 0005 2% O00” ss 5° 000¢ @ 0002 8 0001 |9A8] Des oos 00ol *spueTsy AjeTIO0g Bey YsNOIYy eT[TjJOIg “ET eanBTy ® 000¢ 4YOO14 NV390 O1sIOWd 000s ® > 000r ooor > > 000€ oooe > @ 0002 oo0z & 8 0O00L | / ooo JPAa] Das [2097 Das = 0001 al |v eeuidow oool 2 6 000z oa V uidnew Vv en ened 0002 6 2 oooe e109 a iad oooe & = LUNOW ion 2 2 payeiey 3 8 Se Seg ae SUNN ISL ALS JOS = ee 3 J “S -o8ezTedtyoay njoweny ey ysnoryq esty OTFtToeg 4Aseqy yy WOIF VSTTJoAg °*7T san3tTy NV390 DIsIDVd Ty (Haul wgz vy ouaQ | ansaUIW) yy ealmeW)y eoununw | in! | a1ong | uosuapuay ! 4UON wipp VeveW| vent | vy eoveseg lotion | enaseBuew vy eBunseuay vy eueneuen v POH vy mex W009 | saise3 | y neyoeW v enesexe4 vy manyiH S42 x S,02 3,011 i 3,0r1 ISM DslIWd LSI —— SONVISI NYIVILId—— < ‘SI YIISWV9~ ‘a ‘gq ‘q AMA v eainsew Vv eouGuey WES | ealeyew vy neyayly v eneiew OSVTIdIHONY NLOWWAL ——_————— Vv uid y auioued v 40180, | $,01 3,051 — SONVISI INIT "a 000$ ooor 3 a Q00E 5 oo0z 3 ooo| & |@Ae] Des oos = < ooo1 & ° J =. 3 @ 3 25 young island chain being subaerially eroded to sea level and being carried progressively into deepening water where their fringing reefs ultimately form atolls. A MODEL FOR ISLAND-TYPE DEVELOPMENT The following model is based on an acceptance of the idea that successive volcanic islands are formed over relatively stationary hot- spots on an oceanic lithospheric plate which is moving tangentially into deeper water. Important additional considerations include, the possible effects of asthenospheric bumps, moat-arch development due to lithospheric loading, uplift due to outer gravity highs close to subduction zones, an acceptance of the antecedent-karst influence on atoll form, and the realization that upward reef growth will slow, and ultimately stop, if it enters cool waters. Bearing these points in mind the eleven island types given in Figure 3 can now be illustrated in one dynamic working model (Fig. 14). In Figure 14 new lithosphere is seen to accrete to the oceanic plate margin along the East Pacific Rise as the plates are forced apart by strong upwelling in the viscous asthenosphere below. With distance from this ridge the plate cools and ocean deepening is quite rapid. The seventeen volcanic island-atoll-submerged seamount positions north-west of the oceanic ridge shown in Figure 14 are described below. It should be stressed that probably no island chain actually possesses all of the eleven island-type possibilities at one time. It is very likely, however, that most types are found in major island chains during some stage of their history. This model is extended to show submerged seamounts which were former islands. Position 1. The rigid oceanic plate overrides a hot-spot which injects magma through the lithosphere to form a young, active volcanic island. Isostatic subsidence creates a moat-arch flexuring of ithe crust. Fringing reefs have not yet had time to develop. Position 2. Relatively inactive volcanic island undergoing some residual isostatic subsidence but sinking more rapidly due to the moat development caused by lithospheric loading at position one. By now a fringing reef has developed and elevation of volcanic peaks is being rapidly reduced by subaerial erosion. Any subsidence due to tangential movement caused by crustal cooling is minor. Position 3. Volcanic island with complete fringing reef undergoing no vertical change. Isostatic changes due to its own mass no longer operate and any tangential movement-subsidence caused by crustal cooling or any residual moat effects from position two are counteracted by arch flexuring due to lithospheric loading at position one. Position 4. Volcanic island undergoing uplift due to the arch flexuring created by crustal loading at position one. The fringing reef will be raised out of the water and a new reef develops seaward to wave level. Subaerial erosion continues and will affect both raised reef and basalt. 26 *QQUeZISUe-9DUepISqns JO see DATES 9}EOTPUT sMOzIe TeOTIAeA «60° X97 99S pezedTpUT suUOT]ISOd UseqUeAdS By} JO suOT eUPTdxe tog -eje{d ersydsoyat], OTFtoeg ey. uo AueudoTeAsp odfjQ-puet{st IoJ [epow y “HT ean3tTy 10AnB ole ysowyje oe paBsawqns jeas BurBury oe pasies puejs! yBiy pasies pueys! yBiy Ajewouy Bunjay 10 Buijjamdp BuonS asoydsoueuls¥ Sluawipes 390/14 JINVIDO-GIN Duy GNYISI ¥O LN3NILNOD uolsosa jeuaegns yeow | yur yBry AuaedB sano) uononpqns isea yinos @ouapisqns | 159 QLON 6u1j002 seinBay 1eow Buipeo) aueydsoyyi7 | youe Buipeoj sueydsoyyy | aouapisqns - Buijooo sejnBay dwg 2uaydsoueysy Buipeoy auaydsouny med, aouapisgns - Buyoo9 sejnBay @uoz uORINpAnS 27 Position 5. Volcanic island undergoing subsidence due to crustal cooling- deepening and "lee-of-arch"' deepening. Fringing reef grows upwards and begins to form a barrier reef as the volcanic island is reduced in both elevation and areal size. Position 6. Almost-atoll stage. A few remnant volcanic pinnacles or islets remain in the centre of a large lagoon partly rimmed by low reef- rubble islands. Subsidence due to crustal cooling only. If an asthenospheric bump (see position 9) or a lithospheric loading arch (see position 12) develops here, we would get a raised almost-atoll. Position 7. Crustal cooling-subsidence continues until no volcanic remnants can be seen. Reef keeps growing to wave level and a true atoll develops. Position 8. Typical atoll developing a thick carbonate cap as crustal cooling-subsidence continues. If causes for vertical movement other than cooling-subsidence are not considered this form can be maintained and the carbonate cap continues to thicken until it reaches either a subduction zone or waters too cool for proper reef growth. Position 9. Part-raised or raised atoll develops as an atoll rises up the south-east flanks of an asthenospheric bump. No magmatic outpourings occur. Degree of uplift determines which type of part-raised or raised atoll will develop. Position 10. Raised atoll or part-raised atoll descending the north- west side of the asthenospheric bump undergoes rapid subsidence due to crustal cooling to form a regular atoll again. (No influence of the lithospheric-loading influencing position eleven is indicated here although arch flexuring might in fact occur.) Position ll. Rapid subsidence due to the moat effect of new lithospheric loading offset from the line island chain by a short distance. Atoll form remains intact and carbonate cap thickens quickly. Submergence processes are essentially similar to those at position two. This could occur at any position along the chain where a new hot-spot breaks through or where the atoll in question moves alongside the hot-spot of another island chain e.g. the Tuamotu atolls passing Tahiti's hot-spot. Position 12. Part-raised or raised atoll rising rapidly due to the arch effect generated by lithospheric loading near position eleven. Degree of uplift again influences raised atoll form. Position 13. Typical atoll form returns ag the island passes beyond the moat-arch effects of positions eleven and twelve. Here subsidence is attributable to tangential movement as the crust cools. Position 14. An inundated or drowned atoll develops if the structure moves into water too cool to support algal-coral populations needed to Maintain a sinking carbonate platform at sea level. Drowned forms could also result if rapid subsidence occurs as an atoll enters a subduction ZONE o 28 Position 15. Guyot stage results when the atoll is deeply submerged. Here submergence will be quite slow if only crustal cooling is operating. Guyots (or atolls) near a continental or island arc margin will receive thick sediment layers around their bases. Position 16. Temporary uplift of guyot as it crosses the outer gravity high just before subduction. If this had occurred while the drowned-to- typical-atoll stages were present then a raised atoll form should develop. Position 17. Guyot (or atoll if still in warm waters) will be subducted into the trench where it undergoes accretion-destruction. CONCLUSION It is concluded that island-types on the Pacific plate result primarily from the subsidence of volcanic islands due to the tangential motion of the lithospheric plate. An analysis of melting anomaly island groups such as the Hawaiian, Caroline, Marshall, Tuamotu and Society chains tends to confirm this conclusion, and such peculiarities as raised or drowned atolls can be explained if asthenospheric bumps, lithospheric loading, outer gravity highs and subaerial erosion during Pleistocene low sea level stands are considered. The almost complete absence of islands north of 28°N in the Pacific, other than those attributable to plate collisions, is considered to be due to the combined action of rapid subaerial erosion of basalts and this tangential component. These geomorphic and tectonic processes clearly encourage rapid subsidence of volcanic islands produced over melting anomalies, but if their reduction to sea level occurs during passage through warm tropical waters upward reef growth normally prevents their demise. Rapid subduction or movement into cooler waters eventually cuases upward reef growth to diminish and the atoll becomes submerged. Drowned atolls and guyots may result before final subduction. ACKNOWLEDGEMENTS We are indebted to Dr. W. Rannie of the University of Winnipeg who gave valuable criticisms on several drafts of this paper. We would also like to thank Mr. G. Thomson for his excellent cartography and Mrs. V. Hart for typing the final copy. This paper is an expansion of a paper first delivered to the Annual Meeting of the Association of Canadian Geographers at Laval University, Quebec, May 1976. Financial assistance from the University of Winnipeg is acknowledged. 29 REFERENCES Academy of Sciences. 1964. Skhema Otmetok glu'in morskikh nabigatsionnikh kart 4 general'not batimetricheskot karti okeanov (3 2 4 “&zLaniya) cspokzovannikh pri sostavlenii karti. Mezhuvedomstvennii Geofizicheskii Komitet Prezidiume Akademii Nauk SSSR Moskva. Apple, R. A. and Macdonald, G. A. 1966. The rise of sea level in contemporary times at Honaunau, Kona, Hawaii. Pacif. Scr. 20: 125-136. Bloom, A. L. 1974. Geomorphology of reef complexes. In L. F. Laporte, ed.: Reefs in time and space. Soc. of Econ. Paleontologists and Mineralogists, Spec. Publ. 18: 1-8. Bourrouilh, F. 1976. Karst, subaerial diagenesis and atolls. Reun. Annu. Sci. Terre (Paris), 4: 73. Bourrouilh, F. 1977. Géomorphologie de quelques atolls dits "soulevés" du Pacifique W et SW, origine et évolution des formes recifales actuelles. Second International Symposium on conaks and fossik conak neeks, September, 1975 (Editions du B.R.G.M., Paris), 419-439. Chase, T. E., Menard, H. W. and Mammerickx, J. 19/0. Bathymetry of the North Pacific. Scripps Inst. Oceanogr. and Inst. Mar. Resour., Univ. Calif., San Diego, La Jolla, Calif. Crough, S. T. 1978. Thermal origin of mid-plate hot-spot swells. Geophys. J. R. astn. Soc. 55: 451-469. Curray, J. R., Shepard, F. P. and Veeh, H. H. 1970. Late Quaternary sea-level studies in Micronesia: CARMARSEL Expedition. Bull. Geol. Soc. Am. 81: 1865-1880. Daly, R. A. 1915. The glacial control theory of coral reefs. Proc. Am. Acad. Arts and Sek. 51: 155-251. Darwin, C. R. 1842. On the structure and distribution of coral nreess. Ward, Locke and Co. Ltd. 549 pp. Davis, W. M. 1928. The coral reef problem. Am. Geog. Soc. Spec. Pub. 9: 1-596. Detrick, R. S. and Crough, S. T. 1978. Island subsidence, hot-spots, and lithospheric thinning. J. Geophys. Res. 83: 1236-1244. Dillon, L. S. 1974. Neovolcanism: A proposed replacement for the concepts of plate tectonics and continental drift. In C. F. Kahle, ed.: Plate tectonics - Assessments and neassessments, Mem. Amer. Assoc. Pet. Geol. 23: 167-239. 30 Emery, K. O., Inacey,: Jc. i.,guu-nand LaddesHewS-plo54— Geology of Bikini and nearby atolls. U.S. Geok. Surv. Prof. Paper 260-a: 1-265. Handschumacher, D. 1973. Formation of the Emperor seamount chain. Nature, 244: 150-152. Hanks, T. GC. 1971. The Kuril Trench - Hokkaido Rise System: Large shallow earthquakes and simple models of deformation. Geophys . J. R. astnr. Soc. 23: 173-189. Heezen, B. C. and MacGregor, I. D. 1973. The evolution of the Pacific. Sei. Amer. 229(5): 102-112. Heezen, B. C., MacGregor, I. D., Foreman, H. P., Forristal, G., Hekel, H., Hesse, R., Hoskins, R. H., Jones, E. J. W., Kaneps, A., Krasheninnikov, V. A., Okada, H. and Ruef, M. H. 1973. Diachronous deposits: A kinematic interpretation of the Post Jurassic sedimentary sequence on the Pacific plate. Nature, 241: 25-32. Hoffmeister, J. E. and Ladd, H. S. 1944. The antecedent-platform theory. J. Geol. 52: 388-402. Jackson, E. D. and Shaw, H. R. 1975. Stress fields in central portions of the Pacific Plate: Delineated in time by linear volcanic chains. J.-Geophys. Res. 80: 1861-1874. Jarrard, RK. Ds and Turner, D). Li #1979). Comments on 'lithospheric flexure and uplifted atolls' by M. McNutt and H. W. Menard. J. Geophys. Res. 84: 5691-5694. Keunen, P. H. 1947. Two problems of marine geology, atolls and canyons. K. Ned. Akad. v. Wet. Amsterdam, Verh., afd. Nat. 43(3): 69. Kidd, W. S. F., Burke, FB. and Willison, Ji. Te) LOW/3Si The present plume population. (Abstract) Eos Trans. AGU, 54: 230. Ladd) Ho Sel 97/3). Bikini and Eniwetok Atolls, Marshall Islands. In O. A. Jones and R. Endean, eds.: Biology and geology of conrak NOCKS. New York: Academic Press, 1: 93-112. Ladd, H. S., Newman, W. A. and Sohl, N. F. 1974. Darwin guyot, the Pacific's oldest atoll. Proc. Second International Conak Rees Symposium, 2: 513-522. Leont'yev, O. K., Luk'yanova, S. A. and Medvedev, V. S. 1975. Vertical crustal movements of the Pacific ocean floor according to the results of geomorphological analysis. USSR Oceanology, 14(6): 840-846. Le Pichon, X., Francheteau, J. and Bonnin, J. 1973. Pate tectonics. New York: Elsevier Sc. Publ. Co. 300 pp. 31 Macdonald, G. A. and Abbott, A. T. 1970. Volcanoes in the sea. Honolulu: University of Hawaii Press, 441 pp. MacNeil, F. S. 1954. The shape of atolls: An inheritance from subaerial erosion forms. Am. Jour. Sec. 252: 402-427. McDougall, I. 1964. Potassium-argon ages from lavas of the Hawaiian Islands. Bull. Geok. Soc. Am. 75: 107-128. McDougall, I. 1971. Volcanic island chains and sea floor spreading. Nature Phys. Sci. 231: 141-144. McNutt, M. and Menard. H. W. 1978. Lithospheric flexure and uplifted atolls. J. Geophys. Res. 83: 1206-1212. McNutt, M. and Menard. H. W. 1979. Reply. J. Geophys. Res. 84: 5695-5697. Menard, H. W. 1969. Growth of drifting volcanoes. J. Geophys. Res. 74:. 4827-4837. Menard, H. W. 1973. Depth anomalies and the bobbing motion of drifting islands. J. Geophys. Res. 78: 5128-5137. Moberly, R. and Larson, R. L. 1975. Mesozoic magnetic anomalies, oceanic plateaus, and seamount chains in the northwestern Pacific Ocean. In R. L. Larson, R. Moberly, et al.: Initial reports of the deep sea drilling project (Washington: U. S. Government Printing Office), 32: 945-957. Moore, J. G. 1971. Relationship between subsidence and volcanic load, Hawaii. Bull. Vokcanologique, 34: 562-575. Morgan, W. J. 1965. Gravity anomalies and convection currents. J. Geophys. Res. 70: 6175-6204. Morgan, W. J. 19/2a. Deep mantle convection plumes and plate motions. Bull. Am. Ass. Pet. Geol. 56: 2032213. Morgan, W. J. 1972b. Plate motions and deep mantle convection plumes. Mem. Geol. Soc. Am. 132: 7-22. Newell, N. D. and Bloom, A. L. 1970. The reef flat and 'two-meter eustatic terrace' of some Pacific atolls. Buk. Geok. Soc. Am. 81: 1881-1894. Purdy, E. G. 1974. Reef configurations: Cause and effect. In L. F. Laporte, ed.: Reefs in tume and space, Soc. of Econ. Paleontologists and Mineralogists, Spec. Publ. 18: 9-76. 32 ReaD. Ke L970) Changes in structure and trend of fracture zones north of the Hawaiian Ridge in relation to sea-floor spreading. J. Geophys. Res. 75: 1421-1430. Rotondo, G. M. 1975. Subsidence and emergence of Pacific (volcanic) 4skands and atolls: A case study in the Hawatian-Emperor chain. Honours Geography Thesis. University of Winnipeg, Winnipeg, 107 pp. Rotondo, G. M. 1980. A reconstruction of Linear island chain positions in the Pacific: A case study using the Hawacian-Emperor chain. M.A. Thesis. University of Hawaii, Honolulu, 61 pp. Rotondo, G. M., Springer, V. G., Scott, G. A. J. and Schlanger, S. O. 1981. Plate movement and island integration--a possible mechanism in the formation of endemic biotas, with special reference to the Hawaiian Islands. Syst. Zool. 30: 12-21. Scllater, J. G., Anderson, R. Ns and Bellis Maal. lO7Mre Elevation of ridges and evolution of the central eastern Pacific. J. Geophys. Res. 76: 7888-7915. Sclater, J. G. and Francheteau, J. 1970. The implications of terrestrial heat flow observations on current tectonic and geochemical models of the crust and upper mantle of the earth. Geophys. J. R. astr. Soc. 20: 509-542. Scott, G. A. J., Rotondo, G. M. and Rannie, W. F. 1976. The tangential component in Pacific atoll development, diffusion and demise. Programme and Résumés. The Canadian Association of Geographers Annuak Meeting (Laval), 110-113. Scott, Go Aj J. and Street, J. Ms W976. The role of chemical weathering in the formation of Hawaiian amphitheatre-headed valleys. Zeit. fur Geomorph. 20: 171-189. Shaw, H: R. and Jackson, Es Dis) 19735 Linear island chains in the Pacific: Result of thermal plumes or gravitational anchors? J. Geophys. Res. 78: 8634-8652. Shepard, F. P. 1970. Lagoonal topography of Caroline and Marshall Islands. Bull. Geok. Soc. Am. 81: 1905-1914. Tayama, R. 1935. Table reefs, a particular type of coral reef. Proc. of the Imperial Acad. of Japan, II: 268-270. Watts, A. B. and Cochran, J. R. 1974. Gravity anomalies and flexure of the lithosphere along the Hawaiian-Emperor seamount chain. Geophys. J. R. astnr. Soc. 38: 119-141. Watts, A. B. and Talwani, M. 1974. Gravity anomalies seaward of deep- sea trenches and their tectonic implications. Geophys. J. R. asitna Soc. 36: 57-90. 33 Wharton, W. J. L. 1897. Foundations of coral atolls. Nature, 55: 390-393. Wiens, H. J. 1962. AtolQ environment and ecology. New Haven: University Press, 532 pp. Wilson, J. T. 1963a. A possible origin of the Hawaiian Islands. Can. J. Phys. 41: 863-870. Wilson, J. T. 1963b. Evidence from islands on the spreading of ocean floors. Nature, 197: 536-538. ATOLL RESEARCH BULLETIN NO- 261 ECOLOGICAL PROBLEMS ASSOCIATED WITH DISRUPTION OF DUNE VEGETATION DYNAMICS BY CASUARINA EQUISETIFOLIA L.- AT SAND ISLAND, MIDWAY ATOLL BY STEVEN I- APFELBAUM, JAMES P- LUDWIG AND CATHERINE E- LUDWIG ISSUED BY THE SMITHSONIAN INSTITUTION WASHINGTON, D-C-, U-S-A- SEPDEMBER 983 ECOLOGICAL PROBLEMS ASSOCIATED WITH DISRUPTION OF DUNE VEGETATION DYNAMICS BY CASUARINA EQUISETIFOLIA L- AT SAND ISLAND, MIDWAY ATOLL 1 By Steven I. Apfelbaum , James P. Ludwig and Catherine E. dedi INTRODUCTION Exotic plants and animals may be introduced in ecosystems because of desirable qualities or by accident. Many introductions have caused great harm because of unpleasant characteristics which are realized only after introduction. lLIronwood (Casuarina equisetifolia L.) is one such species. Introduced for shade and ornamental purposes in subtropical and tropical areas, this adaptable and quick growing tree has caused ecological changes which may limit its future introduction. Ironwood can be a Pioneer species that colonizes nutrient depauperate soils, especially nitrogen poor areas, because of its nitrogen fixing capability (Aldrich and Blake, 1932). Equally important is its ability to reproduce by several assexual modes in addition to sexual routes. These character- istics make this species a persistent management problem. This paper presents our observations of Ironwood ecology and this plant's relation- ships with native vegetation, seabirds, and man on Midway Atoll. The Casuarinaceae is a distinctive family of trees and shrubs from dry or saline habitats of southeast Asia and the southwest Pacific. Ironwood branches have a characteristic weeping habit with peculiar jointed leaves in a whorled branching pattern. Male and female flowers are separate with the latter borne in dense spheroid heads near branch ends. Leaf size is reduced with photosynthetic tissues and stomatal openings found in stem interrib spaces, probably an adaptation to prevent dessication. Surprisingly, little ecological, life history, or manage- information is available on the Casuarinaceae. THE STUDY AREA Midway Atoll, located 2100km northwest of Honolulu, Hawaii, has been occupied by man since the early 1800's. Midway was a major link in the first trans-Pacific telegraphic cable system and has been a major U.S. Depicted Ecological Services, P.O. Box 2021, Roosevelt, Utah 84066 “Hasigsieall Research Services, Inc., 312 W. Genesee Street, Iron River, Michigan 49935 Manuscript received Dec. 1980--Eds. naval facility since 1939. Two islands are found in the southeastern area of the enclosed atoll lagoon. Sand, the larger island (Figure 1) is 2.9km by 1.9km, with an area of 482 hectares. It has a maximum elevation of 13.1lm. Eastern Island, 1.5km east of Sand is 320 hectares with an elevation of 10.4m. Before human settlement, Sand Island was a sandy expanse with a naturally depauperate vegetation. Shorelines and dunes were stabilized by the dune binding complex including Scaevola taccada and the prostrate herb, Ipomoea indica. Shifting sands were normal, especially in central areas of the islands. Since settlement, beach erosion on Sand Island has been an expensive problem which com- plicates maintenance of shorelines, buildings, docking facilities and other military structures. The climate is subtropical with an average annual precipitation of 10lcm. Rainfall occurs an average 12 days a month; December through February are the wettest months; March is the driest. Northeastern trades prevail from March through October with stronger westerlies from November to February. Highest mean monthly temperatures approach 30° C. while May, June and November temperatures range from 21-27 C. (Woodward, 1972). Although no data are available on evapotranspiration rates, these are certainly highest during warmest and windiest periods. In 1903, the telegraph company planted Ironwood in the northern windward areas of Sand Island. Ironwood now covers much of the unpaved surface of the island, where it often forms a thick canopy or tangle of saplings. Many other trees and shrubs have been introduced, but, by far, Ironwood dominates the island ecosystem. Some Ironwood individuals exceed a 25m height and 1m diameter at breast height (d.b.h.). Along the northeast shore, this tree forms a thick canopy and litter that may reduce understory vegetation. Ironwood selects against birds of open habitats and favors those species associated with forested areas. ACKNOWLEDGEMENTS We thank numerous Fish and Wildlife Service personnel for providing help in arranging our research endeavors in Midway. Special thanks to Dr. Derral Herbst, Mr. Brent Giezentanner and Dr. William DeMichele for their help in various aspects of manuscript preparation and data col- lection. U.S. Navy personnel, especially CWO Donald Richardson, provided much field support. METHODS AND MATERIALS Vegetation studies were conducted February 15-24, 1979 in Sand Island. Casual observations of Eastern Island vegetation were made during this same time. Beach vegetation dynamics were investigated along representative beach exposures on Sand Island. We measured intercepts for each plant species along 30, 2x25m transects that originated at the seaward foot of the foredune, and went inland. Using this method, rela- tive cover for each plant species was summarized over the north, west and south beach areas of the island. Ten transects were established in 1101y Aempiw ‘pueis| pues “| “614 SOM » SS yoesg Isom JoqieH Jouu| ulew yoeag s,ua;w 7 paysijug 1 Y 1 S 1 ‘s sy00qg y / 1 1 ” Jeng {mm yb 8g: yy] 10N —— | I each of these exposures. Fruit and seed productivity estimates were made for Ironwood. All newly fallen cones located in four 0.25m™ quad- rats were used to estimate and measure fruit production. Seed production estimates were made by counting the number of pairs of woody bracts opened in the cones that had dropped seed. A plant species list was generated for Sand Island (Appendix). Species of noteworthy status, those providing difficulty in identifica- tion, or of uncertain status, were collected and are maintained at the University of Illinois Herbarium, Urbana. Other species were listed as observed. RESULTS Ironwood has wind disseminated samaroid seeds approximating a measurement of 5mm x 2.5mm. Small Ironwoods (having a d.b.h. of 5cm or less and less than 2m in height) produced cones and seeds of identical size as larger older trees. Comparative germination and viability tests were not undertaken. However, Aldrich and Blake (1932) reported an average germination rate of 84% (n=437) for Ironwood seeds washed in mercuric chloride and water. They found seedling mortality to be "low". Over a 15 month period, their control plants attained a height of 40cm compared to test plants innoculated with extracts from root nodules on wild Ironwood which grew to 140cm heights. Ironwood seedling densities along Sand Island runways suggest high germination and seedling success rates. Ironwood seedling density in one location exceeded 75 seedlings per square meter. Fruit production estimates averaged 30 cones/m beneath the test trees (Table 1) and ranged from 21-38 cones. Seed production varied from 3,696 to 5,168 (x=4,602) seeds per meter square. Total estimated seed production for the test trees ranged from 109,880 to 258,400 and averaged 184,000 seeds per tree which assumes a single seed crop per year. TRANSECT RESULTS Frequency distribution for vegetation as a function of distance from the foredune is plotted in Figures 2A-2F. Ironwood and Scaevola were the most frequently encountered species in all locations. Scaevola was encountered more frequently near the foredune and declined inland on the north and south beaches (Figures 2A and 2C). As Scaevola declined, Ironwood became more abundant; Scaevola was almost displaced by Lronwood in the first 25m inland from the foredune, especially in the north and west beach study areas. Data from the west beach (Figure 2B) suggest Ironwood invasion to be far more complete than along other beaches. Ironwood dominated Scaevola from the foredune inland to 18m where Scaevola became slightly more abundant, but only as a decadent under- story element. Scaevola had a relatively uniform distribution inland from the foredune for 25m along the west beach. Most plants except Tournefortia occurred behind the foredunal Scaevola. There Scaevola OvT‘Y8T = x 08g ‘60T OE 00” 8sz (10S :Sspees TeIo] :eeay punoiry °4sSq 0°z094 9ST S°6Z uesH 0°969¢ QLT Iz q eer], 0°g9TS 9ET Be Y 2241 W/Spees 2 wy, aod AQTATJONporg pees pue INI Bey wee ee ek ee ee NS eh eee SO = 0° 6t CC TSL TS 7x $6 G0 UY 90 F€°S Z*IL = @°SY €€-9S-96-15-95-96 9 €/a T°9 49°9) 9€-zS-8%-84-64 E Z/a O'IT =.9°0% —_9S-€€-8%-0€-9€ g zy 1/4 6°L 7 0°vE T1?0°6 Aimee BERGE Oe NG BEE-DOS-BE on & €/¥ eR ob, 1€-GE-VE-ZE-SZ BS Fe oc -ne-E4-zH-99-HE Ta z/¥ ea, ee TE-0€-94-4E Oe Ge Z€-67-87-09-9€ 6 cg T/V¥ "a's FX # pees ‘a's # x souo) (wo) jo zequny qoj,oMeTG Ve], # 2eapend/ee 11 *TToay Aempry ‘pueTs] pues uo erfogxrzestnbe eurzenseD 10F UoOTRONporAg pees ¥ AENAG “T FTIeL Figure 2. Plant Frequency vs. Distance Inland from Foredune Origin: 1O- A: :) Transects 1-10 Ku-22 Sta Og NORTH BEACH fo) Casuarina 0 2 4 6 S 10.212: 14.16) 18: 7205) 220524 fee Foredune Distance (m) 10_B. Transects 11-20 9 WEST BEACH 8 7 6 5 4 3 2 1 0 2 4 6 8 10 12 14 16 18 20 22° 24 26 Cc. Transects 21-30 SOUTH BEACH —_ “NO WR UTDNWOO 0 2 4 6 8 10 12 -14 16 18 =20%) 2255245026 7 Figure 2. (continued) D Plant Frequency vs. Distance Inland from Foredune Origin: 10_ Transects 1-10 NORTH BEACH x Stenotaphrum O---- Euphorbia Absolute Frequency =aNWAUDNOWO 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Foredune Distance (m) 10._ E. 9 Transects 11-20 8 WEST BEACH 7 ° Cynodon 6 O---= Tournefortia 5 KX seece Verbesina 4 3 2 1 0 2 4 6 8 10 12 14 16 18 20 22 24 26 10 _ F. 9 Transects 21-30 8 SOUTH BEACH 7 O----Lobularia {0} Tournefortia 6 XK cecence Verbesina 5 4 3 2 1 plaieivevets a _@---8----@---0----9---§ a 0 2 4 6 8 10 12 14 16 18 20 22 24 26 8 distribution trends hold in the north and south beaches as well, although Bermuda Grass (Cynodon dactylon) also occurred in the foredunal areas. Along the west and south beaches, Tournefortia occurred infrequently from the foredune to at least 20m inland. Along the west and north beaches Scaevola was reduced to an understory layer beneath a closed Ironwood canopy. Scaevola and Ironwood each accounted for nearly 33% of all species intercepted in the transects. Thus, over 60% of all the plant intercepts along the transects resulted from these species. The cover importance of Scaevola and bare ground dropped to 24% each, while Ironwood and Bermuda Grass values were highest in the west beach. Along the south beach, Ironwood was less abundant than Scaevola or bare ground and Tournefortia was nearly as important as Ironwood. Most of the 123 plant species we encountered on Sand Island were exotics. Of these, few were found in the beach areas. Most occurred only where organic soils had been imported or developed near dwellings, or in the shade of larger Casuarina (Neff and DuMont, 1955; Lamoureux, 1961). Ironwood seedlings were present throughout, but only in associ- ation with Scaevola and Tournefortia when present in the foredunes. Seedlings were numerous behind the foredunes along the north beach, but were not found independent of these dune binding shrubs except in areas shaded during most of the day. Black rat (Rattus rattus) damage to native shrubs was not quantified. However, we found severe damage to Scaevola especially inland of the foredune where larger Ironwood were present as canopy elements. Rat damage was found only on Scaevola. The rodents chewed succulent apical and lateral buds which reduced lateral and vertical growth potentials of Scaevola. In some places, particularly along the west beach, damage was so severe that we believe Scaevola is certain to be eliminated. Along the vegetation surveys, Laysan Albatross nest densities (Table 2) varied from 8 to 89 nests per acre. Black-footed Albatross nested in the west and south beaches but no nests were located along the north beach transects. The Albatross species seldom nested together. Black-foots associated with openings between Scaevola clones; Laysans nested within thinned Scaevola clones under Ironwood canopies, or where Ironwood seedlings and saplings grew into a thick bush-like form. DISCUSSION The foredune begins 50-75m from the high tide along the north beach, which was actively building. This beach had dense rounded clones of Scaevola 0.5-1.8m in height, especially between the cross runway and the enlisted men's beach. Immediately behind the foredune were large Ironwood that shaded the foredune at various times of the day and season. Ironwood seedlings were scattered throughout the Scaevola. However, few seedlings were present under the larger Ironwood. Inland of the Ironwood were numerous cultivated plants, especially in yards of abandoned houses. Table 2. Breeding bird nest densities for nests Encountered in 2x25m Vegetation Transects # of Nests by Species Encountered North Beach Black-footed Laysan Transects 1-10 Albatross Albatross 1 1 2. 1 3 il 4 1 5 2 6 1 7 2 8 i) 10 D Nesting density per 500m 0 11 Nesting density per acre 89 Nesting density per hectare 0 220 West Beach Transects 11-20 11 1 12 13 14 15 16 4 17 18 2 19 2 20 4 Nesting density per 500m 8 5 Nesting density per acre 65 40 Nesting density per hectare 160 100 South Beach Transects 21-30 21 1 22 1 1 23 24 25 26 27 28 1 29 2 30 Nesting density per 500m 5 1 Nesting density per acre 40 8 Nesting density per hectare 100 20 10 These included the exotics Chinese Banyan (Ficus microcarpa), Poinsettia (Euphorbia cyathophora), and Bermuda Grass. The west beach was severely eroded even though rip-rap had been previously installed for prevention. In winter, northwest storms subject this beach to erosive winds and waves that develop over the 9.6km (6m) distance to the fringing reef. The tide-line to foredune distance varied from 0-25m. Fallen Ironwood showed the original shore had been undermined and the beach zone lost. Based on comparisons with the north and south beaches (Figures 2A and 2C), 12-18m of beach and foredune have been removed by erosion along this beach. Scaevola is overtopped by Ironwood along this beach. Surviving Scaevola was in very poor con- dition with severe dieback and rat damage evident. Beneath high density Ironwood stands, herbaceous ground cover was absent. In some areas, Scaevola had recently died back and few stems survived. Most stems were leafless and assumed a shriveled-desiccated appearance. Young Crown-beard (Verbesina enceloides) plants invaded dead and dying Scaevola clones. We have no information on the persistence of this species under the Ironwood. Since Crown-beard did not occur in exposed foredunes, it may require ameliorated conditions associated with the larger Ironwoods to establish in the dunes. The west point of Sand Island just west of the paved end of the main runway was dominated by large Scaevola that showed little rat damage. In this area, no Ironwood seedlings were found seaward of a few esta- blished Ironwood trees 5-10 years of age located 80m inland from the tide line. Between the south beach and dump, Scaevola declined and was largely restricted to an undercut sand ridge with a relief of 3-5m from the level of Waldron Blvd. to the ocean. Erosion abatement structures, including wood and steel pilings, and cement breakwalls, have been utilized here. However, most were washed out. Present between the ridge and boulevard were Ironwood, sea grape (Coccoloba uvifera), Scaevola and Tournefortia. Large Tournefortia shrubs up to 5m tall were present east of the naval facility buildings on the ridge. Ironwood seedlings grew in the Scaevola, especially with older Ironwood along the crest of the ridge. To the east, the ridge flattened; Scaevola and Tournefortia became less abundant. In this area, scattered Ironwoods were present in and around several dune blowouts. Dense colonies of Black-footed Albatross nested in these blowouts and associated sparsely vegetated areas. However, little nesting occurred on the beach below blowouts. Sweet Alyssum (Lobularia maritima) was the most common ground cover species in and around blowouts. This plant was especially lush where Albatross defecated, often growing in circular patterns around their nests. We found less rat damage on Scaevola here than along either the west or north beaches. Beach vegetation dynamics on Sand Island result from interactions between native plants, rats, the complement of introduced species, and continuing disturbance by mankind. Native dune shrubs tolerate high sand temperatures, salt spray and prevailing windy conditions. They 11 grow well under these conditions for there is little competition, and unlike most introductions, they are able to compensate for sand burial by differential growth and adaptive growth forms fitted to wind, sand scour and dessication stresses. Adaptations include waxy, succulent and pubescent-reflective foliage. Aerodynamic spheroid to prostrate growth forms such as thick, hemispherical shape of the Scaevola and trailing Ipomoea are important adaptive features. Though adjusted to the environmental stresses of beaches and dunes, these plants seem to have a limited adaptive flexi- bility. Apparently, slight environmental changes can have serious impacts on these plants, probably due to their extreme specialization to a severe environment and relatively slow growth rates. Rat damage and Ironwood intrusion, singly or synergistically, stress Scaevola, the key native species. Scaevola is undoubtedly shade intolerant, growing best in exposed beach sites, with sparse Tournefortia or other shrubs. The establishment and growth of Ironwood in Scaevola clones may eliminate this plant and the entire dune-shrub complex. Micro-habitat changes that occur with Ironwood establishment and growth among dune binding shrubs need investigation. Factors affecting Scaevola may include increased shading, relative humidity, and physical damage effects from branch and fruit fall from Ironwood, allelopathic effects and associated alterations to hydrology and nutrient avail- abilities may also occur. Scaevola germination and seedling establish- ment may be hampered by thick and usually dry Casuarina litter. When these factors are coupled with differential rat feeding pressures on Scaevola this becomes a rather complicated problem for controlled investigations. Scaevola clones are aerodynamically suited to tolerate high winds, sand scour and evaporative stresses. Ironwood was growing only in Scaevola clones when in the beach areas which suggests that establishment is dependent on an altered micro-climate offered by Scaevola clones. Following establishment in a clone, Ironwood seedlings apparently send long tap roots to ground water sources and rapid growth occurs. Lighter red colored infrared tones on photos (Ludwig, et. al., 1979) suggest these Ironwoods are less productive and more water stressed than Lron- woods occurring more inland. However, Ironwood's colonization in Scaevola occurs rapidly and is quickly followed by the establishment of other Ironwood seedlings. This invasion pattern may explain the even size (and possibly age) stands of Ironwood forming bands parallel to the beach, especially along the west beach. It is plausible that Scaevola, Ipomoea and other native plants could be eliminated from Midway. With high seed set, apparent fast growth and invasion rates, Ironwood is a major threat to the remaining Mative plants of Midway. If Ironwood invades the beach zones, severe erosion is likely to occur. JLronwood lacks the growth form and physiology to effectively stabilize the beach areas. Severe erosion problems already occur on the east shore of Eastern Island. Erosion control methods and strategies deserve careful attention at Midway. Rip-rap apparently 12 functions as short-term control of a long-term erosion problem. This method is less effective than natural vegetation erosion control, especially against aeolian sand movements. Native dune binding shrub management schemes, including means to control Ironwood would be especially helpful for long-term erosion control; control of these exotics may also cost less than structural alternatives such as pilings and rip-rap. A well thought-out control plan can also benefit nesting seabirds. Changes in bird populations that occur with Ironwood establishment are important considerations. Although Fairy and Noddy Terns, and Laysan Albatross benefit from increased nesting habitat offered by Ironwood, species such as the Red-footed Booby, Frigate Bird, and Black— footed Albatross which use Scaevola and open areas for nesting seem certain to suffer habitat losses. Comprehensive studies on the management and control of Ironwood should be initiated. Surprisingly, little information is available on managing this species. It is clear that certain areas on Midway are being damaged for continued Navy use and altered for other uses. The cross runway is being invaded rapidly by Ironwood. The runway aprons are almost completely invaded and root-heaving of the pavement by Ironwood will probably destroy the runway in the 1980's. Similar problems are far more advanced on the Eastern Island runways. Safe and effective control methods for Ironwood are not known. However, any chosen method should be amenable to continued human and seabird use. This will require holistic ecosystem management. 13 REFERENCES CITED Aldrich, R.N. and M.A. Blacke, 1932. On the Fixation of Atmospheric Nitrogen by Bacteria Living Symbiotically in Root Nodules of Casuarina equisetifolia. Oxford University Press. 20pp. Lamoureux, Charles H., December 31, 1961. Botanical Observations on Leeward Hawaiian ATolls. Atoll Research Bulletin 79:1-10. Ludwig, James P., Catherine E. Ludwig and Steven I. Apfelbaum, 1979. Observations on Status and Interactions of the Avifauna and Plants of Midway Atoll, Leeward Hawaiian Islands, Between February 1-24, 1979. Ecological Research Services, Inc. Unpublished Report (includes infrared photographs of vegetation). Neff, J.A. and P.A. DuMont, August 15, 1955. A Partial List of the Plants of Midway Islands. Atoll Research Bulletin 45:1-11. Woodward, Paul W. 1972. The Natural History of Kure Atoll, North- western Hawaiian Islands. Atoll Research Bulletin #164. 318pp. 14 APPENDIX LIST OF PLANTS ON MIDWAY ATOLL, HAWAII February 15-24, 1979 OBSERVED VOUCHF.RED ACANTHACEAE Asystasia gangetica (L.) T. Anders. Asystasia Odontonema strictum (Nees) Kuntze AGAVACEAE Agave sp. Century Plant xX Cordyline sp. Colored ti Xx Dracaena sp. Dracaena xX Sansevieria sp. Bowstring hemp AMARYLLIDACEAE Crinum asiaticum L. Spider lily ANACARDIACEAE Mangifera indica L. Mango xX APOCYNACEAE Carissa macrocarpa (Eck). DG. Natal plum xX Catharanthus roseus (L.) G. Don Madagascar periwinkle xX Nerium oleander L. Oleander Plumeria sp. Plumeria; frangipani xX Thevetia peruviana (Pers.) K. Schum Yellow oleander X ARACEAE Alocasia cucullata (Lour.) G. Don Chinese taro xX Anthurium andraeanum Lind. Anthurium xX Colocasia esculenta (L.) Schott Taro xX Dieffenbachia sp. Dumb cane xX Monstera deliciosa Liebmn. Monstera Rhaphidophora aurea Birdsey Pothos; (Sinden Andre) Taro vine Syngonium podophyllum (may be S. angustatum) Schott Xanthosoma sp. Elephant ear; Ape xX ARALIACEAE Schefflera actinophylla (Endl.) Harms ARAUCARLIACHEAE Araucaria heterophylla (Salisb.) Franco BORAGINACEAE Tournefortia argentea L.f. (Messerschmidia argentea (L.f.) Johnst.) CANNACEAE Canna indica L. CARICACEAE Carica papaya L. CARYOPHYLLACEAE Cerastium vulgatum L. Spergularia marina (L.) Griseb Stellaria media (L.) Cyrillo CASUARINACEAE Caruarina equisetifolia L. CHENOPODIACEAE Chenopodium murale L. COMBRETACEAE Terminalia catappa L. COMMELINACEAE Commelina sp. Rhoeo spathacea (Sw.) Stearn Zebrina pendula Schnizl. COMPOSITAE Bidens alba L. B. pilosa L. Conyza bonariensis (L.) Cronq. Gnaphalium sandwicensium Gaud. Pluchea nymphytifolia (Mill.) Gillis Sonchus oleraceus L. Verbesina enceloides (Can.) Gray OBSERVED Octopus tree X Norfolk Island pine X Tree heloptrope X Canna Xx Papaya xX Larger mouseear chickweek Saltmarsh sand spurry Common chickweed Ironwood Nettle-leaved goosefoot Tropical almond X Day flower X Rhoeo : x Wandering Jew X Spanish needle xX Horseweed ‘Ena ‘ena Fleabane Sow thistle Golden crown beard 15 VOUCHERED 16 OBSERVED VOUCHERED CONVOLVULACEAE Ipomoea batatas (L.) Poir. Sweet Potato xX I. indica (Burm.) Merr. Morning glory x I. pes-caprae subsp. Beach morning glory brasiliensis (L.) van Ooststr. X Ipomoea sp. Morning glory X CRASSULACEAE Kalanchoe pinnata (Lan.) Pers. Air plant x CRUCIFERAE Brassica nigra (L.) Koch Black mustard Ki Capsella bursa-pastoris (L.) Medik Shephard's purse x Coronopus didymus GE.) J. ES Smith Swinecress x Lepidium densiflorum Schrad. Xx Lobularia maritima (L.) Desv. Sweet alyssum x CUPRESSACEAE Cupressus sp. Cypress xX CY CADACEAE Cycas circinalis L. Cycad xX CYPERACEAE Cyperus alternifolius L. Umbrella plant xX C. papyrus L. Papyrus ».4 C. rotundus L. Nut grass X Fimbristylis pycnocephala Hbd. X EUPHORBIACEAE Euphorbia cyathophora xX GERANIACEAE Pelargonium sp. Geranium xX GOODENIACEAE Scaevola taccada (Gaertn.) Naupaka X Roxb. (S. frutescens auct. nom. (Mille.) Krause) GRAMINEAE Bromus catharticus Vahl xX Cenchrus echinatus L. Sand bur X (C. hillebrandianus Hitchc.) Chloris inflata Link Swollen finger grass xX Cynodon dactylon (L.) Bermuda grass xX Pers. 17 OBSERVED VOUCHERED GRAMINEAE Digitaria sanguinalis Crab grass X (L.) Scop. var. ciliaris (Retz.) Parl. Eleusine indica (L.) Gaertn. Goose grass xX Eragrostis tenella (L.) Beauv. Love grass xX E. variabilis (Gaud.) Emoloa X Lepturus repens (Forster) R. Br. var. subulatus Fosb. X Poa annua L. Annual blue grass X Tricholaena rosea Nees Natal redtop xX Setaria verticillata (L.) Beauv. Bristly foxtail grass X Sporobolus africanus African Dropseed X Poir.) Robyns et Tournay Stenotaphrum secundatum Buffalo grass Xx (Walt.) O. Ktze. LABIATAE Coleus scutellarioides (L.) Benth. Coleus xX LILIACEAE Aloe sp. Aloe X Asparagus setaceus (Kunth) Jessop Asparagus fern x MORACEAE Ficus benghalensis L. Banyan X F. elastica Hornem. Rubber plant Xx F. microcarpa L.f. Chinese banyan X MALVACEAE Abutilon grandifolium (Willd.) Sweet Hairy abutilon xX Hibiscus sp. Hibiscus X Malva parviflora L. Little mallow X Malvastrum coromandelianum (L.) Garcke False Mallow xX Malvaviscus arboreus Cav. Turks cap xX NYCTAGINACEAE Boerhavia repens L. Alena X Bougainvillea sp. Bougainvillea xX ORCHIDACEAE Unidentified orchids X Vanda sp. X 18 OBSERVED VOUCHERED OXALIDACEAE Oxalis corniculata L. Lady's sorrel x O. martinana Zucc. Pink wood sorrel xX PALMAE Cocos nucifera L. Coconut xX Phoenix sp. Date Palm xX Pritchardia sp. Fan Palm xX Roystonea sp. Cabbage and royal xX PANDANACEAE Pandanus sp. Screwpine; Hala xX PLANTAGINACEAE Plantago lanceolata L. Narrow leaved plantain xX Ps major Iie Broad leaved plantain xX POLY GONACEAE Coccoloba uvifera L. Sea grape Xx POLYPODIACEAE Microsorium scolopendria (Burm.) Copel. Laua'e os Nephrolepis hirsutula (Forst.) Presl. Sword fern xX PORTULACACEAE Portulaca oleracea L. Purslane xX PRIMULACEAE Anagallis arvensis L. Scarlet pimpernel xX ROSACEAE Rosa sp. Rose X RUBIACEAE Gardenia sp. Gardenia X RUTACEAE Glerus (spc Citrus xX Murraya paniculata G:) Jack Mock orange xX SOLANACEAE Capsicum annuum L. Red papper xX Solanum nigrum L. Nightshade xX UMBELLIFERAE Apium tenuifolium (Moench) Hegi Fir-leaved celery xX 19 OBSERVED VOUCHERED URTICACEAE Pilea microphylla (L.) Artillery plant; Liebm. Rockweed xX VERBENACEAE Lantana camara L. Lantana x Vitex trifolia L. Polinalina xX ZINGLBERACEAE Alpinia zerumbet (Pers.) Burtt & R.M. Sm. (A. speciosa K. Schum.) Shell ginger xX Hedychium gardnerianum Lindl. Kahili ginger xX ZY GOPHY LLACEAE Tribulus cistoides L. Puncture vine xX OUT OF ALPHABETICAL ORDER: LEGUMINOSAE Albizzia lebbeck (L.). Benth. Woman's tongue xX Crotalaria incana L. Fuzzy rattle-pod xX Delonix regia (Bojer) Raf. Royal poinciana xX Desmanthus virgatus (L.) Willd. Slender mimosa xX Erythrina variegata var. orientalis (L.) Merr Tiger's claw xX Leucaena leucocephala (Lam.) deWit Koa haole Xx Medicago lupulina L. Hop clover xX Samanea saman (Jacq.) Merr. Monkeypod xX SUBTOTALS : 54 69 TOTAL: 123 "ii ATOLL RESEARCH BULLETIN No- 262 THE FLORA AND VEGETATION OF SWAINS ISLAND BY W. A-WHISTLER ISSUED BY THE SMITHSONIAN INSTITUTION WASHINGTON, D- C-, U-S-A. SEPTEMBER 1983 THE FLORA AND VEGETATION OF SWAINS ISLAND by W.A. Whistler+ INTRODUCTION Swains Island is an isolated atoll lying about 270 km north of Samoa. Although geographically and floristically a part of the Tokelau Islands 160 km to the northwest, it belongs politically to the Territory of American Samoa. The island lies at a latitude of 11°03' S and a longitude of 171°03' W. It has an area of 210 ha and a maximum elevation of less than 6 m (Fig. 1). The island is a ring-shaped atoll with a large, completely enclosed, brackish water lagoon in the center (Fig. 2). In prehistoric. times the lagoon was connected to the sea, but it is now completely landlocked. It is shallow, but in spots reaches a maximum depth of 15 m. The water of the lagoon is not potable, but is used for bathing and washing clothes. Drinking water is obtained from a well, and from water catchment. The rainfall on Swains Island is probably about 250 cm/year, since the Tokelau Islands to the northwest have an average annual rainfall of over 250 cm (Parham, 1971). Although the lagoon is nearly devoid of fish life, it is rich in algae; one particular blue-green alga species (or mixture of species) forms conspicuous, irregular chunks which make the shallow lagoon water appear like a thick vegetable soup (Fig. 3). Buried deposits of a white bivalve shell are found in the lagoon, but this mollusc species apparently disappeared after the lagoon became landlocked. The pretty shells are used by the Swains islanders to make unique leis. Landing on Swains Island is made on the west side at Taulaga, the only village on the island. Besides a small number of thatched, Samoan- style huts ("fale"), Taulaga has a small white church and a large, barn- like copra shed. Leading from the copra shed to the nearby beach are old railway tracks which were once used to transport copra from the shed to the beach for transfer to cargo vessels. Nearby is a large cleared area that may one day be made into an airport runway to link Swains Island by air to Tutuila, the main island of American Samoa. At the present time supplies are brought in by boat from Tutuila several times a year. East of Taulaga, one third of the way around Swains along the jeep road that circles the palm-covered island, is Etena (=Eden), the former residence of the Jennings family, the owners of the island. The imposing colonial-style house now stands abandoned in a state of disre- c Department of Botany,. University of Hawaii, Honolulu, Hawaii. 96822 Manuscript received January 1980--Eds. pair. Nearby are several well-kept graves, a final resting place for some of the original settlers of the island. The Swains islanders are a mixture of Tokelauans and Samoans, mostly the former, with a bit of American and Portuguese heritage as well. At the time of the author's visit, the population was less than fifty. The language usually spoken is Tokelauan, but most of the islanders are also conversant in Samoan and some in English as well. The original Tokelauan name of the island is "Olosega", but this name is no longer used. The name has led to some confusion, since there is another island with the same name in the nearby Manu'a Islands of American Samoa. The original inhabitants of Swains Island were Tokelauan, but when it was "discovered" by the Western world, it was uninhabited. Its discovery is erroneously attributed to Quiros in 1606, but the island discovered by this Spanish explorer is apparently Manihiki in the Northern Cooks. The credit for the discovery goes to an American whaling captain named W.C. Swain in or around 1839. It was visited by the U.S.S. Peacock of the United States Exploring Expedition in 1840. Later, title to the island was obtained by Eli Jennings, an American living on Upolu (now a part of Western Samoa). With his Samoan wife, Malia, and his family, he settled on the island in 1856, and the ownership of the island has remained in the Jennings family ever since. The current head of the family is Wallace Jennings who resides on the island. BOTANICAL HISTORY The first botanical information about Swains Island was gathered by the U.S. Exploring Expedition during the aforementioned visit of the U.S.S. Peacock in 1840. Although plant specimens were collected, they, along with specimens from the Tokelau Islands, were subsequently lost. Pickering (1876) stated, "Lists of plants growing up on them were com- municated to me by Mr. Rich; after the loss of his specimens by ship- wreck." Pickering's list of Swains Island plants included twelve spe- cies--Hedyotis romanzoffiensis ("'Petesia"), Guettarda speciosa, Cordia subcordata, Messerschmidia argentea, Boerhavia tetrandra, Procris pedunculata, Pandanus tectorius, Cocos nucifera, Christella dentata ("Aspidium"), Asplenium nidus, Microsorium scolopendria ("Polypodium") , and Psilotum sp. The next collector to visit Swains was apparently J. Lister in 1891. No listing of his collections were published, but they are deposited at Kew and Cambridge University. One of his specimens--Hedyotis romanzoffiensis--was cited by Fosberg in his revision of the genus (1943). Other unpublished collections were made between 1929 and 1939 by P. Diefenderfer, E. Bryan, and L. Schultz. Diefenderfer, an anthro- pologist working for the Department of Education of American Samoa, collected about 14 species during trips to Swains in 1929 and 1930, but no field notes are known to exist. Bryan collected on Swains during visits in 1935 and 1938. Approximately 82 specimens were collected (mos. 912-55, 1345-74, and some unnumbered ones), the data for which is found in field books stored at the Bishop Museum in Honolulu. The specimens of Diefenderfer and Bryan are also deposited at the Bishop Museum. Schultz, an ichthyologist, visited Swains in 1939 and made a small collection of about 10 specimens, and these are deposited at the Smithsonian Institution. In 1966-67 R.B. Clapp, an ornithologist, visited Swains a number of times and recorded the bird life of the island (Clapp, 1968). Al- though he did not directly discuss the vegetation or flora of the island, he did mention the presence of Cocos, Pisonia, Pandanus, Messerschmidia, and Seaevola. He apparently did not collect any plant specimens. In 1971 B. Parham published a study of the vegetation of the nearby Tokelau Islands, based on his own work and the work of others. It includes a checklist of the flora of Nukuono from specimens collected by K. Wodzicki in 1966-68. The flora of the Tokelau Islands is very similar to that of Swains, but based on Parham's checklist of the flora of the largest of the three atolls, it may be smaller than that of Swains. Parham's paper included the Tokelauan names for the plants; these names were very useful when questioning the Swains islanders about their island's plants. The first and only comprehensive collection of the flora of Swains was made by the author from the 18th to the 21st of May 1976. The four day visit was part of an inventory of the flora and fauna being carried out for the USFWS (1978), and this report, which is as yet unpublished, con- tains much biological information about Swains. Up until that time, only 56 species of vascular plants had been collected or recorded from Swains, but now this number is 95. Only three of the previously reported species were not found during the author's visit--Solanum nigrum, Hedyotis romanzoffiensis, and Annona muricata. Approximately 88 specimens were collected during this visit (nos. W 3352A to W 3439), and these will be deposited at the Smithsonian Institution and the Bishop Museum. THE VEGETATION The vegetation of Swains Island is greatly disturbed and nearly the whole island is covered with coconut palms. It is doubtful if any of the original forest vegetation remains. Due to the short duration of the author's visit, no quantitative work could be done. However, based on the observations made, the vegetation of Swains can be divided as follows: Native vegetation Sand strand Littoral shrubland Littoral forest Coastal marsh Disturbed vegetation Coconut plantation Village land Each of these types of vegetation is discussed below. Sand strand The sand strand or 'Pes-caprae'' formation as it is often called, consists of a small band of herbaceous plants on the seaward margin of the littoral forest (Fig. 4). This vegetation type is poorly developed on Swains, particularly because the most characteristic plant--Ipomoea pes-caprae--is absent. Another characteristic plant of the sand strand-— Vigna marina--is apparently only a recent introduction and was found in only one small patch at Taulaga. The dominant species of the sand strand of Swains Island are Lepturus repens, Fimbristylis cymosa, Boerhavia tetrandra, and Triumfetta procumbens. The first two are common in scattered clumps on the exposed sandy shore above the hightide mark, while the latter two are in less exposed areas. Littoral shrubland The littoral shrubland is the shrub-dominated vegetation on the seaward margin of the littoral forest. In Samoa, this vegetation is dominated by Scaevola taccada, Wedelia biflora, Ficus scabra, and Clerodendrum inerme (Whistler, 1980), but only the first of these species is found on Swains. In addition to the shrubland on the edge of the littoral forest, northeast of Etena there is a large inland area of this vegetation dominated by Scaevola taccada (Fig. 5). The reason for this patch of shrubland in the midst of the coconut groves was not determined, but it probably resulted from some disturbance by the islanders. Other less common plants found in the littoral shrubland are Pemphis acidula, Messerschmidia argentea, Ipomoea macrantha, Cassytha filiformis, and Achyranthes velutina. Littoral forest Originally, most of the island was covered by littoral forest. That which remains today is found along the shores and in scattered patches in the coconut plantation (Figs. 6 and 7). Probably all of the existing littoral forest is secondary and has developed when parts of the coconut plantation were neglected and coconut palms were grad- ually replaced by littoral forest species. ‘Si The dominant littoral tree on Swains is Hernandia sonora, and there are some small patches of nearly pure Hernandia forest away from the immediate coast. The forest floor in these patches is very open, with only scattered Bryophyllum pinnatum, Asplenium nidus, and Microsorium scolopendria on the ground (Fig. 8). Other common littoral forest trees are Pisonia grandis, Neisosperma oppositifolia, Pandanus tectorius, Guettarda speciosa, and Messerschmidia argentea. The latter species is limited to sunny areas, mostly on the forest margins. Less common are Hibiscus tiliaceus, Cordia subcordata, Calophyllum inophyllum, and Barringtonia asiatica. The latter species may have been more common in the past, but only two individuals were seen during the visit. Wallace Jennings reported that he had others cut down because he doesn't like this tree, perhaps because of its potential use as a fish poison. Epiphytes in the littoral forest are few, consisting only of Procris pedunculata, Vittaria rigida, Psilotum nudum, and Psilotum complanatum. Coastal marsh The herbaceous vegetation growing along the margins of the lagoon ean be classed as a coastal marsh. Where disturbed, the vegetation is dominated by Ludwigia octivalvis, Cyperus javanicus, and Paspalum distichum. On the north shore of the lagoon there is a small peninsula extending out into the water (Fig. 2). It is covered by undisturbed coastal marsh vegetation dominated by Eleocharis geniculata and Paspalum distichum, with some scattered Pemphis acidula in higher, drier areas. This is the first record of this species of Eleocharis in Samoa or Tokelau. A specimen of this rush collected by E. Graeffe in 1870 was listed as being collected in "Samoa", but this is probably a mistaken locality, and it may have been collected in Fiji instead. Similar coastal marsh vegetation in Samoa is dominated by Eleocharis dulcis, Cyclosorus interruptus, and Acrostichum aureum, but none of these species is found on Swains. Coconut plantation Most of Swains Island is covered with coconut plantation (Fig. 9). The plantation is in a state of neglect, since copra is no longer exported. Patches of littoral forest species are scattered throughout the coconut palms, and it is apparent that if left undisturbed, most of the palms would be eliminated by other more aggressive littoral forest species. Underneath the coconut palms is a thick, almost impenetrable growth of young coconut palms and the “bird's-nest fern", Asplenium nidus, which exclude nearly all other species from becoming established. Village land The village land consists of areas cleared for houses, roads, and for crops other than coconut. These disturbed areas are dominated by introduced weedy species. The large grassy village green ("malae") at Taulaga (Fig. 10) and grassy areas at Etena are dominated by grasses, sedges, and other herbaceous weeds. The dominant weedy species are Euphorbia hirta, Phyllanthus amarus, Sida rhombifolia, Portulaca oleracea, Boerhavia tetrandra, Spermacoce assurgens, Physalis angulata, Stachytarpheta urticaefolia, Cyperus kyllingia, Cyperus rotundus, Fimbristylis dichotoma, Cenchrus echinatus, Chrysopogon aciculatus, Axonopus compressus, Cynodon dactylon, Eleusine indica, Eragrostis tenella, Lepturus repens, and Paspalum conjugatum. In wet areas, Ludwigia octovalvis is the dominant weedy species. The crops grown for food on Swains Island are Musa paradisiaca, Ipomoea batatas, Carica papaya, Pandanus tectorius (a cultivar), Mangifera indica, Citrus aurantium, Citrus medica, and Artocarpus altilis. These grow around houses and on the edges of the village. West of Taulaga, there is a swampy area where the large aroid Cyrtosperma chamissonis is grown. Alocasia macrorrhiza and Colocasia esculenta are also grown, but to a lesser extent. In addition to the crop plants, some ornamentals are grown, but except for some remnants at Etena, these are mostly in the vicinity of houses at Taulaga. THE FLORA The following is an annotated checklist of the vascular flora of Swains Island. The species are listed in alphabetical order by family under Pteridophyta, Dicotyledonae, and Monocotyledonae. Following the species name is the collection number of the author which is always preceded by a "W'"', while those of the other collectors are preceded by their names. The native names for the species, which are usually the same as in Samoa or the Tokelau Islands, are also given. Pteridophyta ASPLENTIACEAE Asplenium nidus L. "Laumea", which is the Tokelauan name. In Samoa it is called "laugapapa." The bird's-nest fern is very common as an epiphyte or growing on the ground in the forest. The young stems are cooked and eaten. W 3397, Bryan 919. DAVALLIACEAE Nephrolepis hirsutula (Forst.f.)Presl A yery common fern of the forest and particularly in sunny disturbed places. Parham lists the Tokelauan name as “laumailekimoa." W 3399, Bryan 940, 941, 942, and 1352. POLYPODIACEAE Christella dentata (Forssk.)Brownsey & Jermy in Brit. A large ground fern common in disturbed places. This was previously referred to as Dryopteris nymphalis (Forst.f.)Copeland. W 3398, Bryan 943. Microsorium scolopendria (Burm.f.)Copeland "Laumaile'", which is the Tokelauan name. In Samoa it is called "Lau auta." A common epiphyte or ground fern of the forest. It y is also known as Polypodium scolopendria Burm. f. and Phymatodes scolopendria(Burm.f.)Ching. W 3401, Bryan 913, 914, 915, 939, 1353, & 1359. PSITLOTACEAE Psilotum complanatum Sw. An epiphyte growing on the trunks of coconut palms. W 3433, Bryan 1367. Psilotum nudum (L.) Beauv. "Moegaotekimoa" (bed of the rat), according to Mr. Jennings. Parham lists the Tokelauan name as “faleotekimoa'" (house of the rat). An epiphyte occasional on forest trees and coconut palms. W 3359, Bryan 1366. VITTARIACEAE Vittaria rigida Kaulf. var. samoensis (Luerrs.)C.Chr. A small unbranched epiphytic fern, occasional on forest trees. W 3425 and W 3396. Angiospermae DICOTYLEDONAE ACANTHACEAE Hemigraphis alternata (Burm.f.) T. Anders. "Suipi.'" Not seen, but reported by a reliable islander to be growing there. A purple-leafed prostrate herb occasionally cultivated in Samoa. AMARANTHACEAE Achyranthes velutina H. & A. No name was given, but this is called "tamatama'! in Tokelau (a closely related species, Achyranthes aspera, is called "lau tamatama'' in Samoa), It was found in only one locality, on the coast north of Taulaga. It was not previously recorded from American Samoa. W 3420. ANACARDIACEAE Mangifera indica L. "Mago.'' The mango was not seen, but it was reported by a reliable islander to be growing in at least one locality. ANNONACEAE Annona muricata L. "Sasalapa", according to Bryan. This is the same as the Samoan name for the soursop. It is cultivated, or at least it was when Bryan visited the island. Bryan 916. APOCYNACEAE Catharanthus roseus (L.)G. Don A garden escape found around houses and grave sites. W 3374. Neisosperma oppositifolia (Lam.)Fosb. & Sachet "Pulu fao."' A small to medium-sized tree occasional in the forest. In Samoa the name is "fao'', and "pulu" refers to the milky sap of the tree. This species has not previously been recorded from American Samoa. W 3424. Plumeria rubra L. "Pua.'' The frangipani tree is commonly cultivated around houses. Both the red variety (var. rubra) and the white one (var. acuminata) were seen, but only the later was collected. W 3388 ARALIACEAE Polyscias guilfoylei (Bull.)L.H.Bailey "Tagitagi.'' A cultivated shrub found at Etena. It is a common hedge plant in Samoa. W 3391. BORAGINACEAE Cordia subcordata Lam. "Tauanavye." A large tree scattered over the island, In Tokelau it is called "kanaya.'' Qn Swains Island the wood is called "taiuli" and is excellent for posts and carvings, since it is strong and durable. W 3406, Bryan 920. Messerschmidia argentea (L.£.)Johnst. "Tausuni.'' The common "tree heliotrope"' is known as “tauhunu" tn the Tokelau Islands, and is common along the shore and in sunny disturbed areas. It is also commonly known as Tournefortia argentea L.£., but is probably most correctly called Argusia argentea (L.f. Heine. W 3392. our CARICACEAE Carica papaya L. "“Esi."' The papaya is commonly cultivated and sometimes grows wild. Two varieties occur on the island--one called simply “esi" and the other “esi loa.'' The male flowered tree is called “esi tane."' Seen, but not collected. COMPOSTTAE Adenostemma lanceolatum Miq. A weed with white flowers, found in wet, shady places, The same or a similar species is found as a trailside weed in mountain ferests of Samoa. W 3357, Bryan 931. Synedrella nodiflora (L.)Gaertn. A yellow-flowered weed common in disturbed places. W 3437. Vernonia cinerea (L.)Less. A lavender-flowered weed occasional in disturbed places, W 3380, Schultz 11, Bryan 931A and 1371. CONVOLVULACEAE Ipomoea batatas (L.) Lam. "tUmala.'' The sweet potato is occasionally cultivated on the island, W 3418, 10 Ipomoea macrantha R. & S. "Fue itula."" A white flowered morning-glory vine common in the littoral forest. The word "itula" means hour, perhaps referring to the short time while the flower is open in the morning before wilting. The name has not previously been recorded from the Tokelau Islands or Samoa, so it is probably just a local name. W 3393, Bryan 1374. CRUCIFERAE Nasturtium sarmentosum (Forst.f.)Schultz A small weed of shady disturbed places such as in dirt roads and trails. W 3378. CRASSULACEAE Bryophyllum pinnatum (Lam.)Kurz "Pagi.'’ A common weed of disturbed places and naturalized in the forest. Children call this plant "mimiti'(to suck), which refers to their method of obtaining a sweet juice from the flower. It is also known as Kalanchoe pinnata (Lam.)Pers. W 3410, Bryan 928 and 1360 , Diefenderfer 9, 15, and s.n. EUPHORBIACEAE Codiaeum variegatum (L.)Bl. The croton is a common hedge plant in Samoa. At least two varieties are found on Swains. W 3384 and 3430, Bryan 937 and 1357. Euphorbia hirta L. This spurge is common in disturbed gravel and grassy areas around houses. W 3366, Bryan 1373. Euphorbia prostrata Ait. A small, prostrate weed found in the village in gravel and on rock walls. W 3413. Phyllanthus amarus Sch. & Thon. A common weed of disturbed places. Elsewhere incorrectly referred to as Phyllanthus niruri L. W 3402, Bryan 1372, Schultz 12. GOODENLACEAE Scaevola taccada (Gaertn,.) Roxb. "To'ito'i.'' This shrub is common on the coast and in sunny 11 disturbed places inland. The name in Tokelau is "gahu." "To'ito'i" is used on Swains, but this term apparently more correctly refers to the pith of the stems. W 3389, Schultz 13, Diefenderfer s.n. GUTTIFERAE Calophyllum inophyllum L. "Fetau."' This widespread Pacific tree is found scattered in the forest, often reaching a very large size. In Tokelau it is called “hetau." W 3407, Bryan 917 and 1354, and Schultz 5. HERNANDLACEAE Hernandia sonora L. "Pula." This is the second most common tree on Swains Island (second to Cocos). It is called "puka" or "pukavaka" in the Tokelau Islands. W 3395, Bryan 926 and 1368, Diefenderfer s.n. LABIATAE Coleus scutellarioides (L.)Benth. "Fateine."' Coleus is a cultivated shrub with showy leaves. The Samoan name is "patiale", and since Coleus is not reported from Tokelau, "fateine" may be a local name. W 3385, Bryan 936. Ocimum sanctum L. "Militini." The basil is a garden escape that is occasionally found around dwellings, particularly at Etena. It is used to scent coconut oil. W 3372, Bryan 1356. LAURACEAE Cassytha filiformis L. "Fetai." This is a leafless parasitic vine common growing on shrubs and small trees in disturbed areas and in coastal vegetation. W 3367, Bryan 921 and 1345, Schultz 16. LECYTHIDACEAE Barringtonia asiatica (L.)Kurz "Putu." A common coastal tree of the Pacific, but only two mature trees were found during the visit. They may have previously been more common, but Mr. Jennings reported he has had them cut down. The Tokelauan name is “hutu". W 3423. it, LEGUMINOSAE Adenanthera pavonina L. "Lopa."" A tree cultivated for its edible seeds. Occasional in village areas and along roads. W 3386. Delonix regia (Bojer)Raf. "Elefane.'' The poinsiana tree is found cultivated in several places on the island. The name appears to be a local one. W 3383, Bryan 922 and 1358. Vigna marina (Burm.)Merr. A coastal vine widespread in the Pacific, but seen in only one small patch near Taulaga. Mr. Jennings reported it was a very recent arrival. W 3426. LYTHRACEAE Pemphis acidula J.R.& G.Forst. “Gagie.'' A shrub growing on the shore and along the lagoon. It is reported to be the hardest wood on Swains Island, and is used to attach the canoe outrigger. It has not been previously reported from American Samoa, and is rare in Western Samoa. W 3354, Diefenderfer s.n. MALVACEAE Hibiscus rosa-sinensis L. "TAute."" A cultivated shrub with showy red flowers, not seen, but reported by a reliable islander to be growing on the island. Hibiscus tiliaceus L. "Fau.'' The beach hibiscus is scattered in disturbed areas on the island. The Tokelauan name is "hau."'" W 3405, Bryan 933 and 1359. Sida rhombifolia L. "Mautofu."" A shrub with salmon-colored flowers,common as a weed in disturbed areas. W 3365, Bryan 930 and 1370, Schultz 9. MORACEAE Artocarpus altilis (Park.)Fosb. "'Ulu.' Several varieties of breadfruit are cultivated on Swains, and some of the trees are over 50' high. Varietal names include iL3) “"mafala", ‘ulu Elise", and "puou", all of which are also known in Samoa. W 3434. Ficus tinctoria Forst.f. "Mati." Not seen but reported by the islanders to be present. The small orange fruits are eaten. This small tree is also found in Samoa and the Tokelau Islands, and in both places it is also called "mati." NYCTAGINACEAE Boerhavia tetrandra J.R.& G.Forst. "Nuna."" A pink-flowered prostrate herb growing in disturbed places on the island. It is a widespread littoral species in the Pacific. W 3382. Mirabilis jalapa L. A shrub with white flowers, cultivated near Taulaga. W 3422. Pisonia grandis R.Br. "Pu'avai.'' A tree with sticky fruits, found in scattered patches in the coconut-dominated secondary forest. The leaves are used to feed pigs and the wood is used for posts. The Tokelauan name is "pukavai" or "pukakakai."" W 3409. ONAGRACEAE Ludwigia octovalvis (Jacq.)Raven An erect yellow-flowered herb, common as a weed in wet places. W 3415, Bryan 927, Diefenderfer 10. POLYGALACEAE Polygala paniculata L. A weed with tiny white flowers and an aromatic root, uncommon growing in disturbed places. Only a single individual was seen. W 3358. PORTULACACEAE Portulaca oleracea L. "Tamole."' A prostrate, succulent, yellow-flowered herb growing as a weed in sunny disturbed places. W 33/71. 14 RUBIACEAE Gardenia taitensis DC. "Tiale tiale." A white flowered shrub or small tree cultivated around houses. Although this is native to the region, it was probably introduced to Swains. W 3435, Bryan 1355, Diefenderfer s.n. Guettarda speciosa L. "Puapua."' A medium to large littoral forest tree with white flowers, common in the forest. W 3394, Bryan 924 and 935. Hedyotis romanzoffiensis (Cham.& Schlecht.)Fosb. "Kautokiaveka", the Tokelauan name for it. This small shrub was first reported from the island by the U.S.Exploring Expedition and was later collected there by Lister in 1891. However, it was not seen during the most recent visit. One knowledgeable islander said he has not seen the plant growing on the island, but only its fruits which have washed up on the beach. Perhaps, then, it no longer occurs on Swains, but a more detailed search would be needed to verify this. Morinda citrifolia L. "Nonu.'"' A small tree growing in the forest and in disturbed places. This is probably an aboriginal introduction, since in Polynesia it is known for its uses as a medicine, in preparing dyes, and as an emergency food in times of famine. W 3419, Diefenderfer 8. Spermacoce assurgens R.& P, A small white-flowered weed common in disturbed places. It has also been commonly known as Borreria laevis (Lam.)Griseb. W 3376, Bryan s.n. RUTACEAE Citrus aurantium L,. "Moli."" A cultivated species of orange tree found at Taulaga, W 3431. Citrus medica L. "Tipolo," The cultivated citron with a thick, rough peel, growing at Etena. Seen, but not collected. SOLANACEAE Capsicum frutescens L. 15 "Polo." The cultivated red pepper, growing at Taulaga. W 3421, Diefenderfer s.n. Physalis angulata L. "Vivao."' A common weedy herb with whitish flowers. It has a small edible fruit. W 3439. Solanum uporo Dun. "Polo." Not seen, but said by an islander to be growing in the forest. A specimen collected by Schultz was verified by F.R.Fosberg to belong to this species. Parham, however, records Solanum viride R.Br. from Tokelau, but this is possibly a mistaken identification. Schultz 8. This species was misidentified in the USFWS inventory. TILIACEAE Triumfetta procumbens Forst.f. "Totolo." A woody, prostrate, creeping shrub with yellow flowers, common on beaches and sometimes in disturbed sunny places inland. W 3403, Bryan 934, Diefenderfer s.n., Schultz 15. URTICACEAE Laportea ruderalis (Forst.f.)Chew A weed of shady disturbed places. It does not occur in Samoa, but a related species, Laportea interrupta L., does. W 3377, Bryan s.n. Pipturus argenteus (Forst.f.)Wedd. "Fau vine" or "vine." A silvery-leafed tree with white succulent fruit, occasional in disturbed places. In Samoa it is called "fau soga" and in Tokelau it is "hau soga." The bast fiber is used to make fishing lines, nets, and lashings. One islander reported that the trees occurring in Tokelau have a sweet-tasting fruit unlike those in Samoa. W 3404, Bryan 918 and 1369. Procris pedunculata (Forst.f.)Wedd. "Matavao.'' An epiphytic herb with red edible fruit. The Tokelau name is "gahevao'', while in Samoa it is usually called "fua lole", so the name is probably a local one. W 3355, Bryan 932. VERBENACEAE Stachytarpheta urticaefolia Sims "Mautofu."" A shrub with purplish-flowers, common in sunny disturbed places, W 3364. 16 MONOCOTYLEDONAE AMARYLLIDACEAE Crinum asiaticum L. "Lautalotalo."' A large, white-flowered lily cultivated around houses. W 3387, Bryan 929 and 1365. Zephyranthes rosea (Spreng.)Lindl. "Lili." Bryan records the name "suisana", but both of these names appear to be local. A pink-flowered garden escape growing in grassy areas around houses. W 3375, Bryan 955 and 1363. ARACEAE Alocasia macrorrhiza (L.)Schott "Ta'amu."' A large aroid occasionally cultivated on Swains. Seen, but not collected. Colocasia esculenta (L.)Schott "Talo." Taro is cultivated in swampy areas. The variety on Swains is called "talo Niue" which is the common one in Samoa. Bryan 1364, Diefenderfer s.n. Cyrtosperma chamissonis (Schott)Merr. "Pula'ta."" A large aroid commonly cultivated in swampy areas. In Tokelau it is called "pulaka," Seen, but not collected. COMMELINACEAE Commelina diffusa Burm.f. A blue-flowered herb common as a weed in wet places such as in the taro and Cyrtosperma patches. W 3428, Diefenderfer 11. CYPERACEAE Cyperus brevifolius (Rottb.)Hassk, A small sedge with green bracts,. common as a weed in grassy village areas. W 3414. Cyperus compressus L, A low weedy. sedge occasional in disturbed areas. W 3412, Cyperus javanicus Houtt. A coarse sedge growing in wet places along the edge of the lagoon. This is a widespread littoral species which is called "selesele" in Samoa. W 3416. U7 Cyperus kyllingia Endl. "Mutia."' A white-bracted sedge growing as a weed in grassy areas. W 3368, Bryan 951. Cyperus rotundus L. "Mumuta.'' This nut grass is a weed of disturbed and grassy areas. Its tubers are used to scent coconut oil. W 3429. Eleocharis geniculata (L.)R.& S. A low, clumped sedge growing in marshy areas along the edge of the lagoon, mostly on a peninsula on the northeast corner. It was reportedly collected in Samoa by Graeffe in 1871, but since it is otherwise unknown from Samoa or the Tokelau Islands, this may be in error. It does, however, occur in Fiji. W 3352A. Fimbristylis cymosa R.Br. "Tuiseé.'' An indigenous sedge common in sunny littoral areas and also as a weed in open village areas. W 3360 and W 3417, Bryan 952, 954, and 1350, Diefenderfer s.n., Schultz 16. Fimbristylis dichotoma (L.)Vahl An erect weedy sedge common in open village areas. W 3361, Bryan 953. GRAMINEAE Axonopus compressus (Sw.)Beauv. A prostrate grass common in open village areas. W 3412 Cenchrus echinatus L. "Vao tuitui." The sand burr is a common weed of sandy and grassy village areas. W 3370, Bryan 945 and s.n. Chrysopogon aciculatus (Retz.)Trin. A clump-forming weedy grass of open village areas. W 3369. €ynodon dactylon L. An occasional weedy grass of open village areas and disturbed places. W 3436, Bryan 946, Digitaria ciliaris (Retz.)Coel. A small grass with digitate racemes, occasional in disturbed areas. W 3438. 18 Eleusine indica (L.)Gaertn. A coarse grass with digitate racemes, common in disturbed areas, It is called "ta'ata'a" in Samoa. W 3362, Bryan 949 and 1362. Eragrostis tenella (L.)Beauv. ex R.& S. A small delicate grass occasional in open village areas, W 3363, Bryan 950 and 1361. Lepturus repens (Forst.f,)R.Br, A clump-forming grass with an unbranched inflorescence that breaks up into one-seeded segments, common on coastal sands and also as a weed in disturbed places, W 3379 and 3390, Bryan 944 and 948. Paspalum conjugatum Berg. "Vaolima.'' A weedy grass with a t-shaped inflorescence, common in disturbed places. W 3381, Bryan 947. Paspalum distichum L. (usually known as P. vaginatum Sw.) A clump-forming grass growing in large patches in marshy areas along the edge of the lagoon. W 3353A, Bryan 938. Saccharum officinarum L. "Tolo."" Sugar cane was reported to be cultivated, at least until recently, but it was not seen during the visit. MUSACEAE Musa paradisiaca L, Two varieties of banana are growing on Swains Island, but no specimens were collected during the visit. Diefenderfer 18. PALMAE Cocos nucifera L. "Niu." A number of varieties of coconut are grown on Swains Island, including one which in the young stage has an edible husk. Seen, but not collected. PANDANACEAE Pandanus tectorius Park. "Falayao.'' Wild screwpine is common in secondary forest and the neglected coconut plantation, as well as along the seashore, W 3408, 19 Bryan 912 and 1346, Schultz 10. Pandanus tectorius Park. var. ---? "Falakai" or "fala Elise.". This cultivated screwpine is grown for its edible fruit. The bases of the phlanges are chewed uncooked. W 3432. TACCACEAE Tacca leontopetaloides (L.)0O.K. "Masoa."’ The Polynesian arrowroot is cultivated and is somewhat naturalized. In the Tokelau Islands it is called "mahoa."' W 3373, Bryan 923, 1323, and 1351, Diefenderfer s.n. ACKNOWLEDGEMENTS The author wishes to thank Dr. F. Raymond Fosberg and Dr. Marie- Héléne Sachet of the Smithsonian Institution for their help in identifying the plant specimens collected on Swains Island. I also wish to thank my colleagues, A. Binion Amerson, Jr., Terry Schwanner, and Warren Pulich for their help while on the island, and the owner of Swains Island, Wallace Jennings, for his information on the native names and uses for the plants, and for his family's Polynesian hospitality afforded us during the stay on the island. The visit by the author was made during the USFWS inventory of the wildlife and wildlife habitats of the Islands of American Samoa, conducted by Environment Consultants, Inc. (contract. no. 11-16-0001- 5782FA of the Interior Department). For further details of the study of the biota of Swains Island, see this report (1978, mimeograph copy). Ed. note. -- A collection of plants was made on Swains Island and Manihiki some years back and sent to the Smithsonian Institution by Mr. Wm. S. Blankley, but no data were received with the specimens nor sup- plied later. 20 BIBLIOGRAPHY Bryan, E. 1974. Swains Island. Pacific Information Center, B.P. Bishop Museum. Mimeograph copy. Christensen, C. 1943. A revision of the Pteridophyta of Samoa. B.P. Bishop Museum Bull. 177:1-138. Christophersen, E. 1935. Flowering plants of Samoa--I. B.P. Bishop Museum Bull. 128:1-221. Christophersen, E. 1938. Flowering plants of Samoa--II. B.P. Bishop Museum Bull. 154:1-77. Clapp, R.B. 1968. The birds of Swain's Island south central Pacific. Notornis XV(3) :198-206. Fosberg, F.R. 1943. The Polynesian species of the genus Hedyotis. B.P. Bishop Museum Bull. 174:1-101. Holttum, R.E. 1977. The family Thelypteridaceae in the Pacific and Australasia. Allertonia 1(3) :169-234. Parham, B.E.V. 1971. The vegetation of the Tokelau Islands with special reference to the plants of Nukuono Atoll. N.Z. Jour. Bot. 9:576-609. Parham, B.E.V. 1972. Plants of Samoa. N,.Z. Dept. of Sci. and Indust. Res., Info. Ser. 85:1-162. Pickering, C. 1876. The geographical distribution of animals and plants in their wild state. (From USEE, Voll; 19), pt. 2236-37 ™)r Naturalists’ Agency, Salem, Mass. Setchell, W.A. 1924. American Samoa: Part I. Vegetation of Tutuila Island: Part II. Ethnobotany of the Samoans: Part II. Vegetation of Rose Atoll. Carnegie Inst. Wash., Tort. Lab. Pap. 20:1-275. USFWS. 1978. An inventory of the wildlife and wildlife habitats of the islands of American Samoa. USFWS, Portland, Ore. Mimeograph copy. Whistler, W.A. 1980. The vegetation of Eastern Samoa. Allertonia 2(2):45-190. Folu Ane eas Figure 2. ¢ “SWAINS Palms 100 feet ‘The central, brackish ISLAND water lageon of Swains Island. Pil 22 Figure 3. Figure 4. Large, irregular chunks of algae floating in shallow water of the lagoon of Swains Island. 5 RSA 3 < ie 2 ta CS cies ee : " ML Zee eis 1 Gn tana AE ee APR oa Sparse sand strand vegetation near Taulaga. Sy a te pt. [2g Figure 5. Scaevola-dominated shrubland near Etena. Ae ee Pars Cae a tpraie bias ee Figure 6. Littoral forest on the south shore of Swains Island. 23 Open forest floor in littoral forest dominated by Hernandia sonora. Figure 8. Forest on Swains Island dominated by Pandanus tectorius. Figure 7. Pe Figure 9. Coconut palms on the lagoon shore of Swains Island. tracks leading up to the copra shed. 25 ATOLL RESEARCH BULLETIN No- 263 SHELF MARGIN REEF MORPHOLOGY: A CLUE TO MAJOR OFF-SHELF SEDIMENT TRANSPORT ROUTES, GRAND CAYMAN ISLAND, WEST INDIES BY HARRY H- ROBERTS ISSUED BY THE SMITHSONIAN INSTITUTION WASHINGTON, D- C-, U-S-A- SEPTEMBER 1983 SHELF MARGIN REEF MORPHOLOGY: A CLUE TO MAJOR OFF-SHELF SEDIMENT TRANSPORT ROUTES, GRAND CAYMAN ISLAND, WEST INDIES il) Harry H. Roberts — Abstract Side-scan sonar, high-resolution seismic, and echo-sounder data, coupled with the results of other reef-related studies on Grand Cayman Island, show that abundant sediments have accumulated on the deep fore- reef shelf. The most important accumulation sites are on the downdrift northwest and southwest flanks of the island, where gradients from high to low energy are maximized. Shelf-margin reef morphology along the lee or western side changes from a continuous sill-like structure that impounds sediment along most of this sector to a discontinuous reef along the southwestern flank. Isolated reef buttresses, separated by wide sediment-floored channels, characterize this area, where abundant sediments are stored on the lower forereef shelf. The wide channels between reef buttresses provide ave- nues through which sediments produced in shallow-water environments can be transported to deep off-shelf sites of deposition. Echo-sounder traces off the shelf at the southwestern corner of the island display characteristics suggesting depositional slopes. Shelf-margin reef mor- phology strongly indicates that off-shelf sediment transport is occur- ring along the southwestern flank of the island. Side-scan sonar data were extremely valuable for rapidly evaluating the morphological vari- ability of reefs on the forereef shelf. Introduction Recent studies of physical processes interacting with island reef systems in trade-wind settings suggest that around-the-island gradients in both wave energy and current energy favor transport and accumulation of sediment along the lee coast and adjacent shelf (Roberts et al., 1975; Murray et al., 1977; Davies, 1977; Roberts, in press). Both observations and theory show that zones of intense currents (jets or rips) and zones of weak currents (stagnation zones) are systematically distributed around the shores of islands and that prisms of shelf sediment accumulate in response to the deceleration of high-speed currents (Murray et al., 1977). Within quasi-unidirectional wind and wave systems, major low energy or sheltered zones around islands generally correspond to regions where nearshore current fields display minimal velocities. In the northeast trade-wind setting of the Caribbean, these low-energy zones occur on the western sectors of islands. Seem eres 21 iD VO. Bie ARON, OTRO) Ba Pile) =e Es ete 8 4Y Coastal Studies Institute, Louisiana State University, Baton Rouge Manuscript received Jan. 1980--Eds. Carbonate research conducted on the reefs and sediments of Grand Cayman (West Indies), a trade-wind island that fits the above obser- vations concerning energy distribution (Fig. 1), indicates that sedi- ments have accumulated in abundance on the deep forereef shelf along the western (lee) side of the island (Rigby and Roberts, 1976; Roberts, 1977). Although shallow fringing reefs, which are abundant sediment sources, are not evident along the leeward coast, flourishing mid-shelf and shelf-margin reefs are present. Higher energy shelves, compared to low-energy shelves of Grand Cayman, tend to support more coral cover and less open areas of sediment accumulation in both shallow and deep envi- ronments (Roberts, 1974). Sediments produced by both physical and bio- logical degradation of the reef framework in these higher energy shelf areas appear to be largely trapped in the reef matrix and thereby di- verted from primary routes of off-shelf sediment transport. Meaney (1973), Moore et al. (1976), Land and Moore (1977), Ginsburg and James (1973), and Hanna and Moore (1979) have studied various aspects of shelf to basin sedimentation, including sediment budgets, facies relation- ships, and stratigraphic history of off-shelf deposits. The study reported in this paper provides additional data from side-scan sonar, subbottom, and echo-sounder surveys (Fig. 1) concerning identification of optimal sites for shelf-to-basin sediment transport associated with a low-relief Caribbean island. Objectives of this investigation were twofold. Firstly, from pre- vious geological and physical process studies of Grand Cayman, the loca- tion of important sediment sinks and general areas of maximum sediment input to the shelf were identified. It then became important to deter- mine if these areas of accumulation are also sites of significant sedi- ment transport and if reef morphology is linked to this process. Sec- ondly, the usefulness of side-scan sonar for reef-related studies was tested. Instrumentation Three instruments were used in conjunction with accurate location control. These instruments included a side-scan sonar system, a 3.5-kHz subbottom profiler, and a linear chart recording fathometer. All in- struments were deployed on an 1ll-metre boat, which served as a research vessel. Instrumentation was operated simultaneously, and event marks indicating position fixes were automatically recorded on all records at l-minute intervals. The position fix numbers and distances from known points were recorded on paper tape as a permanent record. Each instru- ment is discussed below, with more emphasis being given to side-scan sonar because of its usefulness in this study and its recent importance to marine geology in general. Side-Scan Sonar The first operable side-looking sonars were made by the British in the early 1960s. Side-scan did not become a valuable instrument for marine surveys until the late 1960s. In the 1970s it has become increas-— ingly important as standard instrumentation in marine survey work. For ee a 3 the marine geoscientist, the development of side-scan sonar must be considered a major technological milestone. Through the use of this instrumentation, which is now readily accessible, it is possible to map sea-floor surface features with complete coverage, a task very similar to mapping from aerial photography. Previously, our understanding of sea-floor morphology was derived primarily from profile data such as is generated by a precision depth recorder. Between survey lines extrapo- lations must be made, whereas adjacent side-scan sonar lines may be spaced so that records overlap for continuous sea-floor coverage. Recent development of systems that digitally acquire side-scan data and play it back in an undistorted analog form is yet another major improve- ment in this valuable instrumentation. In an undistorted format spatial distributions of bottom features, textures, and shapes can be easily assessed in a quantitative way, much like mapping and form analyses using air photos. The area of sea floor covered is a swath, commonly to 1,000 metres (500 metres on each side of the source), rather than a line, as is the case with profiling techniques. Objects on the sea floor reflect the acoustic energy, which is received by the towed sonar source. Returned signals are then amplified and printed as various tones on either wet or dry paper. Precise measurements of distances between the vessel and a reflector, as well as shapes, heights, and other relationships, are not possible with conventional side-scan without corrections (Flemming, 1976). The new digital system offers a method for obtaining distortion- free images and therefore the possibility of easily employing this instrumentation for precise topographic mapping (Prior et al., 1979). A conventional side-scan sonar system consists of three basic units: (1) a transducer (or "fish'"), which is the underwater trans-— mitting unit, (2) a steel-reinforced cable, which is used for towing the fish and transmitting signals to the third component, (3) the recorder. For optimum results from a side-scan sonar survey, precise naviga- tional control is needed, and track lines should be arranged so that adjacent records overlap on one channel. Without accurate navigational control, both conventional and the new digital side-scans are of limited use as instruments for collecting quantifiable data from the sea floor. For research in coral reef environments side-scan sonar may be used to collect data on reef shape, orientation, and general configu- ration which may then be compared to physical expressions of the envi- ronment such as wave direction and wave power. Density changes on the side-scan sonograph may also represent well-defined facies changes, e.g., muds to sands. This method is invaluable for the study of shelf reefs that are too deep to be recorded by aerial photography. Other uses in carbonate environments include the determination of sediment trans-— port routes and sediment sinks in deep shelf areas where other methods of observation may be difficult and time consuming. The Klein side-scan system used in this study was coupled to the 3.5-kHz subbottom profiler, and records from both sensors were printed on a single wet-paper recorder, which has three channels. The side-scan 4 has a frequency of 100 kHz with lookout ranges from 25 to 600 metres. We found the 100-metre range to be optimal for the Grand Cayman study. Subbottom Profiler The subbottom profiler is designed so that it fits on the nose of the side-scan sonar fish (Fig. 2). This unit operates at a frequency of 3.5 kHz and is designed to produce details of reflection events in the upper 100-200 feet of the stratigraphic column, depending on the type of sedimentary material. Unfortunately, the acoustic energy is transmitted at relatively low power. In reef and reef-associated areas, the sea floor is generally very hard, which causes much of the acoustic energy to be reflected without penetrating the bottom. Only a few of our records contained useful subbottom information. These records, however, pro- vided additional data concerning sediment thickness on the forereef shelf. Fathometer Depth Recorder A Raytheon Model DE-731 depth recorder was used in conjunction with other instrumentation. This particular instrument was selected for use because of its linear chart, versatile depth ranges, and porta- bility. Although both the side-scan sonar and the 3.5-kHz subbottom profiler records a bottom trace, the fathometer is a much more accurate and convenient method of generating a bathymetric profile. The fathome- ter was run on all survey lines during this study. Our unit is equipped with a narrow-beam transducer, which gives the best resolution of the sea floor. However, in rough seas this transducer does not function well. The system will record in both feet and fathoms (0-410 feet or fathoms is the depth recording range). The operating frequency is 41 kHz, and the sounding rate is 270 pulses per minute in FEET mode and 45 pulses per minute in FATHOMS mode. Survey Position Fixing Instrumentation A Decca Del Norte electronic range-range locating system which em- ploys advanced microwave and digital techniques was used for survey con- trol. This system has a "line of sight" capability, with maximum ranges in the order of 80 km when both remotes and the master receiving antenna are elevated. Distance is obtained by measuring the round-trip travel time of signals transmitted between the master and the remote. Then, 10 or 100 path lengths, selected by digital filtering, are averaged to determine each distance displayed. Ranges are obtained in a matter of milliseconds. Positions can be resolved with this equipment to an accu- racy of 1-3 metres. The instrumentation is very lightweight, easy to install, and reliable under a full range of field conditions. The system used in this study consisted of two remote stations (land based), a master receiving station (boat based), and a printer. All units are powered by two 12-volt car batteries. The remotes are deployed at known survey control points along the coast (Fig. 3). These stations are interrogated by the master unit on the boat, and the distance in metres from each remote to the master antenna on the boat is printed out on paper tape, along with position fix number and time. A l-minute rate for these position checks was used in the Grand Cayman study. As position fixes are taken every 1 minute, an event mark is simultaneously triggered on the side-scan sonar, subbottom, and bathymetric records. Shelf Morphology The shelf surrounding Grand Cayman is narrow, ranging in width from approximately 0.5 km to 2.0 km. Geomorphically, the most distinc- tive features of any given shelf profile are two persistent submarine terraces which can be traced around the entire island (Fig. 4). Although differential reef growth and other generally slower forms of shelf accretion account for a moderate degree of variability in terrace topog- raphy, the seaward break in slope of the shallow terrace generally occurs at a depth of 8-10 metres. The base of this shallow terrace averages 15 metres where the deep terrace is encountered. Except for the seaward margin, most of the shallow terrace is a hardground surface with very little, if any, sediment cover. It is sparsely colonized by reef- building organisms, and is commonly dissected by shallow grooves (Fig. 5). On the lee side, however, localized areas of sediment accumulation are associated with adjacent hardgrounds. Spurs and grooves are not characteristic of the shallow terrace of the central lee shelf (Fig. 6). The seaward margin of the shallow shelf break in slope supports a prolific growth of coral superimposed on a distinct spur and groove struc— ture. Well-defined ridges or spurs of living coral are prograding sea- ward and building toward the surface. The linear depressions in the shallow terrace surface are sometimes discontinuous and therefore do not always extend to the seaward marginof the terrace. Most well-defined grooves either reach the lower terrace or intersect other grooves until the network extends across the upper shelf. It is clear, however, that whether these grooves terminate upslope in actively growing fringing reefs, as is generally the case, or in a limestone sea cliff, common on lee side, they function as pathways for sediment transport to the lower shelf. Spur and groove structure is also typical of the deep shelf ter- race. However, the landward portion of this terrace is frequently an area of sediment accumulation (Fig. 7). Extremely coarse carbonate material (cobble- to coarse-sand-sized sediment) is concentrated at the base of coral-covered spurs of the shallow terrace. Particle size gener- ally decreases to a bimodal sediment of coarse sand-sized constituents in a silt- to clay-sized matrix near the shelf margin. Spurs of living coral that extend landward from the actively growing shelf edge reef tend to break the continuity of the lower shelf sediment belt. Considerable variability is displayed in sediment plain characteristics, in terms of both geometry and sediment properties. High-energy sectors of the shelf tend to have coarse sediment plains that are highly segmented by spur growth. Contrasting low energy shelves tend to have broader unbroken areas of sediment accumulation. Most of these sites occur on the lee (western) side of the island, where sediments can be quite fine grained in localized areas. Depending on relationship to dominant wave direc- tion, spurs that extend into the sediment plain may not be oriented 6 normal to the shelf edge. Roberts (1974) has shown that differences in orientation between spurs and grooves on the shallow and deep terraces are related to progressive changes in direction of dominant waves as they intersect the shelf and refract across it. A thriving reef community is present at the seaward edge of the deep shelf terrace where an abrupt break in slope separates the shelf from deeper off-shelf environments. Morphologically, the shelf margin reef can vary from an unbroken ridge, through regularly spaced massive coral buttresses separated by narrow sediment-floored grooves, to ir- regularly spaced and widely separated coral buttresses. The degree to which the deep reef morphology is exaggerated or amplified appears to depend greatly on the wave energy conditions under which it developed (Roberts, 1974). Along high-energy sectors of the shelf, massive and regularly spaced living coral buttresses protrude into deep water (Fig. 8). These huge coral spurs occasionally coalesce, forming a wide variety of tunnel and cavern structures. The massive buttresses generally have a steep to overhanging seaward profile, with as much as 20-30 metres of relief. Low-energy shelf-margin reefs support thriving coral communi- ties (Fig. 9) but display less exaggerated buttress formation and less steep offshelf profiles. Morphological elements of the reef at these depths have coalesced to form a semicontinuous ridge at the shelf edge which has grown to a height of 3-5 metres above the adjacent deep terrace sediment plain. Inasmuch as this linear topographic feature is infre- quently dissected by narrow grooves, it essentially forms a sill that causes sediment to be impounded behind it. Sediment Transport Routes and Variability of Deep Reef Morphology Previous research on Grand Cayman (Roberts, 1974; Roberts et al., 19753; Murray et al., 1977) has demonstrated that strong westerly di- rected currents exist along both the northern and the southern flanks of the island (Fig. 1). At Grand Cayman's southwestern extremity, where much of the research reported in this paper was concentrated, the com- bined effects of shoaling waves, tidal currents, and westward-flowing backreef lagoon currents from South Sound (Fig. 1) result in the trans- port of sedimentary particles to the lee shelf, where they accumulate. As discussed in a recent paper by Roberts (in press), continuous reefs separating shallow backreef lagoons from the open shelf can be abun- dant sources of sediment to deeper shelf and off-shelf environments. Reefs of this description function as continuous sources of sedimentary particles, first to backreef environments and subsequently to deeper depositional settings outside the lagoon. Coarse sediment bodies tend to accumulate behind the reef as a result of wave overwash processes and at the adjacent backreef shoreline by swash action. Strong currents develop in the downdrift ends of these systems, transporting sediment outside the confines of the lagoon. Such flow is driven by both wind stress on the lagoon and constant input of water to the backreef by breaking waves that generate strong shore-normal surge currents at the reef crest (Roberts and Suhayda, 1977; Suhayda and Roberts, 1977). These 7 processes provide the driving forces for creating a significant flow out of the lagoon. The combined result is to export reef-derived and la- goonal sediment to the adjacent forereef shelf. Although mean condi- tions produce flows sufficient to move sand-sized sediments, storm events create proportionately higher velocities and thereby become im- portant sediment transport events. Even though the movement of sediment to deep shelf environments is reasonably well understood, processes responsible for transporting sedi- ments off the shelf to deeper depositional sites have not been studied in detail. Investigations of off-shelf sediment transport by Meaney (1973), Moore et al. (1976), Land and Moore (1977), Ginsburg and James (1973), and Hanna and Moore (1979), among others, have focused primarily on the products of the transport process. They demonstrate that sedi- ments generated in shallow reef and reef-associated environments are moved off the shelf and into deepwater sedimentary environments. The conditions responsible for displacing sedimentary particles from a shelf domain to a basinal environment are not well understood. Most recently, Hine and Newmann (1977), Hine et al. (in press), and Mullins et al. (in press) have shown, from research on the margins of the Bahama Bank, that large volumes of shallow-water sediments have engulfed Holocene shelf- margin reefs and now reside on the deep flanks of the Bahamian platform. They have attributed much of this off-bank transport to storm-related processes. Islands such as Grand Cayman are somewhat more limited in areas available for sediment generation as compared to vast shallow- water platforms such as the Bahama Banks. There are, however, favored sites where sediment accumulation around islands is focused by the physical dynamics of the island system (Murray et al., 1977; Roberts, in press). Side-scan sonar data indicate that the morphology of Grand Cay- man's shelf-margin reefs provides important clues to interpreting the location of significant off-shelf sediment transport routes. On the lee or western shelf, where sediments collect more abundantly than on higher energy flanks of the island, there are long sections of shelf-margin reef which have coalesced to form a relatively coherent ridge. Sediments are impounded in the lee of this structure and can be transported over the shelf edge only through narrow grooves (Fig. 10). Grooves are active transport routes (Meaney, 1973) especially on high-energy flanks of the island, where they are kept open by tidal ex- change at the shelf edge and wave-related forces (Roberts et al., 1975, 1977). However, only limited amounts of sediment can be fluxed through these narrow passageways to deeper sedimentary environments. Higher energy shelves seem to maintain the integrity of a basic spur and groove structure (Fig. 6), and sill-like structures do not generally develop. The southwestern extremity of Grand Cayman is a site where maximum energy gradients favor sediment deposition. Figures 11 and 12 illustrate the large area of sediment deposition on the deep shelf, as well as the dis- continuous nature of the adjacent shelf-margin reef. Rather than a coalescence of reef elements to form a sill at the shelf edge, which is typical of the Grand Cayman lee side, along the downdrift southwestern flank of the island the shelf-margin reef breaks into irregularly spaced 8 reef masses or buttresses separated by wide channels. These wide chan- nels provide free access for shelf sediments to deeper off-shelf envi- ronments. Such shelf-margin reef morphology has probably developed in response to a constant input of sediment to this accumulation site since sea level rose above the level of the shelf edge (approximately 20-24 metres). Assuming that Grand Cayman has been subject to the same general unidirectional wind and wave system since sea level was at the level of the shelf edge, the island's southwestern flank has been a favored site of sediment deposition. An abundant supply of sediments has probably inundated once-living shelf-edge reefs and produced a mobile sediment substrate that restricts coral attachment and growth. Apparently only the highest topographic points have been able to perpetuate themselves by continued reef growth. Figure 13 summarizes the general sediment sinks and transport routes associated with the southwestern flank of Grand Cayman Island. Shallow-water accumulation zones are found in the sheltered areas of the backreef lagoon. Over-the-reef currents, modulated by the tide and wind stress, drive lagoonal water from east to west. Strong axial currents capable of transporting sand-sized particles to the adjacent shelf develop at the downwind end of the system. Significant shelf sediment accumulation takes place only on the deep shelf terrace. Our 3.5-kHz subbottom profiles show that these deposits are at least 5 metres thick. High-resolution seismic data, showing more penetration from neighboring Caribbean islands with similar shelf morphology, suggest that these deposits may be up to 20 metres thick. Recent studies from the shelf and shelf margin of Little Bahama Bank (Hine et al., in press) illustrate Holocene sediment thicknesses in this range at preferred sites. Shelf-margin reef morphology suggests that along high-energy flanks of the island sediments move off the shelf through narrow, well- defined groove systems. In contrast, the lee shelf-margin reef has fused to essentially prohibit off-shelf transport of significant volumes of sediment. Very narrow (1-3 metres), irregularly spaced grooves offer a few minor pathways through which sediments may be carried off the shelf (Fig. 10). Only at the northwest and southwest extremities of the island where energy gradients are maximized do sediments accumulate in such abundance that reef growth on the shelf edge is affected. At these locations the shelf-margin reef becomes discontinuous (Fig. 12). Large breaks in this sill-like structure are interpreted as major routes for the movement of shallow-water sediments to deep sedimentary environ- ments. Echo-sounder profiles of the southwestern island margin tend to support the depositional nature of this site over steeper higher energy flanks of the island (Fig. 14). Additional high-resolution seismic work, coupled with a coring program, needs to be accomplished in order to verify the extent of off-shelf deposits and to calculate a budget for sedimentation during Holocene times at this preferred site. Conclusions Side-scan sonar, high-resolution seismic, and echo-sounder data, coupled with results from previous studies on Grand Cayman, have led to 9 the following conclusions linking shelf-margin reef morphology and off- shelf sediment transport: 1. Sediments accumulate in abundance on the down-drift south- western flank of Grand Cayman, where gradients in wave and current energy are maximized. An abundant source of sediments to the southwestern shelf is associated with the east to west flushing of South Sound, which is forced primarily by strong reef overwash caused by breaking waves. 2. Shelf-margin reef morphology along the island's southwestern flank changes from a continuous sill-like structure which im- pounds sediments to a discontinuous reef characterized by iso- lated reef buttresses. Wide avenues exist between reef but- tresses through which sediments produced in shallow-water environments can be transported to deep sites of deposition off the shelf. Echo sounder profiles of windward to leeward island margins suggest that the island's southwestern flank is a zone of deposition, as evidenced by less steep "deposi- tional" slopes and slump-like topography. 3. Side-scan sonar data proved to be particularly useful in this study for determining details of shelf and shelf margin reef morphology. This method of acquiring morphological details of bottom features is rapid and quantitative, and allows the geo- morphic variability of large areas of sea floor to be compared without making direct underwater observations. Acknowledgements The research was performed under a contract between the Coastal Sciences Program, Office of Naval Research, Arlington, Virginia, and the Coastal Studies Institute, Louisiana State University, Baton Rouge. Sneider and Meckel Associates of Houston, Texas, and Canadian Hunter Ex- ploration Company of Calgary, Canada, supported a side-scan sonar study of the forereef shelf of Grand Cayman Island which provided valuable insight into the problem of offshelf sediment transport. Special thanks go to Norwood H. Rector and Walker D. Winans for their invaluable tech- nical support during the survey. Illustrations were prepared by Gerry Dunn, and photographic work was accomplished by Kerry M. Lyle. References Davies, P. J. 1977. Modern reef growth - Great Barrier Reef. Proc., 3rd Internat. Coral Reef Symp., Rosenstiel School of Marine and Atmospheric Sciences, Univ. of Miami, vol. 2, Geology, pp. 326- 330. Flemming, B. W. 1976. Side-scan sonar: a practical guide. Internat. Hydrographic Rev., Monaco, LIII(1), 65-92. 10 Ginsburg, R. N., and James, N. P. 1973. British Honduras by submarine. Geotimes 18, 23-24. Hanna, J. C., and Moore, C. H., Jr. 1979. Quaternary temporal framework of reef to basin sedimentation, Grand Cayman, B.W.I. (abst.). Geol. Soc. Amer. Abst. with Progr., 11, 483. Hine, A. C., and Neumann, A. C. 1977. Shallow carbonate-bank-mar gin growth and structure, Little Bahama Bank, Bahamas. Amer. Assoc. Petrol. Geologists Bull., 61, 376-406. Hine, A. C., Wilber, R. J., Lorenson, K., Bane, J., and Neumann, A. C. In the press. Offbank transport of carbonate sands along open, leeward bank margins: Northern Bahamas. Proc., Sedimentary Dynam- ics of Continental Shelves (SANDS) Symp., 26th Internat. Geologi- cal Congress, Paris, July 1980. Land, L. S., and Moore, C. H., Jr. 1977. Deep forereef and upper island slope, North Jamaica. In (Frost, S. H., Weiss, M. P., and Saunders, J. B., eds.) Reefs and Related Carbonates: Ecology and Sedimentology. Amer. Assoc. Petrol. Geologists Studies in Geology, No. 4, pp. 53-67. Meaney, W. R. 1973. Sediment transport and sediment budget in the fore- reef zone of a fringing coral reef, Discovery Bay, Jamaica. Unpub- lished M.S. thesis, Louisiana State University, Baton Rouge, 106 PP- Moore, C. H., Jr., Graham, E. A., and Land, L. S. 1976. Sedimentvtrans— port and dispersal across the deep forereef and island slope (-55 m to -305 m), Discovery Bay, Jamaica. J. Sedimentary Petrol., 46, WASNGi. Mullins, H. T., Neumann, A. C., Wilber, R. J., Hine, A. C., and Chinburg, S. J. In the press. Carbonate sediment drifts in the northern Straits of Florida. Amer. Assoc. Petrol. Geologists Bull. Murray, S. P., Roberts, H. H., Conlon, D. M., and Rudder, G. M2 1977 Nearshore current fields around coral islands: control on sediment accumulation and reef growth. Proc., 3rd Internat. Coral Reef Symp., Rosenstiel School of Marine and Atmospheric Sciences, Univ. of Miami, vol. 2, Geology, pp. 53-59. Prior, D. B., Coleman, J. M., and Caron, R. Ek. 1979. Sea £lloorm mappime microcomputer-assisted side-scan sonar. Proc. Internat. Symp. on Remote Sensing of Environment, Ann Arbor, Mich., 23-27 April 1979, pp W95—208% Rigby, J. K., and Roberts, H. H. 1976. Grand Cayman Island: geology, sediments, and marine communities. Geology Studies, Special Publ. No. 4, Dept. of Geology, Brigham Young Univ., 121 pp. 11 Roberts, H. H. 1974. Variability of reefs with regard to changes in wave power around an island. Proc. Second Internat. Coral Reef. Symp., Great Barrier Reef Committee, Brisbane, 2:497-512. Roberts, H. H. 1977. Field Guidebook to the Reefs and Geology of Grand Cayman Island, B.W.I. 3rd Internat. Symp. on Coral Reefs, Miami, Atlantic Reef Comm., Univ. of Miami, Fisher Island, Miami Beach. Fla., 41 pp. Roberts, H. H. In the press. Physical processes and sediment flux through reef-lagoon systems. Proc. 1l/th Coastal Engr. Conf., Sydney, Australia, 1980. Roberts, H. H., and Suhayda, J. N. 1977. Wave and current interactions on a fringing coral reef crest, Great Corn Island, Nicaragua (abst.). 8th Caribbean Geological Conf., Curacao, 9-24 July, Abstracts Volume, pp. 161-162. Roberts, H. H., Murray, S. P., and Suhayda, J. N. 1975. Physical processes in a fringing reef system. J. Mar. Res. 33, 233-260. Roberts, H. H., Murray, S. P., and Suhayda, J. N. 1977. Evidence for strong currents and turbulence in a deep coral reef groove. Lim- nol. and Oceanog. 22, 152-156. Suhayda, J. N., and Roberts, H. H. 1977. Wave action and sediment transport on fringing reefs. Proc., 3rd Internat. Coral Reef Symp., Rosenstiel School of Marine and Atmospheric Sciences, Univ. of Miami, vol. 2, Geology, pp. 65-70. CARIBBEAN SEA 4 Trisponder stations se: Off-shelf bathymetric profiles + __ Current rips [_] Areas surveyed <—<=a Mean drift Figure 1. Location map of Grand Cayman Island showing the survey areas. Figure 2. The Klein side-scan sonar fish plus 3.5- KHz subbottom profiler used in this study. Figure 3. Trisponder shore loca- tion being installed in prepa- ration for an offshore survey. A_ MEAN SEA LEVEL A 1 i \ ewe Bee 6 ‘\ 5 SHALLOW TERRACE 10 DEEP TERRACE at BUTTRESSES 715 £ € | : 20 a 2 thee Figure 4. Echo-sounder traces across Grand Cay- 0 100 200 26 man's narrow southern forereef shelf (profile A- A') and somewhat wider western shelf (profile B- BY) 6 Shallow and deep terraces are character- istic of each profile. Large coral buttresses with intervening grooves are common along high- energy flanks of the island (A-A'). A rather continuous shelf margin reef is the norm on the lee or western side of the island (B-B'). B MEAN SEA LEVEL SHALLOW TERRACE Depth (m) Figure 5. Surface of shallow terrace (depth ~3 metres). Note the lack of sediment cover, sparse colonization of reef-building organisms, and shallow groove. Figure 6. i! it uit ! i iti | Ha ha AE memes SEDIMENT pecrcntccmin Side-scan sonograph of the shallow shelf terrace on the lee side of the island. Note the lack of spur and groove structure, isolated areas of sediment accumulation, and hardgrounds. Water depth is 5-7 m. Figure 7. Deep shelf terrace sediment plain that is dissected in this locality by a linear spur con- structed by a thriving reef community. Note the rip- pled sediment. These structures are oscillation rip- ples from recent storm waves (water depth 24 metres). *saA0013 petOOTj-jUaUTpes moiieu Aq paejzeiedas sasseijzjnq [e10d paoeds AjTaetnse1 sy BurTMoys JTeys ey JO 10}39es ABisue-ysty e Jo espe JTeys ey} BuoTe sode1z ABspunos-oyoy -g san3Ty $19jQW Ul B@IUDjSIG 007zl oool 008 009 oov 002 0 Sl ssojyow u! yydeg Ol 4M01398019" NOLLV O11 VANV 1S a? SSINHONOY WOLLOG 3DVYYIL YIMOT Figure 9. Diverse coral community typical of the shelf-margin reef (water depth 22 m). *9in3Tj ayy jo doq ay} ye ,Uanjer ou,, Jo eaae 9yq Aq pejqueseidei st o8pe jz TeysS auL ‘pueTST ey punoze saateys Adi1odue azeysty zo [eotdéQ st ute{d qusewtpes peztptequewzieduos e pue sinds papue3xe jo uot}einstjuood styl suteyd quewtpes quecoef[pe ay} ssoise sands [e109 uIZ1ew-JTeYys ey} JO uoTsUajxe pue seAocoi3 pue sands pedoyeansp-[ 129M ey7 AION “pueTST 94} JO qaed ui19jseMm ey. Buorte (setjew ZZ~ Yyydep 199M) jJoo4 uIdiew-JTeYys snonutjzuod rSey AeA ayy 02 TeTTeazed una attjzoad wozJoqqns pue ydeiZouos ueds—apts 2] ey r, "OT ean3sTty a Loaans a #¢ : SGNVS GaxuvW Fiddte | a eee *aspe J[eys ey} Je sasseitqqnq 310 sands [e105 peuTyep-[[em pue pooeds ATaptm ay SION “*FTOYS AeMOT 9YyQ Seydeer ATT eNQUaAS JT erT0yM $3S0M Jy] 0] [etsejzew sty Aatzed sqUeTAND uoose], jJaoi-yoeg *puNnos y Anos AOF Aaepunog piemees oy, se BUTJOR Sjoe1 MOTT[eYS WOTZ pejetsueds seM JueUTpes sty JO yYONW *yUeTF uASJSeMYQNOS S,pueTST By} JO Bee YOTA-JUSWTpss oYyQ 1eO9U JTeYUS SY4} Ssorde UNA aTTJZoOad wojzROqGqGns pue ydeagouos uedS—eptsS “*{] eAn3Tgq — — ———— os a *pepiodsed 910m sadewtT ou e10zo10y4} pue 1ejeM deap B3utoezZ sem peq} tuo yJeuueys arPuos uedS-epts sy *peqzeeuTTep ATaeeTo ‘310dsue1qz yuewtpes J1PYUS-JJO AOZ syjed optm Kq pajeaedas sassaaqz4nq e109 PEZT[BIOT Moz eB JO sqystTsuod eerie Sty} UT UTszeM JFTeys eyL_ ~*Yysty ATeATIeTeI eae soaqe1 UOTE JUSUTpeEsS FTeYs a1syM *juToOg Ysemyjnos ajtsoddo utsiew zTays sayy jo a[tyoad wojjoqqns pue (TeuueYd auO Ajuo) ydeaZouos ueds-apts *z] eansty 401931434 WOLLOBENS | “AMIOUd WOLLOGENS 7H ‘5 . , ai ea Oe perme ire ee ¥ SASS3YLLNA NIOYVW 413HS Shelf edge F=== Shallow reef Shallow shelf terrace Sediment (dominantly sand) (84 Shelf margin reef Lagoon muds and rock floor Figure 13. Sediment sinks and transport routes associated with the south western flank of Grand Cayman Island (South Sound and adjacent shelf areas). Arrows indicate sediment transport directions. D SL 6 100 200 300 400 500 600 700 Ce D’ Figure 14. Echo-sounder profiles showing the variability in shelf and shelf-margin slope morphology around the western end of the island. Note the less steep and more "depositional" configuration to the lee side profiles. DEPTH, M ATOLL RESEARCH BULLETIN No- 264 AN ANNOTATED CHECK LIST OF THE CORALS OF AMERICAN SAMOA BY AUSTIN E- LAMBERTS ISSUED BY THE SMITHSONIAN INSTITUTION WASHINGTON, D-C-, U-S-A- SEPTEMBER 1983 AN ANNOTATED CHECK LIST OF THE CORALS OF AMERICAN SAMOA by Austin E. Lamberts* SUMMARY Reef coral collections from American Samoa are in the National Museum of Natural History, Smithsonian Institution, Washington, D.C., and in the Hessisches Landesmuseum, Darmstadt, W. Germany. The author has a collection of 790 coral specimens for a total of 1547 items known to be from American Samoa. A total of 177 species (including 3 species of non-scleractinian corals) belonging to 48 genera and subgenera (including the genera Millepora and Heliopora) known to date are listed with data as of frequency of occurrence and habitat. INTRODUCTION The territory of American Samoa comprises the six eastern islands of the Samoan archipelago. It is located in the tropical central south Pacific (14°S latitude, 170°w longitude) about 2300 nautical miles (4420 km) southwest of Hawaii and 80 miles (130 km) southeast of Western Samoa. Five of the islands are volcanic in origin and are aligned along the crest of a discontinuous submarine ridge which extends over 300 miles (480 km) and tends roughly northwest by southeast. My collecting was done on the five major inhabited islands of American Samoa which are the largest, Tutuila, Aunu“u (a small island located 1 mi (1.6 km) off the southeast coast of Tutuila), Ofu, Olesega, and Ta“u. The latter three islands are collectively referred to as the Manu“a group and lie about 66 miles (106 km) east of Tutuila. An uninhabited coral atoll, Rose Island is located 100 mi (161 km) east of Tutuila. One other island, Swains Atoll, is considered part of the Samoan group but is geographically a part of the Tokelau Island group and is not included in this study. The first scientist to reach the Samoan (Navigator) Islands was probably Dr. Charles Pickering, a physician maturalist who explored Rose Atoll when ships of the United States Exploring Expedition under Capt. Wilkes met *1520 Leffingwell, N.E., Grand Rapids, Mich., 49505 Revised manuscript received March 30, 1981--Eds. 2 there in October 1839. Specimens he collected were added to those of James D. Dana who visited Tutuila for only four hours and made no coral collection in Samoa. [In 1918 Dr. Alfred Mayor headed an expedition to American Samoa under the auspices of the Carnegie Institution of Washington. During three visits he collected 354 coral specimens which were donated to the National Museum of Natural History (NMNH), Smithsonian Institution and were described by Hoffmeister in 1925. In 1941 the NMNH received a collection of 380 corals from Mrs. Thompson. They were acquired while her husband served wih the U.S. Navy. These specimens were accompanied with no data although it was indicated that all were collected about Tutuila. tin 1967 Drs D.K. Hofman obtained) 23yiconat specimens from Tutuila. These are now at the Hessisches Landesmuseum in Darmstadt, W. Germany and were reported by Pillai and Scheer dn 1973)...” This’ study) duncorpoxra'tels these data with material I gathered in American Samoa. MATERIAL AND METHODS My collections of 690 specimens were made during four trips to Samoa between 1973-79. Specimens were taken from reef flats but mostly from deeper waters using mask and snorkel. Friends participated when SCUBA was used. All specimens were numbered at time of collection and data was recorded in a permanent record. Many photographs were taken of live specimens. All were cleaned, dried and transported to my home in Michigan for further study. They will eventually be placed in the collections of the Bernice P. Bishop Museum, Honolulu, Hawaii. A typical coral reef as herein described may start in shallow inshore waters or a lagoon which might be 2 m deep, ascends to a shallow fore-reef, then to a reef crest usually out of water at low tide, a surge zone with spur and groove formation on windward (SW, Samoa), a sharp reef front dropping 5 - 10 m to a reef terrace and gradually descending to deep water. Most of the reefs have passes (Samoan:ava) of variable width and depth. The maximum width of reefs in American Samoa is about 500 m and most are much narrower. Taema Bank is a drowned barrier reef some three miles off the entrance of Pago Pago harbor. Also mentioned is the Airport lagoon which was dredged in stages from 1942 to 1973 during construction of Pago Pago International Airport complex. This lagoon lies between the runway and the Nu“uuli fore-reef. The dredgings contained some recent fossil coral (Goniopora, Acrhelia) species not found live in Samoa along with mollusc shells of the genus Cypraea with nacre virtually unblemished. Corals are listed systematically by genera and alphabetically by species. Relative abundances are listed as: abundant when they are readily found in large numbers on most reef complexes; the 41 species listed as common are found on most reefs; the 45 species termed sporadic may be common but are noted in my own collection data a few times; those listed as rare were found only once or twice. In such instances the collection location is given with place names of Samoan villages which fronted the reef. Depths at which specimens were found are listed in meters. The Aua line mentioned is that of Mayor”’s study in 1918. This paper lists all corals by specific names given in the literature as coming from American Samoa. Studer”’s (1901) specimens probably did not come from there and have not been included. Specific names which have been changed are listed within brackets with their synonyms. Behind each entry (H) appears if it was described by Hoffmeister (1925) and P&S if it was described by Pillai and Scheer (1973). ANNOTATED LIST Class ANTHOZOA Subclass HEXACORALLIA Haeckel, 1896 Order SCLERACTINIA Bourne, 1900 Suborder ASTROCOENIINA Vaughan & Wells, 1943 Family ASTROCOENLIIDAE Koby, 1890 Subfamily ASTROCOENIINAE Yabe & Sugiyama, 1935 Genus STYLOCOENIELLA Yabe & Sugiyama, 1935 Stylocoeniella armata (Ehrenberg, 1834). Sporadic, lagoons, under rocks or coral growth, (1-2m) Family THAMNASTERIIDAE Vaughan & Wells, 1943 Genus PSAMMOCORA Dana, 1846 Psammocora contigua (Esper, 1795) (H) Abundance, Inner reef flats, lagoons (0-3m) Psammocora folium Umbgrove, 1947 Rare, Reef face; Fagasa (3m) Psammocora nierstraszi van der Horst, 1921 Rare, Reef flats (0-1m) [Psammocora samoensis Hoffmeister, 1925] (H) Synonym P. nierstraszi Psammocora superficialis Gardiner, 1898 Locally common. Reef edge, reef slopes (0-3m) 4 Psammocora contigua var. tutuilensis Hoffmeister 1925 (H) Rare, Reef flats (1-2m) Family POCILLOPORIDAE Gray, 1842 Genus STYLOPHORA Schweigger, 1819 Stylophora mordax Dana, 1846 Sporadic, Passes, reef fronts & terraces (3-10m) Genus SERIATOPORA Lamarck, 1816 Seriatopora hystrix var. gracilis Dana, 1846 Rare, Masefau & Fagatele Bays (2-5m) Genus POCILLOPORA Lamarck, 1816 Pocillopora ankeli Scheer, 1975 Rare, Fagasa reef front (3m) Pocillopora brevicornis Lamarck, 1816 (H) Common, Back reefs (1-2m) Pocillopora cf. bulbosa Ehrenberg, 1834 Sporadic, Lagoons (1-3m) Pocillopora damicornis (Linnaeus, 1758) (H & P&S) Abundant, Inshore lagoons, reef flats (0-5m) Pocillopora danae Verrill, 1864 Rare, Masefau Bay (1m) Pocillopora eydouxi Edwards & Haime, 1816 (H) Common, Reef fronts, surge zones (1-5m) Pocillopora cf. setchelli Hoffmeister, 1929 Rare, Reef flat near surge zone (0-1m) Pocillopora verrucosa (Ellis & Solander, 1786) Abundant, Reef flats, lagoons, reef fronts (1-10m) Pocillopora woodjonesi Vaughan, 1918 Common, one area in Masefau Bay only (2-3m) Family ACROPORIDAE Verrill, 1902 Genus ACROPORA Oken, 1815 Acropora abratanoides (Lamarck, 1816) Rare, Fagasa (2m) Acropora africana (Brook, 1893) (H) Rose Atoll, Dr. Mayor. Acropora aculeus Dana, 1846) Sporadic, Reef slopes, Bays (1-3m) Acropora arbuscula (Dana, 1846) Locally common, Faga”“itua pass (2-3m) Acropora aspera (Dana, 1846) Abundant, Lagoons, back reefs (0-3m) Acropora brueggemanni (Studer, 1878) Rare, Reef slope, Aua line (3m) Acropora cerealis (Dana, 1846) Common, Back reefs, grooves in reef crest (0-2m) Acropora clathrata (Brook, 1893) Rare, Taema Bank (25m) Acropora corymbosa (Lamarck, 1816) (H, P&S) Sporadic, Masefau (1-3m) Acropora crateriformis (Gardiner, 1899) (H) Locally common, reef flats, passes (1-3m) Acropora cuspidata (Dana, 1846) Rare, Faga”°“itua, Masefau passes (1-2m) [Acropora symbicyathus (Brook, 1893)] (H) Synonym A. nasuta Acropora cytherea (Dana, 1846) Sporadic, Reef face, Bays (2-20m) Acropora delicatula (Brook, 1893) Rare, Fagasa ( (2m) Acropora diversa (Brook, 1893) Locally common, Aunu“u, Olesega (0-2m) [Acropora fructicosa (Brook, 1893)] (H) Synonym A. humilis Acropora exigua (Dana, 1846) (H) Sporadic, Lagoons, usually with A. formosa (2-5m) Acropora formosa (Dana, 1846) (H) Abundant, Huge thickets; lagoons (0-20) [Acropora hebes (Dana, 1846] (H) Synonym A. aspera Acropora humilis (Dana, 1846) Abundant, Reef crests, surge zones, passes (0-2) Acropora horrida (Dana, 1846) Rare, Ofu lagoon (1m) Acropora hyacinthus (Dana, 1846) (H, P&S) Abundant, All reef fronts, passes (1-20m) Acropora intermedia (Brook, 1893) Locally common, Passes, lagoons (2-5m) Acropora latistella (Brook, 1893) Common, Reef crests (1-3m) [Acropora leptocyathus (Brook, 1893)] (H) Synonym A. humilis Acropora longicyathus (Edwards & Haime, 1860) Rare, Faga° itua pass (3m) Acropora massawensis (von Marenzellar, 1906) (H) Rare, Aua line, Dr. Mayor. Taema Bank (0-25m) Acropora millepora (Dana, 1846) Rare, Nu“uuli reef crest (0-1) Acropora granulosa (Edwards & Haime, 1860) Rare, Masefau (20m) Acropora nana (Studer, 1878) Common, Back reefs, grooves (102m) Acropora nasuta (Dana, 1846) Common, Reef crest, reef slopes, Bays (1-3m) Acropora nobilis (Dana, 1846) (H) Sporadic, passes, lagoons (3-5m) Acropora pagoensis Hoffmeister, 1925 (H) Rare, Dredged, Taema Bank, Dr. Mayor Acropora palmerae Wells, 1954 Sporadic, Reef crest, surge zones (0-1m) Acropora palifera (Lamarck, 1816) (H) Sporadic, Reef fronts in bays (1-3m) Acropora paniculata (Verrill, 1902) — Rare, Faga itua pass (1-2m) Acropora pinguis Wells, 1950 Rare, Fagamalo and Fagatele Bays (1-2m) [Acropora prolixa (Verrill, 1866] (H) Synonym A. longicyathus Acropora pulchra (Brook, 1893) (H) Common locally, Inner reef flat (1-2m) [Acropora quelchi (Brook, 1893)] (H) Synonym A. cerealis Acropora rambleri (Bassett-Smith, 1890) Rare, Masefau (20m) Acropora robusta (Dana, 1846) Sporadic, Reef slopes, grooves (1-5m) Acropora rotumana (Gardiner, 1899) (H, P&S) Common, Reef edge, surge zones (0-2m) [Acropora samoensis (Brook, 1893)] (H) Synonym A. humilis Acropora schmitti Wells, 1950 Rare, Reef slope, Aua line (3m) Acropora splendida Nemenzo, 1967 Rare, Airport lagoon, Aasu Bay (2-3m) Acropora squarrosa (Ehrenberg, 1834) Rare, Taema Bank (20m) Acropora surculosa (Dana, 1846) Sporadic, Reef slope (2-5m) Acropora spicifera (Dana, 1846) Sporadic, Passes, bays (1-3m) [Acropora syringodes (Brook, 1893)] (H) Synonym A. nana (7) Acropora teres (Verrill, 1866) (H, P&S) Rare, Reef flat (1-3m) [Acropora tutuilensis, Hoffmeister, 1925] (H) Synonym A. clathrata, A. rotumana Acropora valida (Dana, 1846) (H) Sporadic, Lagoons (1-2m) [Acropora vanderhorsti, Hoffmeister 1925] (H) Synonym A. intermedia Acropora variabilis (Klunzinger, 1879) Locally common, Lagoons, Olesega, Ofu Acropora sp. l Sporadic. Passes, Colonies of heavy stalks with blunt tops, brilliant blue in situ (1-2m) Genus ASTREOPORA de Blainville 1830 Astreopora cucullata Lamberts, 1980 Sporadic, Faga°“itua pass Pago Pago Bay (2-4m) Astreopora listeri Bernard, 1896 Rare, Reef flats (0-1m) Astreopora myriophthalma (Lamarck, 1816) Sporadic, Reef flats, lagoons, bays (0-3m) [Astreopora profunda Verrill 1875] (H, P&S) Synonym A. myriophthalma (usually when free rolling) | MA es i> Astreopora scabra Lamberts, 1982 Sporadic, Reef flats, lagoons (0-3m) Genus MONTIPORA de Blainville 1830 Montipora berryi Hoffmeister 1925 (H) Sporadic, Lagoons, reef flats (1-4m) Montipora bilamina Bernard 1897 Rare. WA pone lagoon (3m) Montipora caliculata (Dana, 1846) " Sporadic, passes, back reefs (1-3m) Montipora composita Crossland 1952 Sporadic, Reef face in bays, passes (1-3m) Montipora elschneri Vaughan 1918 (H) Sporadic, Reef flats (0-1m) Montipora foveolata (Dana, 1846) Rare, Faga°“itua pass (0-1m) Montipora marshallensis Wells, 1954 Rare, Faga”“itua pass (1-3m) Montipora ehrenbergii Verrill, 1875 Common, Lagoons, back reefs (0.5-2m) Montipora cf. pulcherrima Bernard, 1897 Rare, Faga°“itua fore reef (1-2m) Montipora acutata Bernard, 1897 Rare, Masefau (30m) Montipora socialis Bernard, 1897 Sporadic, Reef face (0-2m) Montipora spumosa (Lamarck, 1816) (H) Sporadic, Reef flats (0-2m) Montipora trabeculata Bernard, 1897 (H) Sporadic, Ta“u, Olesega reef flats (1-3m) Montipora tuberculosa (Lamarck, 1816) (H) Common, Reef flats, lagoons (0-2m) [Montipora vaughani Hoffmeister 1925] (H) Synonym M. socialis Montipora venosa (Ehrenberg, 1834) (H) Common, lagoons, back reefs (0-3m) Montipora verrilli Vaughan, 1970 (H) Common, Reef flats, fore reefs (0-3m) Suborder FUNGIINA Verrill 1865 Superfamily AGARICIICAE Gray 1847 Family AGARICLIDAE Gray 1847 Genus PAVONA Lamarck 1801 Pavona clavus Dana, 1846 Sporadic, Reef slopes, passes (3-10m) Pavona decussata Dana, 1846 (H) Common, Lagoons, back reefs (1-3m) Pavona divaricata Lamarck, 1846 (H) Common, Reef flats, back reefs, passes (0-3m) Pavona duerdeni Vaughan, 1907 Rare, Taema Bank (30m) Pavona fondifera Lamarck, 1816 (H) Abundant, Reef flats (0-1m) Pavona cf. gigantea Verrill, 1869 Rare, Taema Bank (30m) Pavona maldivensis (Gardiner, 1905) Rare, Masefau (2m) Previously listed as P. (pseudocolumnastrea) pollicata Wells, 1954 Pavona varians Verrill, 1864 Common, Lagoons, reef edges, Taema Bank (2-30m) Genus GARDINEROSERIS Scheer, 1975 Gardineroseris planulata (Dana, 1846) Sporadic, Reef crests, surge zones (0Q-I1m) Genus LEPTOSERIS Edwards & Haime 1849 Leptoseris gardineri van der Horst, 1921 (H) Dredged, Dr. Mayor, Pago Pago Harbor (25-50m) Leptoseris scabra Vaughan, 1907 (H) Dredged, Dr. Mayor, Pago Pago Harbor (15-30m) Genus PACHYSERIS Edwards & Haime 1849 Pachyseris carinata Brueggemann 1879 (H) Rare, Masefau (2m) Pachyseris levicollis (Dana, 1846) (H) Dredged, Dr. Mayor, Pago Pago Harbor; Airport dredgings. Pachyseris speciosa (Dana, 1846) (H) Dredged, Dr. Mayor, Pago Pago Harbor (15-30m) Locally common, Masefau (30m) Genus COSCINARAEA Edwards & Haime 1848 Coscinaraea columna (Dana, 1846) (H) Sporadic, Reef fronts, terraces (1-20m) Superfamily FUNGIICAE Dana 1846 Family FUNGIIDAE Dana 1846 Genus FUNGIA Lamarck 1801 Fungia concinna Verrill, 1864 (P&S) Rare, Airport lagoon (1m) Fungia echinata (Pallas, 1766) Sporadic, Masefau (30m) Fungia fungites (Linnaeus, 1758) (H) Common, Reef terraces, Bays (2-5m) Fungia granulosa Klunzinger 1869 Rare, Pago Pago Bay (30m) Fungia patelliformis Boschma, 1923 (H) Dredged, Dr. Mayor, Pago Pago Harbor (25-30m) Fungia paumotensis Stutchbury, 1833 (H) Rare, Airport lagoon (1m) Fungia repanda Dana, 1846 Locally common, Masefau (3-5m) Fungia scutaria Lamarck, 1816 Rare, Masefau reef (2m) Genus HERPOLITHA Escholtz 1826 Herpolitha limax (Houttyn, 1772) Locally common, Masefau (30m) Herpolitha crassa Dana, 1846 Rare, Afono Bay (15m) Genus LITHACTINIA Lesson 1831 Lithactinia novaehiberniae Lesson 1831 Thompson collection, no data Superfamily PORITICAE Gray 1842 Family PORITIDAE Gray 1842 Genus GONIOPORA de Blainville 1830 Goniopora parvastella Ortman, 1888 Sporadic, Faga~itua Pass (3m) Goniopora samoa [I Bernard, 1903 Locally common, Airport dredgings Goniopora sp. 1 cf. somaliensis Vaughan, 1907 Rare, Reef slopes, Aua line (2m) Goniopora sp. 2 cf. gracilis (Bassett-Smith, 1890) Rare, Utelei, Olesega (1-2m) Goniopora sp. 3 cf. traceyi Wells, 1954 Rare, Olesega (1-2m) Genus PORITES Link 1807 Porites andrewsi Vaughan, 1918 (H, P&S) Abundant, Reef flats, back reefs (0-2m) Porites latistella Quelch 1886 Locally common, Airport lagoon (0-2m) Porites matthaii Wells, 1954 Sporadic, Reef flats, back reefs (0-1m) Porites pukoensis Vaughan, 1907 (H) Rare, Aua line (3m) Porites lobata Dana, 1846 (H, P&S) Sporadic, Back reefs, lagoons (0-5m) Porites lutea Edwards & Haimes, 1851 (H, P&S) 10 Abundant, All collecting sites (0-30m) Porites lutea var. haddoni Vaughan, 1918 (H) “Common, Reef flats, lagoons (0-5m) Porites murrayensis Vaughan, 1918 (H) Rare, Faga°itua lagoon (1m) Porites queenslandi septima Bernard, 1905 Rare, Taema Bank (30m) Porites lichen Dana, 1846 Sporadic, Surf zones, passes, Taema Bank (0-30m) Genus PORITES (SYNARAEA) Verrill 1864 Synaraea horizontalata Hoffmeister, 1925 (H) Sporadic, Masefau, Pago Pago Bay (10-30m) Synaraea faustino Hoffmeister, 1925 (H) Dredged by Dr. Mayor (7-12m) Synaraea undulata Klunzinger, 1879 (H) Abundant, Reef flats, passes, lagoons (0-5m) Genus ALVEOPORA de Blainville 1830 Alveopora allingi Hoffmeister, 1925 (H) Dredged, Dr. Mayor, Pago pago Harbor (25-35m) Alveopora verrilliana Dana, 1872 (H) Sporadic, Reef flats, lagoons, back reefs (0.5-5m) Alveopora viridis (Quoy & Gaimard, 1827) Rare, Fagasa, Utelei (bright green) (1-2m) Suborder FAVIINA Vaughan & Wells 1943 Superfamily FAVIICAE Gregory 1900 Family FAVIIDAE Gregory 1900 Subfamily FAVIINAE Gregory 1900 Genus FAVIA Oken 1815 Favia favus (Forskaal, 1775) (H) Sporadic, Reef flats (0-3m) Favia laxa (Klunzinger, 1879) Rare, Fagasa (15m) Favia pallida (Dana, 1846) (H, P&S) Sporadic, Reef flats, reef terraces (0-5m) Favia rotumana (Gardiner, 1899) (H) Common, Passes, bays (1-10m) Favia speciosa (Dana, 1846) Rare, Faleosoa (on Ta“u) (0.5m) Favia stelligera (Dana, 1846) (H) Sporadic, Reef flats, reef terrces (0-10m) Genus FAVITES Link 1807 Favites abdita (Ellis & Solander, 1786) (H) Common, Reef flats (0-3m) Favites halicora (Ehrenberg, 1834) (H) Common, Reef flats, Taema Bank (0-30m) a Favites chinensis Verrill, 1866 Rare, Masefau, Faga°itua reef flat (1m) Favites russelli Wells, 1954 Rare, Taema Bank (30m) Genus GONIASTREA Edwards & Haime 1848 Goniastrea edwardsi Chevalier 1971 Rare, Breaker’s Point reef flat (0.5m) Goniastrea favulus (Dana, 1846) Sporadic, Faga°“itua pass (0-2m) Goniastrea palauensis Yabe & Sugiyama 1934 Rare, Taema Bank (30m) Goniastrea pectinata (Ehrenberg, 1834) (H) Rare, Poloa, Fagamalo (1-2m) Goniastrea retiformis (Lamarck, 1816) (H) Sporadic, Reef flats, passes (0-3m) Genus PLAYTGYRUS Ehrenberg 1834 [Platygyrus daedalea (Ellis & Solander, 1786)] Name pre-occupied by a Forskaal species, Synonym P. rustica [Meandra esperi (Edwards & Haime, 1857)] Synonym P. rustica Platygyrus lamellina Ehrenberg, 1834 (H) Rare, Masefau, Taema Bank (1-20m) Platygyrus rustica (Dana, 1846) Common, Reef flats, lagoons (0-5m) Genus LEPTORIA Edwards & Haime 1848 Leptoria phrygia (Ellis & Solander, 1786) (H, P&S) Common, Reef flats to Taema Bank (0-30m) [Leptoria tenuis (Dana, 1846)] (H) Synonym L. phrygia Genus OULOPHYLLIA Edwards & Haime 1848 Oulophyllia crispa (Lamarck, 1816) Rare, Masefau (25m) Genus HYDNOPHORA Fisher de Waldheim 1807 Hydnophora exesa (Pallas, 1766) Sporadic, Passes, bays, Taema Bank (2-30m) Hydnophora microconos (Lamarck, 1816) (H, P&S) Common, Reef flats to Taema Bank (0-30m) Subfamily MONTASTREINAE Vaughan & Wells 1943 Genus MONTASTREA de Blainville 1830 Montastrea curta (Dana, 1846) 11 2 Common, Lagoons, reef flats, fore-reefs (0-5m) [Orbicella curta Dana, 1846] Synonym M. curta Genus PLESIASTREA Edwards & Haime 1848 Plesiastrea versipora (Lamarck, 1816) (P&S) Rare, Falesao (im) Genus DIPLOASTREA Matthai 1914 Diploastrea heliopora (Lamarck, 1816) (P&S) Sporadic, Reef slopes, Bay terraces (0.5-10m) Genus LEPTASTREA Edwards & Haime 1848 Leptastrea purpurea (Dana, 1846) (H) Abundant, Inshore waters, reef flats (0-1m) Leptastrea bottae Milne-Edwards & Haime 1848 Rare, Fagamalo (1m) Genus CYPHASTREA Edwards & Haime 1848 Cyphastrea chalcidicum (Forskaal, M/S) Rare, Taema Bank (30m) Cyphastrea cf. gardineri Matthai, 1914 Sporadic, Inshore waters, lagoons (0-1m) Cyphastrea microphthalma (Lamarck, 1816) (H) Rare, Dredged by Dr. Mayor (35m) Genus ECHINOPORA Lamarck 1816 Echinopora lamellosa (Esper, 1795) Locally common, Faga”“itua pass, Masefau (3-5m) Family OCULINIDAE Gray 1847 Subfamily GALAXINAE Vaughan & Wells 1943 Genus GALAXEA Oken 1815 Galaxea clavus (Dana, 1846) Sporadic, Reef terraces, Leone, Fagatele Bays (3-5m) Galaxea fascicularis (Linnaeus, 1758) (H, P&S) Common, Reef flats, terraces (0-25m) Genus ACRHELIA Edwards & Haime 1849 Acrhelia horrescens (Dana, 1846) Rare, Airport dredgings Family MUSSIDAE Ortman 1890 Genus ACANTHASTREA Edwards & Haime 1848 Acanthastrea echinata (Dana, 1846) Rare, Poloa (1m) Genus LOBOPHYLLIA de Blainville 1830 [Lobophyllia corymbosa (Forskaal, 1775)] Reported by Pillai & Scheer. No data. (P&S) Lobophyllia cestata (Dana, 1846) Common, Passes, reef slopes, terraces (2-5m) [Mussa sinuosa (Lamarck, 1816)] (H) Synonym L. costata Genus SYMPHYLLIA Edwards & Haime 1848 Symphyllia nobilis (Dana, 1846) (H) Rare, Matu”“u, Fagatele Bay (0-4m) Family MERULINIDAE Verrill 1866 Genus MERULINA Ehrenberg 1834 Merulina ampliata (Ellis & Solander, 1786) (H) Rare, Fagatele Bay (3m) Family PECTINIIDAE Vaughan & Wells 1943 Genus ECHINOPHYLLIA Klunzinger 1879 Echinophyllia aspera (Ellis & Solander, 1786) Rare, Utelei (30m) Genus OXYPORA Saville-Kent 1871 Oxypora lacera (Verrill, 1864) Rare, Masefau (3m) Suborder CARYOPHYLLIINA Vaughan & Wells 1943 Superfamily CARYOPHYLLIICAE Gray 1847 Family CARYOPHYLLIIDAE Gray 1847 Subfamily EUSMILIINAE Edwards & Haime 1857 Genus EUPHYLLIA Dana 1846 Euphyllia glabrescens (Chamisso & Eysenhardt, Sporadic, Masefau, Avatele passage (3m) Genus PLEROGYRA Edwards & Haime 1848 Plerogyra simplex Rehberg, 1892 Rare, Utelei reef front (1m) Suborder DENDROPHYLLIIDA Gray 1847 Family DENDROPHYLLIIDAE Gray 1847 LB2IL) (CE!) 13 14 Genus TUBASTREA Lesson 1831 Tubastrea coccinea Lesson, 1831 Rare, Aua reef slope, Faga”“itua pass (1-3m) [Dendrophyllia diaphana Dana, 1846] (H Synonym Tubastrea aurea = T. coccinea Genus TURBINARIA Oken 1815 Turbinaria frondens Dana, 1846 Sporadic, Leone terrace, Masefau terrace (2-6m) Turbinaria peltata (Esper, 1794) Rare, Massefau (30m) Subclass OCTOCORALLIA Haeckel 1896 Order COENOTHECALIA Bourne 1895 Family HELIOPORIDAE Moseley 1876 Genus HELIOPORA de Blainville 1834 Heliopora coerulea (Pallas, 1766) Common, Reefs of Ta“u, Ofu, and Olesega only (0-2m) Class HYDROZOA Huxley 1856 Order MILLEPORINA Hickson 1901 Family MILLEPORIDAE Fleming 1828 Genus MILLEPORA Linnaeus 1758 Millepora platyphylla Hemprich & Ehrenberg, 1834 Common, Reef flats, reef fronts (0-3m) Millepora tenera Boschma 1949 Locally common, Ofu back reefs (1-2m) {[Millepora alcicornis Linnaeus, 1758] (H) Synonym Probably M. tenera [Millepora truncata Dana, 1846] (H) Synonym M. platyphylla CONCLUSIONS This check list is neither exhaustive nor final. No attempt was made to collect on every reef and most reef terraces remain relatively unexplored. In all, 174 species of scleractinian corals are presented. These represent 48 genera and subgenera. Also listed are 3 species, one a Heliopora and two of Millepora; though not scleractinian, they certainly are reef formers. In all there are 199 nominal listings of which I considered 22 invalid. Because a coral species was reported from Samoa does not mean that it can be readily collected there. Frequently a coral listed as rare was the only specimen 15 of that kind seen in many hours of searching and may have been the only relict or new colony of its type in the Islands. The number of species found increases with the time spent searching, the astuteness of the collector, his purpose in collecting and where he happens to collect. I was primarily looking for certain g8enera and must certainly have overlooked species of other genera which were not my main concern. I accept responsibility for all identifications listed. Coral taxonomy as based on skeletal differences is an imprecise science and an ongoing search for adjunctive methods to aid in classification is in progress. As long as this state continues, many species determinations must necessarily be considered tentative and this entire study can only be regarded as one in a series. ACKNOWLEDGMENTS I sincerely thank the several diving partners who collected specimens for me in Samoa and for members of my family who supported these efforts. The following Museum curators kindly gave me permission to study Material under their care: Dr. P.F.S. Corneliue (British Museum, Natural History); the late Dr. J.P. Chevalier (Museum National d“Histoire Naturelle); Drs. D-L. Pawson, K. Ruetzler & F.M. Bayer (United States National Museum) and Dr. D. Devaney (Bernice P. Bishop Museum). I am grateful to Dr. John Hoffmeister for his Manuscripts, for encouragement and hospitality, and to Dr. John Wells for assistance in preparation of this paper, for his constant encouragement and for many helpful suggestions. Two of the Samoan visits were made under Research grants #1372 and #1945 from the National Geographic Society, Washington, D.C. REFERENCES Bernard, H.M., 1896. The genus Turbinaria. The genus Astreopora; British Mus. (Nat. History) Cat. Madreporarian Corals 2:106 pp., 33 pls. » 1897. The genus Montipora. The genus Anacropora: British Mus. (Nat. History) Cat. Madreporarian Corals 3: 192 pp-, 34 pls. » 1903. The genus Goniopora. British Mus. (Nat. History) Cat. Madreporarian Corals 4: 206pp.- 14 pls. 16 Bernard, H.M., 1905. Porites ‘of the Indo-Pacific region. British Mus. (Nat. History) Cat. Madreporarian Corals 5: 303 pp., 35 pls. Boschma, H., 1948. The species problem in Millepora. Rijksmus. Nat. Hist. Leiden, Zool. Meded., 22: 1-64; pls. 1-8, one map. » 1953. On specimens of the coral genus Tubastraea, with notes on phenomena of fission. Studies on the fauna of Curacao and other Caribbean Islands 4(18): 100-109, pls. 9-12. Brook, G., 1893. The genus Madrepora: (British Mus. (Nat. History) Cat. Madreporarian Corals 1: 212 PDs, OD. DLs Chevalier, J.P., 1971. Les scléractiniaires de la Mélanesie francaise....I. EXp. Frangaise sur les récifs coralliens de la Nouvelle Calédonie. 5: L—3 10 36) pais. » 1975. les scléractiniaires de la Mélanésie frangaise...II. Exp. Frangaise sur les récifs coralliens de la Nouvelle Calédonie. 7: 1-410, 42 pls. Crossland, C., 1952. Madreporaria, Hydrocorallinae, Heliopora and Tubipora. Scient. Rep.Gt. Barrier Reef. Exped”. 6:39 385-2575 Sié™ pis’. Dana, J.D., 1846-49. Zoophytes: U.S. Exploring Exped. 7: 740° pp. (€1846)3 Atlas 61 pls. (1849). Dinesen. Z.D., 1980. A revision of the coral genus Leptoseris (Scleractinia: Fungiina: Agariciidae). Men QLdy Mus 20) Gis 18— 23/55) pasion be GK. Doederlein, L., 1902. Die Korallengattung Fungia. Abh. Senckenberg. naturf. Ges. 27: 162 pp., 25 pls. Gardiner, J.S., 1898. On the perforate corals collected by the author in the South Pacific. Zool. Soc. London Proc. 1898: 257-276, pls. 23-24. » 1899. On the astraeid corals collected by the author in the South Pacific. Zool. Soc. London Proc. 1899: 734-764, pls. 46-49. Hoffmeister, J.E., 1925. some corals from American Samoa and the Fiji Islands. Carnegie Inst. Wash. Pub. 343: 90 pp., 23) pls’. Hoffmeister, J.E., 1926. The species problem in corals. Am. J. Sci. 12 (5): 151-156. » 1929. Some reef corals from Tahiti. J. Wash. Acad. Sci. 19 (16): 357-365. Horst, C.J. van der, 1921. The Madreporaria of the Siboga Expedition. Pt 2, Madreporaria Fungida. Siboga-Expeditie (Leiden), Mon. 15 b: 53-98, pls. 1-6. » 1922. Madreporaria: Agariciidae (no 9, Percy Sladen Trust Exped.) Linnean Soc. London Trans. (Zool.) II, 18: 417-429, pls. 31-32. Lamberts, A.E., 1980. Two new species of Astreopora Cnidaria, Anthozoa, Scleractinia) from the Mid-Pacific. Pac. Sci., 34 (3): 261-267. » 1982. The reef coral Astreopora. (Anthozoa, Scleractinia, Astrocoeniidae). A revision of the taxonomy and description of one new species. Pac. Sci. 36(1):. 83-105. Herpolitha and Fungia scutaria. A study of morphological, geographical and statistical differences. Subm. for Publ., Pac. Sci. Matthai, G., 1914. A revision of the recent colonial Astraeidae possessing distinct corallites. fTrans. Linn. Soc. London (Zool.) II, 17: 1-140, 38 pls. » 1928. A monograph of the Recent meandroid Astraeidae. British Mus. (Nat. History) Cat. Madreporarian Corals 7: 1-288, 72 pls. Mayor, A.G., 1924a. Structure and ecology of Samoan reefs. Carnegie Inst. Wash. Publ. 340, Pap. Dept. Mar. Biol. 19: 1-25, pls. 3-10. » 1924b. Growth-rate of Samoan corals. Carnegie Inst. Wash. Publ. 30, Pap. Dept. Mar. Biol. 19: 51-72, 26 pls. Nemenzo, F., 1964. Systematic studies on Philippine shallow-water scleractinians. VY. Suborder Astrocoeniida (part). Bull. Nat. and Applied Sci., Philippines, 18(3-4): 193-223, 12 pls. Pillai, D.S.B., and G. Scheer, 1973. Bemerkungen uber einige Riffkorallen von Samoa und Hawaii. Zol. » 1983. The reef corals Lithactinia and Polyphyllia (Anthozoa, Scleractinia, Fungiidae) with notes on 17 18 Jahrb. (Abt. Syst. Oekol. Geogr. Tiere) 43(100): 446-476. Quelch, J.J., 1886. Report on the reef-corals. Voyage H.M.S. Challenger Repts. Sci. Results, Zool. (rondon) V6)! s) W=—2038) 2 pls. Rehberg, H., 1892. Neue und wenig bekannte Korallen. Naturwiss. Ver. Hamburg Abh. 12: 1-50, 4 pls. Scheer, G., & p Zly ZG, Z_ Bho Ficus bengalensis L. WS, Zils 425 Zc URTICACEAE Pouzolzia zeylanica(L.)Benn. EOS, Zi,» Z2, Bo CASUARINACEAE Casuarina equisetifolia L. HO52, Zl, 22, Z3. CANNACEAE Canna indica L. ES), 23% MUSACEAE Musa paradisiaca L. 35 Bil, ZG, BZSo AMARYLLIDACEAE Agave sp. UEC AZ2 5 WAS! 0 DIOSCOREACEAE Dioscorea alata L. ES5, Zl 225 ere LILIACEAE Gloriosa superba L. HOSS pZiceecior Rhoeo spathacea (Sw.) Stearn ley RAPA 5 745} 6 Asparagus racemosus Willd. S64 64S} c COMMELINACEAE Commelina benghalensis L. HO54 5 Zl, (22h corre a ee? eS rE ARECACEAE Areca catechul L. ST Zale Cocos nucifera L. MSiy (Lilie Liles orem PANDANACEAE Pandanus odoratissimus L.f. Is, zZ4. ARACEAE Alocasia macrorrhiza (L.) Schott Mes Ally BA Colocasia esculenta (L.) Schott MES 5 Ad 5 ABS CYPERACEAE Cyperus kyllingia Endl. # 15) ALG As AS5 Bho GRAMINEAE Spiniflex littoreus Merr. 1b AIR 4S) 5 Alc Saccharum officinarum L. IGS YH Z474c Setaria italica Beauv. i ils AAAS Bes Aho ACKNOWLEDGMENTS The authors would like to express their gratefulness to (the late) Dr. N. K. Panikkar, former Director, National Institute of Oceanography, Goa, India, for the interest he took in this investigation, to Dr. S. Z. Quasim and Dr. T.S.S. Rao for their help. They would like to thank Prof. M. C. John, Head of the Department of Botany, C.M.S.College, Kottayam, India, and Mr. M. K. Menon, Taxonomy Division, Kerala Forest Institute, Peechi, Trichur, India, for the help rendered to identify some of the plants. This work was done during the tenure of a project sponsored by the Indian National Science Academy (INSA) and one of us (K.S.P.) is thankful for the award of the fellowship. REFERENCES Gardiner, J.-S. 1906. The fauna and geography of the Maldive and Laccadive Archipelagoes, being the account of the work carried out and of collections made by an expedition during the years 1899 and 1900, Vol. 2, Cambridge: University Press. Prain, D- 1890. A list of Laccadive plants. Sc. Mem. Med. Off. Army India, 5: 47-70. 1892-94. Botany of the Laccadives, being natural history notes from H.M.I.M. Survey Steamer “Investigator”...J. Bombay Nat. Hist. Soc., 7: 268-95; 1892; 8: 57-86, 1893; 488, 1894. (Reprinted in Memo. and Memor. 301-89, 1894.) ? ? ? ? 2 ? ? ? ? 2 ? ? P] ) ? ? ? 2 ? © STACHYTARPHETA INDICA =~ IPOMOEA PES-CAPRAE + BLUMEA MEMBRANACEA e SPINIFEX LITTOREUS ° KYLLINGA MONOCEPHALA ZB SEA GRASS BED 1 KM Figure 2. Kavaratti Island. Diagrammatic representation of the distribution of some terrestrial plants. a a ) cy , ) ») ? ) P) ? ) ? Ps P) P) Pp) ( MORINGA OLEIFERA © CALOPHYLLUM INOPHYLLUM © TOURNEFORTIA ARGENTEA + CASUARINA EQUISETIFOLIA % PANDANUS ODORATISSIMUS t PEMPHIS ACIDULA Figure 3. Kavaratti Island. Diagrammatic representation of the distribution of some terrestrial plants. Plate 1. Extensive bed of Thalassia on the intertidal area - i A nt eed ities SS a Plate 2. Huge bulk of dead Thalassia washed ashore Plate 4. Pemphis acidula on the lagoon side of the beach ATOLL RESEARCH BULLETIN No- 267 AVIFAUNA OF THE SOUTHWEST ISLANDS OF PALAU BY JOHN ENGBRING ISSUED BY THE SMITHSONIAN INSTITUTION WASHINGTON, D- C-, U-S-A.- SHA wsals aes) ‘Guam : i bebelcaon Soe eee Bk eer c ‘ Qs3 Korér, @; 7 ae Pee Won s a Yew! Angaure - Peleliu Sonsorol -Pulo Anna N Merir PALAU Major archipelago and Southwest Islands 0 50 100 Figure 1. Major islands of Palau, including the six Southwest Islands. AVIFAUNA OF THE SOUTHWEST ISLANDS OF PALAU by John Hagieiae INTRODUCTION The Palau Archipelago (7° 20' N, 134° 30' E) lies at the westernmost edge of the Pacific, just north of the equator and nearly equidistant from New Guinea to the south, the Philippines to the west, and Guam to the northeast (Figure 1). As a part of Micronesia, Palau became a United States Trust Territory following World War II. The government is now in a transitional state, and is shifting from a trust to independent status. The Southwest Islands of Palau are composed of six tiny islands, each less than 2 km?, extending 600 km southwest of the capital, Koror. The islands are Sonsorol and Fanna (the Sonsorol Islands), Pulo Anna, Merir, Tobi, and Helen. Other place names for the islands, and areas, are listed in Bryan (1971). Tobi and Helen, the southernmost of the group, lie only 400 km north of western New Guinea. All of the islands are of low elevation, with a substrate of coralline rubble interspersed with sandy areas. Most of the islands harbor minor deposits of phosphate, much of which was removed before World War II during the Japanese administration (Hutchinson 1950). The islands support relatively verdant forests, with coconut (Cocos nucifera) being the dominant species on most. Other trees include Artocarpus spp., Ficus spp-, Calophyllum inophyllum, Barringtonia asiatica, Pandanus sp., Tournefortia argentea, Scaevola taccada, Neisosperma oppositifolia, and Eugenia javanica. Other than Helen, which has a large encircling outer reef and an inner lagoon, the islands are surrounded by fringing reefs that generally extend 200-600 m from land before dropping off steeply into ocean depths. These fringing reefs form rocky flats that are exposed at low tides. Politically, the islands are part of Palau, but the residents are culturally distinct and speak a separate language. Historically, all the islands except Helen have been inhabited by Micronesians related to those of other outer islands in the Western Carolines (Eilers 1935, 1936). Though densely populated at one time, only a few families reside } U.S. Fish and Wildlife Service, Honolulu, Hawaii Manuscript received July 1981 -- Eds. there today. The economy remains at a subsistence level, with copra the nearly sole source of income; other minor trade items include coconut syrup, shells, and handicrafts. On Helen, sea cucumbers are also collected, dried, and exported for consumption in the Orient. Contact with the outside world is made every 3-4 months by ship from Koror. This "field trip ship" stops for 1-2 days at each island, purchases copra, delivers staples, and fulfills other needs of the residents. The avifauna of the Southwest Islands is undescribed, although large seabird colonies are present on Fanna and Helen. From Helen, Owen (1977a) recorded the Great Frigatebird (Fregata minor) and Lesser Frigatebird (Fregata ariel) and Yamashina (1940) recorded the Sooty Tern (Sterna Fuscata) and Crested Tern (Thalasseus bergii). Two unpublished reports, a checklist (Owen 1977b) and a field guide (Engbring 1981), give distribution and relative abundance of Southwest Island seabirds. Outside of these references little else is available on the birds of the region. METHODS The following report is based on two trips I made to the islands while working in Palau as a Smithsonian-Peace Corps Volunteer. One trip was in the fall from 9-20 November 1977, and one was in the spring from 18-26 May 1979 ("spring" and "fall" in this report refer to seasons of the Northern Hemisphere). During each of these trips the ship generally spent 1-2 days at each island, and I spent several hours per day on shore making general observations. Seabirds were also frequently recorded from the ship as it waited a few hundred meters from the outer edge of the reef. I spent a total of 6 daylight hours on Fanna, 14 on Sonsorol, 15 on Pulo Anna, 8 on Merir, 26 on Tobi, and 19 on Helen. Offshore (within sight of land) I spent 6 daylight hours at Fanna, 22 at Sonsorol, 8 at Pulo Anna, 6 at Merir, 16 at Tobi, and 10 at Helen. At Helen I stayed one night on shore, when I was able to observe the large number of birds returning to roost at dusk. Whenever possible, I questioned the local residents regarding avifauna. Additional information was contributed by Warren King, Dennis Puleston, and Thomas Ritchie, who spent 18 and 19 October 1979 on Helen and Merir while traveling on the M.S. Lindblad Explorer; by Greg Bright, who visited the region from 24 November to 2 December 1978; and by Robert Owen, who spent 30 years in Palau and visited the Southwest Islands on several occasions. THE ISLANDS Sonsorol) Tsillands;) 5au202 NF els2e shee Because of their proximity, two islands are included in this group, Sonsorol (136 ha), which has about 25 residents, and Fanna (54 ha), an uninhabited island located 2 km north of Sonsorol. Residents of Sonsorol regard Fanna as a reserve, but make occasional foraging expeditions by dugout canoe to Fanna for fish, coconut crabs, and birds. Both islands are covered by a forest of tall trees with a relatively well-formed canopy and a moderately dense understory. Several huge, stately Ficus and Artocarpus grow on Fanna. Fanna harbors spectacular seabird colonies. The Black Noddy (Anous minutus) and Red-footed Booby (Sula sula) nest in immense numbers. Although less plentiful, White Terns (Gygis alba) are also abundant. In Palau, Fanna is the only known nesting site for Great Frigatebirds, and possibly Lesser Frigatebirds as well. Also resident are the Brown Noddy (Anous stolidus), and a few Brown Boobies (Sula leucogaster). Only four seabirds are known to reside on Sonsorol, none in profuse numbers. In order of abundance these are the Brown Noddy, the White Tern, the Black Noddy, and the White-tailed Tropicbird (Phaethon lepturus). Fruit bats (Pteropus sp.) are conspicuous arboreal denizens on both Sonsorol and Fanna, but are not seen on the other Southwest Islands. Pulo Anna; 4° 40' N, 131° 58' E Pulo Anna (50 ha) is covered by large trees, with a relatively open understory. A shallow, open, brackish swamp, approximately 200 by 200 m, is located in the center of the island. The swamp is littered with decaying logs, remnants of mangrove trees that were cleared by U.S. military forces after World War II during a mosquito control program. Water level fluctuates with the tides, though there is no above-ground connection with the ocean. Approximately 20 or fewer people live on the island. Resident seabirds include an abundance of Brown Noddies and White Terns, and lesser numbers of White-tailed Tropicbirds and Black Noddies. Great Frigatebirds commonly soar above the island, but are not known to nest on Pulo Anna. Migratory shorebirds regularly use the swamp, which provides an excellent resting and feeding area despite its limited size. Meri 4 LOY ON. 1325 19 Merir (90 ha) is moderately elongated, just over 2 km from the northern to southern tip. A typhoon in the mid-1960's destroyed much of the vegetation, and a thick growth of medium-sized trees has since grown. Numerous large, dead trees still extend above the post-typhoon canopy. A shallow, heavily overgrown swamp is present on the southern, interior portion of the island, but because it is overgrown by shrubs, few shorebirds utilize it. Merir is riddled with mosquitos, and this, along with the dense understory, makes the interior generally inhospitable. In recent years only one family of fewer than ten people has resided on the island. Brown Noddies are the most abundant species on the island, with lesser numbers of White Terns and White-tailed Tropicbirds. King et al. (1980) recorded Black Noddies in moderate numbers in 1979. Frigatebirds, mostly Great but a few Lesser, regularly soar above and roost on the island, but are not known to nest. . fopr: 3 Of NS isl ti se With about 70 people, Tobi (60 ha) is the most heavily populated of all the Southwest Islands. Much of the triangular island is covered with tall coconut groves that are relatively well manicured and have open understories. A shallow, centrally located swamp, which is partly planted with taro (Colocasia esculenta), is largely the result of pre-war phosphate mining by the Japanese. The small amount of open water provides good but limited habitat for migratory shorebirds. Scattered throughout the swamp area are large earthen mounds, also the result of mining activities. The limited amount of native forest on the island contains several massive specimens of Ficus and Calophyllum. Seabird densities on Tobi are similar to those on Pulo Anna, with healthy populations of Brown Noddies and White Terns, and many fewer White-tailed Tropicbirds and Black Noddies. Great Frigatebirds are commonly seen soaring overhead. Helens: 22.2759") Nw fl S1ier49 "eer Unlike the other Southwest Islands, Helen is an atoll and consists of a large reef that encircles an open lagoon (100 km?). The only dry land, which is at the northern tip of the reef, is low and small (ap- proximately 25 ha), and is mostly sand. At low tide, conspicuous sand spits extend to the north and south of the crescent shaped island. Though the island was historically uninhabited, residents of Tobi, nearly 75 km away, made occasional forays to Helen. When this study was made, fewer than ten people lived on Helen, but the population varies depending on the number of "visitors" from Tobi or other Southwest Islands. The vegetation consists almost exclusively of large coconut trees, medium-sized Tournefortia trees, and a few sparse clumps of grass. Impressive numbers of seabirds reside on Helen, and seabird density is greater here than on any other Southwest Island. The superb quality of Helen as a nesting site is probably due to its isolation, its beaches which are protected from large waves by the outer reef, and its lagoon which supplies an abundant food supply. There are sizable colonies of Crested Terns, Black Noddies, Sooty Terns, and Red-footed Boobies, and moderate numbers of Brown Boobies and Black-naped Terns (Sterna sumatrana). White Terns recently began nesting on Helen in small numbers. Both Great and Lesser Frigatebirds commonly soar near the island and roost in the tall coconut trees. Neither species is thought to nest regularly on Helen, but a male Lesser Frigatebird was recorded on a nest in 1969 (Owen 1977). AVIFAUNA Forty-seven species of birds have been recorded from the Southwest Islands (Table 1), of which 14 are resident and 33 are migrant or vagrant. Four additional genera have been recorded that are not identified to species (Table 1). Out of the 14 resident species, 11 are seabirds and three are land birds. The 11 species of resident seabirds represent four families: Phaethontidae (one species), Sulidae (two species), Fregatidae (two species), and Laridae (six species). Conspicuously absent is the family Procellariidae. Most nonresidents are migratory shorebirds. Several recent new bird records for Palau (Engbring and Owen 1981, King et al. 1980) were nonresidents recorded from the Southwest Islands. These are the Red-tailed Tropicbird, Masked Booby, Chinese Goshawk, Bush Hen, Brown Shrike, and Lanceolated Warbler. Nonresident Birds Though a number of vagrant and migratory species have been recorded from the Southwest Islands (Table 1), the list is no doubt incomplete. Any of the migratory species already recorded from the Palau Archipelago (Engbring 1981, Owen 1977c) are likely to occur in the Southwest Islands as well. The majority of migrants are shorebirds from the Eastern Eurasian Region that are moving south during the boreal winter; a few are birds from New Guinea or Australia that are traveling north during the austral winter; and a small number are probably east-west migrants from Southeast Asia, the Philippines, or Indonesia (Baker 1951). The most common shorebirds (5-20 regularly seen at any one time on each island during migration) include Lesser Golden Plover, Ruddy Turnstone, Whimbrel, and Gray-tailed Tattler. Important habitat types utilized by shorebirds include the small inland swamps on Pulo Anna and Tobi, reef flats, and sandy beaches. Unidentified Species A number of birds were observed that were not positively identified: Shearwater - Puffinus sp.: One all dark shearwater was seen about 80 km north of Sonsorol on 26 May 1979. Its size and color matched that of the dark phase of the Wedge-tailed Shearwater, Puffinus pacificus, but there are several all dark shearwaters in the Pacific with which the bird could have been confused. This was the only Procellarid that I saw in 18 days at sea. Tattler - Heteroscelus sp.: Tattlers were regularly observed on most of the islands. On the basis of call, I identified Gray-tailed Tattlers on Merir and Tobi. King et al. (1980) identified Gray-tailed Tattlers on Helen and Merir. Unidentified Tattlers could possibly be the Wandering Tattler, Heteroscelus incanus, a migrant in Palau which is less common than the Gray-tailed Tattler. Table 1. Distribution and status of Southwest Island birds. Common and scientific names follow the American Ornithologists' Union (1982) check-list whenever possible. Other names are from Owen (1977c) and King et al. (1975). Status Symbols R - Resident; nests within the Southwest Islands and is generally FA sO PU ME TO HE present year-round. Different classes of resident birds are indicated with lower case letters as follows: b — Breeding species on the island; nests, eggs, or young recorded. p - Probable nester on the island, but nests, eggs, or young not recorded. t - Transient; recorded near (generally within sight of) land, but is not thought to nest on the island. May or may not roost on the island. Migrant; migratory species not resident in the Southwest Islands. Vagrant; accidental occurrence of a normally non-migratory species. Abundance Symbols Single individual recorded on one or more occasions. Uncommon; 2-10 birds recorded on at least one visit. Common; 11-50 birds recorded on at least one visit. Numerous; 50-1,000 birds recorded on at least one visit. Abundant; over 1,000 birds recorded on at least one visit. Island Symbols Fanna. Sonsorol. Pulo Anna. Merir. Tobi. Helen. Table 1, continued Island Species FA SO PU ME Shearwater genus (M) Puffinus sp. White-tailed Tropicbird (R) Phaethon lepturus Red-tailed Tropicbird (M) Phaethon rubricauda Masked Booby (V) Sula dactylatra Brown Booby (R) Sula leucogaster Red-footed Booby (R) Sula sula Great Frigatebird (R) Fregata minor Lesser Frigatebird (R) Fregata ariel Cattle Egret (M) Bubulcus ibis Pacific Reef Heron (R) Egretta sacra Little Egret (M) Egretta aaemaeea. Plumed Egret (M) Egretta intermedia Chinese Goshawk (M) Accipiter soloensis Red Junglefowl (R) Gallus gallus Bush Hen (V) Amaurornis olivaceus Black-bellied Plover (M) Pluvialis squatarola Lesser Golden Plover (M) Pluvialis dominica 2 Mongolian Plover (M) Charadrius mongolus Little Ringed Plover (M) Charadrius dubius Oriental Plover (M) Charadrius meredten Common Greenshank (M) Tringa nebularia Wood Sandpiper (M) Tringa glareola Gray-tailed Tattler (M) Heteroscelus brevipes Table 1, continued Species Tattler genus (M) Common Sandpiper (M) Little Curlew (M) Whimbrel (M) Black-tailed Godwit (M) Bar-tailed Godwit (M) Ruddy Turnstone (M) Rufous-necked Stint (M) Stint genus (M) Curlew Sandpiper (M) Snipe genus (M) Common Tern (M) Black-naped Tern (R) Sooty Tern (R) Little Tern (M) Crested Tern (R) Brown Noddy (R) Black Noddy (R) White Tern (R) Nicobar Pigeon (V) Oriental Cuckoo (M) Cuckoo genus (M) Hawk-Owl genus (M) Heteroscelus sp. Actitis hypoleucos Numenius minutus Numenius phaeopus Limosa limosa Limosa lapponica Arenaria interpres Calidris eueieoiiges Calidris sp. Calidris ferruginea Gallinago sp. Sterna hirundo Sterna sumatrana Sterna fuscata Sterna albifrons Thalasseus bergii Anous stolidus Anous minutus Gygis alba Caloenas nicobarica Cuculus saturatus Cuculus sp. Ninox sp. Gray-streaked Table 1, continued Island Species FA SO PU ME TO HE Collared Kingfisher (R) Halcyon chloris Bee-eater genus (M) Merops sp. Dollar bird (M) Eurystomus orientalis Barn Swallow (M) Hirundo rustica Yellow Wagtail (M) Motacilla flava Brown Shrike (M) Lanius cristatus Lanceolated Warbler (M) Locustella lanceolata Flycatcher (M) Muscicapa griseisticta It is not certain whether the Little Egret can be separated from the Snowy Egret (E. thula), which has not been recorded from Palau. I Saw two white egrets wading on reef flats along the shore at Tobi on 15 November 1977. Both were alike, with narrow plumes on the nape, black beaks, orange-yellow lores, black legs (with a greenish tinge), and greenish-yellow toes. The Mongolian Plover is similar to the Greater Sand Plover (C. leschenaultii). Prior to my visit to the Southwest Islands I regularly observed both species in Koror, Palau, and considered the two separable on the basis of size, leg length, and leg color, among other field traits. Some consider this as two species, C. veredus and C. asiaticus. The Rufous-necked Stint is similar to two other small Calidrids, the Little Stint (C. minuta) and the Semipalmated Sandpiper (C. pusilla), and would be difficult to separate from them in winter plumage. The individual I observed on Helen on 22 May 1979 was entering breeding plumage, and had an even wash of reddish color on the breast and neck. I used this trait to separate it from the other two species, neither of which have been recorded from Palau. Recorded by King et al. (1980). 10 Snipe -,Gallinago sp.: I flushed three snipe on Tobi on 14 November 1977, and King et al. (1980) observed one on Helen on 18 October 1979. None of these individuals were identified to species, though it is likely that one or more were Swinhoe Snipe, Gallinago megala, the only species of snipe collected from Palau. Stint - Calidris sp.: I observed two stints in winter plumage, one on Helen on 13 November 1977, and one on Tobi on 17 November 1977. These appeared to be and most likely were Rufous-necked Stints, Calidris ruficollis. However, they could not be safely separated from the winter plumage Little Stint, Calidris minuta, or Semipalmated Sandpiper, Calidris pusilla, neither of which has been recorded from Palau. Hawk-owl - Ninox sp.: An unidentified, small brown owl was first reported from Helen on 28 November 1978 (Bright 1978). On 18 October 1979, another owl was observed that was identified as the Brown Hawk-Owl, Ninox scutulata (King et al. 1980). The owl was most likely the Brown Hawk-Owl, as it is a widespread species in Southeast Asia that migrates to the Philippines. However, there are several other Ninox spp. that reside on nearby islands with which the Brown Hawk-owl could conceivably be confused. Cuckoo - Cuculus sp.: I observed one cuckoo on Tobi which was either the Oriental Cuckoo, Cuculus saturatus, or the Common Cuckoo, Cuculus canoris. Bee-eater - Merops sp.: I observed a flock of eight bee-eaters on Tobi on 21 May 1979. Tentatively these have been identified as the Rainbowbird, Merops ornatus, an Australian species. All the birds were in immature plumage, however, and further comparison of the Australian species and two Philippine bee-eaters should be made. In addition to the above unidentified birds, Bright (1978) observed an all black bird with a long tail on Tobi on 29 November 1978. The individual was at least 36 cm long, and had dark legs, but a lighter bill. It perched in a small tree near the edge of the swamp. The bird was probably a male Common Koel, Eudynamys scolopacea. Resident Land Birds Pacific Reef Heron - Egretta sacra. The reef heron is resident on all of the Southwest Islands, and is conspicuous as it feeds on reef flats at low tide. The population on each island probably numbers no more than 15-20 individuals. No nests have been recorded. Based on its widespread insular distribution one can assume that the reef heron is a capable overseas wanderer, but no patterns of movement are evident in the Southwest Islands. On Helen, records indicate a variation in population size; one bird was recorded in September 1969 (Owen, field notes), eight birds in November 1977 (this study), three birds in May 1979 (this study), and eleven birds in October 1979 (King et al. 1980). 11 This population fluctuation could be due to ingress/egress, reproduction, or simply counts of varying completeness. It is unlikely that reef herons are overlooked on Helen, but birds may be roosting on derelict ships on the surrounding reef, and thus missed during a count. White and dark phase birds are represented in about equal proportions on all the islands. Red Junglefowl - Gallus gallus. Domestic junglefowl are regularly heard and seen on Sonsorol, Pulo Anna, Merir, and Tobi. The species is commonly raised by residents, and is likely to be found on any of the Southwest Islands, particularly near villages. The species was probably introduced by early island settlers. A few birds are probably feral, but this is difficult to determine. Early reports indicate that the junglefowl was valued more for its feathers, which were used for fishing lures, than for its flesh (Johannes 1981). Collared Kingfisher - Halcyon chloris. A few, evenly dispersed individuals or pairs can be located on any of the Southwest Islands. The population is estimated at 20 or fewer on each island. I assume the species is resident, but found no nests. On Helen, only one or two birds have been recorded at any time, and these are possibly vagrants from other Southwest Islands, New Guinea, or Indonesia. Resident Seabirds Estimates of the size of nesting colonies are summarized in Table 2, and species accounts are as follows: White-tailed Tropicbird - Phaethon lepturus. Although nowhere abundant, individuals and small groups can be found commonly on all of the Southwest Islands but Helen. Population size is estimated at under 50 individuals at any one time on each of the islands of occurrence. The tropicbird's absence from Helen can probably be explained by the limited amount of forest, which serves as nesting habitat. Though I recorded no birds from Fanna, the species is probably resident here. Birds were found in equal numbers in spring and fall, indicating negligible variation in nesting season and no definite migratory pattern. Though no nests have been recorded, the species presumably nests in the Southwest Islands. Elsewhere in Micronesia, the tropicbird has been found to nest throughout the year (Brandt 1962), as is probably the case in the Southwest Islands. Red-footed Booby - Sula sula. The Red-footed Booby is abundant on the two islands on which it nests, Fanna and Helen, and sightings are possible near any of the other Southwest Islands. Boobies generally spend the day foraging over the open ocean, and population estimates are best made in early morning or at dusk as the birds leave or return to land. On Helen, it was possible to spend two evenings on the island and estimate numbers as the birds returned to roost. On Fanna, the population estimate is derived from a count of active nests. The total adult population (flying birds) is around 5,000 on Fanna and 2,500 on 12 UtzvJ, 9ITUM uoTOH TqQoO] ITI9W euuy oTng To1osuos euuey Appon eT Appon umoig uly], pe se19 uzay, £}00Sg ule], pedeu-yoetTg Patqe estag AesseyT PpAtqezestTiqg eer Aqoog umoig SPpuPTS] }JSeMYyINOS 9Yy} UT SaTUOTOD pitqess JUepTSeA AOF sajzewTASe uoTe[ndog °Z eTqQeL 13 Helen. Nearly all birds (over 90%) are of the white rather than dark color phase. The Red-footed Booby is a colonial nester, and constructs nests of leaves, grass and twigs. On Fanna, the booby nests high in trees along the perimeter of the island, and to lesser extent in the interior. Favorite nest trees are Tournefortia and Artocarpus. Residents of Sonsorol state that the booby roosts so profusely at times that nest trees are injured, and indeed, several trees were conspicuously defoliated in May 1979. There were at least ten distinct sites in May 1979, each with nearly 100 active nests. Thus, there were about 1,000 active nests on the island. Young were at all stages of development. On Fanna, peak nesting activity occurs during spring months, and there is little or no nesting in the fall. A nesting cycle was apparently beginning in November 1977, when adult birds were on the ground picking up twigs and sitting on nests up in trees. However, I could see no young or eggs from below. On Helen, the colony is smaller, but density is greater. Birds nest in the relatively low Tournefortia trees, and on rare occasions in the much taller coconut trees (both Tournefortia and coconut trees are utilized for roosting). About 265 downy young, along with a few nearly fledged birds, were counted in May 1979. In October 1979, 91 young at all stages of development were counted (King et al. 1980), and in November 1977, 25 young were found (this study). The pattern indicates nesting throughout the year, with a probable peak in spring months. Brown Booby - Sula leucogaster. The Brown Booby is known to nest only on Helen and, in very limited numbers, on Fanna. On Helen, the colony numbers from 500 to 1,000, but on Fanna, fewer than 25 are present. The species can probably be sighted near or possibly roosting on any of the other Southwest Islands. On Helen, pairs nest in shallow lined scrapes in the sand, often just above the high tide line. Concentrations of nesting birds are located under Tournefortia trees on the northern and southern portions of the island. A few young are raised throughout the year, but the peak nesting season is in spring months. In November 1977, I counted 10 downy young and saw no incubating adults. Likewise, there was only minor nesting activity in November 1978, when only one nest was found (Bright 1978) and in October 1979, when 11 active nests were located (King et al. 1980). In May 1979, the peak of the presumed nesting season, I counted 60 downy young of all sizes, along with at least 20 incubating adults. Large numbers of birds returned at dusk to roost on the Island. Residents of Sonsorol informed me of a small colony of fewer than 25 birds that recently began nesting on Fanna. Although I visited Fanna in both fall and spring and observed Brown Boobies in the area, I discovered no nests. This new colony may succeed provided it is not unduly disturbed by humans, and provided the relatively exposed beaches 14 prove suitable as nesting sites. It is possible that only Helen, whose beaches are protected by an outer reef, is capable of sustaining a stable colony of nesting Brown Boobies. Great Frigatebird - Fregata minor, and Lesser Frigatebird - Fregata ariel. Frigatebirds occur uncommonly but widely on the oceans around Palau, and can characteristically be seen soaring above any of the Southwest Islands. Great Frigatebirds roost on all of the Southwest Islands. Lesser Frigatebirds have been recorded from Merir and Helen, but no doubt frequent the other Southwest Islands as well. Discussion of these two species is combined partly because of the incomplete information regarding relative numbers of each species. Out of 400 frigatebirds at Fanna in May 1979, I identified nearly 150 individuals, all of which were Great Frigatebirds. Only a few individuals, all Great, were identified at Pulo Anna, Merir, and Tobi. Thus, the great majority of frigatebirds on these- islands appears to be Great Frigatebirds. At Helen, I found approximately equal numbers of the two species in May 1979, as did King et al. (1980) im October 1979. In May 1969, however, Owen (1977a) found 25 to 30 Great and over 100 Lesser Frigatebirds on Helen. Although Great Frigatebirds roost on all the Southwest Islands, only Fanna is reported to have a nesting colony. Residents informed me that the birds nest high in the trees in the spring of the year. In May 1979 when about 400 frigatebirds were present, I observed birds entering tall trees during the day, but I could locate no nests. Occasional sporadic nesting may occur on other Southwest Islands as well. Residents have reported nesting on Merir, and in May 1969, Owen (1977a) recorded one male Lesser Frigatebird on a nest at Helen Island. The following number of frigatebirds was recorded during several trips to the region: May Nov. Nov. May Oct. 1969 1977 1978 1979 1979 (Owen (this (Bright (this (King et 1977) report) 1978) report) al. 1980) Fanna over 400 100 Pulo Anna 60 15 Merir 34 over 10 moderate 150 numbers Tobi 26 1 Helen over 300 25) moderate 130 numbers 15 The largest concentrations are found throughout the year on Fanna and Helen. The number of birds on each island varies, suggesting that birds travel from one island to another. The data also indicate that birds concentrate to nest at Fanna during the spring months. Frigatebirds are highly mobile, and much of the population may originate from or move to areas outside Palau. For example, Lesser Frigatebirds that nest on the Line Islands have been recorded in the vicinity of the Southwest Islands and beyond, a distance of over 6,000 km (Sibley and Clapp 1967). Black-naped Tern - Sterna sumatrana. This species occurs only on Helen, where the population is 200-500 birds. It roosts and nests on shipwrecks on the surrounding reef. In May 1979, the species was con- spicuous, and small groups could be seen foraging above the lagoon or circling near shipwrecks. Only a few were seen near the island itself, either resting on sand spits at low tide or circling overhead. On this same trip I visited an abandoned ship east of the island, where about 50 terns perched on and circled the ship. One chick and about 20 eggs were found on the deck. Sabino Zacharias, a resident of the island, informed me that greater numbers of birds resided at the other three shipwrecks on the reef. The nesting season appears to be in spring months only. Despite the relative abundance of Black-naped Terns in May 1979 and the apparently well established nesting population, there are no records of sightings during the fall. The disappearance of the population outside the breeding season is puzzling, since they are relatively sedentary elsewhere in the Palau Archipelago. Sooty Tern - Sterna fuscata. Helen harbors the only colony of Sooty Terns in the Southwest Islands. This highly pelagic species returns to land only to nest, and, depending on the reproductive cycle, numbers fluctuate from a few hundred to tens of thousands on Helen. Despite the occasional abundance of birds at Helen, sightings of Sooty Terns near the other Southwest Islands are rare. During my two trips through the region, I heard and saw Sooty Terns only at Helen. At Helen, eggs are located in shallow scrapes on the ground, usually within the interior of the island well above the high tide line. The major nesting colony is located in the central and eastern portion of the island, which is a relatively open area interspersed with small grass clumps. MThis colony extends to well within the interior of the island during a peak nesting season. Another small colony, possibly a distinct population, is located on the beach on the southwest side of the island. Birds appear to avoid nesting under the trees. The nesting of Sooty Terns on Helen appears to follow no distinct annual cycle. On several trips, the following estimated numbers of nests and young were recorded: 16 Nov. 1977 (this report) five nests and 15 nearly grown young 150 to 200 adults (east side) From this limited data, Nov. 1978 (Bright 1978) 500 nests no estimate of adults (southwest side) May 1979 (this report) 10 nearly grown young 50 adults (southwest side) Oct. 1979 (King et al. 1980) 37,876 eggs and small chicks and 3,000 nearly grown young 82,000 adults (east side) it appears that the only concentration of nesting birds during this 2-year period was in the fall of 1979. This is in contrast to the normal spring breeding peak for most seabirds of the region. different nesting seasons, 1962))< Crested Tern - Thalassius bergii. Elsewhere in Micronesia, the species seems to have several but these are poorly described (Brandt The Crested Tern nests only at Helen, where it can regularly be observed in large numbers resting on sand spits or foraging within or near the lagoon. season, the adult population is estimated at around 7,000. During the nesting Uncommon visits are made to other Southwest Islands as well, and I recorded small groups near Pulo Anna, Merir, and Tobi. The Crested Tern exhibits a distinct nesting season, with peak activity in spring and little or no nesting activity during the remainder of the year. Nov. 1977 (this report) 12 chicks No eggs 2-3,000 adults Nov. 1978 (Bright 1978) No chicks No eggs Adults not estimated May 1979 (this report) No chicks 3,250 eggs incubated 7,000 adults The following numbers illustrate the pattern: Oct: 1979 (King et al. 1980) 10 small chicks 20 eggs being incubated 440 adults I7/ In May 1979, the birds were at or near the height of their breeding cycle. The colony was located on the northern tip of the island on a level, open, sandy area just above the high tide line. Single eggs were deposited directly on the sand with no nest,being made. By pacing, I estimated the,size of the colony at 425 m , there being about 240 eggs in every 25 m or about 4,080 total eggs. It appeared that nearly a fifth of these eggs were abandoned, and I thus estimated a total of 3,250 active nests. According to King et al. (1980) this is probably the largest nesting colony of Crested Terns in Micronesia. A small amount of nesting occurs outside the spring breeding season. In October 1979 King et al. (1980) noted a small colony (about 20 eggs) on the eastern side of the island between the Sooty Tern colony and the beach. Although the Crested Tern is fairly sedentary in Palau and large numbers can generally be found roosting and feeding at Helen throughout the year, they apparently wander from Helen Island outside of the nesting season. King et al. (1980) observed only 440 roosting adults in October 1979, a marked decrease from the 7,000 or more that were present in spring of the same year. During their absence from Helen, the birds possibly disperse to the northern coast of New Guinea. Brown Noddy - Anous stolidus. The Brown Noddy is widespread, and can be found on all the Southwest Islands except Helen. On Sonsorol, Pulo Anna, and Tobi, Brown Noddies reside at approximately the same densities. On each of these islands, I estimate the nesting population to number in the high hundreds or low thousands. At Merir, the population is slightly larger, and on Fanna, it is smaller, at least during spring months. The small size of the population on Fanna may be due in part to interspecies competition for nesting sites with Black Noddies, which nest in profusion on Fanna in spring. The Brown Noddy breeds moderately throughout the year, with a decided peak during spring months. Nests are placed in trees, frequently in the crown of a coconut or pandanus. The bird is relatively solitary in its nesting habits, and generally only one nest is placed in a tree. Certain populations of Brown Noddies apparently indulge in seasonal migrations in the Southwest Islands, though in the main Palau Archipelago, numbers are similar throughout the year. In November 1977, I recorded no Brown Noddies from Pulo Anna or Tobi, yet in May 1979, the species was nesting in abundance on both islands. On Merir and Sonsorol, however, birds were present in both fall and spring. Possibly the Pulo Anna and Tobi birds migrate to Sonsorol or Merir during the fall, but they may also journey to regions outside of the Southwest Islands. It was suggested by a resident of Tobi that the complete absence of noddies in November 1977 was the result of overharvesting the birds with a gun, rather than a natural phenomenon. Black Noddy —- Anous minutus. A colonial and abundant nester on Fanna and Helen, the species occurs in much lesser numbers on the other Southwest Islands. Peak nesting occurs in spring on Fanna, but on 18 Helen nesting activity continues throughout the year. At Fanna in November 1977, the species was abundant, but I found no nests. In May 1979, the colony was nesting profusely around the perimeter of the island up to 100 m inland. Nests, placed in branch crotches, were constructed of twigs, leaves, and other debris, and were heavily caked with excrement. They were placed at all levels in medium-sized trees. Counts at ten random points within the colony revealed an average of 64 active nests within a 20 m radius of each point. I estimated the total area of the colony at nearly 20 ha, and the total number of active nests at 10,000. At any time during the day a dense cloud of several hundred to several thousand birds could be seen foraging within sight of the island. In contrast to Fanna, the colony on Helen did not exhibit such marked seasonality in nesting. On all trips that I or other visitors have made to the island, a large number of birds was nesting regardless of the season. On Helen, the Black Noddy nests nearly exclusively in the low Tournefortia trees. In November 1977, I estimated 1,700 active nests at all stages of development, from eggs to fully fledged young. In May 1979, I recorded about 1,000 nests. King et al. (1980) in October 1979, recorded roughly 1,200 nests. Outside of Fanna and Helen, there are no large colonies of Black Noddies in the Southwest Islands. In November 1979, I saw none at Pulo Anna, Merir, or Tobi. In May 1979, a very few were present at Sonsorol, Pulo Anna, and Tobi, but in all cases they were vastly outnumbered by Brown Noddies. King et al. (1980) observed moderate numbers on Merir in October 1979, but they were outnumbered by Brown Noddies 20 or 30 to one. Presumably a few birds nest on other Southwest Islands, although it remains to be documented. From the limited information I have from the Southwest Islands, I detected no major movement patterns. Wherever Black Noddies are abundant there were no or few Brown Noddies, and superficially it appears that some form of interspecific competition exists. However, I feel that more is involved than mutual exclusion due to competition for food, nest sites, or other habitat parameters. A possible partial explanation is the influence of man on the two species of noddies. The Black Noddy may be susceptible to disruption by humans, as they are abundant on the traditionally uninhabited islands of Fanna and Helen. The Brown Noddy, however, may be more tolerant of human disruption, and has persisted on islands inhabited by man. White Tern - Gygis alba. The White Tern is common to abundant on all the Southwest Islands except Helen, where a recently established colony of under 50 birds resides. The largest concentration is on Fanna, where several thousand birds nest. Lesser numbers, in the hundreds or low thousands, are found in the forests of Sonsorol, Pulo Anna, Merir, and Tobi. 19 Unlike most other seabirds, the White Tern is not strongly averse to humans, and frequently resides within or near villages. Individuals or pairs forage far out over the ocean, and are usually not seen feeding near land. Birds do not return nightly to roost, as individuals and small groups can occasionally be seen or heard flying over water after dark. Birds roost and nest in trees, usually high in large spreading trees such as Ficus, Calophyllum, or Artocarpus. When over land, birds are raucous and conspicuous, especially during morning hours. The White Tern nests throughout the year in Micronesia (Baker 1951), and presumably does so within the Southwest Islands as well. Though the tern is not a highly colonial nester, several pairs usually occupy the larger, more desirable trees. A peak in nesting activity may occur in spring. On Fanna, Pulo Anna, and Tobi in May 1979, numerous birds repeatedly landed and lingered in the foliage of the upper canopy, and were noisy and active as if defending territories. Birds were evenly distributed throughout the forest except on Fanna, where the colony of White Terns did not overlap with the dense and extensive colony of Black Noddies. Though I could not locate eggs or young, a few individuals perched on branches and appeared to be incubating. A nesting cycle had apparently begun or was just beginning. In November 1977, White Terns on these islands were decidedly less active. Though a peak in nesting may occur in spring, nesting activity has been recorded in other months as well. In November 1977 on Sonsorol, I noted White Terns carrying small fish, possibly for feeding young. In October 1979, an incubating bird was observed on Helen (King et al. 1980). The small colony of White Terns on Helen became established in 1978. In November 1977, no White Terns nested or roosted on Helen. A year later, Bright (1978) found at least 20 terns on the island, and nesting was reported by residents. The colony has remained on the island at least through the fall of 1979, as I found birds in May 1979, and King et al. (1980) found a few in October of the same year. CONCLUS ION Though perhaps depauperate from a worldwide perspective, species diversity of seabirds in the Southwest Islands is comparable to other Micronesian island groups: there are eleven resident seabirds in the Southwest Islands, about nine in Yap, ten in the Marianas, nine in Truk, ten in Ponape, sixteen in the Marshalls, and ten in the Gilberts (Fisher 1950, Baker 1951, Brandt 1962, Amerson 1969, pers. observ.). The Marshall Islands group has a species diversity noticeably greater than the other island groups. ,The Marshalls, however, cover a relatively vast area on the northeastern edge of Micronesia, where components of the Hawaiian avifaunal community are represented. The seabirds of the Southwest Islands are almost exclusively tree-nesters, suggesting that humans or other predators have excluded certain 20 ground-nesting species. Micronesia, on the other hand, might simply not provide the nesting habitat or food required for many seabirds. The Southwest Islands are heavily vegetated, a condition that certain ground nesting species avoid, and waters may be infertile, a likely case for offshore tropical waters where there are no major upwellings (King 1967). Seabirds of the Southwest Islands presently survive under relatively undisturbed conditions, though in the past there might have been considerable human pressure on the resource. Introduced predators appear to be a minor problem, as I saw no rats, cats, or dogs while on the islands. Rats are almost certainly present, as they are on most Pacific islands, but they are apparently not abundant. Pigs were raised on Sonsorol and Tobi, but those that I saw were penned or tethered. The only actual predation I witnessed was on Fanna, where a land crab was eating a Black Noddy downy young. A locally catastrophic event occurred on Helen in May 1979, when a gravid green sea turtle (Chelonia mydas) wandered through the Crested Tern colony, destroying a swath of eggs nearly a meter wide. Seabirds are well adapted to such natural disturbances, but most of man's activities are more destructive. It is perhaps no coincidence that the two largest concentrations of seabirds occur on Fanna and Helen, islands that have both been historically uninhabited or otherwise protected from excessive human intrusion. It is probable that only a few birds could exist on islands that sustained high human populations. On Tobi in the 1800's, 3-400 Micronesians resided in a continual state of near famine (Holden 1836) and any bird that lingered on the island was no doubt quickly consumed. From 1832-1834, Holden (1836) was a castaway on Tobi, and states that "during our stay there, scarcely a solitary sea-fowl was known to have alighted on the island." Many of the Southwest Islanders now reside in the capital of Koror, and the pressure of large human populations has somewhat diminished. Threats from outside harvesting still remain. Korean fishermen recently devastated seabird colonies in the Southwest Islands (Johannes 1981). In May 1979, two Taiwanese vessels were apprehended for illegal harvesting of birds, fish, and turtles. A Taiwanese vessel was in Helen Lagoon when the Lindblad Explorer visited Helen in 1979 (W. King, pers. comm.). Pillaging by outside boats is a common occurrence. With greater public awareness and more education, Palauans are expressing increasing concern for their unique natural resources. On past trips to the Southwest Islands, eggs and birds have been occasionally taken by field trip members. These incursions are more the result of unbounded curiosity than any real subsistence needs; an educational lecture would do much to minimize disturbances. Disruption of colonies is particularly damaging during nesting, when incubating adults are easily frightened off their nests and eggs and young are lost. Because of their high densities, birds on Helen are especially susceptible to such losses. On Helen, a warden has been designated to assist in the protection of seabird colonies; positive actions such as these will assure the continued existence of Palau's seabird colonies. 21 Acknowledgments I would like to first thank Robert P. Owen, who initiated this project and supported it throughout its duration. Warren King's timely contribution of his, Dennis Puleston's, and Thomas Ritchie's observations is much appreciated. Greg Bright helpfully offered his observations of the islands. Storrs Olson and John Farrand, Jr., kindly aided in the handling of specimens. Helpful comments on the manuscript were contributed by Dr. Cameron Kepler, Kay Kepler, Roger Clapp, and Warren King. Dr. Derral Herbst contributed much of the botanical information. Funding for the field work was supplied in part by the National Audubon Society through the efforts of C. John Ralph and George Peyton, Jr. A number of Palauans cheerfully offered information and assistance, and I would especially like to thank Sabino Zacharias, Marianos Carlos, and Antonio Andres. References American Ornithologists' Union. 1982. Thirty-fourth supplement to the American Ornithologists' Union check-list of North American birds. Auk (Supplement) 99(3): 16p. Amerson, A. J. Jr. 1969. Ornithology of the Marshall and Gilbert Islands. Atoll Res. Bull. No. 127: 348p. Baker, R. H. 1951. The avifauna of Micronesia, its origin, evolution, and distribution. Univ. Kan. Pub. Mus. Nat. His. 3(1): 359p. Brandt, J. H. 1962. Nests and eggs of the birds of the Truk Islands. Condor 64(5):416-437. Bright, G. 1978. Ornithological notes from the Southwest Islands, 24 November to 2 December 1978. Unpubl. report, Office of the Chief Conservationist, Koror, Palau. 2p. Bryan, E. H., Jr. 1971. Guide to place names in the Trust Territory of the Pacific Islands. Pac. Sc. Inf. Center, Bernice P. Bishop Museum, Honolulu. (pages not numbered) Sibley, F. C., and R. B. Clapp. 1967. Distribution and dispersal of Central Pacific Lesser Frigatebirds Fregata ariel. Ibis 109: 328-337. Eilers, A. 1935. Westkarolinen, 1. Halbband: Songosor, Pur, Merir. In G. Thilenius (ed.), Ergebnisse der Stidsee—-Expedition 1908-1910. II, B, IX, part 1. Friederichsen, De Gruyter, Hamburg. - 1936. Westkarolinen, 2. Halbband: Tobi, Ngulu. In G. Thilenius (ed.), Ergebnisse der Sudsee-Expedition 1908-1910. II, B, IX, part 2. Friederichsen, De Gruyter, Hamburg. 22 Engbring, J. 1981. A field guide to the birds of Palau. Unpubl. report, Office of the Chief Conservationist, Koror, Palau. 113p. Engbring, J. and R. P. Owen. 1981. New records of birds in Micronesia. Micronesica 17(1&2):186-192. Fisher, H. I. 1950. The birds of Yap, Western Caroline Islands. Pacific Science IV(1):55-62. Holden, H. 1836. A narrative of the shipwreck, captivity, and suffering of Horace Holden and Benjamin Nute. Weeks, Jordan and Co., Boston. Hutchinson, G. E. 1950. Survey of existing knowledge of biogeochemistry, 3. The biogeochemistry of vertebrate excretion. Bull. Amer. Mus. Nat. Hist. 96: 232-233. Johannes, R. E. 1981. Words of the lagoon; fishing and marine lore in the Palau District of Micronesia. Univ. of California Press, Berkeley. 245p. King, B. F., E. C. Dickinson, and M. W. Woodcock. 1975. A field guide to the birds of South-East Asia. Collins, London. 480p. King, W. B. 1967. Preliminary Smithsonian identification manual; seabirds of the tropical Pacific Ocean. U.S. Nat. Mus., Smithsonian Institution, Washington, D.C. 126p. King, W. B., D. Puleston, and T. L. Ritchie. Ms dated 1980. Bird populations of Helen and Merir Islands, Southwestern Palau. Unpublished. /7p. Owen, R. P. 1977a. New bird records for Micronesia and major island groups in Micronesia. Micronesica 13(1):57-63. 1977b. Terrestrial vertebrate fauna of the Palau Islands. Unpubl. report, Office of the Chief Conservationist, Koror, Palau. 15p. MO Fier. A checklist of the birds of Micronesia. Micronesica 13(1):65-81. Yamashina, Y. 1940. Some additions to the list of the birds of Micronesia. Tori 10:673-679. ATOLL RESEARCH BULLETIN No- 268 RECENT HISTORY OF A FRINGING REEF, BAHIA SALINA DEL SUR, VIEQUES ISLAND, PUERTO RICO BY IAN G- MACINTYRE, BILL RAYMOND AND ROBERT STUCKENRATH ISSUED BY THE SMITHSONIAN INSTITUTION WASHINGTON, D- C-, U-S-A.- SEPTEMBER 1983 RECENT HISTORY OF A FRINGING REEF, BAHIA SALINA DEL SUR, VIEQUES ISLAND, PUERTO RICO by Ian G. Macintyre,1 Bill Raymond, 2 and Robert Stuckenrath? Introduction The effect of U. S. Navy training activities on the shallow-water reefs at the eastern end of Vieques Island, Puerto Rico, was investigated during a 1978 ecological survey that included the drilling of three short core holes into an Acropora palmata (Lamarck) reef off the east coast of Bahia Salina del Sur (Figure 1). Radiocarbon dates of five core samples yield new information on the accumulation rates of A. palmata reef sections and provide further evidence that framework communities of many sea-level reefs are migrating leeward over loose, back-reef sediments. General Setting Bahia Salina del Sur is a small, crescent-shaped embayment (approximately 1 km wide and 1 km long) on the south coast of Vieques Island and close to its eastern end (Figure 1). The Thalassia sea- grass and sand and rubble floor in this area do not exceed a depth of 7m (Raymond, 1978). Shallow reefs fringe the promontories on the eastern, western, and northern shores of the bay, and two extensive sand beaches border its northeastern and northwestern corners. The fringing reef off the west side of the bay consists of a well- developed Acropora palmata community. Small coral heads grow beneath the open framework of A. palmata, which extends to a depth of 5m, where a halo of sand separates the reef from adjacent broad beds of Thalassia. This halo of sand may be related to the feeding activity of fish and sea urchins (Ogden and Zieman 1977). Banks and mounds of Porites porites (Pallas)--which resemble the near-shore banks of Porites off the west coast of Barbados (Macintyre 1968) and off the southeast coast of St. Croix (Adey 1975)-- have developed around two distinct promontories on the north coast of Bahia Salina del Sur. Small scattered stands of Acropora palmata occur in ) association with these Porites buildups. During the May, 1978 survey it was observed that naval bombardment had destroyed the eastern end of this near-shore community. During a subsequent survey following Hurricane David, Raymond and Dodge (1980) found that storm waves had Tyational Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560. ~Ocean Research and Survey, Inc., Fort Lauderdale, Florida 33136. 3Radiation Biology Laboratory, Smithsonian Institution, Washington, D.C. 20560. Manuscript received Jan. 1982--Eds. almost completely destroyed the entire north-shore Porites community, along with most of the A. palmata on the south coast of Vieques. The reef cored during this study (designated S-5 reef in Antonius and Weiner's 1978 survey) juts out obliquely from about the center of the eastern shore of Bahia Salina del Sur and is protected in part by a large promontory that forms the eastern entrance to the hay and by the fringing reef adjacent to this promontory, which consists of Montastrea, Siderastrea, and Diploria coral heads. Additional protec- tion is afforded by the A. palmata reef surrounding Roca Alcatraz, an island 1 km south of S-5 reef (figure 1). S-5 reef has the characteris- tic zonation of shallow-water Caribbean reefs dominated by Acropora palmata in the reef crest and shallow fore reef (Figures 2, 3D,E,F) (see, for example, Dahl et al. 1974; Adey 1975). At a depth of 4m, the A. palmata community gives way to a mixed coral-head community that includes Montastrea annularis (Ellis and Solander), Diploria strigosa (Dana), and Siderastrea siderea (Ellis and Solander). Small scattered colonies of both Acropora cervicornis (Lamarck) and Acropora prolifera (Lamarck) were found in the shallow fore reef during the 1978 survey, but subsequently were almost entirely removed by storm surge associated with Hurricane David (Raymond and Dodge 1980). The seaward slope of S-5 reef levels off at a depth of 8 m, where it grades into the sediment floor of the bay (Figure 2). The back reef shoreward of the reef crest is composed of large colonies of Montastrea annularis on rubble and pavement, which grade into sand and rubble; only a few colonies of M. annularis occur at the inner limit of the drill-site transect (Figures 2, 3A,B,C). Its faunal zonation indicates that S-5 reef has developed under moderate wave-energy conditions (Geister 1977). The algal ridges or Palythoa-Millepora reef-crest communities characteristic of high wave- energy reefs are absent here, as are Acropora cervicornis or Porites porites communities in low wave-energy reefs. Wave agitation does appear to be strong enough to prevent any significant accumulation of the fragile Acropora cervicornis either in the deeper fore-reef slope or in the protected back-reef sand flats. Core Descriptions Three core holes were drilled at 50-m intervals along a transect crossing S-5 reef and adjacent to the eastern coast of Bahia Salina del Sur (Figure 1)--two into the reef crest in a water depth of about 0.5 m and one into the shallow fore-reef slope in a water depth of 2 m below mean sea level (Figure 2). Core hole 1, drilled in four intervals into the reef crest to a depth of 6.4 m, yielded the following material: 1. O-.61 m.--This interval consisted of fresh sections of Acropora palmata with a comparable amount of fragments bored and encrusted by Homotrema rubrum, coralline algae, and serpulids. 2. .61-1.83m.--This section was made up of fresh and bored sections of Acropora palmata and Diploria strigosa, along with some encrusted (by Homotrema rubrum and coralline algae) rubble consisting of A. palmata, D Diploria sp., and Porites porites. 3. 1.83-3.35--Sections of A. palmata and Diploria clivosa were found throughout and cave-in rubble at the top of this interval. 4. 3.35-6.40 m.--Only cave-in rubble was collected from this interval. On-site observations indicated that the drill had dropped through a section of sand at this point. Core hole 2 consists of one core interval drilled to a depth of 1.83 m below the surface of the reef. Except for a 6-cm core of bored and encrusted Diploria strigosa, the material here was mainly A. palmata bored to various degrees by sponges, molluscs, and worms and encrusted by Homotrema rubrum, coralline algae, and serpulids. Core hole 3, drilled to a depth of 4.88 m below the surface of the reef, consists of three core intervals: 1. O-1.83 m.--This interval is characterized by extensive submarine lithification, so that core sections are predominently agglomerate limestcne. These cores, which are identical to those described from the shallow fore reef off Galeta Point, Panama (Macintyre 1977), consist of extensively bored and cemented agglomerations of crustose coralline algae, Millepora sp., Porites sp., and Acropora palmata. The multicyclic boring and submarine lithification have in some places destroyed much of the original skeletal framework, which has been replaced by Magnesium calcite cement. Other material collected from this interval consists of bored, infilled, and cemented A. palmata and other coral debris. 2. 1.83-3.35 m.--Core sections contained mainly Acropora palmata, both fresh corals and samples bored by sponges, worms, and molluscs. Extensive cave-in material was present at the top of this interval. 3. 3.35-4.88 m.--Extensive cave-in rubble occurred in this interval. Two cores of bored Acropora palmata were also collected here. Radiocarbon Dates Five radiocarbon dates were obtained from fresh samples of Acropora palmata, which had been collected from the base of core intervals so as to reduce the error in estimating the depths of recovery for the dated samples. Even so, it is not known whether the last material to be cored is in place at the base of the core interval, since a core barrel can punch through a section of the reef and carry a sample below its real depth of recovery. The lack of any significant difference in the two dates from core hole 3, the poor recovery in the last core interval, and the drill-worn condition of the lower sample dated suggest that this core sample was carried below its true depth of recovery. Radiocarbon dates and the accumulation rates for the inter- vening reef sections are given in Table l. TABLE 1 RADIOCARBON DATES AND ACCUMULATION RATES, BAHIA SALINA DEL SUR REEF Estimated Interval Depth of of Reef Core Depth Recovery Section Radio- Accumulation Interval below Reef Dated carbon Rate Sample (m) Surface (m) (m) Date (m/1000 yrs) Hole 1: Core l 0-.61 6! 0-0.61 190+90 aval Core 1 0-.61 61 190+90 -61-1.83 0.62 Core 2 -61-1.83 ILS tis) 2155+80 Hole 2 Core 1 0-1.83 183 0-1.83 860+90 Qreilks Hole 3 Core: 2 IP at}SI3} 5355) 33 55)5) 0-3.35 2020+70 1.66 Core 2 1.88-3.35 3555) 2020+70 3.35-4.88 * Core 3 3.35-4.88 4.88 2020+70 *Estimates invalidated owing to poor recovery in this core interval. Summary and Conclusions Excluding the lowest section of core hole 3 (where the estimates were discounted as invalid) we calculated that the Acropora palmata framework of S-5 reef has an average accumulation rate of about 2m/1000 years, which is lower than the average of 3.9m/1000 years reported for the A. palmata facies of the fringing reef off Galeta Point, Panama (Macintyre and Glynn 1976). This difference can be attributed to the changing rates of sea-level rise in the late stages of the Holocene transgression. Sea-level curves estahlished for several areas in the Atlantic and Pacific oceans show a distinct decrease in the rate of sea-level rise, from 3,000 to 4,000 years B.P. (Macintyre and Glynn 1976). As pointed out in the study of Galeta Reef, accumulation rates there decreased considerably about this period of time because changing sea levels reduced the availability of vertical space for reef development. Wherever A. palmata communities have experienced rapid changes in sea level, however--for example, at the shelf edge off Florida 7,000 to 9,500 years ago (Lighty et al. 1978)--the mean accumulation rates have been estimated at 6.6 m/1000 years, the maximum rate reported being 10.7 m/1000 years. The dates from the Vieques cores suggest that shallow-water Acropora palmata framework that is less than 2,000 years old can be expected to have accumulation rates around 2m/1000 years. In addition, the penetration of more than 3 m of sand at the base of core hole 1 lends support to Shinn's (1980) observation that some shallow-water A. palmata framework may accrete leeward over back-reef sands "by corals establishing themselves on storm-derived rubble periodically transported onto the leeward side of the reef flat" (p. 651). Observations of S-5 reef before and after Hurricane David indicate that both dead and living A. palmata, along with coral head debris, migrated several meters over the back-reef sands in this area. Furthermore, the extensive and multicyclic cementation present at the top of the shallow fore-reef core hole 3 is a characteristic associated with slowly accumulating reef facies (Macintyre, 1977). This combination of relatively little present-day reef growth in the shallow fore reef and leeward migration of the reef flat indicates that S-5 reef is in a mature stage of reef development, extending laterally into the Bahia Salina del Sur. Acknowledgments Thanks go to Robin King, Mike Wolfe and Greg McIntosh, as well as the Navy E.0O.D. divers of Roosevelt Roads, P.R. for assisting with the field work. Also, thanks to the Navy helicopter pilots who air- lifted the coring equipment from San Juan to Vieques. W. T. Boykin's assistance with drafting is gratefully acknowledged. References Adey, W. H. 1975. The algal ridges and coral reefs of St. Croix: Their Structure and Holocene development. Atoll Res. Bull., 187:1-67. Antonius, A. and A. Weiner. 1978. A quantitative biological and health assessment of selected coral reefs in Vieques (Puerto Rico) and the U. S. Virgin Islands. Report submitted to EG&G/U.S. Navy/U.S. Dept. of Justice, 1978. Dahl, A. L., I. G. Macintyre, and A. Antonius. 1974. A comparative survey of coral-reef research sites. Atoll Res. Bull. 172:37-120. Geister, J. 1977. The influence of wave exposure on the ecological zonation of Caribbean Coral Reefs. Pages 23-99, in D. L. Taylor, Editor, Proceedings, Third International Coral Reef Symposium, Volume 1, Miami, Florida: Rosentiel School of Marine and Atmospheric Science. Lighty, R. G., I. G. Macintyre, and R. Stuckenrath. 1978. Submerged early Holocene barrier reef south-east Florida shelf. Nature 275:59-60. Macintyre, I. G. 1968. Preliminary mapping of the insular shelf off the West coast of Barbados, W.I. Caribbean Jour. Sci., 8:95-100. Macintyre, I. G. and P. W. Glynn. 1976. Evolution of modern Caribbean fringing reef, Galeta Point, Panama. Am. Assoc. Petroleum Geologists Bull. 60:1054-1072. Macintyre, I. G. 1977. Distribution of submarine cements in modern Caribbean fringing reef, Galeta Point, Panama. Jour. of Sed. Petrology, 47:503-516. Ogden, J. C. and J. C. Zieman. 1977. Ecological aspects of coral reef-seagrass bed contacts in the Caribbean. Pages 377-382. In D. L. Taylor, editor. Proceedings, Third International Coral Reef Symposium. Volume 1, Miami, Florida: Rosentiel School of Marine and Atmospheric Science. Raymond, Bill, 1978, The marine sediments of a Naval Bombing range, Vieques, Puerto Rico: Report submitted to EG&G, U.S. Navy, Us iS Depts o£ Gusticey) Deck Wo7sr Raymond, W. F. and R. E. Dodge. 1980. 1979 Hurricane damage to coral reefs of Vieques. Report submitted to U.S. Navy. Shinn, E. A. 1980. Geologic history of Grecian rocks, Key Largo Coral Reef Marine Sanctuary. Bull. Mar. Sci. 30:646-656. *Apngas STU}? UE peTTTAp seToy eto 9e1y, oy] JO uoT}eDOT |yW pue ‘keq STYyI UT SjJooet BUTBUTAF JO UOTINGTAISTpP 9YyW fans Tap eurTes eryeg ‘pueTs] senbetA jo uozAeooT ZuTMoys dew xeput “{ sin3Tq € C SaYalawoily INOAIA *seToy 2100 943 WOLF peTeAODe1 VsoYy, pue xdeFINS sy. UO sjuUsUOdWOD Jeet JUeUTWOp ZSuTMOYsS ‘q0esuer} eTOY-9100 oy, BUOTe Joo G-S JO UOT IeS-sSOID oTJeWaYDS *7Z sANsTy S@P!OB14SD SA440q &) |21090590 ye S}JDj|NUUD Dad4ysoyUOW 4 sayisod sayiiog A psoBisys olsojdiq 3) ——— —— Ze ‘dd ‘SSNDAIA *ds pioday1w | DSOAIJD DIVOIdIq EGE yNS 130 VNIIvVS VIHVd apBjD aus}}O409 asoysn4d se DyDW od DiodolDy es S-S 433y IVWHOD *ds pasjsosapis (e) S1UJODIAIaD DIOdOIDY eK QN3931 OOE 00z SYH3LIW OOL S N eNOTMORO SY3LAW Figure 3. Bottom photographs of S-5 reef taken along transect shown in Figure 2. A. Isolated colonies of Montastrea annularis on sand and rubble bottom, at 5 m along transect. B. and C. Back- reef M. annularis colonies at 30 and 50 m, respectively. D, E, and F. A. palmata community on the reef crest in the vicinity of core hole 1 and 2, and on the shallow fore-reef, near core hole 3. ATOLL RESEARCH BULLETIN No- 269 THE INVERTEBRATES OF GALETA REEF (CARIBBEAN PANAMA) : A SPECIES LIST AND BIBLIOGRAPHY BY JOHN CUBIT AND SUELYNN WILLIAMS ISSUED BY THE SMITHSONIAN INSTITUTION WASHINGTON, D- C-, U-S-A- SEPTEMBER 1983 CONTENTS Abstract Introduction Explanation of Listings Porifera Coelenterata Platyhelminthes Sipuncula Annelida Arthropoda Mollusca Ectoprocta (Bryozoa) Brachiopoda Echinodermata Chordata Acknowledgments Literature Cited page THE INVERTEBRATES OF GALETA REEF (CARIBBEAN PANAMA) A SPECIES LIST AND BIBLIOGRAPHY by John cubits and Suelynn WMulidems” ABSTRACT The fringing coral reef at Galeta Point, on the Caribbean Coast of Panama, has been under intensive study for approximately ten years. The combined studies of the reef represent approximately 5,000 person hours of field sampling and have documented the presence of approximately 775 species of invertebrates. A list of these species is presented here together with annotations to all known sources of information pertaining to the occurrence of these species on Galeta Reef. For most species these records are the southernmost in the Caribbean Sea. INTRODUCTION The following is an inventory of the invertebrates that have been found on Galeta Reef, Panama, together with all known sources of information pertaining to the occurrence of these species on the reef. At present such data are lacking for Caribbean reefs, but are needed to formulate rational policies of resource management and to serve as baseline information for measuring natural and man-caused changes of the environment (FAO, 1969). This need was recently reiterated by the United Nations Environment Program (UNEP,1981). We have compiled this list from published papers, unpublished reports, personal communications, our own observations, and the set of specimens in the reference collection of the Galeta Point Marine Laboratory. This listing has been restricted only to those invertebrates studied on, or 1. Smithsonian Tropical Research Institute, Box 2072, Balboa, Panama. 2. Present address: 9 Second Street, Route 4, West Riverside, Missoula, Montana 5980 Manuscript received May 1982 -- Eds. 2 collected from, Galeta Reef itself; it does not include species reported from nearby areas or the general Caribbean coast of Panama. Galeta Reef has been under intensive investigation for approximate- ly ten years. Most of the reef studies have been monitoring surveys designed to determine the species composition of the reef and to document temporal changes in the distribution and abundance of the biota of the reef. This reef was established as a biological reserve in the late 1960s. Intensive monitoring of the reef biota was started by Charles Birkeland and others in 1970, beginning with a three-year program Figure 1. Map of Caribbean Sea showing the location of Galeta Point (9°24'18"N, 79°51'48.5"W) (marked by an arrow at lower left). Figure 2. Schematic cross section of the reef at Galeta Point. The reef platform (10 to 300 m wide) is in shallow water (less than 40 cm deep), and is occasionally exposed above the level of the tide (shown as a dashed line). The seaward edge of the reef has various profiles (shown in the figure as the solid and dotted lines) which terminate at 3 to 10 m depth at a base of sand or coral rubble. The reef platform encloses a lagoon and channels and is backed on the landward side by mangroves and sand beaches. supported by the U.S. Environmental Protection Agency (see Birkeland et al., 1976). Subsequently the monitoring was expanded to include physical factors in a set of projects supported by the Smithsonian Institution Environmental Sciences Program. In addition, the reef has been studied by a number of visiting investigators. Overall, the information in this inventory has been derived from the efforts of approximately 50 people who have conducted a variety of studies, of variable duration, during the period of 1969 to 1980. Im all, we estimate that this represents approximately 5,000 person—-hours of sampling effort of reef invertebrates. The presence of approximately 775 species of macroinvertebrates has been documented in these investigations of the reef. In these studies certain taxonomic and ecological groups have received more attention than others. For instance, the gastropods, polychetes, and certain groups of decapods have been more thoroughly collected, while the sponges, ascidians, bryozoans, and smaller crustaceans have not. There is also more information regarding those invertebrates that are major occupiers of primary substratum on the shallow reef platform than for those species that are mobile or occur on the subtidal reef slope and sand bottom. Description of the Reef The Galeta Reef is in the southwestern Caribbean Sea (9°24'18"N, 79°51'48.5"W). The Galeta Point Marine Laboratory, situated directly on the reef platform, is the southernmost marine laboratory in the Caribbean (see map, Fig. 1). The reef is near the western end of a system of fringing reefs that stretch for approximately 250 km along the Caribbean coast of Panama. The majority of these reefs are now at their post-climax stage, having passed through their period of most active coral growth more than 2,000 years ago. The general structure of this type of reef is of a broad platform, bordered on the landward side by mangroves, and often enclosing a lagoon. On the seaward side, the platform slopes into 3 to 10 m of water before reaching a sand bottom (Macintyre and Glynn, 1976; Fig. 2). The surface of the reef platform is at the lower level of the intertidal zone. The range of the tides on this coast is only! about 30 cm, so the reef platform is never deeply under water. Wave action tends to maintain water over the reef even during the lowest low tides; however, during calm weather the reef platform may be exposed above water level for long periods of the day, subjecting the biota of the platform to extremes of desiccation, solar radiation, high temperatures, rainfall, and predation by shorebirds. There are approximately 30-40 such instances of reef exposure each year, varying in duration from 1 to 14 hours. Other than the extreme low tides, the reef is subject to relatively little disturbance. Galeta Point is south of the Caribbean "hurricane belt" (the area traversed by hurricanes and tropical storms) (Neumann et al., 1978), and is thus protected from this source of periodic disruption to which most other Caribbean reefs are exposed. Salinity and seawater temperature have been monitored on this reef for approximately seven years: there is no evidence that the subtidal biota are ever exposed to extremes of any of these factors. Mean seawater temperature is approximately 29°C with the range of variation confined to plus or minus a few degrees (except during the extreme low tides previously mentioned, when temperatures in shallow pools of standing water on the reef platform may reach 35°C to 40°C). Salinities average approximately 33 ppt, also with little variation (except for those organisms above water level which may be exposed to heavy rains). Most of the hard substrata of the reef platform are covered with algae, primarily the two red algae Acanthophora spicifera (Vahl) Borgesen and Laurencia papillosa (Forsskal) Greville. The seagrass Thalassia testudinum Koenig and Sims occupies much of the area of loose sediment. The biota of the subtidal reef slope consists of various species of foliose and crustose coralline algae, some fleshy algae, and live corals. Most of the species in this inventory were collected from the reef platform. Explanation of Listings All entries on this list are followed by notations which refer to the following: (1) published information regarding the occurrence of the species on Galeta Reef, (2) to whom to attribute the determination of the species, and (3) the presence of voucher specimens in the Galeta laboratory reference collection. Because of the large number of entries, we have had to abbreviate these notations. The meanings of the abbreviations are listed at the end of the inventory and follow this form: 1. Multiple capital letters are the initials of those persons who have made the species determinations of the specimens collected from Galeta Reef. 2. The single capitals B, D, F, and G refer to appendices in Birkeland et al. (1976), the single most comprehensive survey of Galeta Reef. 3. E/73-E76 refer to reports of the Environmental Sciences Program for the years numbered. 4. Lower case letters denote references listed under Literature Cited. 5. + signifies voucher specimens of the species are present in the reference collection at the Galeta Point Marine Laboratory. To aid users of this list and to avoid compounding errors, we have noted any variations in nomenclature and spelling among the sources. We refer the user to the sources in the annotations for the authors of the species. Abbreviations Used SPECIES DETERMINATIONS AR Amada A. Reimer BM 8B. Macurda CAC C. A. Child CB Charles Birkeland cc C. Cutress DLM David L. Meyer DLW Diana L. Werder DS Diane Stoecker EK Eugene Kaplan GLH Gordon L. Hendler HD Hugh Dingle IT Ina Tumlin JC John Cubit JD Judith Dudley JH Janet Haig JR Joseph Rosewater JRY Joyce Redemske Young JS James Stames JSG John S. Garth JW J. Wells IWE Jd. Wo Porter KBM Kaniaulono B. Meyer KS Ken Sebens KR Klaus Ruetzler LGA Lawrence G. Abele PAA Peter A. Abrams PG Peter W. Glynn RB R. Bullock RLC Roy L. Caldwell RHG Robert H. Gore RHM R. H. Millar RM Raymond B. Manning RO Randy Olson RS Rick Steger SS Stephen Shuster SW Suelynn Williams VB Victoria Batista LITERATURE REFERENCES B, D, F, G = appendices B, D, F, and G in Birkeland et al., 1976. E73, E74, E75, E76 = reports of the Environmental Sciences Program of the Smithsonian Institution (Environmental Monitoring and Baseline Data from the Isthmus of Panama - 1973, 1974, 1975, 1976, respectively). = Fauchald (1977) = Birkeland (1974) = Bertsch (1975a) = Reimer (1975) = Gore and Abele(1976) = Macintyre and Glynn (1976) = Sebens (1977) Meyer (1977) = Sebens (1976) = Bertsch (1975b) = Hendler (1977) = Abrams (1976) = Koehl (1977) = Yee and Chang (1978) = Lawrence (1976) = Sebens (1982) namuyvr onpB rh» Soe hoan op i] Sebens and DeRiemer (1977) Gore (1977) Porter (1972) Gore and Abele (1973) Olson (1979) Birkeland et al. (1976) Vasquez—Montoya (1979) Batista (1980) Abele (1972) = Powell (1971) Smith (1973) Meyer (1973) dd = Brattegard (1974) NMS K EqQerH HR Ts a f wou ot ee = Lasker (1979) ££ = Lehman and Porter (1973) gg = Spivey (1976) hh = Henry and McLaughlin (1975) ii = Jackson (1973) 43 = Rutzler and Sterrer (1970) kk = Child (1979) 11 = Southward (1975) mm = Caldwell (1981) OTHER + signifies this species is currently represented in the reference collection of the Galeta Point Marine Laboratory. PORIFERA Anthosigmella varians E73, E74, E75, E76, v, q Craniella sp. E73, E74, E/5, E/6 Geodia sp. F Niphates erecta KR, y Placospongia sp. E75 Sigmadocia caerulea KR, y Sigmadocia sp. KR, y Spongia sp. KR, y Tedania ignis KR, y COELENTERATA (by Order) HYDROIDA Millepora alcicornis c Millepora complanata B, E73, E74, E76; £5) Gi pvemteuein Millepora moniliformis t Millepora spp. Vv Stylaster rosaceus DLM, + Unidentified sp. y CERIANTHARIA Ceriantheopsis americanus y Cerianthus sp. ey ar ACTINIARTA Aiptasia tagetes By ly oq oe Anthopleura krebsi Bekesact Anthopleura sp. 3) O/B) sar Bartholomea annulata Ls uey: Bunodeopsis antilliensis 2 Bunodeopsis globulifera KS, ? in y Condylactis gigantea i bbb Epiphellia n. sp. B, q, + Lebrunia coralligens r Lebrunia danae r Phyllactis flosculifera q, P. floculifera [sic] in CGB, E73, E74, E75, E76, + Phymanthus crucifer GG, Bi, E73, E74, SE7i6),, Goes Phymanthus sp. E75 Stoichactis helianthus CG, i Telmatactis americana Breet Telmatactis roseni B, + Telmatactis vernonia 16 CORALLIMORPHARTIA Paradiscosoma neglecta r Rhodactis sancti-thomae r Ricordea florida r, v, Recordia in CC, JRY, + ZOANTHIDEA Isaurus duchassaingi AR, B, E73, E/6, q, + Isaurus tuberculatus q Palythoa caribaeorum B, E73, E/4, E76, g, n, q, v, + Palythoa gigantea E74 Palythoa sp. E/5, E/6 Palythoa spp. Vv Palythoa sociatus y Palythoa variabilis B, E74, d, g, n, q, y, + Palythoa (= Protopalythoa) grandis q Parazoanthus parasiticus Parazonathus swiftii Zoanthus pulchellus AR, + Zoanthus sociatus AR, B, F, E73, E74, E75, E76, g, d, q, y, + Zoanthus solanderi AR, B, E73, E74, E75, E76, + Z. solandri [sic] in g, q Zonathus sp. E76 RHIZOSTOMAE Cassiopea ?xamachana JC SCLERACTINIA (by family) Astrocoeniidae Stephanocoenia michelinii JW, £, Stephanocoencia [sic] in io oP Pocilloporidae Madracis decatis JW, t, + Acroporidae Acropora palmata t, v Acropora cervicornis t Agariciidae Agaricia agaricites JWO, B, E73, E74, E76, £, vs + Agaricia agaricites forma agaricites t Agaricia agaricites forma danae E Agaricia agaricites forma crassa t Agaricia agaricites forma purpurea t Agaricia agaricites forma humilis t Agaricia tenuifolia t Agaricia spp. Vv Helioseris cucullata t Siderastreidae Siderastrea siderea DIM, Bi £5) Gin ace aaveyGiees Siderastrea radians By E73, EVGs yt uitee yore Poritidae Porites astreoides JW, B, E/3, E74,) B/G), £5) Game enyaies PR. astroidessin’ Ey sea Porites branneri SWE eats ct Porites divaricata t Porites furcata By E73), E745) Gy) tye camel Porites porites tay Porites sp. E76 Faviidae Colpophyllia amaranthus t Colpophyllia breviserialis t Colpophyllia natans JW. ty Diplora clivosa eg Gla. AY Diploria strigosa t Favia fragum DIM, B, E/73,E74,E7/ 6,0 1i,)etsmeyeeeess Manacina areolata SMS WsaP Montastrea annularis JW, £5 .t, Montastrea cavernosa JW, t, +,, Gel) eke MIL Rhizangiidae Astrangia solitaria Beat Meandrinidae Dichocoenia cf. stellaris JWP, + Dichocoenia stokesii Bo iby 4 D. stokesia in E76 Meandrina meandrites t Meandrina meandrites var. meandrites JW, + Mussidae Isophyllia multiflora t Isophyllia sinuosa PE, 15 5 © Mussa angulosa M25 5 & Mycetophyllia lamarckana JW, t, + Mycetophyllia sp. B t Caryophyllidae Eusmilia fastigiata t Dendrophylliidae Tubastraea aurea t GORGONACEA Erythropodium caribaeorum B, E73, E/4, E76, q Gorgonia flabellum f Gorgonia spp. Vv Gorgonia ventalina PLATYHELMINTHES Class: Turbellaria Unident. species y 12 SIPUNCULA Aspidosiphon broki Aspidosiphon speculator Aspidosiphon spinoscutatus Aspidosiphon spp. (7 species) Dendrostomum sp. Golfingia rimicola Golfingia spp. (4 species) Lithacrosiphon spp. (5 species) Lithacrosiphon sp. 3 Paraspidosiphon fisheri Paraspidosiphon speciosus Paraspidosiphon spinoso-scutatus Paraspidosiphon steenstrupi Paraspidosiphon spp. (7 species) Paraspidosiphon sp. 4 Phascolosoma antillarum Phascolosoma perlucens Phascolosoma varians Phascolosoma spp. (7 species) Phascolosoma spp. 3, 4 Themiste spp. (3 species) Unident. species ANNELIDA (by family) Ampharetidae Isolda bipinnata Isolda pulchella Melinna n. sp. Biase x x B B xX Bye B F Bie kis 2 in) B Bis) Ba Bis Lys B F Bais Baek, Bie: B F B y/ a x B Amphinomidae Amphinomid sp. 1 B, FE, + Amphinomid sp. 2 B, + Eurythoe complanata Bo Wo By Gly & Hermodice carunculata B, a, q, y Linopherus canariensis a (family Phyllodocidae in B) Unident. species y Aphroditidae Aphrodita diplops Aphrodita n. sp. B Arabellidae Arabella mutans B, F, a, x, y, + Arabella sp. indet. a Ariciidae (listed thus by Vasquez—Montoya, 1979) Naineris laevigata x Naineris mutila x Naineris setosa x Scoloplos armiger x. Chrysopetalidae (Palmyridae in B) Bhawania goodei B, a, + Bhawania riveti + Cirratulidae Cauleriella hamata x Cauleriella sp. indet. B, a Chaetozone sp. indet. B, a, y Cirratulus cirratus ? in a, C. cirratulus in B Cirriformia luxuriosa B, + (specimen in collection from Pacific) Cirriformia punctata Byway) 13 14 Dodecaceria concharum Tharyx sp. indet. Dorvilleidae Dorvillea rubrovittatus Driloneresis nuda Schistomeringos longicornis Eunicidae (Leodicidae in F) Eunice afra Eunice antennata aedificatrix Eunice aphroditois Eunice (Nicidion) cariboea Eunice filamentosa Eunice vittatopsis Eunice websteri Eunice sp. indet. Lysidice ninetta Lysidice sp. Marphysa amadae Marphysa depressa Marphysa n. sp. Marphysa sp. indet. Nematonereis unicornis Palola siciliensis Palola sp. indet. Flabelligeridae (Chloraemidae in B) Pherusa capulata Pherusa inflata Piromis americana Glyceridae Glycera abranchiata B, £74, a a, D. rubrovittata in B x as x i aa els, so 5 Elo oF 5 15 El5 wv a, +, E. caribaea [sic] in B, F lis Ele ae x Bieta sia Bs a x y a x B a ay x WR tbo oe Bera x Whe Gig oe + (no identifier on voucher specimen) Glycera oxycephala Glycera tesselata Glycera sp. Goniadidae Goniada acicula Hesionidae Hesione picta Ophiodromus obscurus Lumbrineridae Lumbrineris inflata Lumbrineris sp. aff. latreilli Lumbrineris tetraura Lysaretidae Lysaretid sp. Oenone fulgida Maldanidae Axiothella rubrocincta Nereidae Ceratonereis mirabilis Neanthes galetae Neanthes n. sp. 1 Neanthes sp. indet. Nematonereis sp. Nereis callaona Nereis panamensis Nereis n. sp. A Nereis riisei Nereis sp. Nereidae sp. indet. < 15 Lumbrinereis in B a a (in family Arabellidae in B) Mp a, + riseii [sic] in B, x 16 Perinereis elenacasoi Perinereis anderssoni Perinereis sp. indet. A Perinereis sp. indet. Platynereis dumerilii Platynereis sp. indet. Pseudonereis gallapagenesis Onuphidae Onuphis nebulosa Onuphis vermillionensis Onuphis sp. Opheliidae Armandia bioculata Oweniidae Owenia collaris Paraonidae Aricidea suecica Phyl lodocidae Anaitides erythrophyllus Anaitides sp. cf. lamellifera Eulalia myriacyclum Sige orientalis Poecilochaetidae Poecilochaetus johnsoni Polynoidae Halosydna leucohyba Halosydna sp. 1 B, a, x (in family Eunacidae in B) B (in family Eunacidae in B) a, erythrophylla [sic] in B x B, F, a, + B 5 ie ali) G1 Harmothoe sp. indet. Harmothoe hirsuta Lepidonotus humilis Lepidonotus neophilus Lepidasthenia varius Sabellariidae Phragmatopoma sp. indet. Sabellaria alcocki Sabellaria floridensis Sabellidae news Spe Demonax leucaspis Demonax sp. Hypsicomus torquatus Hypsicomus phaeotenia Megalomma sp. Megalomma sp. aff. pigmentum Megalomma roulei Megalomma vesiculosum Pseudopotamilla reniformis Sabella melanostigma Sabella sp. 17 Sabella sp. 18 Sabella sp. Sabellidae sp. indet. Sabellastarte magnifica Serpulidae Serpulid sp. 1 Serpulid sp. 2 Spirobranchus giganteus Spirorbis sp. B, a B, + (specimen in collection from Pacific) B, a, + B, a ? ina B +, B, F a D4 x a, Megaloma [sic] in B B, a B, a, + B B y a 5 3 17 18 Sigalionidae Psammolyce spinosa B, a, = Sthenelais verruculosa x Spionidae Boccardia polybranchia x Malacoceros indicus x Nerinides cantabra x Prionospio cirrifera x Prionospio heterobranchia texana By al Pseudopolydora antennata x Syllidae Autolytus anoplos Autolytus n. sp. Autolytus cf. magnus Haplosyllis spongicola Langerhansia cornuta Langerhansia mexicana Odontosyllis sp. Opisthosyllis brunnea Pionosyllis sp. indet. a Syllidae, unident. fragments a . ry . + ie8) at, ep eed eh ech eG rub S oe Le] ie¥} ab Syllis longissima xX Trypanosyllis taeniaformis X ¥; Typosyllis aciculata B, a, + (specimen in collection from Pacific) Typosyllis fuscosuturata a Typosyllis sp. A B Typosyllis prolifera Bs 7 ania Typosyllis variegata B Terebellidae Eupolymia nebulosa Bo WG Gly Euthelepus pascua Loimia medusa Pista fasciata Polycirrus sp. Polycirrus sp. aff. haematodes Streblosoma crassibranchia Terebellidae sp. indet. Thelepus setosus Trichobranchidae Trebellides stroemi CRUSTACEA: COPEPODA (by order) CALANOIDA Unident. species CRUSTACEA: ISOPODA (by family) Anthuridae Accalathura sp.? Idoteidae Cleantis planicauda Cirolanidae Cirolana parva Excirolana mayana Excorallanidae Alcinora sp. Excorallana tricornis x B, a, + ARTHROPODA SS SS 19 20 Ligiidae Ligia sp. y Limnoriidae Limnoria sp. y Sphaeromatidae Paracerceis caudata SS Stenetriidae Stenetrium serratum SS CRUSTACEA: AMPHIPODA (by family) Gammaridae Elasmopus sp. y CRUSTACEA: DECAPODA: REPTANTIA (by family) Porcellanidae Clastotoechus nodosus Wey el, © Megalobrachium poeyi B; JH, (e+ Megalobrachium roseum Bye Hin einact Megalobrachium soriatum 5 dhly Gio a Neopisosoma angustifrons es. sy = Pachycheles chacei Bi Hee Pachycheles cristobalensis Bi Hs er mets Pachycheles serratus By JH eis), GA seat Pachycheles susanae WS G5 Wa o Petrolisthes armatus By JH) Chet Petrolisthes galathinus aes MSs Gq sp Petrolisthes jugosus By JH, "e, + Grapsidae Aratus pisonii EK, y Goniopsis cruentata Grapsus grapsus Pachygrapsus gracilis Pachygrapsus marmoratus Pachygrapsus transversus Percnon gibbesi Plagusia depressa Sesarma cinereum Sesarma curacaoense Portunidae Callinectes sp. Majidae Acanthonyx petiverii Epialtus sp. = E. ?longirostris Macrocoeloma subparallelum Microphrys bicornutus Mithrax acuticornis Mithrax coryphe Mithrax commensalis Mithrax sculptus? Mithrax spinossimus Mithrax sp. Mithrax verrucosus Pitho aculeata Stenorhynchus seticornis Thoe puella Xanthidae Carpilius corallinus Cataleptodius floridanus Domecia acanthophora Eriphia gonagra 21 JC JSG, + petriverii [sic] in B B JSG By JSC B, F, JSG, E74, E/5, E76, x, y, + B, JSG B, ISG, > JRS, JS EK JC RHG, Leptodium in B, JSG, LGA, + 8, ISG B, JSG 22 Leptodius floridanus Micropanope sp. Panopeus be rmudensis Panopeus harttii Panopeus herbstii Panopeus sp. Panopeus sp. aff. occidentalis Paraliomera dispar Pilumnus dasypodus Pilumnus holosericus Pilumnus lacteus Pilumnus reticulatus Pilumnus sayi? Pilumnus sp. Platyactaea setigera Platypodia spectabilis Xantho denticulatus Calappidae Calappa sp. Gecarcinidae Cardisoma guanhumi Dromiidae Dromidia sp. Ocy podidae Ocypode quadrata Uca burgersi Uca sp. Palinuridae Panulirus argus Panu lirus guttatus x B, JoG B, JSG, LGA RHG, + AKG hq Win ae B, JSG x B, JSG, LGA, + 5 WiNG5 a: B, JG, LEGAL e+ B Biis Giauct RHG, + B, JSG RHG, Actaea in B, JSG, + By JSG, LGA, RHC. RHG, Xanthodius in B, JSG, + JC RHG JC JC JC 23 Scyllaridae Scyllarus sp. JC Parthenopidae Heterocrypta macrobranchia? B, RHG Leucosiidae Uhlias limbatus B, JSG Paguridae Paguristes cadenati JC Paguristes grayi PAA, m, + Paguristes cf tortugae PAA, m, + Pagurus bonairensis PAA, m, + Pagurus brevidactylus PAA, m, + Coenobitidae Coenobita clypeatus PAA, m, + Diogeniidae Calcinus tibicen PAA, JH, m, + Clibanarius antillensis PAA, m, + Clibanarius sp. y Clibanarius tricolor PAA, m, + Dardanus venosus PAA, m, + Dardanus sp. fo) Petrochirus diogenes RHG, P. bahamensis in PAA, m, + Petrochirus sp. fo) Pinnotheridae Pinnotheres maculatus JSG Pinnixa ?faxoni JSG Hapalocarcinidae Pseudocryptochirus RHG 24 CRUSTACEA: DECAPODA: NATANTIA (by family) Alpheidae Alpheus armillatus Bienes Alpheus armatus Alpheus bahamensis qa Q wo w Alpheus cristulifrons Alpheus floridanus Alpheus formosus Alpheus normanni Alpheus nuttingi Alpheus paracrinitus Alpheus peasei Alpheus ridleyi Alpheus schmitti Alpheus simus Alpheus sp. Alpheus viridari Automate rectifrons Metalpheus rostratipes Salmoneus ortmanni Synalpheus anasimus Synalpheus brevidactylus RHG Synalpheus fritzmuelleri B Synalpheus herricki B Synalpheus minus Synalpheus pandionis Synalpheus sp. Synalpheus tenuispina Synalpheus townsendi Thunor rathbunae ny wm no Dn woes weewtewneehwehweheOelekeOCUleOK * nT wD we DD Callianassidae Callichirus acanthochinus x Gnathophyllidae Gnathophyllum americanum Hippolytidae Hippolyte curacaoensis Lysmata intermedia Thor manningi Palaemonidae Periclimenes americanus Stenopus hispidus Stenopus scutellatus Penaeidae Penaeus duorarum Penaeus sp. Sicyonia parri Trachypenaeus similis Processidae CRUSTACEA: Ambidexter symmetricus Processa bermudensis Processa fimbriata Processa sp. aff. hemphilli STOMATOPODA Gonodactylus austrinus Gonodactylus bredini Gonodactylus oerstedii Gonodactylus spinulosus Meiosquilla lebouri Pseudosquilla ciliata Nannosquilla sp. 25 nw ww < RM, B, y, + RM, B, y, + RM, B, y, + HD and RS, + RLC and RS RM, x, y, + x 26 CRUSTACEA: MYSIDACEA Siriella chierchiae dd Bowmaniella bracescui dd Bowmaniella sewelli dd Amathimysis cherados dd Amathimysis gibba dd Brasilomysis castroi dd Cubanomysis jimenezi dd Mysidopsis brattstroemi dd Mysidopsis velifera dd Mysidopsis arenosa sp. nov. dd Mysidium columbiae dd Mysidium gracile dd Mysidium integrum dd CRUSTACEA: CIRRIPEDIA Balanus sp. ala Balanus trigonus gg Balanus venustus hh Chthamalus angustitergum al Chthamalus bisinuatus Val Chthamalus rhizophorae 11 Chthamalus sp. y Newmanella radiata Bg Tetraclita stalactifera ia PYCNOGONIDA Achelia sawayai Bie Kat Anoplodactylus allotrius kk Anoplodactylus batangensis batangense in B, kk Anoplodactylus evelinae B, kk, + (specimen in collection from Pacific) Anoplodactylus galetensis Anoplodactylus insigniformis Anoplodactylus jonesi Anoplodactylus monotrema Anoplodactylus multiclavus Anoplodactylus pectinus Anoplodactylus spp. Anoplodactylus stri Anoplodactylus trispinosus 27 kk Anoplodactylus viridintestinalis kk Ammothella appendiculata Ammothella exornata Ammothella marcusi Ammothella rugulosa Ammothella spp. Ammothella spinifera Ascorhynchus castellioides Ascorhynchus latipes Callipallene emaciata Callipallene sp. Endeis spinosa Eurycyde gorda Eurycyde raphiaster Eurycyde sp. Nymphon floridanum Nymphopsis duodorsospinosa Pallenopsis schmitti Pigrogromitus timsanus Rhynchothorax architectus Rhynchothorax sp. Tanystylum birkelandi Tanystylum geminum Tanystylum isthmiacum difficile Tanystylum sp. B, kk, + kk, + CAC, kk, + B, kk, + (specimen in collection from Pacific) B, kk 28 MOLLUSCA SCAPHOPODA Dentalium gouldi KBM, + Dentalium antillarum x POLY PLACOPHORA Acanthochitona hemphilli Acanthochitona interfissa Acanthochitona pygmaea Acanthochitona spiculosus Acanthochitona unident. sp. Acanthopleura granulata Calloplax janeirensis Chiton viridis Choneplax lata Ischnochiton papillosus Ischnochiton pectinatus Ischnochiton purpurascens Lepidochitona liozonis COI oO Sse) ibs) bie Se ici eo esi ies GASTROPODA: PROSOBRANCHIA Acmaea antillarum B Acmaea pustulata Bee Alvania aberrans GB, + Anachis catenata CBee Biemct Anachis crassilabris F Anachis obesa SIRS) CB Antillophos sp. 1 CBanch Architectonica nobilis KBM, + Arene cruentata CB, B, Arene tricarinata B 29 Astraea caelata DLW, B, + Astraea phoebia KBM, IT, B, + Bailya intricata B, F Bailya parva KBM, + Balcis intermedia B Balcis sp. l B Batillaria minima KBM, D, F, f£, y, + Bittium varium B Bursa cubaniana B Bursa granularis KBM, + Caecum sp. y Calliostoma jujubinum KBM, + Cantharus auritulus F Cantharus tinctus Cerithiopsis eme rsoni F Cerithium eburneum KBM, B, £, x, + Cerithium litteratum KBM, B, JR, £, x, y, + (cf. C litteratum (Young) by CB in +] Cerithium variabile B, D Charonia variegata Bo Og @ Cheilea equestris B, Cheila [sic] in B Cittarium pica B Columbella mercatoria KBM, + Conus daucus fo) Comins wus) B Coralliophila abbreviata KBM, + Coralliophila aberrans CB, + Coralliophila caribaea B Crassispira fuscescens KBM, + Crassispira leucocyma CB, + Crassispira nigrescens JR Crassispira tampaensis x Crepidula plana B Crucibulum auricula KBM, f£, + Cyclostremiscus beaui B 30 Cymatium muricinum Cymatium nicobaricum Cymatium pileare Cyphoma gibbosum Cypraea cinerea Cypraea zebra Cypraecassis testiculus Daphnella lymneiformis Diodora cayenensis Diodora dysoni Diodora cf. minuta Diodora variegata Drillia albinodata Drillia sp. lL Drupa nodulosa Emarginula phrixodes Emarginula pumila Engina turbinella Epitonium candeanum Epitonium lamellosum Epitonium occidentale Epitonium sp. l Fasciolaria tulipa Fissurella angusta Fissurella barbadensis Heliacus bisulcatus Heliacus cylindricus Heliacus infundibuliformis Hemitoma octoradiata Hemitoma sp. Hipponix antiquatus Hipponix subrufus Hyalina albolineata Hyalina avena Hyalina tenuilabra KBM, + KBM, B, + KBM, B, o, + KBM, b, + KBM, + KBM, B05) KBMS Bi. Ev7/O5nesn Oles GBs Bt Gis 15 ae Olys Wo. dis “s KEM Biy) JRen et B RS CBy JRG + B, D, Morula nodulosa KBM, + B KBMo Be One Xouct ,» infunibuliformis [sic] in F KBM, B, F, x, + B 31 Janthina janthina KBM, + Latirus carniferus RB, KBM, JR, +, carnifera [sic] in B Latirus distinctus y Latirus infundibulum fo) Leucozonia nassa RB, + Leucozonia ocellata KBM, B, + Littorina angulifera KBM, y, + Littorina angustior JC, (KBM, + as L. lineata) Littorina lineolata B, D Littorina meleagris D Littorina nebulosa KBM, y, + Littorina tessellata KBM, + Littorina ziczac KBM, D, + Lucapina suffusa KBM, + Mangelia fusca B, + Marginella gracilis x Melongena melongena KBM, x, + Melongenidae sp. fo) Mitra nodulosa KBM, + Mitra sp. B Modulus modulus KBM, B, f£, + Morula nodulosa see Drupa nodulosa Morum oniscus KBM, o, + Murex dilectus KBM, + Murex pomum KBM, KBM, o, + Murex recurvirostris rubidus KBM, G, GLH, + cf. Murex woodringi KBM, + Nassarius vibex KBM, F, x, + Neosimnia acicularis G3, Nerita fulgurans KBM, D, + Nerita peloronta KBM, D, + Nerita tessellata KBM, D, y, + Nerita versicolor KBM, D, + Neritina virginea DLW, KBM, JR, f, x, y, +, virgines [sic] in F, virginica [sic] in f 32 Nitidella nitida Nitidella sp. 2 Nodilittorina tuberculata Oliva reticularis Olivella petiolita Opalia crenata Opalia pumilio Petaloconchus sp. cf. erectus Pisania pusio Planaxis lineatus Planaxis nucleus Polinices hepaticus Polinices lacteus Prunum gut tatum Psarostola monilifera Purpura patula Risomurex muricoides Risomurex roseus Risomurex sp. Rissoina bryerea Rissoina decussata Rissoina multicostata Smaragdia viridis Strombus gigas Strombus pugilis Strombus raninus Tectarius muricatus Tegula fasciata Thais deltoidea Thais haemastoma, var A Thais haemastoma Thais rustica Tonna maculosa Tricolia adamsi B B KBM, D, + KBM, + DLW, + CB, BB, + B, pumilo [sic] in B Onnex KBM, B, + lactens [sic] in f KBM, JR, + B KBMS Bion KBM Be JR + SRY sea tee Bi in Xs ck KBM, D, + KBMin Bis Reet 35 DIRS Oo GB Bs Diy JR fo) fo) KBM, + DLW, KBM, B, + Tricolia bella KBM, CB, B, F, + Tricolia thalassicola KBM, + Trivia quadripunctata DLW, KBM, JR, + Turritella exoleta KBM, + Vasum muricatum DLW, B, + Vermetidae y Voluta musica DLM, + GASTROPODA: OPISTHOBRANCHIA (by order) Anaspidea Aplysia dactylomela EK, KBM Aplysia parvula KBM Aplysia sp. KBM Bursatella leachii pleii EK, y, KBM Dolabrifera dolabrifera KBM Petalifera ramosa KBM Phyllapylsia engeli KBM Stylocheilus longicauda KBM Cephalaspidea Aglaja evelinae KBM Atys riiseana x Bulla occidentalis KBM, x Bulla striata KBM, f, + Chelidonura spp. KBM Haminoea antillarum x Haminoea elegans KBM Ildica sp. KBM Micromelo undata DS, SW, KBM Sacoglossa Bosellia marcusi KBM Bosellia memetica KBM Caliphylla mediterranea KBM 34 Cyerce antillarum Elysia ornata Elysia papillosa Elysia picta Elysia tuca Lobiger souverbii Oxynoe antillarum Placida dendritica Phyllobranchillus sp. Stiliger sp. Tridachia crispata Notaspidea Berthella tupala Berthellina quadridens Pleurobranchus areolatus Nudibranchia Aegires sublaevis Aphelodoris antillensis Berghia coerulescens Berghia creutzbergi Bornella calcarata Cadlina rumia Catriona tina Chromodoris clenchi Chromodoris kempfi Chromodoris sp. Coryphella dushia Dendrodoris krebsii Discodoris evelinae Discodoris mortenseni Dondice occidentalis KBM KBM KBM KBM KBM KBM KBM KBM KBM KBM KBM, + 35 Doriopsilla nigrolineata h Doto divae KBM Felimare bayeri h, KBM Glaucus atlanticus KBM Godiva rubolineata KBM Hexabranchus sanguineus h, KBM Hypselodoris ruthae h, KBM Okenia evelinae h, KBM Phidiana lynceus KBM Phyllidiopsis molaensis h Platydoris angustipes h Scyllaea pelagica KBM Spurilla neopolitana KBM Tambja oliva h, KBM Tritonia bayeri KBM Tritonia wellsi KBM GASTROPODA: PULMONATA Melampus coffeus KBM, + BIVALVIA Americardia media x Anodontia pectinata x Anomia simplex DLW, JR, + Arca imbricata It, sl, I, O54 sp Arcopsis adamsi ET, Bao kiseks! Xie Asaphis deflorata KBM, + Barbatia domingensis G3, By = Barbatia tenera BM, B, + Brachidontes modiolus JR Brachidontes citrinus B Brachidontes exustus F, exhustus [sic] in ii, y Brachidontes recurvus B 36 Brachidontes sp. Chama macerophylla Chione cancellata Chlamys imbricata Codakia costata Codakia orbicularis Codakia orbiculata Codakia pectinella Coralliophaga coralliophaga Corbula caribaea Corbula contracta Corbula cubaniana Crassinella martinicensis Crassinella lunulata Crassostrea rhizophorae Crassostrea sp. Ctena orbiculata Cumingia antillarum Cyathodonta semirugosa Diplodonta punctata Diplodonta semiaspera Donax denticulatus Echinochama arcinella Erycina emmonsi Erycina periscopiana Gastrochaena hians Gouldia cerina Gregariella coralliophaga Isognomon alatus Isognomon bicolor Isognomon radiatus Laevicardium laevigatum Lima pellucida Lima scabra Lima scabra form tenera jj KBM, B, + sue 5 Jats! a B B B, F, £, x, (as Ctena insite x B » ts + Lioberus castaneus B Lithophaga antillarum KBM, f, + Lithophaga bisulcata B34 I, i Lithophaga nigra 5 Wo Ie Lucina leucocyma x Lucina pensylvanica B Macoma constricta x Macoma tenta B Modiolus americanus KBM, B, + Musculus lateralis JR, £, + Ostrea equestris DLW, JR, + Phacoides muricatus x Phacoides pectinatus KBM, CB, B, F, ii, + Pinctada radiata KBM, B, F, + Pinna carnea JR, + Pseudochama arcinella B Pteria colymbus DLW, KBM, JR, + Sphenia antillensis B, + Spondylus americanus SW Solemya sp. aff. occidentalis x Strigilla sp. Tellina alternata Li Tellina exerythra x Tellina fausta DLW, JR, £, x, + Tellina listeri x Tellina nitens x Tellina promera ii Tellina versicolor x Tellina vespusiana x Teredo sp. ¥ Trachycardium muricatum DLW, + Venericardia sp. aff. tridentata x CEPHALOPODA Octopus sp. E75, K 38 ECTOPROCTA (BRYOZOA) Arborella dichotoma JDeet Bugula sp. y Caberea carabaoda JD eet Caulibugula dendrograpta SDS se Celleporaria albirostris IDS ae Chlidonia pyriformis JD Gemillipora sp. y Gemelliporidra multilamellosa JD eeaaeect Lichenopora buskiana JID, Retoporelliria evelinae JD Steganoporella magnilabris IDF alate Stylopoma informata IDE Trematooecia aviculifera JD; aay + Trematooecia turrita JD, 225 Tubucellaria cereoides JD, + BRACH LOPODA Discinisca strigata B, + (specimen in collection from Pacific) ECHINODERMATA (by class) ECHLNOLDEA Arbacia punctulata DLM, + Brissopsis elongata DLM, + Brissus unicolor DEMG) Bis Bi7iGy Kemet Diadema antillarum B, B74, E75, E76, Ky) (Ol vane Echinometra lucunter NVA VSG NIA s Ms Og 3 39 Echinometra viridis B, E74, E75, E/6, k, o Echinoneus cyclostomus B, E76, k, + Eucidaris tribuloides DLM, B, E/6, k, 0, y, + Halodeima floridana x Lytechinus variegatus DLM, B, E74, E75, E76, k, 0, p, x Yor Lytechinus williamsi DIM, + Meoma ventricosa DLM, + Paraster floridiensis DLM, E76, k, + Plagiobrissus grandis DIM, + Tripneustes ventricosus DLM, E76, k, v, x, +, T. esculentus in B ASTEROLIDEA Ophidiaster guildingii B Oreaster reticulatus DLM, B, + OPHIUROLDEA Amphiodia repens B Amphiodia sp. L B Amphipholis sp. A B Amphipholis sp. B Amphipholis gracillima x Amphiura (Monamphiura) sp. B Amphiura (Nullamphiura) sp. B Axiognathus squamata B Ophiactis savignyi DLM, B, x, + Ophiocantha ophiactoides B Ophiocoma echinata DIM, B, + Ophiocoma pumila DLM, B, + Ophiocoma sp. y/ Ophiocoma wendti DIM, B, + Ophioderma appressum DIM, B, y, + 40 Ophioderma brevicaudum DIM, BS Ophioderma brevispinum DLM, B, + Ophioderma cinereum DIM, Bo-+ Ophioderma rubicundum DLM, + Ophiolepis paucispina DEM, Bite Ophiomyxa flaccida DIM, + Ophionereis reticulata DEM, B, + Ophiothrix angulata DLM, B, + Ophiothrix cf. lineata DLM, + Ophiothrix suensonii DLM, + Ophiozona impressa DLM, + Ophiozonoida (?) sp. B (this may be new genus; EK, pers. comm.) CRINOIDEA Comactinia echinoptera DLM Comactinia echinoptera: cf. var. valida cc Comactinia echinoptera ci. var. meridionalis cc Comactinia meridionalis DLM, + Nemaster rubiginosa cc Nemaster discoidea cc HOLOTHUROIDEA Euapta lappa JC Holothuriid sp. JC CHORDATA ASCIDICEA Ascidia interrupta DS 41 Clavelina sp. y Clavelina picta RHM Cystodytes dellechiajei RHM Didemnum spp. DS Didemnum sp. B RHM Didemnum sp. C RHM Didemnum sp. D RHM ? Didemum sp. E RHM Distaplia (? bermudensis) RHM Ecteinascidia conklini var. minuta DS Ecteinascidia turbinata RHM Eudistoma sp. A RHM Eudistoma sp. B RHM Pyrua vittata DS Polysyncraton (? amethysteum) RHM Rhopalaea abdominalis RHM Trididemnum cyanophorum (= T. solidum) RHM, RO, v, w Trididemum sp. A RHM NOTE: RHM identifications are provisional. ACKNOWLEDGMENTS We thank the following people for their assistance in preparing this species inventory: Victoria Batista, Charles Birkeland, Edwin Bourget, Leo Buss, Roy Caldwell, Hugh Dingle, Kristian Fauchald, Joan Ferraris, Robert H. Gore, Eugene Kaplan, Arilla Kourany, Haris Lessios, David Meyer, Kaniaulono Meyer, Randy Olson, James Porter, Klaus Ruetzler, Michael Robinson, Argelis Roman, Joseph Rosewater, Kenneth Sebens, Stephen Shuster, Richard Steger, and Janie Wulff. This study was supported by the Smithsonian Institution Environmental Sciences Program and the Smithsonian Tropical Research Institute. 42 LITERATURE CITED Abele, Lawrence G. 1972. A review of the genus Ambidexter (Crustacea: Decapoda: Processidae) in Panama. Bull. Mar. Sci., 22(2): 365-380. Abrams, Peter A. 1976. Field guide to the hermit crabs of Galeta and vicinity. Smithsonian Tropical Research Institute. 4 p. (with subsequent revisions by PAA) unpubl. Batista, Victoria. 1980. Estudio de las comunidades que habitan las raices del mangle rojo Rhizophora mangle L. de Punta Galeta, Costa Atlantica de Panama. Dissertation. Fundacion Universidad de Bogota Jorge Tadeo Lozano, Bogota, Colombia. Bertsch, Hans. 1975a. Distributional and anatomical observations of Berthella tupala (Opisthobranchia: Notaspidea). The Nautilus, 89(4): 124-126. Bertsch, Hans. 1975b. Additional data for two dorid nudibranchs from the southern Caribbean seas. The Veliger, 17(4): 416-417. Birkeland, Charles. 1974. The effect of wave action on the population dynamics of Gorgonia ventalina Linnaeus. Studies in Tropical Oceanography, 12: 115-126. Birkeland, Charles, Amada A. Reimer and Joyce Redemske Young. 1976. Survey of marine communities in Panama and experiments with oil. EPA-600/3-76-028, National Technical Information Service, Springfield, VA 22161. Brattegard, Torleiv. 1974. Mysidacea from shallow water on the Caribbean coast of Panama. Sarsia, 57: 87-108. Caldwell, Gloria S. 1981. Attraction to tropical mixed-species heron flocks: proximate mechanism and consequences. Behavioral Ecology and Sociobiology, 8: 99-103. Child, C. Allan. 1979. Shallow-water Pycnogonida of the Isthmus of Panama and the coasts of Middle America. Smithsonian Contributions to Zoology, 293: 1-86. Connell, J. H. 1978. Diversity in tropical rain forests and coral reefs. Science, 199: 1302-1310. FAO. 1969. Symposium on investigations and resources of the Caribbean Sea and adjacent regions. FAO Fisheries Report No. 71.1. Fauchald, Kristian. 1977. Polychaetes from intertidal areas in Panama, with a review of previous shallow-water records. Smithsonian Contributions to Zoology, 221: 1-81. 43 Gore, Robert H. 1976. Shallow water porcelain crabs from the Pacific coast of Panama and adjacent Caribbean waters (Crustacea: Anomura: Porcellanidae). Smithsonian Contributions to Zoology, 237: 1-30. Gore, Robert H. 1977. Neopisosoma angustifrons (Benedict, 1901): The complete larval development under laboratory conditions, with notes on larvae of the related genus Pachycheles (Decapoda Anonura, Porcellanidae). Crustaceana, 33(3): 284-300. Gore, Robert H. and Lawrence G. Abele. 1973. Three new species of Porcellanid crabs (Crustacea, Decapoda, Porcellanidae) from the Bay of Panama and adjacent Caribbean waters. Bull. Mar. Sci., 23(3): 559-573. Hendler, Gordon. 1977. The differential effects on seasonal stress and predation of the stability of reef-flat echinoid populations. Proceedings, Third International Coral Reef Symposium, Rosenstiel School of Marine and Atmospheric Science, Univ. of Miami, Fl 33149, pp. 217-223. Henry, D. P., and P. A. McLaughlin. 1975. The barnacles of the Balanus amphitrite complex (Cirripedia, Thoracica). Zoologische Verhandelingen, 141: 1-254, + 22 plates. Jackson, J. B. 1973. The ecology of molluscs of Thalassia communities, Jamaica, West Indies. I. Distribution, environmental physiology, and ecology of common shallow-water species. Bulletin of Marine Science, 23: 313-350. Koehl, M. A. R. 1977. Water flow and the morphology of zoanthid colonies. Proceedings, Third International Coral Reef Symposiun, Rosenstiel School of Marine and Atmospheric Science, Univ. of Miami, FL 33149, pp. 437-444. Lasker, Howard R. 1979. Light dependent activity patterns among reef corals: Montastrea cavernosa. Biol. Bull., 156: 196-211. Lawrence, John M. 1976. Covering response in sea urchins. Nature, 262: 490-491. Lehman, John T. and James W. Porter. 1973. Chemical activation of feeding in the Caribbean reef-building coral Montastrea cavernosa. Biol. Bull., 145: 140-149. Macintyre, I. G. and P. W. Glynn. 1976. Evolution of modern Caribbean fringing reef, Galeta Point, Panama. Am. Assoc. Petrol. Geol. Bull., 60(7): 1054-1072. Meyer, D. L. 1973. Feeding behavior and ecology of shallow-water unstalked crinoids (Echinodermata) in the Caribbean Sea. Mar. BOs, 225 WOst2s)- 44 Meyer, Kaniaulono B. 1977. Dorid nudibranchs of the Caribbean coast of the Panama Canal Zone. Bull. Mar. Sci., 27(2): 299-307. Neumann, €. J., G. W. Cry, E. L. Caso, B. R. Jarvinen. 1978. ‘Tropical! cyclones of the North Atlantic Ocean, 1871-1977. U.S. Department of Commerce, NOAA, National Weather Service, Environmental Data Service. Olson, Randy. 1979. An ecological investigation of Trididemnum cyanophorum (Lafargue and Duclaux, 1979): a compound tunicate with symbiotic algae. STRI Short-term Fellowship Unpublished Report. Porter, James W. 1972. Ecology and species diversity of coral reefs on opposite sides of the isthmus of Panama. Bull. Biol. Soc. Wash., 2: 89-116. Powell, N. A. 1971. The marine bryozoa near the Panama Canal. Bull. Mar. Sci., 21(3): 766-778. Reimer, Amada A. 1975. Effects of crude oil on the feeding behavior of the zoanthid Palythoa variabilis. Environ. Physiol. Biochem., 5): 258-206). Ruetzler, K., and W. Sterrer. 1970. Damage observed in tropical communities along the Atlantic seaboard of Panama. BioScience, 20: 222-224. Sebens, Kenneth P. 1976. The ecology of Caribbean sea anemones in Panama: utilization of space on a coral reef. In G. O. Mackie (ed.), Coelenterate Ecology and Behavior, Plenum Pub. Corp., New York, ‘pp. 67-77. Sebens, Kenneth P. 1977. Autotropic and heterotropic nutrition of coral reef zoanthids. Proceedings, Third International Coral Reef Symposium, Rosenstiel School of Marine and Atmospheric Science, Univ. of Miami, FL 33149, pp. 397-404. Sebens, Kenneth P. 1982. Intertidal distribution of zoanthids on the Caribbean coast of Panama: Effects of predation and desiccation. Bulletin of Marine Science, 321: 316-335. Sebens, K. P. and K. DeRiemer. 1977. Diel cycles of expansion and contraction in coral reef Anthozoans. Mar. Biol., 43: 247-256. Smith, Ralph I. and James T. Carlton (eds.). 1975. Light's Manual: Intertidal Invertebrates of the Central California Coast, 3d ed. Univ. of California Press. 716 p. Smithsonian Institution Environmental Sciences Program. 1974. Environmental Monitoring and Baseline Data 1973. Tropical Studies. Roberta W. Rubinoff (ed.). Smithsonian Institution, Washington, DC. 45 Smithsonian Institution Environmental Sciences Program. 1975. Environmental Monitoring and Baseline Data 1974. Tropical Studies. Donald M. Windsor (ed.). Smithsonian Institution, Washington, DC. Smithsonian Institution Environmental Sciences Program. 1976. Environmental Monitoring and Baseline Data 1975. Tropical Studies. Donald M. Windsor (ed.). Smithsonian Institution, Washington, DC. Smithsonian Institution Environmental Sciences Program. 1977. Environmental Monitoring and Baseline Data 1976. Tropical Studies. Donald M. Windsor (ed.). Smithsonian Institution, Washington, DC. Smith, Wayne L. 1973. Record of a fish associated with a Caribbean sea anemone. Copeia, 1973(3): 597-598. Southward, A. J. 1975. Intertidal and shallow water Cirripedia of the Caribbean. Studies on the fauna of Curacao and other Caribbean islands, 46: 1-53. Southward, A. J., and W. A. Newman. 1977. Aspects of the ecology and biogeography of the intertidal and shallow-water balanomorph cirripedia of the Caribbean and adjacent sea-areas. FAO Fisheries Reports, 200: 407-425. Spivey, H. R. 1976. The Cirripeds of the Panama Canal. Corrosion and Marine-fouling, 1: 43-50. UNEP (United Nations Environment Programme). 1981. Intergovernmental meeting on the action plan for the Caribbean Environment Programme. Report of the meeting. UNEP/CEPAL/IG.27/3. Vasquez—Montoya, Rafael. 1979. Peuplements des herbiers de Thalassia testudinum et d'Halodule sp. de la Cote Caraibe de Panama. Ph.D. These. A. L'Université D'Aix-Marseille II. 40 p. + Appendices. Yee, Gloria B. de and Carmen Chang. 1978. Mortalidad de los Erizos en la Costa Atlantica de Panama. ConCiencia, 5(1): 7-8. ATOLL RESEARCH BULLETIN No- 270 HERMATYPIC CORAL DIVERSITY AND REEF ZONATION AT CAYOS ARCAS, CAMPECHE, GULF OF MEXICO BY TERENCE M- FARRELL, CHRISTOPHER F- D’ELIA, LAWRENCE LUBBERS, III, AND LAWRENCE J- PASTOR, JR- ISSUED BY THE SMITHSONIAN INSTITUTION WASHINGTON, D- C-, U-S-A.- SEPTEMBER 1983 *sqoesuezq Adaans pue seorzy sokeDd JO uoT,eSOT ‘“T “ht wy l eee Cera | OOE€ OSI O I861 3,210G YVA 3 Of ,8S ol6 & N ,SS 21 002 sepit Buludg Mo7 oe je JuDHsawyz — HERMATYPIC CORAL DIVERSITY AND REEF ZONATION AT CAYOS ARCAS, CAMPECHE, GULF OF MEXICO by Terence M. Farrell!/3, Christopher F. Deal, Lawrence Lubbers, eseae U and Lawrence J. Pastor, Jr.274 ‘Abstract Ecological features of emergent coral reefs in the Campeche Bank region of the Gulf of Mexico are not well described. In a study of reef zonation and diversity of CayosS Arcas, the most southerly of these, the coral reefs surrounding three sand cays were found to exhibit a greater diversity of scleractinian coral species than has been reported previously for the Campeche Bank region. Hermatypic coral coverage was high and coral growth appeared vigorous. However, calcareous algae of the genus Halimeda, that are known to be abundant and therefore important producers of calcareous material in emergent reef structures to the north, were not evident. Noteworthy aspects of reef zonation included: 1) a non-emergent reef crest composed of unconsolidated coral rubble and encrusting calcareous algae, but no algal ridge, 2) extensive monospecific stands of Acropora cervicornts on the shallow reef flats, 3) proliferation of Acropora palmata at depths where one might typically find Acropora cervicornis in other localities, and 4) poor representation and coverage by species of the genus Agartcta. This zonation and the component species" growth forms suggest that high energy wave action is an important environmental factor determining community structure. Introduction Relatively few published reports relate to the species composition and ecology of recent bioherms in the Gulf of Mexico. One reason for this is that the Gulf of Mexico does not contain extensive areas of coral reef. Nonetheless, in addition to the reefs off of Veracruz (Smith, 1954) there are six well developed emergent reef structures in the Campeche Bank region off of the western shore of the Yucat4n Peninsula (Glynn, 1973; Logan, 1969). The largest and most northerly of these is Alacran Atoll which has been the site of several geologically oriented studies (Hoskin, 1963; Kornicker et al., 1959; Kornicker and Boyd, 1962; Folk, 1967). The others are less well known, but have been 1Chesapeake Biological Laboratory, Center for Environmental and Estuarine Studies, University of Maryland, Solomons, Maryland 20688-0038. 2Virginia Institute of Marine Science, Gloucester Point, Virginia 23062 3Present Address: Zoology Department, Oregon State University 97331 4present Address: Water Chemistry Division, Geomet Technologies, Inc., Environmental Consultants, 520 Eroadhallow Road, Melville, New York 11747 Contribution No. 1377. Center for Environmental and Estuarine Studies of the University of Maryland. Manuscript received Jan. 1983--Eds. described to some extent (Agassiz, 1888; Logan et al., 1969). We visited on two occasions the most southerly of the Campeche reef structures, Cayos Arcas. The cays comprising this structure are at the northern boundary of Mexico's offshore petroleum resources, and a deepwater oil terminal has been built in the sheltered waters south of the cays since our last visit (Orme, 1982). In the course of performing an environmental survey focusing on reef development and zonation, we found well-developed reefs with greater diversity of hermatypic corals than has been reported previously for the Campeche Bank region. In the present paper we document and discuss these and other relevant ecological observations. Study Site Cayos Arcas consists of three coral and sand cays on a shallow water platform about 3 to 4 sq. km. in area which rises above the Campeche Bank west of the Yucat&n Peninsula, Mexico (Fig. 1). Water depth around the cays is about 40 m. The cays envelop a small, protected lagoon that is a popular refuge for local shrimp and shark fisherman located at 91° 58'30"E long. and 20° 12'55"N lat., about 300 km SW of Alacran Atoll. Logan et al. (1969) and Ginsbu:rg and James (1974) have characterized Cayos Arcas and neighboring reefs and cays as isolated praminences capped by zoned reefs at the shelf margin. Kornicker and Boyd (1962) have described the geological origin of the Campeche Bank as an “underwater extension of the Yucatan Peninsula... [that is] probably Miocene limestone" with a thin cover of Pleistocene and Recent calcareous sediments. Campeche Bank reefs have apparently been able to keep pace with the Holocene transgression; this implies that reef accretion there occurred at the substantial rate of 20 to 40m during the last 9,000 years (Logan, 1969) or perhaps faster: more recently Mcintyre et al. (1977) proposed that Yucatdn reefs have approached the emergent-reef status within the last 2,000 to 3,000 yrs. In any case, it is clear that accretion is rapid on the Yucatan reefs. Easterly to northeasterly trade winds prevail and probably account for the typical northwest trend of arcuate windward reef margin characterizing Cayo del Centro (Fig. 1). Such reef orientation has been reported for other bioherms on the Campeche Bank (Kornicker and Boyd, 1962; Folk, 1967). Fram April to September, winds in the area are lighter and more variable (20 to 30 km/hr) than they are from October to March when speeds of 30 to 35 km/hr are cammon and are often associated with cold fronts or "northers" (Folk, 1967). Hurricanes are not uncommon to the area, Hurricane Allen having passed several hundred km to the north of Cayos Arcas several months before we performed our Survey- The tidal range is small (~1.0 m). We do not have mean minimum water temperature for Cayos Arcas; however, we suspect it is between 20° and 22° C, close to those reported for nearby Veracruz and Progresso, Mexico (Milliman, 1973) and by the U. S. Fish and Wildlife Service (1954). Thus reefs at Cayos Arcas probably experience mean minimum temperatures near 21°C, below which optimal reef development does not occur (Milliman, 1973). Glynn (1973) reports that the thermal climate of the reefs on the margin of the Campeche Bank is probably more favorable than it is closer to shore, citing the suggestion of Logan et al. (1969) that the absence of coral reefs on the eastern sector of the shelf is due to the periodic upwelling of cold water there. Surveys of the coral community were carried out by skin and SCUBA diving. We used a transect method keyed to changes in depth and distance offshore and selected a major topographical feature, i.e., beach, reef crest, deep trench as a benchmark for the starting point for a compass bearing traversing various zones of the benthic community. We chose the transects as being generally representative of reef zonation at Cayos Arcas. A check list of the most abundant sessile invertebrates (primarily hermatypic corals) was developed after an intensive survey of the first transect. At this site a 30 m long chain marked at one meter intervals was laid on the bottom starting at the reef crest and moving towards deep water. We noted species composition and dominance within ten meters of this chain and estimated the total percent living coverage, depth in meters and any significant changes in topography or coral composition with distance from the starting point. Aerial photographs of the transects taken from a helicopter at an altitude of about 200 m were used to confirm our estimates of percent coverage and the representativeness of the transects chosen. Results Table 1 gives a summary list including all coral species identified in all five transects during our study. The list contains 20 species we identified and 5 species we suspect were present and is certainly indicative of the most common corals in the shallower (<20 m) zones of the reef. Had the study lasted longer and extended to deeper areas, more species would undoubtedly have been found (see Discussion). In fact, it would be surprising if species reported by Smith (1954) to be present off Veracruz are not also present at Cayos Arcas (Table 1). Observations along transects were completed at 5 locations (Figure 1). These data have been summarized in graphic form (Figure 2). The most developed reef at Cayos Arcas, in terms of physical structure and coral coverage, occurs as a three kilometer long, arcuate structure to the northwest of the central cay (Figure 1). This reef can be seen in the upper right portion of Plate 1, an aerial photograph viewing Cayos Arcas from the southeast. We investigated reef flat and lagoonal areas of this reef in Transect 2. Transect 1 encompassed the reef crest and fore reef of a nearby section of reef that was similar in physical and biological structure to the fore reef area along arcuate reef face (Plate 2). Taken together Transect 2 and the fore reef section of Transect 1 provide a good picture of the main biological and structural zones occurring on the major Cayos Arcas reef. The most obvious feature of the reef was an extensive reef flat, over 100 meters wide, almost completely covered by a dense, monospecific stand of Acropora cervicornis. To the lee of this stand the bottom gradually sloped from less than one meter to three meters. On this slope a more diverse assemblage of hermatypic corals existed (predominantly members of the genera Acropora, Montastrea, and Diploria), in which substratum coverage ranged fran 20-60% and decreased with distance from the reef flat. This back reef area gave way to sandy substrata in the lagoon that harbored numerous patch reefs not crossed by the transect. To the windward side of the reef flat a small, non-emergent reef crest existed. The crest was composed of unconsolidated coral rubble encrusted with calcareous red algae. No true algal ridge was present. On the forereef the zoanthids Palythoa caribbea and Zoanthus sociatus were the daminant epibenthic fauna between one and three meters. Below this zoanthid zone, at depths between three and seven meters, Acropora palmata was the dominant scleractinian, covering nearly 75% of the substratum (Plate 3). Massive corals, dominantly the genera Montastrea and Diplorta and gorgonians were abundant below seven meters (Plates 4 and 5) in a diverse community extending to approximately 350 meters fram the crest, and to a depth of 18 meters where sand substratum was again encountered. To the lee of the reef crest in Transect 1 the reef flat was absent and the back reef area consisted of a shallow (one meter) expanse of sandy substratum in front of the largest cay, in which scleractinians were scarce. Transect 3 crossed a nearby, small, protected reef. Its zonation pattern was very similar to the previously discussed larger, exposed reef but it lacked a reef crest and its zonation was both horizontally and vertically compressed. The remaining two transects were completed at each end of the largest reef. Transect 4, located at the more protected southern end, displayed zonation that was similar to the exposed forereef, except that it was horizontally compressed so that the Montastrea - Diplorta canmunity occurred in water several meters shallower than it did on the windward face of the reef. Transect 5, located at the northwestern end of the reef, traversed an eight meter deep channel that curved around the edge of the reef flat. In this channel the bottom was composed of unconsolidated coral rubble and sediment. The face on the far side of the channel rose to within three meters of the surface. Benthic cover on top of this rise was daminated by the zoanthid Palythoa cartbbea. Species distributions on this crest and the slope beyond it were similar to those seen on the exposed reef face. However, the slope was more gradual and coral coverage was more extensive. Substratum coverage was 70 to 90% beyond 500 m at a depth of 20 m.- Here was one of the few places we observed extensive growth of Acropora cervicornis below three m depth: a 30 m wide stand occurred at 8 m depth. 5 Four transects were located on the large arcuate reef. From these transects and less detailed observations made from a helicopter, the distribution of major reef zones on the reef have been mapped (Figure 3). Discussion The hermatypic scleractinian coral diversity of Cayos Arcas consists of at least 20 species from 13 genera. This diversity is greater than is believed to exist off Veracruz or has been reported for Alacran Reef: for the former there are records of 14 to 16 species and for the latter there are records of 18 species (Glynn, 1973). Given the geographical isolation of this site, this diversity seems surprisingly high, but is not, of course, as high as has been recorded in Jamaica (Wells, 1973), in Curacao (Bak, 1974; cited in Loya, 1976), in Cuba (Zlantarzsky, cited in Loya, 1976), in Belize (Cairns, 1982), and on the Atlantic coast of Panama (Porter, 1972). Relatively little is known about reefs in the southern Gulf of Mexico, but we believe that nearshore turbid water conditions and a lack of suitable substratum affect growth; it is also likely that minimum winter temperatures are close to the lower limits at which extensive reef growth may occur, especially near the coast where occasional upwelling is believed to occur (cf. Logan et al., 1969). It is possible that seasonal temperature lows exclude species unable to tolerate them; however, the presence of species of the genus Acropora, which are unable to tolerate the colder temperatues encountered in Bermuda, indicates that minimum temperatures are considerably higher than in Bermuda. Our field work was most extensive in shallow water; additional study in deeper waters could most probably increase the number of species found. Loya (1976) has discussed the increase in known species richness which occurred with increasing study in other areas. Logan (1969), who made the only published ecological observations on Cayos Arcas that we encountered, made generally similar observations to ours about community structure. However, Logan (1969) did not report seeing the presence of a very dense monospecific stand of Acropora ecervicornts on the shallow reef flat as we note here. Similar zonation is also found off Belize (Cairns, 1982) and off the east coast of the Yucatan peninsula (W. Adey, J. W. Porter, pers. comm.). There is no doubt that Logan (1969) would have recognized and cammented on that impressive stand of Acropora had it been present during his study. We cannot explain this difference, but suspect that a real change in community structure occurred in the interim. Neither we nor Logan (1969) observed calcareous green algae of the genus Halimeda- This observation was unexpected as Halimeda is extremely common on the nearby Alacran reef (Hoskin, 1963; Kornicker and Boyd, 1962). We searched for this coralline algae but did not encounter living Halimeda nor obvious skeletal remains. however, we were unable to examine sediments microscopically to verify our field observations. Haltmeda is the dominant producer of carbonate sediments on a reef off 6 Belize (Wallace et al., 1977) and presumably Alacran (Hoskin, 1963). Its absence at Cayos Arcas may result in lowered rates of calcium carbonate deposition. High wave energy levels may account for some of the species distributions observed on these reefs (Logan, 1969). The depth to which the forereef Palythoa and Acropora palmata dominated zones extended, and the lack of Acropora cervicornis and members of the genus Agaricia on the forereef is probably a result of intense wave action during storms. In backreef areas, where lower wave intensities predominate, the zonation was compressed so that the coral-head communities existed closer to the water surface. Our observations indicate that well developed reef communities exist at Cayos Arcas. These communities contain the most diverse hermatypic coral assemblage found to date on the western Yucatan shelf. Further investigation will be necessary to determine if this apparent difference in diversity is real or due to the limited study most other locations in this region have received. However, we suspect that coral diversity throughout the area is richer than it is generally perceived to be. A continuing environmental monitoring program was instituted before the construction of the oil terminal, and further studies to assess the ecological impact of the facility have been discussed by Orme (1982). References Agassiz, A. 1888. Three cruises of the U. S. Coast and Geodetic Steamer "Blake": Harv. Mus. Comp. Zool., 14:70-73. Cairns, S.- De 1982. Stony corals of Carrie Bow Cay, Belize, pp. 271-302. In: Rutzler, K., and I. G. Macintyre, eds., The Atlantic Barrier Reef Ecosystem at Carrie Bow Cay, Belize, I. Structure and communitteg. Smithsonian Institution Press. Washington, D.C. BOK ie een lars 1967. Sand cays of Alacran Reef, Yucatan, Mexico: Morphology- J, Geol. 75:412-437. Ginsburg, R. N-, and James, N.- Pe 1974. Spectrum of Holocene reef-building communities in the Western Atlantic. Section 7 of "Prinetples of Benthie Comminity Analysts," Zeigler, A. M., Ks. Re Walker, E. J. Anderson, E- G. Kaufman, R. N. Ginsburg, and N. P. James, contributors. Div. of Mar. Geol. Geophys. RSMAS. University of Miami, Fla. Glynn, P. W. 1973. Aspects of the ecology of coral reefs in the Western Atlantic region, pp. 271-324. In: Jones, O. A., and Re Endean, eds., Biology and Geology of Coral Reefs, Vol. II., Academic, N.Y. Hoskin, G. M- 1963. Recent carbonate sedimentation on Alacran Reef, Yucatan, Mexico, NAS-NRC. Publ. 1089:1-160. Kornicker, L. S., and Boyd, D. We 1962. Shallow water geology and environments of Alacran reef complex, Campeche Bank, Mexico. Am. Assoe. Petrol. Geol. Bull. 46:640-673. Kornicker, L. S., Bonet, F., Cann, Re, and Hoskin, C. M. 1959. Alacran Reef, Campeche Bank, Mexico. Univ. Texas Publ. Inst. Mar. Sct. 6:1-22. Logan, B- We 1969. Coral reefs and banks: Yucatan shelf, Mexico. Mem., Am. Assoc. Petrol. Geol. 11:129-198. Logan, B. W., Harding, J-e Le, Ahr, We Me, Williams, J. D., and Snead, R. G. 1969. Carbonate sediments on reefs, Yucatan shelf, Mexico, Part I, Late Quaternary sediments. Mem., Am. Assoc. Petrol. Geol. 11:1-128. Loya, Y. 1976. Effects of turbidity and sedimentation on the community structure of Puerto Rican corals. Bull. Mar. Set. 26:450-466. Macintyre, I. G., Burke, Ro Be, and Stuckenrath, R. 1977. MThickest recorded Holocene reef section, Isla Perez core hole, Alacran Reef, Mexico, Geology. 5:749-754. Milliman, J. D. 1973. Caribbean coral reefs, pp. 1-50. In: Jones, O. A., and R. Endean, eds., Biology and Geology of Coral Reefs, Vol. I- Academic, N.Y. Orme, We A., Jr- Cayo Arcas: New Oil Port 70 Miles Offshore. R & D Mextco. Vol. 2, Noe 11:22-25. Porter, J. W. 1972. Patterns of species diversity in Caribbean reef corals. Ecology 53:745-748. Smith, F. G. W. 1954. Gulf of Mexico Madreporaria. U. S. Dept. Fish and Wildlife Serv. Fish. Bull. 89:291-295. U. Se Fish and Wildlife Service. 1954. Gulf of Mexico: its origin, | waters, and marine life. Fishery Bulletin of the Fish and Wildlife Service, Vol. 55. Wallace, R. J., and Shafersman, S.- D. 1977. Patch Reef Ecology and Sedimentology of Glovers Reef Atoll, Belize.--In Reef and Related Carbonates--Ecology and Sedimentology, Edited by S. H. Frost, M. P. Weiss and J. B. Saunders. Published by the American Assoc. of Petroleum Geologists. Tulsa, Oklahoma. pp. 37-52. Wells, J. W. 1973. New and old scleractinian corals from Jamaica. Bull. Mar. Set. 23:16-58. Table 1. Hermatypic scleractinian coral species occurring at Cayos Arcas. "?" indicates probable identification. '"*" indicates species reported found at Cayos Arcas by Logan et al. (1969) that we did not encounter. Species in parentheses were reported present at Veracruz by Smith (1954) are probably also present, but we did not observe them at Cayos Arcas in our survey. Suborder Astrocoeniida Family Pocilloporidae Madracis decactis Family Acroporidae Acropora palmata Acropora cervicornts Suborder Fungiida Family Agariciidae Agaricta agaricites Family Siderastreidae Siderastrea siderea Siderastrea radtans Family Poritidae Porites asterotdes Porites porttes (Porites furcata) Suborder Faviida Family Faviidae Favta fragun Diplorta eltvosa Diploria labyrinthiformts Diploria strigosa Colpophyllta natans Colpophyllia brevisertalis Montastrea annularts Montastrea cavernosa Solenastrea sp-* Manietna areolata (Cladoeora arbuscula ) Family Meandrinidae Meandrina meandrites Diehoecoenia strokest ? Family Mussidae Mussa angulosa Mycetophyllta lamarekiana Family Oculinida (Oculina diffusa ) Suborder Caryophylliina Family Caryophylliidea Eusmilta fastigtata DEPTH (meters) TRANSECT 1 Palythoa al Sand/Rubble tn, palmata—>| Montastrea-Diploria——\>|+ Sand/Rubble— 12 18) TRANSECT 2 ; |-——A. cervicornis ——~|=~—— Montastrea—Dipioria —~l<- Sand/Rubble —> 3 100 200 300 400 TRANSECT 3 A. cervicornis Palythoa |Montastrea-Diploria}~—l ++ 1 1p. paimata|<—-Montastrea-Dipioria—>| 0 3 6 9 12 15 TRANSECT 4 Palythoa-A. cervicornis |sand/Rubbiel-—_! —-| Montastrea—Diptoria |<— Sand/Rubble 200 300 100 100 200 300 400 12 TRANSECT 5 Montastrea-Diploria | Montastrea-Diploria Serafsbiele! la Palythoa-A. paimata A. cervicornis |<—Montastrea-Diploria——> METERS Fig. 2. Transect profiles at Cayos Arcas. meee ) Ye ae ihe: (eigan JB409) ySaID yaoy OP ale ), Esueuipagresoo7 || Aerial view of the Cayos Arcas from the southeast Hae i Uh HH) maligne entral cay and the reef viewed from Plate 2. Aerial photograph of the c the east = Plate 3. Underwater photograph of the Acropora palmata zone on Transet l. Taken at approximately 4 m depth eet EME -v teased oak “ar ween = ete Plate 4. Photograph of the Montastrea-Diploria zone taken in water 10 m deep (Transect 1) Plate 5. Photograph of the Montastrea-Diploria zone taken in water 10 m deep (Transect 1) ATOLL RESEARCH BULLETIN No- 271 CAY SAL BANK, BAHAMAS: A BIOLOGICALLY IMPOVERISHED, PHYSICALLY CONTROLLED ENVIRONMENT BY WALTER M-GOLDBERG ISSUED BY THE SMITHSONIAN INSTITUTION WASHINGTON, D- C-, U-S-A- SHRP MBE Rwend63 CAY SAL BANK, BAHAMAS: A BIOLOGICALLY IMPOVERISHED PHYSICALLY CONTROLLED ENVIRONMENT by Walter M. galdeeres- ABSTRACT Cay Sal Bank is a shallow water, oceanic platform whose lagoonal surface is 9-l6m below sea level. Benthic communities on the bank are divided into four major zones based upon biotic composition and substrate. These are (1) rubble- Lobophora (2) Sargassum-gorgonian-sponge (3) Halodule and associates and (4) a patchy Thalassia zone. Sediment is largely restricted to the western portion of the lagoon, especially in zone 3. Although occasional patch reefs are noted, the bank lagoon is virtually devoid of coral reefs and coral communities. The submerged, leeward bases of islands and cays represent the principal substrate for the development of scleractinian corals, but these do not appear to form a reef framework. Scleractinian development on the windward sides of the islands is negligible. Patch reefs and spur and groove systems are usually poorly developed on the outer bank slope to depths approaching 30m. The best developed coral communities occur below this depth with the exception of the southwestern sector where reefs are smothered in sediment. The biological structure of the bank lagoon is interpreted as being controlled largely by wind and periodic storm forces that result in frequent resuspension and eventual offbank transport of sediment, especially to the southwest. Cay Sal is not a drowned bank; it is a submerged platform on which biological impoverishment appears to be maintained through disturbance phenomena engendered by an open and poorly developed rim. These stresses prevent establishment of more complex coral reefs or coral communities, and promote domination by fleshy algae and other more tolerant organisms. tpepartment of Biological Sciences, Florida International University, Miami, Florida 33199, U.S.A. (Manuscript received March 1983 - Eds.) INTRODUCTION Cay Sal Bank is a shallow, detached carbonate bank lying roughly 100 km south of the Florida Keys, 54 km north of Cuba and 50 km west of the Great Bahama Bank (Fig. 1). It is 105 km by 66 km in its greatest dimensigns, and constitutes an overall area of nearly 4000 km*. The rim is lined with a scattering of islands and rocks especially along the northern and eastern margins. Over 99 percent of the bank including the southern flank and the entire center are completely submerged, primarily in depths ranging from 9-16m. Few studies have been made of this region in spite of its size and proximity to U.S. coastal waters. Agassiz (1894) visited the bank, briefly describing some of its geomorphic features; a description of the bathymetry of the bank slope (Malloy & Hurley, 1970) and stratigraphic studies from a well drilled to 5766m by Standard Oil Company (Myerhoff & Hatten, 1974) have made more recent contributions to our knowledge of the area. However, descriptions of the marine communities of Cay Sal Bank have apparently not been published. This paper describes the nature and distribution of the shallow-water communities of Cay Sal Bank by aerial and satellite photography, coupled with ship-based bottom truthing by SCUBA observation and dredge sampling. Physical factors including storm tracks and frequency, wind and wave data and sediment depths on the bank lagoon are analyzed and related to community structure. Materials and Methods A total of 18 days were spent on Cay Sal Bank, primarily during the summer months of 1980-1982. Biological observa- tions were made at 97 stations scattered across the shallow lagoon and outer margin to a depth of 60 m (Fig. 2). These consisted of simple visual surveys to confirm composition of the benthos, hand collections assisted by SCUBA, and 5 minute Capetown dredge tows. Samples of all identified materials have been deposited in the FIU museum. All species except as noted were identified by the author. Sediment depths were recorded at 27 stations (1982 only) using a steel probe. Where sediments exceeded a depth of one meter, a 2 1/2 HP water pump was employed to force sea- water through a 5 meter length of PVC pipe. Sediment fluidized in this manner enabled the pipe to quickly penetrate to bedrock. The names of emergent islands used in this paper correspond to those given in British Admiralty Chart No. 1217 (Fig. 2). Coordinate locations have been modified according to more recent data (see appendix). RESULTS a. The Lagoonal Environment The lagoonal surface of the bank can be divided into four major biotic zones (Fig. 3). The northwestern sector with its included sand ridges is characterized by a sparse but consistent cover of seagrasses and algae including Halodule wrightii, Caulerpa spp., Syringodium filiforme and various species of calcareous chlorophytes (Fig. 4A). Members of this community (hereafter referred to as the Halodule community) are summarized in Table l. A denser Halodule community appears to be responsible for several of the large dark patches noted in satellite imagery of this zone. The sediment cover of this quadrant ranges from 2 cm to lm. The deeper sand accumulations occur behind and south of Double Headed Shot Cays, (hereafter referred to as DHS Cays) particularly in association with the intersecting sets of bedforms prominent in the western part of the zone, and those trending NE to SW 20 km to the east. The Halodule zone grades into a sediment-bare, rubble bottom east of Muertos Cays. This northeastern sector is covered by a mixed Sargassum-gorgonian-sponge community. The rubble characteristic of the northeast bank lagoon continues throughout the southeast sector but without as much vegetation. The bottom is covered primarily by a scattering of the brown alga Lobophora variegata, with an occasional cluster of sponges and gorgonians as above. Along the southern and eastern borders of this zone the rubble is interspersed with aggregations of corals, especially Diploria spp., Agaricia agaricites and Montastrea annularis, together with sponges and gorgonians (Fig. 4B). For the most part these do not form patch reefs (i.e., no appreciable relief above bottom). However, two reef areas are encountered along the western edge of this zone as noted in figure 3. One of these near 23°34' and 79°48' consists of numerous but small (1-2m2) Diploria, Porites and Montastrea patches rising lm above the bottom (depth = 7-8m). The most significant patch reef area, several km2 in extent, is located 10 km southwest of Damas Cays. This subzone was characterized by thickets of Acropora cervicornis rising to a depth of 6m from a 10m bottom (Fig. 4C). Scattered colonies of Montastrea annularis, Agaricia agaricites and Colpophyllia natans contribute to the framework. It may be Significant that much of the rubble substrate in this zone ~ consists of what appears to be recent Acropora cervicornis. There is little evidence of recolonization. The last zone consists of a sigmoidally shaped area extending across the bank from Cay Sal to the Damas Cays. This area is characterized by patches of Thalassia testudinum which become somewhat more extensive toward the southwestern (leeward) side. Turtle grass becomes particularly well developed in the lee of larger islands on the bank, especially the Double-Headed Shot Cays and the Anguilla Cays (Fig. 4E). Farther behind the latter group, Thalassia grades into a Halodule-calcareous green algae subzone (Fig. 3). At the edges of this area Thalassia intermingles with other communities. This is particularly notable west of Damas Cays where zonation overlap is extensive (Fig. 3). The Damas Cays area is also notable for the existence of several "blue holes" (Capt. Bob Klein, pers. comm.). One of these located at 23°49'87 and 70°47'28, 2.4 km west of the islands, was briefly investigated. It measures approximately 100m across and 100m deep, beginning on the bank at a depth of 10-13m (surface to bottom = 110-113m). The surrounding area is a Thalassia-gorgonian-sponge bottom, grading into colonies of Montastrea cavernosa and Agaricia agaricites at the edge of the blue hole. The vertical walls are covered with Lobophora variegata to a depth of 18m, below which Halimeda goreauil dominates. Submersible observations at the bottom reveal numerous Strombus gigas shells apparently the result of the animal becoming entrapped while migrating through the surrounding turtle grass (E. Shinn, pers. comm.). A wider and slightly deeper blue hole is located a few km farther west (Fig. 4F). The sediment cover of the Thalassia zone is highly variable. Through most of this region the range is 2-5cm, increasing to 20-60cm under Thalassia itself. Just north of Cay Sal Island in an area covered by a mixed community of scattered angiosperms and calcareous green algae, a sand body 4-4.5 meters deep was encountered (Fig. 4G). The area covered by this accumulation was not determined, but several sediment stations taken around the periphery of Cay Sal indicates that it is highly localized. b. The Bank Rim and Slope The only areas characterized by substantial coral development are the bank slope below 30m and the submerged portions of the islands. Most of the larger cays have been examined and appear to be uniform with regard to their flora and fauna from the littoral zone to the base of the island (Table 1). The sublittoral portions are characterized by an intertidal bench cemented with an unidentified encrusting coralline alga. Immediately below this surge zone, dropping vertically to a depth of 7-8 m, is a coral community consisting of yellow and purple sea fans (Gorgonia ventalina and G. flabellum) plus a variety of other gorgonians, corals and hydrocorals, especially Millepora complanata (Fig. 5A). In general the amount of scleractinian development is greater along the northern border of islands, but only along the lagoonal side where Montastrea annularis, Diploria spp. Siderastrea siderea, Agaricia agaricites and Porites porites become especially numerous (Table I, Fig. 5B). However, the coral communities appear to be insufficiently developed under the best of circumstances to prevent erosion of the underlying substrate. Large blocks of island material are usually found adjacent to the cays and these serve as substratum for additional albeit superficial coral development (Fig. 5C,D). Shallow water coral development along the oceanic side of the islands is not appreciable. Acropora palmata, for example, is found only in isolated pockets (e.g. between Water Cays and some of the Damas Cays. There is no "palmata zone" (cf. Geister, 1977) characteristic of any of the islands. Along the eastern bank there is little difference between exposed. and sheltered sides of the islands with regard to coral development. The same species of coral as noted above form spurs 4m) sand body restricted to the north side of Cay Sal Island. The virtual absence of sediment on the eastern margin and its accumulation toward the southwest suggests active transport. Moreover, the smothering of the outer reef slope coral communities around Cay Sal Island provides evidence that this transport is offbank, as confirmed recently by seismic profiles (Hine, personal communication). Wind and storm generated flows are likely agents of offbank sediment transport (Hine et al., 1981; Hubbard et al., 1981). Two categories of storms to consider are acute, periodic tropical storms occurring in summer and the more regular, chronic disturbances associated with the passage of winter frontal systems. A chart depicting the approximate path of tropical storm and hurricane systems passing within 100 km of Cay Sal Bank is presented in Figure 8. Although no data are given on storm intensities, 32 cyclonic storms have been noted since 1871, plus an additional 4 tropical depressions. Nine storms or hurricanes have crossed the southeastern bank in the vicinity of the Anguilla Cays, 9 more have crossed (or passed parallel) in an east-west direction, while another 7 crossed the bank near Cay Sal. Given the openness of the bank, severe storms and hurricanes are certain to effect damage, even on deeper reefs (cf. Woodley, 1980). However, the overall importance of tropical storms on Cay Sal is difficult to assess. With an average of 3 storms per decade, Cay Sal is less frequently affected by such systems than the Florida Keys or Little Bahama Bank where an average of 7-8 storms per decade occurs (Neumannisetyall) 1977 ;) Hine, 1977). | During the Last (decade only one hurricane has passed near this area (1981); more- over, the pattern of storm crossings does not correspond with either the degree of community development or the pattern of observed sediment accumulation. The small amount of hydrographic/meteorological informa- tion available for the area is summarized in Figure 9. Winds are principally from the east during most of the year but display a prominent shift to the north and northeast during the winter. This change corresponds with the increase in percent of sea and swell near the bank. The passage of frontal systems from the north and northeast is a reliable and persistent winter phenomenon in this region (U.S. Naval Weather Service Command, 1975) and may account for the following observations. 1) Acropora cervicornis rubble is common in the south- eastern sector of the bank while living colonies are relative- ly uncommon. Storm forces may provide rubble substratum through recurrent cycles of Acropora growth and recovery (Gilmore & Hall, 1976; Tunnicliffe, 1981) followed by storm destruction. The dominance of an unstable rubble substrate in turn reduces the chance of coral survival and recoloni- zation (Goreau, 1959; Stoddart, 1974; Pearson, 1981). 2) The best developed shallow coral communities are on the protected lagoon side of the northern cays; the poorest development is on the unprotected ocean side. The reason for this contrast may be the abrupt transition between shallow and deep water that allows large waves to pound the outside of these cays. For example, a 50 km hr-1 wind from the north or northeast will produce waves at least 3.2 m high (U.S. Army CERC, 1973). Such wind/wave conditions are probably common near Cay Sal (see below). 10 3) A Thalassia zone first noted in 8m depth behind northern Dog Rocks during July, 1981, was replaced by rubble twelve months later. Aerial photographs taken during May, 1982 revealed crescentic "blowout" structures in Thalassia beds behind Water Cays in 8-9m depth (Figs. 6D,E), and north of Cay Sal in similar depths (Fig. 4C). These are known to result from storm damage and indicate the direction of energy propagation (Patriquin, 1975). The blowouts on Cay Sal Bank are concave from the north. Storm-induced bottom currents and wave activity, are capable of considerable sediment resuspension and transport (Hine et al., 1981; Murray et al., 1977) known to be detrimental to coral development (Dodge et al., 1974; Loya, 1976). The amount of transport can be estimated using established relationships (Figs. 3-15, 3-29, 4-20 and 4-21 in U.S. Army CERC, 1977) between wind stress and maximum induced motion on the sea floor (Umax(-d). Northeast and easterly winds near Cay Sal reach speeds of 50 km hr-l, 20-25% of the time during October-April. Winds during the other months approach this speed only 6-12% of the time (U.S. Naval Weather Service Command, 1975). Winds of 50 km hr7! from the east in llm water depth (average lagoon depth) will generate waves 1.4m high, with periods of 4.7 sec and will produce Umax(-d) of 25 cm sec™ -1 on the lagoon floor. This is within the generally accepted range of 15 — 30 cm sec7l required for fine to moderate sized sand grain motion (U.S. Army CERC, 1977; see also G@iscussion in Hine et al., 1981). The principal limitatvon to bottom current generation with easterly winds on Cay Sal is the limited fetch (65 km). However, with winds from the northeast, fetch increases 2 1/2 fold. Thus a 50 km hr7 wind will produce waves 1.6 m high, with periods of 5.2 sec and will produce Umax(-d) of 47 cm sec-l. This figure is well above critical velocity and may account for accumulation of sediment toward the southwest, as well as disturbance to the lagoon and SW bank slope communities. Thus the physical environment of Cay Sal Bank appears to be sufficiently vigorous to produce direct wave stress as well as current-induced sediment stress. These conditions, while by no means unique, combine with the historically derived lack of a protective rim to produce high energy channels into the bank interior. The result is the mainte- nance of a virtually reefless environment. ddl Table 1. Marine plants and invertebrates characteristic of Cay Sal Bank Lagoon. Zones: Halodule, 2 = Thalassia, 3 = Rubble-Lobophora, 4 = Sargassum- gorgonian-sponge, 5 = Island-littoral Angiosperms Halodule wrightii Ascherson Thalassia testudinum Koenig Syringodium filiforme Kutzing Algae Avrainvillea nigricans Decaisne Caulerpa prolifera Lamoroux Caulerpa cupressoides Agardh Cladophora sp. Dasycladus vermicularis Krasser Dictyopteris justii Lamoroux Dictyosphaeria cavernosa Boergesen Dictyota dentata Lamoroux Galaxaura squalida Kjellman Halimeda incrassata Lamoroux Halimeda lacrimosa Howe Halimeda opuntia (Lamoroux) Laurencia papillosa (Forsskal) Lobophora variegata Womersley Microdictyon sp. Padina sanctae-crucis Boergesen Penicillus capitatus Lamarck Penicillus dumetosus (Lamoroux) Penicillus pyriformis Gepp Rhipocephalus phoenix Kutzing Sargassum cymosum Agardh Sargassum hystrix Agardh Sargassum polyceratium Taylor Sargassum vulgare Agardh Stypopodium zonale Papenfuss Turbinaria turbinata Kuntze Udotea spinulosa Howe Sponges Anthosigmella varians var. incrustans Spheciospongia vesparium (Lamarck) Gorgonians Eunicea spp. Gorgonia flabellum Linn. Gorgonia ventalina Linn. Muricea muricata (Pallas) Muriceopsis flavida (Lamarck) (D&M) 12 Plexaura flexuosa Lamoroux Plexaura homomalla (Esper) Plexaurella spp. Pseudopterogorgia americana (Gmelin) Pterogorgia anceps (Pallas) Scleractinians Acropora cervicornis (Lamarck) Agaricia agaricites (Linn.) Diploria labyrinthiformis (Linn.) Diploria strigosa (Dana) Montastrea annularis (E&S) Porites astreoides Lamarck Porites porites Lamarck Siderastrea siderea (E&S) Molluscs Acanthopleura granulata Gmelin Acmea antillarum Sowerby Antigonia listeri Gray Chione paphia Linn. Chiton squamosus Linn. Echininus nodulosus Pfeiffer Glycymeris undata Gmelin Laevicardium laevigatum (Linn.) Littorina zic-zac Gmelin Livona pica Gray Nerita peloronta Linn. Nerita versicolor Gmelin Purpura patula Linn. Strombus costatus Gmelin Strombus gigas Linn. Tais rustica Lamarck Tectarius muricatus Linn. Arthropods Grapsus grapsus (Linn.) Metapenaeopsis cf. goodei (Smith) Portunus bahamensis Rathbun Portunus ordwayi (Stimpson) Portunus spinimanus Latreille Tetraclita sp. Echinoderms Astichopus multifidus (Sluiter) Astropecten duplicatus Gray Oreaster reticulatus (Linn.) UWWN Ww U1W Ww - 8 eT ea ce 0 Of 8 OOK ell el 2 OL cell oll OO nN = > 13 REFERENCES Adey, W., Adey, P., Burke, R. and Kaufman, L. 1977. Holocene reef systems of eastern Martinique. Atoll Res. Bull. 218:1-40. Agassiz, A. 1894. Reconnaissance of the Bahamas and the elevated reefs of Cuba in the steam yacht "Wild Duck" January to April, 1893. Bull. Mus. Comp. Zool. Harvard. 26:81-84. Buden, D.W., and Schwartz, A. 1968. Reptiles and birds of Cay Sal Bank, Bahama Islands. Quart. Journ. Fla. NGA, BOI6o SlSZI90-320. Burrell, D.C., and Schubel, J.R. 1977. Seagrass system oceanography. In: McRoy, C.P., and Helfferich, C. (eds). Seagrass ecosystems. Marcel Dekker, New York, pp. 196-232. Connell, J.H. 1978. Diversity in tropical rain forests and coral reefs. Science 194:1302-1310. Connell, J.H., and Slayter, R.O. 1977. Mechanisms of succession in natural communities and their role in community stability and organization. Amer. Natur. dLaLal g abat abe) aba Davis, W.M. 1928. The coral reef problem. Am. Geog. Soc. Spec. Pub. 9, reprinted by AMS Press, New York, pp. L589 5 DOdGe eRe Hia | Alnkerr,eRaGy, cand Thompson), Jin el974~. | Conal growth related to resuspension of bottom sediments. Nature 247:574-577. Dollar, S.J. 1982. Wave stress and coral community structure alin latelielstal, (Cereal itacaes) 108 Val Enos, P. 1974. Surface facies map of the Florida-Bahamas plateau. Geol. Soc. Amer. map with supplementary statement. Geister, J. 1977. The influence of wave exposure on the ecological zonation of Caribbean coral reefs. In: Gimelowmcey, IRsNo p WeSVleie, Dalhop (GslS)a irs Siete) siovedbs Coral Reef Symp. Miami, Vol. 1:23-30. Gillis, W.T. 1976. Flora and vegetation of Cay Sal. Bahamas Naturalist (summer) :36-41. 14 Gilmore, M.D., and Hall, B.R. 1976. Life history, growth habits and constructional roles of Acropora cervicornis in the patch reef environment. Jour. Sed. Petrol. 4679 19—522). Ginsburg, R.N., and Lowenstam, H.A. 1958. The influence of marine bottom communities on the depositional environment of sediments. J. Geol. 66:310-318. Glynn, P.W. 1968. Mass mortalities of echinoids and other reef flat organisms coincident with mid-day low water exposures in Puerto Rico. Mar. Biol. 3:226-243. Goodbody, I. 1961. Mass mortality of a marine fauna following tropical rain. Ecology 43:150-155. Goreau, T.F. 1959. The ecology of Jamaican coral reefs I. species composition and zonation. Ecology 40:67-90. Goreau, T.F., and Land, L.S. 1974. Fore-reef morphology and depositional processes, north Jamaica. In: Laporte, L.F. (ed) Reefs in space and time. Soc. Econ. Paleontol. Mineral. Spec. Pub. 18, pp. 77-89. Greene, C.H., and Schoener, A. 1982. Succession on marine hard substrata - a fixed lottery. Oecologia 55: 269>2aa— Hartog, C. den. 1977. Structure, function, and classification in seagrass communities. In: McRoy, C.P., Helfferich (eds) Seagrass ecosystems. Marcel Dekker, New York, IIo WSIS Hine, A.C. 1977. Lily Bank, Bahamas: history of an active eolite sand shoal. Jour. Sed. Petrol. 47-1552 "saa Hine, A.C., and Neumann, A.C. 1977. Shallow carbonate bank margin growth and structure, Little Bahama Bank, Bahamas. Am. Assoc. Pet. Geol. Bull. 61:376-406. Hine, A.C., Wilber, R.J., Neumann, A.C., and Lorenson, K.R. 1981. Offbank transport of carbonate sands along open, leeward bank margins: northern Bahamas. Mar. Geol. 4255327-—=348) Hine, A.C., Wilber, R.J., and Neumann, A.C. 1981. Carbonate sand bodies along contrasting shallow bank margins facing open seaways in northern Bahamas. Am. Assoc. Pet. Geol. Bull. 65:261-—2907 Hubbard, D.K., Sadd, Jcl., and Roberts, HoH. Loss Ss them.one of physical processes in controlling sediment transport patterns on the insular shelf of St. Croix, UlS) Vascoum Islands. In: Abstr. 4th Intl. Coral Reef Symp. Manila, Philippines, P. 30. 15 Jones, J.A. 1977. Morphology and development of south- eastern Florida patch and Taylor, D.L. (eds reefs. In: Ginsburg, R.N., ) Proc. 3rd Intl. Coral Reef Symp. Miami. Vol. 2:231-236. Lighty, R.G., Macintyre, I -G., and Stuckenrath, R. 1978. Submerged early Holocene barrier reef, southeast Florida shelf. Nature 275:59-60. Lighty, R.G. 1981. Fleshy algal domination of a modern Bahamian barrier keef: example of an alternate climax reef community. Abst. 4th Intl. Coral Reef Symp. Manila. p. 37. Loya, Y. 1976. Effects of water turbidity and sedimentation on the community structure of Puerto Rican corals. Bull. Mar. Sci. 26:450-466. Macintyre, 1I1.G. 1967. Submerged coral reefs, west coast of Barbados, West Indies. Can. Jour. Earth Sci. 4:461-474. Malloy, R.J., and Hurley, R.J. 1970. Geomorphology and geologic structure: Straits of Florida. Geol. Soc. America Bull. 81:1947-1972. Milliman, J.D. 1973. Caribbean coral reefs. In: Jones, O.A. Endean, R.E., (eds) Biology and geology of coral reefs. Academic Press, New York, pp. 1-50. Meyerhoff, A.A., and Hatten, C.W. 1974. Bahamas salient of North America. In: Burk, C.A., and Drake, C.L., (eds). The geology of continental margins. Springer- Verlag, Wew York, pp. 429-446. Murray, S.P., Roberts, H.H., Conlon, D.M., and Rudder, G.M. 1977. Nearshore current fields around coral islands: control on sediment accumulation on reef growth. In: Ginsburg, R.N., and Taylor D.L. (eds) Proc. 3rd Intl. Coral Reef Symp. Miami, Vol. 2:53-60. Neumann, C.J., Cry, G.W., Caso, E.L., and Jarvinen, B.R. 1978. Tropical cyclones of the North Atlantic Ocean, 1871-1977. Nat. Climatic Ctr. Asheville, NC, USA. 190 Iba). Newell, N.D., Imbrie, J., Purdy, E.G., and Thurber, D.L. 1959. Organism communities and bottom facies, Great Bahama Bank. Bull. Am. Mus. Nat. Hist. 114:177-228. NOAA. 1973. Environmental conditions within specified geographical regions. Offshore east and west coasts of the United States and in the Gulf of Mexico. US Dept. Comm. Washington, DC. USA. pp. 1-735. UU 16 Odum, E.P. 1969. The strategy of ecosystem development. Science 164:262-270. Odum, E.P. 1971. Fundamentals of Ecology, 2nd Ed. W.B. Saunders, Philadelphia, 574 pp. Patriquin, D.G. 1975. "Migration" of blowouts in seagrass beds at Barbados and Capriacou, West Indies and its ecological and geological implications. Aquatic Bot. 12163-1389" Pearson, R.G. 1981. Recovery and recolonization of coral reefs. Mar. Ecol. Prog. Ser. 4:105-122. Porter, J.W. 1973. Ecology and composition of deep reef communities of the tongue of the ocean, Bahama Islands. Discovery 9:3-12. Roberts, H.H., Rouse, L-J., Jr., Walker, N.D., and Hudson taueane 1982. cold water stress in Florida Bay and northern Bahamas: a product of winter cold-air outbreaks. Journ. Sed. Petrol. 52:145-155. Rutzler, K., Macintyre, I.G. 1982. The habitat distribution and community structure of the barrier reef complex at Carrie Bow Cay, Belize. In: Rutz ler-eK., Macintyre, 1.G., (eds). The Atlantic barrier reef ecosystem at Carrie Bow Cay, Belize. I. Structure and communities. Smithsonian Contr. Mar. Sci. 12. pp. 9-45. Schlager, W. 1981. The paradox of drowned reefs and carbonate platforms. Geol. Soc. America. Bull. 922197-2i1 Scoffin, T.P. 1970. The trapping and binding of subtidal carbonate sediments by marine vegetation in Bimini Lagoon, Bahamas. Jour. Sed, Petrol. 40:249-273. Sheppard, C.R.C. 1982. Coral populations on reef slopes and their major controls. Max. Ecol. Prog.s Ser Wci8.3=125). Sousa, W.P. 1980. The responses of a community to disturbance: The importance of successional age and species’ life histories. Oecologia 45:72-81. Stoddart, D.R. 1974. Post-hurricane changes on the British Honduras reefs: re-survey of 1972. In: Cameron, A.M. et al. (eds) Proc. Second Intl. Symp. Coral Reefs. Great Barrier Reef Comm, Brisbane 2:473-483. 17 Tunnicliffe, V. 1981. Breakage and propagation of the stony coral Acropora cervicornis. Proc. Natl. Acad. SGilo WaZd2qyoe2usile U.S. Army Coastal Engineering Research Center. 1977. Shore protection manual V.1. U.S. Govt. Printing Office, Washington, D.C. pp. 1-180. United States Naval Weather Service Command. 1975. Summary of synoptic meterological observations, North American Coastal marine areas, Vol. 4. National Climatic Center, Asheville, NC., USA. pp. 80-146. Voss, G.L., Voss, N.A. 1960. An ecological survey of the marine invertebrates of Bimini, Bahamas, with a consideration of their zoogeographical relationships. Bull. Mar. Sci. Gulf and Carib. 10:96-116. Wilson, P. 1909. Report on the botanical exploration of the islands of Salt Key Bank, Bahamas. Jour. NY. Bot. Garden. 10:173-176. Woodley, J.D. 1980. Hurricane Allen destroys Jamaican coral reefs. Nature. 287:387. West Indies Pilot. 1957. Hydrographic Dept. British Admiralty, London, 5th ed. v. 3. Wust, G. 1964. Stratification and circulation in the Antillean-Caribbean basins. Columbia University Press, New York, pp. 1-201. ACKNOWLEDGMENTS This study was made possible through shiptime grants supported by the Florida Institute for Oceanography. I am grateful to Captain R. Millender, Jr., the crew of R/V Bellows and the staff of FIO for their cooperation and assistance in making a success of these cruises. I thank the Government of the Bahamas, Ministry of Fisheries for their cooperation and courtesy in granting permission to conduct research in Bahamian waters. Funding for aerial photography was provided by a grant to the author from Florida International University. I thank Keith Wylde for his expert piloting; M. McLean and M. Upright took the aerial photographs. P. McLaughlin and R. Lemaitre identified the crustaceans and A. Labonte provided the equipment used in sediment depth determinations. I thank my colleague J.C. Makemson for drafting the pen and ink drawings and labels accompanying the figures in this paper, and Capt. Bob Klein for providing the aerial photograph of the Damas Cay bluehole (Fig. 4F). Finally I thank A.E. Hine for comments that considerably improved the manuscript. FIGURE LEGENDS Figure 1. Geographic position of Cay Sal Bank from ERTS/ LANDSAT imagery. Scale bar = 10 km. Figure 2. British Admiraly Map No. 1217 (Rev. 1977). Inset: Station positions on Cay Sal Bank. Figure 3. ERTS/LANDSAT composite depicting the biological zones and subzones of Cay Sal Bank. Encircled numbers indicate thickness of sediment in cm. Sand waves in northwest lagoon are covered with Halodule as are NE-SW oriented sand waves to the east. Dark region between these structures is result of denser accumulations of Halodule and calcareous green algae. Note sand accumulation near Cay Sal on the southwest corner. Double Headed Shot Cays, Dog Rocks, Damas Cays and Anguilla Cays are also visible along the bank margin. Figure 4. Communities of Cay Sal Bank Lagoon: (A) Halodule-Caulerpa-calcareous green algae community typical of the central lagoon. Note numerous volcano-like burrows, possibly of callianassid shrimp; Sea star Oreaster reticulatus lies next to scale bar, = 60cm; depth = 13m at 23°50'N and 80°20'W 13 km SE of Elbow Cay. (B) Rubble dominated bottom along southeast bank is occasionally colonized by coral clusters composed of gorgonians, especially Pseudopterogorgia spp., and scleractinians Montastrea annularis, Agaricia agaricites and Porites porites (vertical view, Depth: 13m). (C) Acropora patch reef southwest of Damas Cays in 7-8m depth at 23°34'N and 79°48'W. (D) Aerial view of Thalassia development, eastern Water Cay; scale bar = 5m. Note crescentic blowouts indicating bankward storm direction from the north. (E) Underwater detail of above; crescent is 10m in diameter; depth = 8-9m. (F) Blue hole 5-6km west of Damas Cays; note coral patches developed on edge under boat; scale bar = 100m. (G) Sand body 4.0-4.5m deep in 8m of water, 2km north of Cay Sal. Divers are measuring sand depth by inserting 5m length of PVC pipe. Note oriented megaripples indicating sand motion, and sparse colonization of sediment by Halodule and calcareous green algae. Figure 5. Figure 6. Figure 7. Figure 8. Communities of the Bank Rim: (A) Intertidal bench with typical wave resistant Gorgonia spp. from lagoon side of Bellows Cay (see appendix map). (B) Coral development below the surge zone with extensive cover of Agaricia agaricites and large (=1m3) colony of Montastrea annularis: lagoon side Crenula Cay, 0-6m (see appendix map). Scale bar = 60cm. (C) Eolianite blocks broken from lagoon side of northernmost Dog Rocks; scale bar = 2m. (D) Colonization of above by Millepora complanata and small colonies of Diploria strigosa and Montastrea annularis; scale bar = 60 cm. (E) Ocean side Elbow Cay showing lack of coral development on island base. Note spur and groove- like system and scour holes; scale bar = 60 cm, depth = 3-10m. Communities of the Outer Reef Slope: (A) Deep spur systems in Nicholas Channel south of Anguilla Cays, 23°22'N and 79°34'W. Note profusion of gorgonians and sponges. Scleractinian development is occasionally moderate but generally poor. Spur height = 3-4m; Depth = 20-25m. (B) Edge of escarpment at above location. Note gorgonians and sponges but poor scleractinian development; Depth = 35m. (C) Development of Agaricia agaricites and porites astreoides on the edge of the escarpment off Elbow Cay; flabellate gorgonian is Iciligoria schrammi. Depth = 30m. (D) Escarpment off north Cay Salplanketed in fine sediment of undetermined thickness. Coral at center is mud-dwelling sclearactinian, Meandrina danae = 12 cm long. Note conch trails (Strombus gigas) above; Depth = 30m. (E) Deep spurs on the escarpment north of Rompidas Ledge composed largely of platey growths of Montastrea annularis. Comparison of fathometer profiles from Cay Sal Island northward at 15 to 30m depth. Arrow indicates increased inflection of outer reef slope at 20m. Distances north of Cay Sal: 1 = 3km, 2 = 4km, 3 = 5.5km, 4 = 6.5km, 5 = 8km. Note smooth surfaces indicative of sediment drowning near Cay Sal and increased reef development toward Rompidas. Tropical storm and hurricane track passing within 100 km of Cay Sal Bank, 1871 through 1981. Year Figure 9. of each track indicates direction of continued motion. Data from Neumann et al. (1978) with additions from NOAA Mariner's Weather Log (1977-1982). Climatic and hydrographic conditions near Cay Sal Bank. Data compiled from West Indies Pilot (1957), Wiist (1964), NOAA (1973) and U.S. Naval Weather Service Command (1975). Aualonpe ; = —. — = rure 0-5 km Figure 7 ——— hurricane - — — tropical storm @*0 ee tropical depression FLORIDA 1952 1933a \ is % > ° : ) | 1928 a : 7 Uf. Se 1926 x [7 <] A ° . Figure 8 % Sea and Swell Conditions >2m month sea swell observations © OCTOBER May 18 8 4,448 i _ MARCH August 15 6 6,417 *'L| FREQUENCY November 25 I5 S55 February 20 l2 4,667 oer” aM 26| | %WIND BOs FREQUENCY pr” eee =52,995 Ker S* 6 oo cas\ o °? ss & ANNUAL SURFACE o & SALINITY ABs 36:00-3632%0 N=50 a, “t TEMPERATURE \ Og ES 24-4 - 28-9°C cy Y Figure 9 18 APPENDIX The lack of basic information on Cay Sal Bank is perhaps no better reflected than by considerable errors in its charted position (British Admiraly 1217; Defense Mapping Agency 11451; NOAA 11013). The purpose of this note is to correct mapping errors by employing aerial and satellite photography coupled with ship-based navigational techniques and bottom soundings. Additional information is presented on the biotic composition and morphology of major islands. Data on the bank were obtained during three cruises of the R/V Bellows in the summers of 1980 through 1982. Position fixing aboard the vessel employed by simultaneous use of a 7100 Micromarine LORAN C Navigator computer, plus a Micrologic ML-320 LORAN-C Navigator as a backup. An ITT Decca Marine 801 satellite navigation computer and a Decca RM 914 radar unit (77 km range) were used to confirm LORAN data. Bathymetry information was obtained using a Raytheon Explorer III recording fathometer (to 75 fathoms) and a Raytheon DE-731 recording fathometer to (410 fathoms). All islands and rocks were surveyed by oblique aerial photography from an altitude of 600 meters. These were supplemented by aerial photographs of the Anguilla Cays made available by the U.S. Defense Intelligence Agency. The low altitude photographs were employed in conjunction with ERTS/LANDSAT imagery and shipboard position fixing in the construction of a map of the bank, accurate to within + 300 meters. Results of the mapping of Cay Sal Bank are depicted in Figure 1. Comparison with the 1890 British Admirality Chart (Fig. 2) shows an error between 1 and 5 km in the position of the islands, the magnitude of which is greatest in the southeastern portion of the bank. The shape of larger islands has been more accurately depicted and some have been named (Crenula Cay, North and South Dangerous Rocks and Bellows Cay). The bathymetry of the bank as Originally presented appears to be essentially correct for the relative position of the 5 fathom curve. Only minor corrections have been inserted. The position of the 25 fathom (=100 F) curve has been fitted using satellite imagery (text fig. 3). Some of the shoal water areas depicted on the British chart (and copied on all other charts) could not be located despite numerous attempts. Most notably, areas such as Lavanderas Rocks, east of Cay Sal and "Dangerous Shoal" depicted on the central eastern border (Fig. 2) are no 19 shallower than 3.5 to 4 fathoms. This is also true for the shoal areas near the center of the bank. Repeated crossings have indicated that the lagoon is generally no shallower than 3.5 fathoms (6.4m) at MSL. The exception to this rule is a small (vlkm2) area on the western bank referred to as Rompidas Ledge, where the bottom shoals to less than two fathoms, and large scattered heads of Montastrea annularis project close to the surface. Navigational maps place Rompidas over 5km from its actual position. However, the site is now marked by a cargo ship, M/V Cork that ran aground on Rompidas in 1983. The location of this submerged shoal can now be seen clearly from a distance of over 15km. APPENDIX FIGURE LEGENDS Figure 1. Chart of Cay Sal Bank with revised coordinates according to LORAN and radar positioning; twenty- five fathom (=100F) curve fitted from satellite imagery. Figure 2. Comparison of new chart (solid lines) with British Admirality Chart No. 1217 (dashed lines) showing 25 fathom curve and position of major islands. When the 24° and 80° coordinates of the two maps are overlapped errors of up to 5km are shown along the southeastern sector of the bank. U.S. Defense Mapping Agency No. 11461 is virtually identical with the British map. Figure 3. Islands of Cay Sal Bank. (A) U.S. Air Force photograph of south Anguilla Cay; scale bar = 500m. Note embayed margins and sand shoals. Salinity of saline lake in June, 1982 was 37.6Y,, byconductivity. Lake Margins are covered with cyanobacterial mats (Oscillatoria sp.) along with those of an unidentified red photosynthetic bacterium. A Similar lake on north Anguilla Cay retained a Sallaniity 70 1451775 )ci (B) Surface of south Anguilla Cay from eastward facing dune crest looking north: Development of palms (Coccothrinax argentata Brown) and scrub vegetation. Eastern dune face is steeply sloping and eroded. Poorly cemented eolian sand grains are typical of the windward side. (C) Lagoon (western) side of south Anguilla Cay: bedded structure of well-cemented eolianite cliffs. (D) Cay Sal from 600m looking toward southern Florida Straits. Unpaved airstrip at northern tip of island ends at edge of hypersaline lagoon. Highest portion of island is 10m ridge at the eastern tip (lower left). Note sandy shoals around island and weakly developed blowout structures at lower right corner. Scale bar = 150m. (E) Elbow Cay is typical of most islands on Cay Sal Bank, consisting of karstified eolianite and coral rubble colonized by maritime vegetation, primarily Sesuvium portulacastrum Linn. and Tournefortia gnaphalodes Brown. See Wilson (1909) and Gillis (1976) for additional notes on Cay Sal Bank terrestrial flora. This and other rocky islands of the bank serve as nesting sites for enormous numbers of sooty and brown noddy terns during the summer months. See Buden and Schwartz (1968) for a review of herpeto- and avifauna of Cay Sal. a 2 TS 30 ee I rl, == wit? Ln fon Cnn A re Sn ner re It Appendix Fig. 2 ‘Sty xtpueddy ee E Appendix Fig. 3 ATOLL RESEARCH BULLETIN No. 272 HENDERSON ISLAND CSOUTHEASTERN POLYNESIA): SUMMARY OF CURRENT KNOWLEDGE BY F. R- FOSBERG, M--H-SACHET AND D- R- STODDART ISSUED BY THE SMITHSONIAN INSTITUTION WASHINGTON, D- C-, U-S-A- SERVE MB Ess er3 "O86T ‘TI-S Jays SuUOCTITpS YIg fUuReDQ BYI JO JeYD ITAJOWAYIEg [eisuey ay} uo peseq ‘ue|adQ ITJTOeg YANoSs ‘eaie SuTpuNoiins pue pueTS] uosiapueqH “*T *3Tq oe EN (Qe NYI A) 6D S)-0'8 ve 319NG nosusan3aH© Contents MME OGUCE LONE ers che: 56a ctisie sale = eveus a) eee © oie 0 Cel ew hehe Geopncalplnya aera ove ccde eueiedeueieyavararchorsyaveksienerorerocieate ee AEGINA COMO By? ave rezeve oc) erte aisioi dlewel cern teecolelousls DUS CON GIES cchore)seftcyasisiss eyerensne wolerer erin es hav ears Later history ...... eHavenoHoy aie enelane oO OC OO OODb OOK OKO SCHEME EAC (SE UGTES! 5 os sone ci oxareuswereyere) a4 less) ew @ 4a seriayors Ye Geology ........ 9o000CDDDDDD0D0DDDNDDDODDDONDOOS Vegetation and flora ..... 900000 9000000000000000 Reptiles ..... 90000000000000000 50000000 900000000 Terrestrial arthropoda ...... 000000 9000000000000 MTVS' OCHA 5) Sire, crvoperrs «oi 'sises evace Shaper ers) acters se ten shisietienacees sheveroieiene GC AUISHHA CCA Fieve eusiere ole sev aveuene 6 eee 9900000 g000000000 ari cheMonlttiis at Laya.ctolancte-cbeitel etettoneveataletelie tence caves Riclisiehsvcaste Marine fauna ...... eieyenesene Races Suoiece Quel a Bie eiene.e-e ee Other Invertebrates ............. go00000000000 Scientific importance and Conservation ......... Acknowledgements 2.2.5... ce cee cece reer seen esces Appendix 1. A revised list of the vascular plants of Henderson Island ........ p0000000000 Appendix 2. A revised list of the marine mollusks of Henderson Island by Harald A. INevelGie ooooc0ncKDCGdD0N> 90000000 p0000000000000 Appendix 3. Resolution of the Pacific Science Association adopted at the XV Pacific Science Congress ..... 500000000000000000000 90000000000 RereeENCOS goouangocqn0do000D0g00000D000000000000 29 34 40 41 NE Point low trees AA cliff approx.15m high 128 20 W South Pt Fig. 2. Henderson Island (from the Admiralty chart). HENDERSON ISLAND (SOUTHEASTERN POLYNESIA): SUMMARY OF CURRENT KNOWLEDGE by F. R. Fosberg*, M.-H. Sachet* and D, R, Stoddart** INTRODUCTION The tropical seas are liberally sprinkled with coral islands. Many of them are associated with continents and large continental islands, in relatively shallow water, rising from continental shelves. Many, also, are in deep water - atolls, barrier reef islets round high islands, 'almost atolls', tops of drowned karsts, and a few moderately elevated atolls. These last are among the most fascinating of all, scientifically. There is no obvious reason to think that these are anything but ordinary atolls that have been tectonically elevated a few tens of metres above present sea level. Yet several features are frequently observed that are not evident on the sea-level atolls which are pres- ent in the coral seas in such large numbers. Terra rossa soils cover the limestone tops of some of them. Phosphate, earthy or indurated, or both, covers the tops and fills pits and crevasses of some, oc- casionally in enormous quantities, and is present at least in some quantities on most or all of them. Fantastically eroded, deeply and sharply pinnacled and pitted limestone surfaces are common. Endemic species of plants and animals, very rare on low atolls, are found in some numbers on almost all raised atolls of which we have even meagre knowledge. Whether or not these phenomena are related is at present not clear. Much further work on as many as possible of these islands is needed to elucidate this problem. The basic difficulty of the above statement is that, of the 20 or 30 such ‘oceanic’ islands or groups of islands, most have been greatly altered by long-established human occupancy, or phosphate min- ing, or both. Of the exceptions, the "Rock Islands' of Palau and the Lau Group of Fiji are rugged karst, not comparable with raised atolls; Medinilla has been used as a bombing target; only Aldabra and Henderson remain reasonably unaltered. We are not here considering the many "continental’ limestone islands. * Botany Department, Smithsonian Institution **Geography Department, Cambridge University Aldabra and Henderson are topographically and physiographically very different, though both are probably raised atolls. Aldabra has been studied intensively during the past 17 years, is now well-known, and is legally protected. Henderson is relatively poorly known, and protected only by its remoteness and unsuitability for human habitation. During the past year the isolation and pristine condition of Henderson have been and are seriously threatened by a project of a wealthy American to build a house, landing facilities, and an airstrip on it. This is being opposed by scientific and conservation bodies, which are petitioning the British Government to deny permission to carry out this project. This circumstance has brought out and under- scored the paucity of reliable scientific information, except of a reconnaissance nature, about Henderson. This has caused the ARB editors to bring together a summary of what is known of the geography, history, ecology, flora and fauna of this island, with a bibliography of pertinent literature. This paper is, therefore, a factual record of the published information on Henderson: it sets down what has been discovered, at what time, and by whom, about the island. GEOGRAPHY Henderson is an elevated limestone island situated in 24°22'S and 128°20'W. Its nearest neighbours are Pitcairn, 200 km to the west- southwest; Oeno, 200 km to the west; and Ducie, 360 km to the east. It rises as an isolated conical mound from depths of ca 3.5 km, on a trend line which continues that of the Tuamotus and Gambiers eastward to Ducie, and is presumably a reef-capped volcano. The island has a greatest length of 9.6 km and greatest width of 5.1 km, based on the Admiralty chart; its area is 37 sq km. It is usually said to rise about 33 m (100 ft) above sea level. Early authors stressed the flatness of its summit, but those on the Mangarevan Expe- dition were impressed by a central depression which they interpreted as a former atoll-lagoon. The upper surface consists of an intricate dissected limestone, with pits and crevasses 3-7 m deep. The island is surrounded by steep cliffs of bare limestone, with occasional pocket beaches. There is a fringing reef 200 m wide, at least on the north and northwest sides backed by a wide beach (St John and Philipson (1962)). No meteorological records are available, but the island lies in the Southeast Trades, and from its location probably has a mean annual rainfall of 1500 mm. The tidal range at springs is probably close to that of the Gambiers and eastern Tuamotus (1.0 m) (Admiralty Tide Tables 1983). Tidal measurements at Ducie by Rehder and Randall (1975) showed a regular semidiurnal tide. The top of the island, as well as any land at the bases of the cliffs, is densely vegetated by tangled scrub and scrub-forest, but the central part of the depression and the makatea are more sparsely covered. In places, where the forest is taller and the canopy more complete, it is possible to walk freely for short distances. The tallest trees are Pandanus tectorius Parkinson, which in places rises as an emergent above the general canopy. The crowns of such emergents are conspicu- ously pyramidal or conical. The dried fallen leaves of Pandanus cover the ground in many places. The scrub and much of the scrub-forest is in many areas so dense and tangled that walking through it is impossible without the constant and vigorous use of a machete, and exhausting and slow even with the use of one. Such scrub is as likely to be on dissected limestone as on solid soil, adding to the difficulty of traversing it. In some parts the difficulty is increased by the presence of Caesalpinia bonduc, a tangled vine beset with hooked prickles, which amply explain and justify a mame used in Hawaii for this widely-distributed species, '‘wait-a-bit'. Fresh water is almost completely absent. Slight dripping has been observed from the roofs of certain caves. A spring from a rock cleft below high tide level at the north end of the island has been reported (Naval Intelligence Division 1943, 92), but its degree of permanence is unknown. Presumably there is some development of a Ghyben-Herzberg lens within the island, but nothing is known of this. Biogeographically the island is very interesting because of its remoteness from obvious source areas. Comparison of its habitats with those of sea level and slightly-elevated atolls in the Tuamotus, in terms of effective salinity, proportions of different substrata (sand, dissected limestone, cliffs, level soil, etc.) is of great potential interest, but has yet to be considered except in a very preliminary Manner. Study of the effects of geologically long continuous exposure above water, compared with the very short history of emergence of the sea-level atolls, could be rewarding. None of these lines of research can develop very far without much more information about the island than we have at present. Comparison with Aldabra would then be profit- able. ARCHAEOLOGY As noted above, Henderson has been, in historic times, uninhabited, with only brief visits by Pitcairn Islanders and occasional scientific parties. However, on one such visit, in 1971, Dr Yosi Sinoto, of the Bishop Museum, discovered and made preliminary investigations on an archaeological site at the north end of the island. With his kind per- mission we quote his preliminary account of this discovery from a paper read in Nice in 1976: "Henderson Island, known also as Elizabeth Island, is located about 105 miles northeast of Pitcairn Island. This tiny, raised, coral- limestone island is flat-topped with 100-ft-high cliffs rising from the shorelines. Since some time before its discovery by Quirds in 1606, the island has been uninhabited (Markham 1904). In 1971, while pros- pecting on the north shore, we found five shelters, one of which in- cluded burials, and a cave. The cave is situated at the base of a cliff at the back of the beach flat. Test pits in front of the cave revealed three cultural layers. The top of Layer II was a hard, coral- pebble-paved layer indicating an occupational floor. At the bottom of Layer III we found a fireplace on top of the sterile deposit. "More than 250 portable artifacts were uncovered from the excava- tions. These included 100 fishhooks and blanks, of which 75 are pearl- shell, and 90 coral (Porites sp.) abraders for making fishhooks. There were 36 basalt adz sections and fragments. This is striking because basalt rocks and pearl shells are not available from the island, and the distribution of these artifacts in the three cultural layers is revealing. The lowest layer yielded only pearl-shell fishhooks, Hawaiian-Marquesan-type coral files, and basalt adzes, all broken be- yond type identification, except that cross sections could be recognized as quadrangular to trapezoidal. The quantity of these artifacts de- creased in the middle layer and was drastically reduced in the top layer, where hammer-oyster-shell hooks and Henderson-type coral files appeared. In the top layer, fossilized Tridacna-shell adzes appeared. Gradual material adaptation - the gradual change from the use of imported ma- terials to the use of local resources - is excellently demonstrated here. Pearl-shell fishhook types found were early Marquesan, Phase II, and coral files were Hawaiian-Marquesan types, previously found only in those two island groups. There is no doubt that the early Henderson material culture had a close affiliation with the early Marquesan cul- ture; as the materials that were brought to Henderson were exhausted, the locally available resources were exploited. There were eight pieces of volcanic glass, resembling pitchstone fragments, associated with basalt adzes and pearl shells. These are also foreign to the island but may suggest contact with Pitcairn Island, where pitchstone is available. Another shelter yielded artifacts made only of local materials. "A charcoal sample collected at the bottom of the cave site was dated at A.D. 1160+110 (1-6344) and charcoal from the top of the middle layer was dated at A.D. 1455+105 (1-6343). Thus the span of the occu- pation at this site was more than 300 years. Quirds's party landed on Henderson in 1606 and found pandanus trees, but no inhabitants. What- ever the reason for the disappearance of the inhabitants, it must have happened just prior to Quirds's visit." DISCOVERY The island is named after Captain James Henderson, of the Hercules, who called there on 17 January 1819: Beechey (1831, I, 64) proposed that Henderson's name be applied to it, rather than that of the vessel Elizabeth, then used on charts, on the grounds that the Hercules visit preceded that of the Elizabeth by several months. Beechey also er- roneously suggested that both ships had been preceded by the crew of the wrecked whaler Essex. In fact Hercules was first, followed by Elizabeth, Captain Henry King, on 1 March 1819, and members of the crew of the Essex from 20 December 1819 until 5 April 1820. Beechey's vessel H.M.S. Blossom called on 3 December 1825, and was responsible for the first scientific observations. 5 Beechey's account of the discovery of Henderson has been followed by several later authors, including the Admiralty Handbook (Naval In- telligence Division 1943, 92) and St John and Philipson 1962, 176). As early as 1837, however, Moerenhout suggested that Henderson was among the islands discovered by Pedro Fernandez de Quirés in 1606, a proposal adopted by Meinicke (1876), Beltran y Rézpide (1882-3), Caillet (1884), Markham (1904) and Sharpe (1960). Maude (1968, 66) commented that "there can be no doubt as to the identification of these islands’. Accounts of the Quirés expedition Quirés sailed from Callao, Peru, on 21 December 1605, in his flag- ship San Pedro y San Pablo, together with the Almiranta and San Pedro. He gives the following account in his Narrative, edited by Markham (1904) : "On the 25th [ January 1606] we saw the first weeds; and on the 26th we saw birds of several kinds flying together. On this day, at 11 o'clock, we discovered the first island in latitude 25°, and reckoned it to be 800 leagues [ca 4740 km ] from Lima. It has a circumference of 5 leagues [30 km], many trees, and a beach of sand! (Markham, ed. 1904, I, 192). This island, subsequently identified as Ducie Atoll, was variously termed Luna-Puesta and La Encarnacién. Quirds stood off to westward without landing. "Still steering on the same course, on the 29th of January, at dawn, we sighted another island near, and presently stood towards it. The launch to the S.W. found a port in a small bay, where she anchored in 27 fathoms, and almost on shore. The ships did the same. ... Three men were sent from the Almiranta in a dingey to land. Fearing to remain they came back quickly, bringing certain fruits known to some on board, which were too unripe to eat. They said that the landing was very bad for a dingey, and would be much worse for larger boats. This island was supposed to be 870 leagues [ 5160 km ] from Lima. It is 10 leagues [ 60 km] round. It is massive, moderately high, open, having groves and plains. It is steep, too, and its beaches are rocky. It is only inhabited by birds. Its latitude is 24°45'. It was named 'San Juan Bautista’; and as it had no port where we could get wood and water, we con- tinued our voyage to the W.N.W." (Markham, ed. 1904, I, 193). San Juan Bautista is the island identified as the present Henderson. The discovery of the two islands is also described by the Chief Pilot, Gaspar de Leza. The first, Ducie, which he called Anegada, was met with on 26 January 1606 in latitude 25°S, 1000 leagues [ 5900 km] from Callao. During the 27th they sailed on, and at 10 leagues [ 60 km] NW by N determined their latitude as 24°50'S. On the 28th they made 30 leagues [ 180 km ] ona westerly course. 'This day we again saw a great number of birds of many kinds, chiefly grey gulls and terns.' The discovery of Henderson is described as follows: "29th. Second Island: Sin Puerto. - 24°45'S., 1075 leagues 6375 km J from Callao. In the morning we saw another island, about 6 to 7 leagues [ 35-42 km ] long, N. and S., all flat, with a hill to the S. It is all clean rock round the coast. The distance from the 'Anegada' is about 75 leagues [ 445 km ]. ... This island is very green, and full of trees and open spaces. The wind which blew over this island brought a smell of flowers and herbs: for they were abundant. The Almiranta got out a skiff, and sent it to the shore with three persons. They jumped on shore, but were afraid to leave the boat. They brought back certain fruits and herbs, and said that they saw pebbles of different colours on the beach, and stones which they did not know, but which were pleasant to the sight. ... To the NE. of the place where we had been there was a beach, which appeared to be larger than the first; and if any one should chance upon this island at any time, the N.E. side should be taken to find this beach." (Markham, ed. 1904, II, 330-331). Yet a further name for Henderson is provided by the second-in- command, Luis Vaez de Torres, when he states that the second island discovered was ‘about 10 leagues [ 60 km ] in circumference. We named it San Valerio’ (Markham, ed. 1904, II, 465). Juan de Iturbe on the same voyage describes Henderson as ‘seventy leagues [ 415 km ] distant from the first, completely round and uniform of aspect with sheer cliffs. It would be seven leagues [ 42 km ] in circumference' (Kelly, ed: 1966, Tk; 281). Finally, Fray Martin de Munilla, chaplain to the fleet, gives a more circumstantial account: "an island, a little over ten leagues [ in circumference ] [ 60 km ] was sighted rising from the sea about eight varas 6.7 m; 1 vara = 84 cm ]. It was flat and round, the higher parts bore a uniform aspect, but formed after the manner of riven rock with some high cliffs facing the sea. ... We saw a small beach between two morros [ bluffs Ae ... Two men went ashore and brought back a fruit like a green pineapple [Pan- danus ]. Two Chinese who were on board the capitana said that the fruit was edible and that it was plentiful in China. Re- turning presently they reported that the harbour was not suit- able, but that there were fish in abundance. There, too, they found some trees, though these were small, but they had seen no sign of people. ... This island would be sixty leagues from the other [ 355 km from Ducie ] and in relation to each other they stood EW 1/4 NWSE. It lies in latitude 24-3/4°S ." (Kelly, ed. 1966, I, 153-155). Account of Captain King After the Quirds expedition there are no further recorded visits to Henderson until that of the Hercules on 17 January 1819: we have seen no account of that occasion. However, King (1820) has described his visit with the Elizabeth on 1 March 1819. He found "a large island on the weather-beam, .... as level as a bowling- green. ... [ we ] endeavour to land at a sandy-beach not far distant from the ship, which, after some difficulty, we accom- plished. After hauling the boats up among the trees, we all went up in different directions; within hail of each other, in quest of vegetables or animals; but, after a search of four and a half hours, we returned to the boats, having seen one parrot, and shot a few pigeons. The island abounded with young trees and underwood, nor did we observe the smallest appearance of quadrupeds, except here and there a rat; the ship's name Elizabeth, was now given to the island. The British Colours were displayed on the island, and greeted with three cheers, and a bumper of grog was drank to the health of his Majesty. While these ceremonies were performing, a proper person was em- ployed in carving the ship's name, and the other particulars upon a tree, near the spot we landed. ... We landed on the south-west part of the island, among some coral rocks, at the back of which is the beach before mentioned. It appears about six leagues in circumference, and we found no anchorage. C The latitude of Elizabeth's Island is 24°26'S., longitude west of Greenwich 127°50'." (King 1820, 381-382). The wreck of the Essex The destruction of the whaler Essex, Captain George Pollard, by a whale on 20 November 1819 on 0°40'S., 119°O'W, and the subsequent voy- age in small boats of the survivors to Henderson and beyond provided the origin of the Moby Dick story made famous by Melville. The boats arrived at Henderson on 20 December, after drifting for a straight-line distance of 2100 km. Most of the party left again for the Juan Fernan- dez Islands after a few days at Henderson. Their boats became separated and the survivors suffered appalling privations: in the captain's boat the cabin boy, Owen Coffin, was selected by lot to be killed and eaten after the food was finished, and another man who died was also cannihale ised. The first mate's boat was finally rescued in 33°45'S, 81°03'W, close to their destination, after a voyage of some 4000 km. The three crew members who had remained on Henderson were finally taken off on 5 April 1820. Chase (1821; Gibbings, ed. 1935) wrongly identified their first landfall as Ducie, but it was clearly Henderson: first, because of their description of the island, and second, because they found there a tree carved with the words 'The Elizabeth' (Gibbings, ed. 1935, 60) which had been there ten months before. The island was described by Chase as "about six miles long and three broad; with a very high ragged shore, and surrounded by rocks; the sides of the mountains were bare, but on the tops it looked fresh and green with vegetation" (Gibbings, ed. 1935, 52). Chappel described it as "about eight or nine miles round, low and flat, nearly covered with trees and underwood" (ibid, 78). Of particular interest is Chase's record of a "fine white beach" in the northwest (ibid, 70). The Essex narrative is retold by Heffernan (1981), and mention is made below of other observations made on the island. Account of Captain Beechey's visit The most graphic and detailed accounts of Henderson in the early literature are those resulting from the hydrographic survey made by H.M.S. Blossom under Captain F. W. Beechey during a single day in December 1825. Beechey's own account is as follows: "At noon on the 2d of December, flocks of gulls and terns indicated the vicinity of land, which a few hours afterwards was seen from the mast-head at a considerable distance. At daylight on the 3d, we closed with its south-western end, and dispatched two boats to make the circuit of the island, while the ship ranged its northern shore at a short distance, and waited for them off a sandy bay at its north-west extremity. "We found that the island differed essentially from all others in its vicinity, and belonged to a peculiar formation, very few instances of which are in existence. ... The island is five miles in length, and one in breadth, and has a flat sur- face barely eighty feet above the sea. On all sides except the north, it is bounded by perpendicular cliffs about fifty feet high, composed entirely of dead coral, more or less porous, honeycombed at the surface, and hardening into a compact cal- careous substance within, possessing the fracture of secondary limestone, and has a species of millepore interspersed through it. These cliffs are considerably undermined by the action of the waves, and some of them appear on the eve of precipitating their superincumbent weight into the sea; those which are less injured in this way present no alternate ridges or indication of the different levels which the sea might have occupied at different periods, but a smooth surface, as if the island, which there is every probability has been raised by volcanic agency, had been forced up by one great subterraneous convulsion. The dead coral, of which the higher part of the island consists, is nearly circumscribed by ledges of living coral, which pro- ject beyond each other at different depths; on the northern side of the island the first of these had an easy slope from the beach to a distance of about fifty yards, when it terminated abruptly about three fathoms under water. The next ledge had a greater descent, and extended to two hundred yards from the beach, with twenty-five fathoms water over it, and there ended as abruptly as the former, a short distance beyond which no bottom could be gained with 200 fathoms of line. Numerous echini live upon these ledges, and a variety of richly coloured fish play over their surface, while some cray-fish inhabit the deeper sinuosities. The sea rolls in successive breakers over these ledges of coral, and renders landing upon them extremely difficult. It may, however, be effected by anchoring the boat, and veering her close into the surf, and then, watching the opportunity, by jumping upon the ledge, and hastening to the shore before the succeeding roller approaches. In doing this great caution must be observed, as the reef is full of holes, and the rugged way is strewn with sea-eggs, which inflict very painfull wounds; and if a person fall into one of these hollows, his life will be greatly endangered by the points of coral catching his clothes and detaining him under water. The beach, which appears at a distance to be composed of a beautiful white sand, is wholly made up of small broken portions of the differ- ent species and varieties of coral, intermixed with shells of testaceous and crustaceous animals. "Insignificant as this island is in height, compared with others, it is extremely difficult to gain the summit, in con- sequence of the thickly interlacing shrubs which grow upon it, and form so dense a covering that it is impossible to see the cavities in the rock beneath. They are at the same time too fragile to afford any support, and the traveler often sinks into the cavity up to his shoulder before his feet reach the bottom. The soil is a black mold of little depth, wholly formed of decayed vegetable matter, through which points of coral every now and then project. "The largest tree upon the island is the pandanus, though there is another tree very common, nearly of the same size, the wood of which has a great resemblance to common ash, and possesses the same properties. We remarked also a species of budleia, which was nearly as large and as common, bearing fruit. It affords but little wood, and has a reddish bark of considerable astringency: several species of this genus are to be met with among the Society Islands. There is likewise a long slender plant with a stem about an inch in diameter, bearing a beauti- ful pink flower, of the class and order hexandria monogynia. We saw no esculent roots, and with the exception of the pandanus, no tree that bore fruit fit to eat.'"' (Beechey 1831, I, 61-64). A more succinct account was provided by Lieut. Peard, also on board H.M.S. Blossom: "On the 2nd December [1825 ] several Noddies and Boatswains' birds were seen about the Ship, and we made Elizabeth Island which like the last [ Ducie ] is of coral and uninhabited; but I suppose 70 feet high and 16 or 18 miles in circumference. The cliffs in many parts, more particularly the North part are 10 washed by the sea into curious and fantastic Arches, and large caverns are formed into which the waves dash and force a passage through wide openings in the top. A Beach of the most dazzling whiteness and apparently composed of the finest sand every here and there presented itself, and seemed to invite us to the shore. Our boats however made the circuit of the Island and found it by no means an easy access, some of the Officers landed by wading through the Surf, and discovered that the beach was composed of coral, madrepore and shells bleached by the sun." (Gough, ed. 1973, 75). LATER HISTORY Apart from scientific investigations by visiting expeditions, much of the later history of Henderson is connected with that of neighbour- ing Pitcairn, discovered by Carteret in 1767 and settled by the Bounty mutineers in January 1790. The settlers remained unaware of Henderson until the arrival of the Elizabeth in 1819 (hence the currency of the name Elizabeth on Pitcairn until at least mid-century), and did not visit the island until 4-11 March 1843, according to the Pitcairn Island Register (Murray 1854, 281). The visit led to 'a very unfavourable re- port' on the island. The visit is described in some detail by Brodie (1851, 17-18): "Not long ago, eleven of these islanders, along with John Evans (one of the three resident Europeans), were carried to Henderson's, or Elizabeth Island, in an American whaling ves- sel, on an exploring expedition. The landing was anything but good, and the soil not near so rich as that of their own island, being of a much more sandy nature. Water there appeared to be none; but, after a long search, they found a fresh-water spring below high-water mark. Some cocoa-nuts, which had been pur- posely carried there, were planted upon the best ground they could find. Several goats had been likewise shipped for turn- ing out, but were actually forgotten until some time after they were returned on board. They were only a few hours on the island, and, therefore, were unable to form or give any detailed description of it. Elizabeth Island is of a peculiar formation, very few instances of which are known, viz., dead coral, more or less porous, elevated in a flat surface, probably by vol- canic agency, to the height of eighty feet. It is five miles in length, one in breadth, and thickly covered with shrubs, which makes it difficult to climb. It was called Henderson's Island after the captain of the ship Hercules of Calcutta, though first visited by the crew of the Essex, an American whaler, two of whom landed on it after the loss of their ship, and were subsequently taken off by an English whaler, who heard of their fate at Valparaiso. They are very anxious to procure a small vessel or large boat, of about twenty tons burden, to enable them to visit this island at pleasure, and bring off house-timber as required, as likewise to convert it into a run for their live stock; thus relieving their little island from 11 that burden, and enabling them to direct the whole of its capabilities to the use of man. They have established a sort of Bank among themselves, in which a large part of the money paid by vessels for refreshments, is suffered to accumulate for the purpose of purchasing a small vessel." The next visit from Pitcairn to Henderson did not take place until 16 August 1851: "Twelve of the inhabitants sailed in the Joseph Meigs for the purpose of visiting Elizabeth Island. On their arrival at the island they discovered a human skeleton, and as nothing could be found that may lead to discover who this unfortunate indi- vidual was, it must remain a mystery." (Pitcairn Island Register, in Murray 1854, 295). This visit was followed by another on 11 November 1851: "Thirty-eight of the inhabitants sailed in the ship Sharon, of Fairhaven, for the purpose of visiting Elizabeth Island. On Friday, 14th, after a boisterous passage of three days, they ‘landed upon Elizabeth Island, when they immediately set about wooding the ship, and exploring the country, which is evidently . of coral formation. The soil is very scanty, and totally un- _f£it°for cultivation. Various specimens of marine shells are dispersed all over the surface of the island, which, in combina- tion with the thickly scattered pieces of coral, renders travelling both difficult and dangerous. Water is found on the north-west part of the island slowly dripping from the roof of a cave, which cannot be reached without the aid of ropes. The island rises about sixty feet above the level of the sea. Eight human skeletons were also found upon the island, lying in caves. They were doubtless the remains of some unfortunate seamen, as several pieces of a wreck were found upon the shore." (Murray 1854, 295-296). Since then, Henderson has been visited by Pitcairn Islanders on a fairly regular basis, chiefly to cut miro wood, Thespesia populnea, from which carvings are made for sale to visitors. Formal possession of Pitcairn for the British Crown, as a British Colony by settlement, was taken by Capt Russell Elliott, H.M.S. Fly, on 29 November 1838, and the island came under the administration of the Western Pacific High Commission in 1898. Although Capt King, of the Elizabeth, had informally raised the British flag on Henderson in 1819, the island was not formally annexed (at the same time as Oeno and Ducie) until 1902, when a party from Pitcairn raised the flag on 10 July. All three islands were included with the administration of Pitcairn in 1938. Pitcairn itself is governed by an Island Council, under the authority of a Governor resident at the British Consulate-General in Auckland, New Zealand. Henderson and the other two islands remain, of course, uninhabited. 12 Table 1. Visitors to Henderson Island: summary Date Visitor 1606 Quirés 29 Jan 1819 James Henderson 17 Jan Hercules 1819 Henry King 1 Mar Elizabeth 1819 20 Dec - 1820 Crew of the Essex 5 Apr 1825 F. W. Beechey 3 Dec H.M.S. Blossom 1827 Hugh Cuming 9 Oct 1838 Capt R. Elliott 29 Nov HeMsS:.. Ely 1843 First visit by 4-11 Mar Pitcairn islanders 1851 Second visit by 16 Aug Pitcairn islanders 1851 Third visit by 11 Nov Pitcairn islanders 1877 Wreck of Allen Gowie 13881 Grice, Summer & Co 1900 Ge Edis 1902 Visit by Pitcairn 10 July islanders 1907 Cem Cem Hililaise) Spal Sept Arundel, A. E. Stephen 1912 D. IR antes Aug-Sept J. R. Jamieson Activity Discovery Re-discovery Re-discovery Survival Survey Biological collections Possession Phosphate survey Phosphate survey Accession Phosphate survey; bird collection Phosphate survey; various collec- tions Main publication Markham, ed. 1904; Kelly, ed. 1966 King 1820 Gibbings, ed. 1935 Heffernan 1981 Beechey 1832 Hooker and Arnott 1841 St John 1940 and various papers on shells North 1908 Ogilvie-Grant 191l3a, 1913b; St John and Philipson 1962; Tait 1912, Smith 1913 1922 Mar-Apr 1934 16-22 June 1937 Aug 1943 Nov. 1948 Aug 1957 3-4 Feb 1957 1971 Jan 1981 Whitney South Sea Expedition R. H. Beck, E. H. Quayle, C. C. Curtis Birds; plants Mangarevan Expedi- tion - H. St John, F. R. Fosberg, E. C. Zimmerman, C. M. Cooke, D. E. Anderson Plants, insects, molluscs J. R. Rivett- Survey Carnac, H.M.S. Leander Adm Richard E. Byrd and party Survey Survey, light built Capt G.S. Webster H.M.C.S. Awahou W. H. Lintott Plants, birds R. Tomarchin with chimpanzee H. A. Rehder, J. E. Randall, Y. Sinoto Archaeology, marine biology A. M. Ratliff(e?) Survey 13 Murphy 1924a and later papers; Brown 1931, 1935; Brown and Brown 1935 St John and Philipson 1962 St John and Philipson 1962; Williams 1960 McLoughlin 1971 14 All the islands were visited during a defence reconnaissance by H.M.S. Leander, Capt J. R. Rivett-Carnac, in August 1937, when Beechey's chart of Henderson was revised and a flagpole raised. According to Bourne and David (in prep.) further visits are said to have taken place by United States parties in 1943 and 1966. A light was erected on a steel tower 6.7 m tall at a height of 38 m by the Colonial Vessel Awahou, Suva, Capt G. J. Webster, on 11 August 1948. Because of maintenance difficulties it was abandoned in 1954 (this information is provided from Admiralty archives by Lt Cdr David). SCIENTIFIC STUDIES The first formal scientific studies were those carried out during the visit of H.M.S. Blossom in 1825 when plant collections were made and subsequently reported by Hooker and Arnott (1832) and Hemsley (1885). On 9 October 1827 Mr. Hugh Cuming visited the island on a general collecting trip, gathering specimens of plants, mollusk shells, and various other groups of animals. He spent only one day there, according to the following, from a letter to Wm. J. Hooker dated "March 21st, SS 2s "On the 9th made Elizabeth [ Henderson ] Island, a high coral island without a lagoon, covered with shrubs and palms Pandanus ] principally. Jessamines fi probably Jasminum didymum ] and Laurels [ probably Pittosporum sp. with aromatic foliage ] but few in flower. In the clefts of rocks collected some fine ferns. On the llth made Pitcairn Island. ..." (St John 1940). During phosphate explorations in September 1907, A. E. Stephen col- lected birds and made incidental observations, both reported by North (1908). The first substantial study and collections, however, were those carried out by D. R. Tait and J. R. Jamieson in August and Sep- tember 1912. No full account of this investigation has appeared, but birds were reported by Ogilvie-Grant (1913a, 1913b), marine molluscs by Smith (1913), and plants by St John and Philipson (1962). Extracts, at least, from Tait's diary and report exist in a manuscript letter to Sir John Murray (1913). The two major studies of the island are: (1) That of the Whitney South Sea Expedition in March and April 1922. E. H. Quayle and C. C. Curtis collected plants and birds, the former reported in Brown's Flora of Southeastern Polynesia (1931-1935) and the latter in a wide range of publications cited below. (2) The Mangarevan Expedition in 1934 spent the period 16-22 June on Henderson. H. St John and F. R. Fosberg collected plants, reported by St John and Philipson (1962), E. C. ; Zimmerman insects, and C. M. Cooke land molluscs. The invertebrate col-= lections were reported in a wide range of systematic papers. No formal ornithological observations were made during this visit, though notes on birds were made, but not published, by Fosberg. 15 In 1957 W. H. Lintott visited Henderson with several Pitcairn Is- landers on 3-4 February. His bird observations were reported by Williams (1960) and his plant collections by St John and Philipson (1962). Fi- nally, in January 1971, two brief visits were made by H. A. Rehder, J. E. Randall and Y. Sinoto, aboard the Westward, during the National Geographic Society-Oceanic Institute Expedition (which also made the first comprehensive study of Ducie: Rehder and Randall 1975). It was during this expedition that Sinoto made the first preliminary studies of pre-European Polynesian habitation on Henderson. GEOLOGY Most writers on Henderson state that it is an elevated atoll with original lagoonal summit depression preserved; some have speculated on the recency of its uplift. It appears, however, to be very similar to other makatea islands in the central and east Pacific, in which the main limestones are broadly of mid-Tertiary age and in which the topography results from post-uplift erosion. McNutt and Menard (1978) have sug- gested that many of these islands have resulted from crustal loading by an adjacent volcano, which in the case of Henderson would be Pitcairn. Pitcairn stands only 347 m above sea-level, but rises 3.5 km from the ocean floor. Two phases of surface vulcanism have been identified, with K-Ar ages of 0.46-0.63 and 0.76-0.93 million years (Duncan et al. 1974). The total span of volcanism for the whole Pitcairn cone must be much greater, however, and the crust on which it stands has an age of roughly 30 million years. McNutt and Menard (1978) calculate the amount of uplift of Henderson caused by the Pitcairn loading to be 32 m (compared with an actual uplift which they state to be 30 m); Oeno and Ducie are not uplifted, because the former is in Pitcairn's moat and the latter beyond the arch. The location of Henderson along a prolongation of the Tuamotu- Gambier axis has already been mentioned. Basalts at Mururoa in the eastern Tuamotus have been dated at 6-8 million years at a depth of 438 m (Labeyrie et al. 1969). The surface volcanics of the Gambier Archipelago (maximum elevation 441 m) are also of similar age (4.77- 5.98 m yr: Bellon 1974; 5.33-7.15 m yr: Brousse et al. 1972). These and the dates for Pitcairn suggest a volcanism migration rate of 11 cm/yr. It seems likely that the limestones of which Henderson are com- posed are of late Tertiary age, and may have been exposed for a few million years. The ‘lagoonal' topography may well be a karst erosion feature, and the columns and pinnacles within the depression also karst features rather than patch reefs. The low-lying areas surrounding the high core at least on the leeward side could (by comparison with makatea islands elsewhere) be a last interglacial reef. Actual geological investigations of Henderson are limited to pros- pecting for phosphate deposits. The first such survey was carried out in 1881 by Grice, Summer and Co of Melbourne (then lessees of Malden) ; they found only 200 tons of guano. A permit to exploit was held by Capt J. Rasmussen during 1903-1907, but was not taken up. G. C. Ellis 16 and J. T. Arundel of the Pacific Phosphate Company, aboard the Tyrian, made a brief survey in 1907. No useful deposits were found, but Hutchinson (1950, 213) quotes analyses of two samples with Ca3P50 contents of 8.5 and 18.0% respectively. In 1908 a twelve-month license to prospect on Henderson, Oeno and Ducie was issued to James Banks and James Watt, who made a preliminary visit to the first of these (these details are derived from papers in the Ministry of Defence Hydrographic Department archives very kindly made available by Lt Cdr A. C. F. David to Dr W. R. P. Bourne, who drew them to our attention). A license for them to exploit guano was issued to them on 14 December 1909, to extend from 1 April 1912 to 31 March 1924, with the right to occupy the island, erect buildings, and to cut and use timber and other vegetable growth, and the obligation to plant quick-growing trees on two conspicuous points, and to erect a beacon 25 ft high. Banks visited Henderson in July 1912 at the time of the survey of the island by D. R. Tait and J. R. Jamieson. On 11 October 1912 the rights were transferred to a new company, Henderson Island Limited, under the chairmanship of Sir John Murray, and Banks became the Company's agent. During this survey a house and six sheds were built of corrugated iron to house the survey party. Tait's own report, dated 20 January 1913, in the Hydrographic Office archives, was ex- tremely disappointing, and on 30 January Watt reported the Company's intention to give up the lease: 'the island was useless not only in regard to the supply of phosphates, but for any other purpose.' The lease was accordingly terminated, and the Company dissolved. VEGETATION AND FLORA What was evidently Pandanus was reported at Henderson by Munilla during the Quit6és expedition in 1606, and again by Beechey in 1825. The first collections were made by Lay and Collie during the Beechey expedition: four species were reported from these collections by Hooker and Arnott (1841, 64-69) and three more by Hemsley (1885, 15). These were: Asplenium nidus L. (in Hemsley 1885, 15) Euphorbia sparrmannii Boiss. (as E. ramosissima Hooker and Arnott, the Henderson specimen being their type) Glochidion pitcairnense (F.Br.) St. J. (as Bradleia? glochidion in Hooker and Arnott 1841, 69) Tournefortia argentea L. (in Hemsley 1885, 15) Canthium odoratum (Forst.f.) Seem. (as Chiococca odorata in Hooker and Arnott 1841, 65) Guettarda speciosa L. (in Hemsley 1885, 15) Ixora fragrans (Hooker and Arnott) Gray (as Cephaelis? fragrans in Hooker and Arnott 1841). Since then, four major collections of plants have been made. First, D. R. Tait collected 91 numbers representing 55 species in August- 17 September 1912; the collection was determined by St John nearly fifty years later (St John and Philipson 1962). Second, E. H. Quayle and C. C. Curtis collected some twenty species, including four ferns, during the Whitney Expedition in 1922. This material was included in Brown's Flora of Southeastern Polynesia (Brown 1931, 1935; Brown and Brown 1935), where Santalum hendersonense was described as a Henderson endemic. Most of the Whitney collections were also cited by St John and Philipson (1962), though curiously these authors do not include the Whitney Ex- pedition in their list of botanical collections. Third, large collec- tions were made by St John and Fosberg during the Mangarevan Expedition in 1934, and published both in numerous systematic papers and as a com- prehensive listing by St John and Philipson (1962). Finally, W. H. Lintott collected 25 species in 1957, and these too were reported by St John and Philipson (1962). St John and Philipson mention that J. H. Maiden collected 'a few common species', said to be reported in his 1896 paper on Pitcairn, but this paper does not in fact mention Hender- son plants. The flora listed by St John and Philipson (1962) includes 8 ferns and 55 angiosperms; to these should be added Sesuvium portulacastrum L., and Capparis sandwichiana DC. collected during the Whitney Expedition and by Lintott, and inadvertently omitted from their list. The plants are listed with some revision of nomenclature in Appendix 1. In addi- tion to the main listings by Brown (1931, 1935), Brown and Brown (1935), and St John and Philipson (1962), Henderson plants collected by the Mangarevan Expedition have been included in many systematic papers, notably by Copeland (1938), five species of ferns; Skottsberg (1937), two species of Liliaceae; von Poellnitz (1936), Portulaca; Skottsberg (1938), Santalum; Heimerl (1937), Peperomia; and Sherff (1937), Bidens. It is of interest that no less than eight species, or 12 per cent of the recorded flora, have only been collected on one occasion, by D. R. Tait in 1912. Six species and five varieties of angiosperms are described as endemic to Henderson, not including the new variety of Korthalsella margaretae defined by Brown (1935) but reduced to K. vitiensis by St John and Philipson (1962, 180), or the new variety Polypodium . euro- phyllum C. Chr. var. hendersonianum E. Br. (in Brown and Brown 1931) which they reduce to Microsorium vitiense (Baker) Copeland. The endemic species and varieties presently accepted are: Peperomia hendersonensis Yuncker (in Yuncker 1937, 16-17) Celtis paniculata Planch. var. viridis F. Br. (in Brown 1935, 32) Santalum hendersonense F. Br. (in Brown 1935, 66) Myrsine hosakae St John (in St John and Philipson 1962, 189-190) Nesoluma st-johnianum H. J. Lam and Meeuse (in Lam and Meeuse 1938, 153-154) Geniostoma hendersonense St John (in St John and Philipson 1962, 190) 18 Heliotropium anomalum Hooker and Arnott var. candidum St John (in St John and Philipson 1962, 192) Canthium barbatum (Forst. f.) Seem. var. christianii Fosb. forma calcicola Fosb. (in Fosberg 1937) Bidens hendersonensis Sherff (in Sherff 1937, 6) var. hendersonensis Sherff (in Sherff 1937, 6) var. subspathulata Sherff (in Sherff 1937, 7) Comments on some of these species are given in Appendix 1. Other taxa originally defined from Henderson Island material, but not endemic to the island, include Euphorbia ramosissima Hooker and Arnott (= E. Sparrmannii Boiss. in Appendix 1), Cassia glanduligera St John (in St John and Philipson 1962, 181-184), also in the Australs; and Dianella intermedia Endl. var. gambierensis F. Br. (in Brown 1931, 152), also on Mangareva. Four adventive species are listed: Cocos nucifera. This is recorded as being planted as early as 1843 by the Pitcairn Islanders (Brodie 1851, 17). Trees were found by Stephen in 1907 (North 1908), by Bank (1909) (a dozen trees divided between the north and west landings), and by Tait (1912). Collected by the Mangarevan Expedition in 1934, when Fosberg noted that the trees were ‘all young’. Probably repeatedly planted by the Pitcairn Islanders over the years. Cordyline terminalis, collected only by the Mangarevan Expedi- tion in 1934, when Fosberg noted half a dozen plants. Aleurites moluccana, collected only by the Whitney Expedition in 1922. Achyranthes aspera, collected only by Tait in 1912, and the only one of the four not a deliberate introduction. In addition James Bank in his report of 5 January 1909 records plant- ing limes and oranges, and these are mentioned, together with potatoes, by Maude (1951, 63). Besides the vascular plants, the Mangarevan Expedition also col- lected three species of Fungi, five lichens and ten bryophytes, all listed by St John and Philipson (1962). An earlier list of the bryo- phytes was given by Bartram (1940). MAMMALS There are no native mammals on Henderson. Several have, however, been landed since the island was discovered. Goats were first taken to Henderson from Pitcairn in 1843, but through inadvertence were not landed before the vessel left (Brodie 1851, 17). Three were, however, released during the visit of the Whitney Expedition in 1923 (Beck 1923), but had disappeared by the time of the Mangarevan Expedition in 1934. 19 Pigs were landed by D. R. Tait in 1912, but of these there is no sub- sequent record. Mice are mentioned as being numerous at the north land- ing by James Bank (1909), but are not otherwise recorded. The only Numerous introduced mammal is the Polynesian Rat. King (1820) found it there in 1819. Bank mentioned it as numerous at the north landing in 1909, and Stephen had also found it present in 1907 (North 1908). Speci- mens were collected by the Whitney Expedition and listed under Rattus exulans (Peale) by Tate (1935). BIRDS The Quirdéds expedition recorded seabirds in the neighbourhood of Henderson - Gaspar de Leza specifies 'grey gulls and terns" - in January 1606. Much later, in 1819, King (1820) recorded a parrot and a few pigeons, and later in the same year the castaways from the Essex re- corded tropicbirds in holes, with young and eggs, and also 'small birds, about the size of a blackbird', roosting in the trees (Gibbings, ed. 1935, 55, 79). The first collections of birds, however, were made by A. E. Stephen in 1907, and the specimens described by North (1908). D. R. Tait and J. R. Jamieson also made collections in 1912, and these were reported by Ogilvie-Grant (1913a, 1913b). The major contribution to the orni- thology of Henderson was, however, the Whitney Expedition in 1922, which resulted in a long series of papers referred to below. Subsequently, W. H. Lintott made some observations in 1957, and these were incorporated in Williams's (1960) paper on the birds of Pitcairn. A comprehensive summary of knowledge of the birds of Henderson is in preparation by Bourne and David. This section therefore simply keys the published literature on the seabirds, shorebirds and land birds, and the manuscript records by Beck and Quayle of the Whitney Expedition. Nomenclature follows that of du Pont (1976) who listed most or all of the birds known from the island. Seabirds Pterodroma ultima Murphy Murphy's Petrel, Oeno Petrel Recorded by du Pont (1976). Pterodroma neglecta (Schlegel) Kermadec Petrel Collected by Beck and Quayle in 1922. Recorded by Murphy and Pennoyer (1952, 27); as breeding by Williams (1960). P. ultima and P. neglecta are regarded as distinct by Williams and du Pont (1976) and both recorded by them for Henderson. Pterodroma alba (Gmelin) Phoenix Petrel Collected by Quayle and Beck in 1922, called Henderson Petrel. Recorded by Murphy and Pennoyer (1952,33); and as breeding by Williams (1960) and King (1967). 20 Pterodroma arminjoniana heraldica (Salvin) Herald Petrel Recorded by Murphy and Pennoyer (1952, 39); and as breeding by Williams (1960) and King (1967). Puffinus nativitatis Streets Christmas Shearwater Shearwaters of undetermined species were recorded as 'very plenti- ful' by Stephen in 1907 (North 1908). This species recorded as probably breeding by Williams (1960) and King (1967). Apparently not collected on Henderson by the Whitney Expedition in 1922. Puffinus pacificus pacificus (Gmelin) Wedge-tailed Shearwater Collected by Beck in 1922. Recorded as breeding by Murphy (1951) and Williams (1960). Gygis alba candida (Gmelin) White Tern Noted as 'plentiful' and egg reported by Stephen in 1907 (North 1908). Recorded as G. candida (Gmelin) by Ogilvie-Grant (1913a, 1913b). Collected and noted as a white-footed form by Quayle and Beck in 1922. Recorded as breeding by Williams (1960). Anous stolidus pileatus (Scopoli) Common Noddy Noted as 'not so plentiful’ by Stephen in 1907 (North 1908). Re- corded as A. leucocapillus (Gould) by Ogilvie-Grant (1913a, 1913b). Collected by Beck and Quayle but not common in 1922. Recorded as breed- ing by Williams (1960) and Baker (1951). Anous tenuirostris minutus Boie Black Noddy Rare, one collected by Beck or Quayle in 1922. Procelsterna coerulea skottsbergii Bonaparte Blue-grey Noddy, Grey Ternlet Seen and collected by Beck and Quayle in 1922, not common. Re- corded as P. coerulea (Bennett) by Ogilvie-Grant (1913a, 1913b) and as P. c. skottsbergii in Peters (1934). Recorded as breeding by Williams (1960). Phaethon rubricauda subsp. (Gmelin) Red-tailed Tropicbird Recorded as breeding by Beck in 1922, and Williams (1960), based on local reports. Sula dactylatra personata Gould Masked Booby One individual collected by Quayle in 1922. Recorded as common, with chicks, in January 1957, by Lintott (Williams 1960). ee 21 Sula leucogaster plotus (Forster) Brown Booby Sight record in 1957 recorded by Williams (1960). Sula sula rubripes Gould Red-footed Booby Recorded by Ogilvie-Grant (1913a, 1913b) (as S. piscator) and by Murphy (1936); noted as probably breeding by Williams (1960). Henderson specimens were included by Grant and Mackworth-Praed (1933, 118) under their new species §. nicolli, but this is now regarded as a colour phase of S. sula. Fregata minor subsp. (Gmelin) Greater Frigatebird Described as ‘numerous’ by Stephen in 1907 (North 1908). Seen and collected by Beck and Quayle in 1922. Recorded as probably breeding by Williams (1960), based on local information. Shorebirds Numenius tahitiensis (Gmelin) Bristle-thighed Curlew Summer migrant, collected by Quayle and Beck in March-April 1922 (Stickney 1943). Heteroscelus incanus incanus (Gmelin) American Wandering Tatler Summer migrant, recorded in March-April 1922 (Stickney 1943). Calidris alba (Pallas) Sanderling Recorded by Stephen in 1907 (Ogilvie-Grant 1913a, 1913b); seen but not collected by Quayle in 1922. Wading birds Egretta sacra sacra Gmelin Reef Heron One individual seen by Beck and Quayle in 1922. Land birds Porzana atra North Henderson Island Rail, Henderson Island Crake Collected by Stephen in 1907, who noted it as 'plentiful', and described as Porzana atra n.sp. Black Water Crake by North (1908). Col- lected by Tait in 1912 and independently described by Porzana murrayi n.sp. by Ogilvie-Grant (1913a), a name abandoned by Ogilvie-Grant (1913b). Recollected in 1922 by Quayle and Beck of the Whitney Expedi- tion and assigned to a new endemic genus as Nesophylax ater (North) by Murphy (1924). Described under North's name, with a colour plate, by Ripley (1977, 235, plate 29), without reference to Murphy (1924). Listed as breeding by Williams (1960). 22 The widespread and closely related Porzana t. tabuensis Spotless Crake occurs on nearby Oeno (Murphy 1924, Amadon 1942, Williams 1960). Ptilinopus purpuratus insularis (North) Henderson Island Fruit Pigeon Described in flocks of twenty or more by Stephen in 1907, and named as Ptilopus insularis n.sp. by North (1908). Collected by Tait in 1912 and described as Ptilopus coralensis Peale by Ogilvie-Grant (1913a). Listed as Ptilopus insularis North by Ogilvie-Grant (1913b). The Whitney collections in 1922 were listed under the same name by Murphy (1924). Named as an endemic subspecies of Ptilinopus purpuratus (Gmelin), widely distributed in the Societies and the Tuamotus, by Ripley and Burckhead (1942). Listed as still common and breeding by Williams (1960). Vini stepheni (North) Henderson Island Parrot Noted as 'not very plentiful' by Stephen in 1907, and described as Calliptilus(?) stepheni n.sp. by North (1908). Collected by Tait in 1912 and described as Vini hendersoni n.sp. by Ogilvie-Grant (1913a). Named as Vini stepheni (North), with a colour plate, in Ogilvie-Grant (1913b). Collected by Beck and Quayle of the Whitney Expedition in 1922 and said to be common; and listed by Amadon (1942). Listed as breeding but apparently not very common by Williams (1960). An endemic species. Acrocephalus vaughani taiti (Ogilvie-Grant) Henderson Island Warbler Collected by Tait in 1912 and named Acrocephalus taiti n.sp. by Ogilvie-Grant (1913a, 1913b). Collected by Quayle and Beck of the Whitney Expedition in 1922, said to be very common; and listed as Conopoderas vaughani taiti (Ogilvie-Grant) by Murphy and Mathews (1929). Listed as breeding by Williams (1960), who also notes the presence of A. v. vaughani (Sharpe) on Pitcairn. An endemic subspecies. REPTILES Lizards were apparently first observed by Stephen in 1907, when he found them 'very plentiful' (North 1908). Six skinks were collected by the Whitney Expedition in 1923 and listed by Ortenburger (1923) and later by Burt and Burt (1932) as Emoia cyanura (Lesson), a widespread species. A gecko has been seen but we do not know of specimens or an identifica- tion. The green sea turtle, Chelone mydas (L.), comes ashore to lay its eggs on the few beaches (Quayle 1922). TERRESTRIAL ARTHROPODA No special effort has ever been made to collect any of the Hender- son Island arthropods, except the insects, which were gathered by Zimmerman in 1934. Even this can only be regarded as preliminary, being the results of one man's work for only six days. A longer, less hurried effort, with light traps, Berlese funnels and other special methods, could be expected to yield a tremendous increase in the known inverte- brate fauna of the island. 23 A discussion written by Dr. Frank G. Howarth, of B. P. Bishop Museum, Honolulu, states the case very well: "The [terrestrial ] arthropod fauna of Henderson I. is still quite poorly known. Only about [40] species have been recorded to date, of which about [a third] are likely endemics. Judging from the recorded lushness and diversity of the flora, the insect fauna should be at least an order of magnitude greater. Zimmerman (1935) wrote that a number of endemic species were collected during the week's stay of the Mangarevan Expedition. Apparently, only a few taxonomic groups have been worked up from those collections, as only 15 families of arthropods are repre- sented in the published records. Based on the known faunas of other small Pacific islands, one would expect to find at least 100 families and a total arthropod fauna of a few hundred species of which approxi- mately 50% would be endemic to Henderson or perhaps also to Pitcairn I. For example, there are apparently no published records of Lepidoptera (moths), which is second only to the Coleoptera in numbers of species on other Pacific islands. Neither are there any records for Collembola, Orthoptera, Myriapoda, or native Hymenoptera, all of which should be ex- pected there. "Many insects and relatives are probably endemic to the Pitcairn Group. As the fauna and flora on the inhabited island of Pitcairn it- self become more ravaged by goats and other man-caused perturbations, Henderson Island will become more important as a refuge or Noah's Ark for many of these restricted species. "A number of special habitats, which undoubtably occur there, have not been faunistically surveyed. For example, being a raised coralline island a subterranean fauna should exist there, of which the aquatic or "anchialine' underground fauna should be especially well developed with Many native species. A significant terrestrial cave fauna may also have evolved there. "Distant described 3 new species of Issidae in 1913, and none of these species have been subsequently reported on again. Their status may be problematical. Fennah, 1958, reviewed the fulgorid fauna of SE Polynesia but apparently missed Distant's 1913 paper (!). Fennah de- scribed a 4th Issidae as an endemic subspecies with the type subspecies endemic to Pitcairn I. Zimmerman collected a nice series of Catacanthus taiti on the Mangarevan Expedition. The species is still known only from Henderson (based on our collections). Related species occur in the Society and Marquesas Is., and based on the impressive, conspicuous size and color of C. taiti, the fact that it hasn't been found elsewhere, sug- gests that it is endemic. Both Coleotichus and Ugyops have many native restricted species in the Pacific, thus, it is probable that these un- identified specimens represent at least native species, and may be en- demic. The weevils are among the best known groups of arthropods in the Pacific; therefore the 2 listed species are undoubtedly endemic and are of special interest to biogeographers, evolutionists, ecologists and others. 24 "Based on the above lack of entomological data and the possibility of environmental disturbance, if not by the current venture then by some fool liberating goats or the like, I think it is abundantly clear that we should attempt to launch or assist in a modern entomological/ecologi- cal expedition to this island to fill this critical lacuna. Of equal import to science is the predictable occurrence of excellently preserved and highly significant paleontological material in the limestone sink- holes." Insecta Stephen found a butterfly abundant in 1907 (North 1908), and Tait states that he sent insects to the British Museum (Natural History) in 1912, but of these we have found only a few published records (Distant 1913). Otherwise most of the insect records published for Henderson are of collections made by Zimmerman on the Mangarevan Expedition in 1934. According to Frank J. Radovsky (in litt.) there are at least 33 species of insects recorded from the island, of which 11 (acc. Frank G. Howarth in litt.) are, so far as known, endemic. We are only able to give a partial list of these, with sources. Thysanoptera Thrips albipes Bagnall (in Moulton 1939). Rhynchota Atylana parmula thalna Fennah (1958). Endemic. Catacanthus taiti Distant (1913). Endemic. Coleotichus sp. (Distant 1913), Possibly endemic. Devagama fasciata Distant (1913). Endemic. Devagama insularis Distant (1913). Endemic. Devagama maculata Distant (1913). Endemic. Lallemandana insignis insignis (Distant) (Hamilton 1980). Endemic. Peregrinus maidis Ashmead (Fennah 1958). Ugyops sp. (Fennah 1958). Possibly endemic. Coleoptera Hypothenemus eopolyphagus Beeson (1940). Microcryptorhynchus orientissimus Zimmerman (1936). Endemic. Nesonos brunneus Zimmerman (1938). 2S) Notioxenus cylindricus Jordan (Zimmerman 1938). Rhyncogonus hendersoni Van Dyke (1937). Endemic. Stephanoderes pacificus Beeson (1940). Stephanoderes vafer Blandford (Beeson 1940). Hymenoptera Cardiocondyla nuda Mayr subsp. nereis Wheeler (1936). Monomorium floricola (Jordan)(Wheeler 1936). Tapinoma melanocephalum (Fabr.) var. australe Santschi (Wheeler 1936). Technomyrmex albipes (F. Smith) (Wheeler 1936). Tetramorium guineense (Fabr.)(Wheeler 1936). Nylanderia vaga Forel var. crassipilis Santschi (Wheeler 1936). Diptera Dacus setinervis Malloch 1938 (Drew 1975). Arachnida Three species of spiders collected by the Mangarevan Expedition are listed for Henderson by Berland (1942): Thorellia ensifera (Thorell) Theridion paumotui Berland Cyrtophora moluccensis Doleschall. Crustacea No land crabs have been recorded from Henderson. A very large cenobite, perhaps Birgus, was captured by a member of the party in 1934, but the specimen may not have been saved. Four species of terrestrial isopods, none of them endemic, are recorded from Mangarevan Expedition collections by Jackson (1938). They are Philoscia truncata Dollfus, P. fasciata Jackson, Spherillo montivagus Budde-Lund, and S. marque- sarum Jackson. 26 LAND MOLLUSCA Land Mollusca were collected by C. Montague Cooke, Jr., during the Mangarevan Expedition. One species was previously recorded, but at least 12-15 additional species were found (Cooke 1934, 44). Cooke and Kondo (1960, 256) estimated the fauna at 18 species. The following records have been published: Achatinellidae Tornatellides (Tornatellides) oblongus parvulus n. subsp. (in Cooke and Kondo 1960, 255), endemic subspecies. Tubuaia hendersoni n.sp. (in Kondo 1962, 36-38), endemic species. Endodontidae Minidonta hendersoni n.sp. (in Solem 1976), endemic species. Helicarionidae Diastole (Diastole) glaucina Baker (in Baker 1938, 50), endemic species; Helicinidae Orobophana solidula (Gray) (in Cooke and Kondo 1960, 255). In addition, Cooke and Kondo (1960, 256) mention specimens from Henderson in the following genera: Elasmias, Lamellidea and Torna- tellinops (Achatinellidae); Syncera (= Assiminea) (Assimineidae) ; Melampus (Ellobiidae); Georissa (Hydrocenidae); Nesopupa and Pupisoma (Pupillidae); and Thaumatodon. MARINE FAUNA As mentioned above, the schooner Westward made only brief stops at Henderson Island on her trip from Pitcairn to Ducie Atoll and back. Actually only one full day and two afternoons were spent there, and the only extensive collection made was of mollusks. Fishes The diving group spent their time searching for and collecting fishes and checking for the presence of Acanthaster planci (Linnaeus), the Crown-of-Thorns. J. E. Randall (pers. comm.) received the impres- sion during the diving operations that the fauna was richer than that of Ducie (Rehder and Randall, 1975, 21-26). He has made no list of species collected and seen, feeling that such a list would be without value considering the shortness of the stay at the island. 27 Mollusks See Appendix 2. Other Invertebrates No. material other than mollusks were collected during the Westward visit, in large measure due to the absence of Dennis M. Devaney during this segment of the trip. One noteworthy comment is that no specimens of Acanthaster planci were seen by the divers despite the fact that one of the programs carried out on the Westward was a survey of the presence of the Crown-of-Thorns in southeastern Polynesia. Beechey (1833, 49) mentions the presence of ‘numerous echini' on the reef flat, probably Diadema savignyi Michelin or D. setosum (Leske), as he comments on their capability of inflicting ‘painful wounds." Beechey also mentions seeing some '‘cray-fish' in the cavities on the reef (Panulirus species). SCIENTIFIC IMPORTANCE AND CONSERVATION : Access to Pitcairn Island (and thus to other islands of the group) requires a license issued by the Office of the Commissioner for Pitcairn, issued by the Governor after the visit has been approved by the Pitcairn Island Council; casual visitors may land at the discretion of the Island Magistrate. There are no conservation measures applicable to Pitcairn or to its associated islands. In 1969 Henderson, Ducie and Oeno were all included in a list of Pacific islands proposed for international sci- entific supervision, possibly under the proposed ‘Islands for Science' Convention (Douglas 1969, 463). No action was taken on this proposal. In 1982 it became known that proposals had been made to the British Government by a wealthy American citizen, who wished to take up residence on Henderson in exchange for development assistance on Pitcairn. This proposal, when it became known, led to considerable concern in the sci- entific community, which was openly voiced at the XVth Pacific Science Congress in Dunedin, New Zealand. Appendix 3 gives the text of a reso- lution on Henderson Island adopted at this Congress. There has been a growing interest in island biology, first taking on a scientific character with the work of Charles Darwin, but in the last few decades receiving greater and greater scientific attention. One of the preoccupations of this interest has been to determine what the conditions were on different types of islands before humans and especially before Europeans arrived and brought about drastic changes in the nature and functioning of these ecosystems. Very inadequate historical evidence exists, and for most islands none at all. In Hen- derson we have, preserved, a fine example of one of the most interesting types of island. It has the advantages of being small and remote, and of having a simple enough biota that its relationships, processes and functioning may possibly be understood with adequate investigation. 28 It is certain that undescribed species exist, especially of smaller and less conspicuous animals. It is equally certain that many of the species inhabiting the island, known or unknown, are threatened by the proposed disturbances, and will immediately become endangered if the de= velopment project is carried forward. The amount of attention being given to endangered species at present indicates that, whether for philo- sophic or practical reasons, a real value is attached to our co-inhabitants of the globe by the better elements of our Western culture. This should not lightly be brushed aside. The study of islands as microcosms of more complex ecosystems has the practical significance of enabling us to gain some insight into the functioning of the larger and infinitely more complex ecosystems in which the majority of humanity live. Hence it would seem folly to permit the destruction of the only remaining intact example of one of the most im- portant classes of islands that could form an important component of this study. Even its very scarcity or uniqueness would seem to enhance its value, as it does with so many other, mostly less important things. ACKNOWLEDGEMENTS Most of the text and compilation is the work of the authors, but we wish to express our thanks to W. R. P. Bourne, C, C. Christensen, Lt Cdr A. C. F. David, Frank G. Howarth, Frank J. Radovsky, Harald A. Rehder, and Yosi Sinoto for substantial contributions of information, and to Lenore Smith for typing the manuscript. Note While the present report was being assembled, other naturalists expressed their concern for the future of Henderson Island natural eco- systems in the following report: Serpeli J. ,. Collards IN.) Davis Sia vand aWelllis 7S uel 98eer Submission to the Foreign and Commonwealth Office on the future conservation of Haiderson Island in the Pitcairn Group. London: World Wildlife Fund-UK, International Union for Conservation of Nature and Natural Resources, and International Council for Bird Preservation. 26 pp. The need for more adequate knowledge of the biota and ecology of Henderson Island is of such urgency that the Smithsonian Institution, in cooperation with the Royal Society, is actively planning a biological and geomorphological survey of the island, to take place during 1984 if the necessary permits can be secured and funds can be raised. 29 Appendix 1. A revised list of the vascular plants of Henderson Island. No additional collections have come to our attention since the ac- count of the flora by St John and Philipson (1962) was published, but much work has been done on the Pacific flora since then, and some names have been changed. Two species collected by Lintott were inadvertently omitted by St John and Philipson. Also our concepts of some taxa differ from those of the authors of that account. Such revisions and changes are presented, with a few explanatory remarks and comments, in the fol- lowing list. Asplenium lobulatum Mett. Asplenium nidus L. Asplenium obtusatum Forst.f. Davallia solida (Forst.f.) Sw. Nephrolepis biserrata (Sw.) Schott Nephrolepis exaltata (L.) Schott Perhaps an alternative identification of the preceding. Cyclophorus blepharolepis C. Chr. Polypodium vitiense Baker Microsorium vitiense (Baker) C. Chr. Polypodium euryphyllum var. hendersonianum E. Br. We do not see much to be gained from extreme segregation of the genus Polypodiun. Polypodium scolopendria Burm.f. Phymatodes scolopendria (Burm.f.) Ching Pandanus tectorius Parkinson Pandanus sp. of St John and Philipson (1962) Lepturus repens (Forst.f.) R. Br. Thuarea involuta (Forst.f.) R. and S. Henderson is the eastern extreme of this widespread Indo- Pacific beach grass. 30 Fimbristylis cymosa R. Br. (s.1.) Fimbrystylis sp. of St John and Philipson (1962) *Cocos nucifera L. A few trees, originally planted. *Cordyline fruticosa (L.) Chev. Cordyline terminalis (L.) Kunth (Cordyline fruticosa Goepp.) (nom. nud.) This has frequently been called C. terminalis under the as- sumption that C. fruticosa (L.) Chev. is an illegitimate later homonym of C. fruticosa Goepp., but that was based only on a reference to a name Dracaena fruticosa H. Berol. that was ap- parently never published. Dianella intermedia var. gambierensis F. Br. Peperomia hendersonensis Yuncker Endemic to Henderson. Celtis paniculata var. viridis F. Br. Procris pedunculata (Forst.) Wedd. Korthalsella rubescens (v. Tiegh.) Lecomte Korthalsella vitiensis (v. Tiegh.) Engler Santalum hendersonense F. Br. Endemic to Henderson. *Achyranthes aspera var. pubescens (Moq.) Townsend From the brief descriptive remarks by St John and Philipson (1962) this seems to be the widespread var. pubescens (Moq.) as defined by Townsend, Kew Bull. 29 (1974), 473. Boerhavia tetrandra Forst.f. Boerhavia diffusa var. tetrandra (Forst.f.) Heimerl *Species thus marked are introduced. 31 Pisonia grandis R. Br. Portulaca lutea Sol. ex Forst.f. Sesuvium portulacastrum L. Represented by Lintott H 22 (CHR), not listed by St John and Philipson (1962). Cassytha filiformis L. Hernandia sonora L. Capparis sandwichiana DC. Represented by Lintott H 24 (CHR), not listed by St John and Philipson (1962). Lepidium bidentatum Mont. Pittosporum arborescens Rich. ex Gray Caesalpinia bonduc (L.) Roxb. Cassia glanduligera St John Close to and formerly considered identical with C. gaudi- chaudii H. and A., of Hawaii. C. glanduligera is also known from the Austral Islands. Sesbania coccinea (L.f.) Poir. Sesbania speciosa (Soland.) R. Br. var. tuamotuensis R. Br. Sesbania atollensis St John The specimen, Lintott H 1 (CHR) on which the Henderson Island record of Sesbania atollensis St John is based could not be lo- cated at Christchurch in 1983 according to Miss B. M. Macmillan (pers. comm.). Suriana maritima L. *Aleurites moluccana (L.) Willd. Euphorbia sparrmannii Boiss. Euphorbia ramosissima H. and A. (non Loisel.) Glochidion tahitense var. pitcairnense F. Br. Endemic to Henderson and Pitcairn Islands. 32 Triumfetta procumbens Forst.f. Thespesia populnea (L.) Sol. ex Correa Xylosma suaveolens subsp. haroldii Sleumer Pemphis acidula Forst, Eugenia rariflora Benth. Meryta brachypoda Harms Endemic to Henderson and the Austral Islands. Myrsine hosakae St John Endemic to Henderson; tree 7 m tall. Nesoluma st-johnianum Lam and Meeuse Endemic to Henderson, Geniostoma hendersonense St John Tree 3-8 m tall; endemic to Henderson. Beechey's (1825, 63-64) ‘species of budleia'. Jasminum didymum Forst.f. St. John (1940) suggests that Cuming's "Jessamine" may be this, but does not include it in the 1962 paper. We have no definite record based on a specimen. No complete list of Cum- ing's "Elizabeth Island" plants has come to our attention. Alyxia stellata (Forst.) R. and S. Ipomoea macrantha R. and S. Ipomoea grandiflora sensu F. Br. non (Choisy) Hallier Ipomoea glaberrima Bojer Cordia subcordata Lam. Heliotropium anomalum var. candidum St John Endemic to Henderson. 33 Tournefortia argentea L.f. Messerschmidia argentea (L.f.) I. M. Johnst. Argusia argentea (L.f.) Heine This seems merely to be a Tournefortia adapted to saline strand habitats rather than related to Argusia. Premna obtusifolia R. Br. Premna integrifolia L. Lycium carolinense var. sandwicense (A. Gray) Hitch. Lycium sandwicense A. Gray There seem to be almost no differences between the Central Pacific strand Lycium and its relative on both coasts of sou- thern North America. Canthium barbatum f. calcicola Fosb. Canthium odoratum (Forst.f.) Seem. Guettarda speciosa L. Ixora fragrans (H. and A.) A. Gray Cephaelis fragrans H. and A. Morinda umbellata var. forsteri (Seem.) Fosb. Timonius polygama (Forst.) Robins. Scaevola sericea var. tuamotuensis (St John) Fosb. Bidens hendersonensis Sherff var. hendersonensis Sherff Perhaps the only species of Bidens that reaches tree size. Endemic to Henderson. Bidens hendersonensis Sherff var. subspathulata Sherff Endemic to Henderson, if indeed distinct from var. hendersonensis. Fitchia nutans Hook.f, Not found on Henderson since the original collection by Hugh Cuming, which is suspected to have actually come from Tahiti. The labels of some of Cuming's collections are known to have been mixed. Senecio stokesii F. Br. 34 Appendix 2. A revised list of the marine mollusks of Henderson Island by Harald A. Rehder. In 1913 a list of marine mollusks collected at Henderson Island was published by E. A. Smith (1913). This collection was made by J. R. Jamieson and D. R. Tait during their stay on the island while carrying out a survey of the phosphate deposits. Before this list the only spe- cies known from this island were those described by Broderip and Sowerby from specimens collected here by Hugh Cuming and possibly also by Beechey. In January 1971 I spent parts of two days on the island making col- lections on the reef flat at the large beach on the north coast and also on the adjoining cliffs. In the following list those species collected by me and not appear- ing in the 1913 paper by Smith are marked with an asterisk*. The names in Smith's publication, when different, are cited under the presently accepted name. Haliotis pulcherrima Gmelin, 1791 Patelloida conoidalis (Pease, 1868) Acmaea conoidalis Pease Patella flexuosa Quoy and Gaimard, 1834 Patella stellaeformis Reeve, 1842 Broderipia iridescens (Broderip, 1834) An examination of a large number of specimens of this genus leads me to believe that Broderipia rosea (Broderip, 1834) and B. subiridescens Pilsbry, 1890, represent growth stages of iridescens. Pseudostomatella (Stomatolina) speciosa (A. Adams, 1850) Stomatella speciosa A. Adams Cantharidus marmoreus (Pease, 1867) Calliostoma roseopictum E. A, Smith, 1913 Turbo petholatus Linnaeus, 1758 Turbo argyrostomus Linnaeus, 1758 Nerita morio (Sowerby, 1833) Nerita melanotragus Smith, 1884 In my Ducie report (Rehder and Randall, 1975, 29) I erroneously reported this species as Nerita haneti Recluz, 1841. Nerita plicata Linnaeus, 1758 35 Littorina coccinea (Gmelin, 1791) Littorina obesa Sowerby, 1832 Nodilittorina pyramidalis pascua Rosewater, 1970 Littorina trochoides Gray, 1839 Royella sinon (Bayle, 1880) Rhinoclavis sinensis (Gmelin, 1791) Cerithium rubus Deshayes, 1843 Cerithium tuberculiferum Pease, 1869 Cerithium atromarginatum Bavay and Dautzenberg Cerithium nassoide Sowerby, 1855 Cerithium egenum Ganildl, 1849 Cerithium rarimaculatum Sowerby, 1855 *Dendropoma maximum (Sowerby, 1825) Epitonium torquatum (Fenaux, 1943) Epitonium perplexum (Pease, 1868) For a discussion of this identification see my report on the marine mollusks of Easter Island (Rehder, 1980, 52). Ianthina ianthina (Linnaeus, 1758) Ianthina communis (Lamarck, 1822) Vanikoro plicata (Recluz, 1844) Strombus mutabilis Swainson, 1821 *Lambis truncata (Lightfoot, 1782) *Lambis (Harpago) rugosa (Sowerby, 1842) Polinices (Mamilla) simiae (Deshayes, 1838) Mamilla simiae Deshayes Natica gualteriana Recluz, 1844 Natica dillwyni Payraudeau, 1826 Cypraea cumingi Gray, 1832 Cypraea irrorata Gray, 1828 Cypraea goodalli Gray, 1832 Cypraea fimbriata Gmelin, 1791 Cypraea minoridens Cypraea childreni Gray, 1825 Cypraea cicercula Linnaeus, 1758 Cypraea dillwyni Schilder, 1922 Cypraea margarita Gray, 1828, not Dillwyn, 1817 36 Cypraea helvola Linnaeus, 1758 Cypraea poraria Linnaeus, 1758 Cypraea caputserpentis Linnaeus, 1758 *Cypraea maculifera Schilder, 1932 Cypraea subteres Weinkauff, 1881 Cypraea scurra Gmelin, 1791 Cypraea isabella Linnaeus, 1758 *Cypraea mappa Linnaeus, 1758 Cypraea schilderorum (Iredale, 1939) Cypraea arenosa Gray, 1824 *Cypraea ventriculus Lamarck, 1810 Trivia edgari Shaw, 1909 Trivia oryza Lamarck, 1810 Casmaria erinacea (Linnaeus, 1758) Cassis (Casmaria) vibex (Linnaeus, 1758) Morum ponderosum (Hanley, 1858) Bursa (Colubrellina) granularis (Roding, 1798) Bursa (Colubrellina) affinis (Broderip, 1833) Maculotriton serrialis (Laborde, 1838) Maculotriton bracteatus (Hinds, 1844) var. Phyllocoma convoluta (Broderip, 1833) Bursa (Craspedotriton) convoluta (Broderip) Drupa morum Roding, 1798 Drupa horrida (Lamarck, 1816) Drupa clathrata (Lamarck, 1816) *Drupa elegans (Broderip and Sowerby, 1829) Drupa ricinus (Linnaeus, 1758) *Drupa (Drupina) grossularia Roding, 1798 Morula uva (Roding, 1798) Drupa morus (Lamarck, 1822) Morula granulata (Duclos, 1832) Drupa tuberculata (Blainville, 1832) var. Morula dealbata (Reeve, 1846) Thais (Thalessa) intermedia (Kiener, 1835) *Thais (Thalessa) affinis (Reeve, 1846) 37 Nassa sertum (Bruguiére, 1789) Iopas sertum (Bruguiére) Vexilla vexillum (Gmelin, 1791) Vexillum vexillum (Chemnitz, 1788) Vexillum taeniata (Powis, 1836) Quoyula monodonta (Blainville, 1832) Quoyula madreporarum (Sowerby, 1834) Euplica palumbina (Gould, 1845) Columbella turturina sensu Smith, 1913, not Lamarck, 1822 Euplica varians (Sowerby, 1832) Columbella varians Sowerby Pyrene obtusa (Sowerby, 1832) Columbella obtusa Sowerby Engina fuscolineata E. A. Smith, 1913 Engina rosacea (E. A. Smith, 1913) Tritonidea rosacea E. A. Smith Tritonidea difficilis E. A. Smith, 1913 Without an examination of the holotypes of the last two species I am uncertain of their proper generic assignment. Caducifer decapitata fuscomaculata (Pease, 1860) Caducifer cylindrica (Pease, 1868) Colubraria nitidula (Sowerby, 1833) Alectrion papillosa (Linnaeus, 1758) Nassa papillosa (Linnaeus) Nassarius (Telasco) gaudiosa (Hinds, 1844) Nassa gaudiosa Hinds Latirus nodatus (Gmelin, 1791) Mitra (Mitra) stictica (Link, 1807) Mitra pontificalis Lamarck, 1811 Mitra (Mitra) coffea Schubert and Wagner, 1829 Mitra fulva Swainson, 1829 Mitra (Strigatella) auriculoides Reeve, 1845 Mitra (Strigatella) litterata Lamarck, 1811 Mitra maculosa Reeve, 1844 38 Vasum armatun (Broderip, 1833) Neither I nor Jamieson and Tate found this species during our visits to Henderson, although this is the type locality for the species, described by Broderip from material collected by Cuming in 1827. It is found from Rose Atoll, Eastern Samoa, and the Ellice and Phoenix Islands, southeastward to Henderson Island. Conus lividus Hwass, 1792 Conus ebraeus Linnaeus, 1758 Conus chaldeus Roding, 1798 Conus hebraeus var. vermiculatus Lamarck, 1810 Conus miliaris Hwass, 1792 Conus nanus Sowerby, 1833 Conus ceylonensis var. nanus Sowerby *Conus sponsalis Hwass, 1792 Conus tessulatus Born, 1778 Conus tesselatus Born Conus rattus Hwass, 1792 *Conus sanguinolentus Quoy and Gaimard, 1834 Conus retifer Menke, 1829 Conus solidus Sowerby, 1834 Conus tulipa Linnaeus, 1758 Conus tenuistriatus Sowerby, 1856 Conus glans var, tenuistriatus Sowerby Conus pennaceus Born, 1778 Conus pennaceus var. episcopus Hwass 1792 Bulla species (juvenile) Melampus flavus (Gmelin, 1791) Melampus luteus Quoy and Gaimard, 1832 Arca avellana Lamarck, 1819 Arca maculata Sowerby, 1833 Acar divaricata (Sowerby, 1833) Arca (Acar) domingensis sensu Smith, not Lamarck, 1819 Barbatia parva (Sowerby, 1833) Arca (Barbatia) parva Sowerby *Lima lima (Linnaeus, 1758) Lima bullifera Deshayes, 1863 39 Spondylus species Codakia (Epicodakia) bella (Conrad, 1837) Lucina (Codakia) divergens Philippi, 1850 Tridacna maxima (Roding, 1798) Tridacna crocea sensu Smith, not Lamarck, 1819 Tridacna squamosa sensu Smith, not Lamarck, 1819 Trapezium oblongum (Linnaeus, 1758) Libitina guiniaca (Chemnitz 1784) Chama asperella Lamarck, 1819 Chama jukesii Reeve, 1847 It is with some hesitancy that I assign the many valves that I found on the beach to this species. Both Lamarck's species and Chama spinosa Broderip, 1835, described from the Tuamotus, and with which I had originally identified my specimens, have white interiors. Most of my specimens are strongly tinged with purple within, and Lamarck mentions a variety marked with purple inside. Until a series of fresh, unworn specimens can be com- pared with the types the proper identification of this species will be in doubt. The true Chama jukesii Reeve from Australia may be a related but distinct species. Arcopagia (Scutarcopagia) scobinata (Linnaeus, 1758) Tellina scobinata Linnaeus Semele australis (Sowerby, 1832) The known molluscan fauna, which is twice as large as that recorded from Ducie, is typically Polynesian, and most of the species are those commonly found in the Tuamotus, in which island group Henderson should faunally be included, A few species, such as Nerita morio and Nodilitto- rina pyramidalis pascua show an affinity with the Easter Island-Pitcairn- Rapa subprovince. 40 Appendix 3. Resolution of the Pacific Science Association adopted at the XV Pacific Science Congress. Feb. 1-11, 1983. Dunedin, New Zealand. Henderson Island WHEREAS, elevated coral islands are few in number and of great biologi- cal and geological interests; and WHEREAS, most such islands have been drastically altered by man through commercial exploitation; and WHEREAS, Henderson Island, in the Pitcairn Group, is a raised coral island of twelve square miles, uninhabited and untouched except for occasional visits by inhabitants of Pitcairn, 100 miles distant, to obtain wood of the miro trees growing at the margin of the wooded in- terior of the island; and WHEREAS, Henderson Island is the only habitat of a number of endemic species of angiosperm plants, birds, land snails, and insects, dis- covered during very limited surveys of the island; and WHEREAS, Henderson Island, because of its being a raised coral island with narrow fringing reefs, narrow sandy beaches, and steep coral cliffs, has a marine environment unique to that part of eastern Poly- nesia; and WHEREAS, preliminary investigations on the island have revealed the presence of important archaeological sites, suggesting early occupation by the Polynesians; and WHEREAS, a private individual is seeking permission to live on Henderson Island and to build a house, a jet airstrip, and loading facilities for ships; BE IT RESOLVED that the Pacific Science Association urges the British Government not to permit the proposed development before: (1) a detailed biological survey of the island has been carried out, in which the par- ticipation of responsible scientific agencies should be encouraged; (2) the likely ecological effects of the proposed development have been assessed; and (3) the views of Pitcairn Islanders on the proposed de- velopment have been obtained. NOTE ON HENDERSON ISLAND RESOLUTION On March 1, 1983, in the House of Lords, Lord Melchett asked Her Majesty's Government a number of questions on the proposed occupancy of Henderson Island, including whether they agree with the view expressed in the Inter- national Biological Programme's Report in 1968 that Henderson Island should be preserved as an "island for science." Pacific Science Association Information Bulletin 35 (1-2): 17, 18-19, April 1983. 41 REFERENCES Amadon, D. 1942. Birds of the Whitney South Sea Expedition, I . Notes on some non-passerine genera, 2. Am. Mus. Novit. 1176: 1-21. Baker, H. B. 1938. Zonitid snails from Pacific islands. Part 1. Southern genera of Microcystinae. Bull. Bernice P. Bishop Mus. 158: 1-102. Bank, J. 1909. Extract from a report from Mr James Bank to Consul Simons, His Majesty's Deputy Commissioner for Pitcairn and other islands in its vicinity. Hydrographic Department, Ministry of Defence, archives, M65489/20.* Bartram, E. B. 1940. Mosses of southeastern Polynesia. Occ. Pap. Bernice P. Bishop Mus. 15: 323-349. Beck, R. H. 1920-23, Extract from Journal ... Whitney South Sea Expedi- tion. Manuscript in the Bird Division of the American Museum of Natural History. Beck, R. H. 1923. The voyage of the France. Nat. Hist. 23: 33-34. Beechey, F. H. 1831. Narrative of a voyage to the Pacific and Beering'’s Straits ... in His Majesty's Ship Blossom ... 1825-28. London: Henry Colburn. 2 vols. Vol. 1: xxvi, 470 pp. Beeson, C. F. C. 1940. Scolytidae and Platypodidae of the Mangarevan Expedition. Occ. Pap. Bernice P. Bishop Mus. 15: 191-203. Bellon, H. 1974. Histoire géochronologique des fles Gambier. Cah. Pacif. 18: 245-251. Beltran y Roéspide, R. 1884. Las Islas Tahiti: Descubrimiento. La Polinesia (Madrid), 143-151. Berland, L. 1942. Polynesian spiders. Occ. Pap. Bernice P. Bishop Mus. 17: 1-24. Bourne, W. R. P. and David, A. C. F., in prep. Henderson Island, Central South Pacific, and its birds. Manuscript. Brodie, W. 1851. Pitcairn's Island, and the islanders in 1850. London: Whittaker and Co. 260 pp. Brousse, R., Philippet, J. C., Guille, G. and Bellon, H. 1972. Géochrono- métrie des Iles Gambier (Océan Pacifique). C. R. hebd. Séanc. Acad. sci., Paris 274: 1995-1998. eee Eee EEE ee ee ee ————— * Items marked * are cited with permission of Lt Cdr A. C. F. David. 42 Brown, E. D. W. and Brown, F. B. H. 1931. Flora of southeastern Polynesia. II. Pteridophytes. Bull. Bernice P. Bishop Mus. 89: 1-123. Brown, F. B. H. 1931. Flora of southeastern Polynesia. I. Monocoty- ledons. Bull. Bernice P. Bishop Mus. 84: 1-194. Brown, F. B. H. 1935. Flora of southeastern Polynesia. III. Dicotyledons. Bull. Bernice P. Bishop Mus. 130: 1-386. Caillet, X. 1884. Iles découvertes par Pedro Fernandez de Quirés du s 21 décembre 1605 au 2 mars 1606, dans sa traversée de Callao a 1'fle Gente Hermosa. J. off. Etabl. Frang. Océanie, 33: 135-138. Chappel, T. 1830. An account of the loss of the Essex from having been struck by a whale in the South Seas, with some interesting particu- lars of the sufferings of her crew on a desert island and in their boats at sea. London: Religious Tract Society. Chase, 0. 1821. Narrative of the most extraordinary and distressing shipwreck of the whale-ship Essex of Nantucket, which was attacked and finally destroyed by a large spermaceti-whale in the Pacific Ocean, with an account of the unparalleled sufferings of the cap- tain and crew during a space of ninety-three days in open boats, in the years 1819 and 1820. New York: W. B. Gilley. 128 pp. Cooke, C. M., Jr. 1935 see Gregory, H,E. 1935, Cooke, C. M., Jr. and Kondo, Y. 1960. Revision of Tornatellinidae and Achatinellidae (Gastropoda, Pulmonata). Bull. Bernice P. Bishop Mus. 221: 1-303. Copeland, E. B. 1938. Ferns of southeastern Polynesia. Occ. Pap. Bernice P. Bishop Mus. 14(5): 45-101. Distant, W. L. 1913. On a small collection of Rhynchota made by Mr David R. Tait at Henderson's Island. Ann. Mag. Nat. Hist., ser. 8, vol. 11: 554-557. Douglas, G. 1969. Draft check list of Pacific oceanic islands, Micro- nesica, 5: 327-463. Drew, R. A. I. 1975. Zoogeography of Dacini (Diptera: Tephritidae) in the south Pacific area. Pacific Insects. 16: 441-454. Dunean, R. A., McDougall, I1., Carter, R. M. and Coombs, Di Sy 1974 Pitcairn Island - another Pacific hot spot? Nature, Lond. 251: 679-682. 43 du Pont, J. E. 1976. South Pacific Birds. Delaware Mus. Nat. Hist. Monogr. Ser. 3: i-xii, 1-218, illus. Fennah, R. G. 1958. Fulgoroidea of south-eastern Polynesia. Trans. R. ent. Soc. 110: 117-220. Fosberg, F. R. 1937. Some Rubiaceae of southeastern Polynesia. Occ. Pap. Bernice P. Bishop Mus. 13(19): 245-293. Gibbings, R., ed. 1935. Narratives of the wreck of the whale-ship Essex of Nantucket which was destroyed by a whale in the Pacific Ocean in the year 1819, told by Owen Chase First Mate, Thomas Chappel Second Mate and George Pollard Captain of the said vessel, together with an introduction and twelve engravings on wood by Robert Gibbings. London: Golden Cockerel Press. 88 pp. Gough, B. M., ed. 1973. To the Pacific and Arctic with Beechey: the journal of Lieutenant George Peard of H.M.S. 'Blossom', 1825-1828. Cambridge: Hakluyt Society (ser. 2), 143: x, 272 pp. Grant, C. H. B. and Mackworth-Praed, C. W. 1933. Sula nicolli, sp. nov., White-tailed Red-footed Booby. Bull. Br. Orn. Club. 53: 118-119. Gregory, H. E. 1935. Mangarevan Expedition. Bishop Mus. Bull. 133: 33-71. Contains reports by C. M. Cooke, Jr., H. St John, P. H. Buck, K. P. Emory, J. F. Stimson and E. C. Zimmerman, the first two and the last with information on Henderson Island. Grindle, G. 1920. Letter dated 3 December 1920. Hydrographic Depart- ment, Ministry of Defence, archives, M65489/20.%* Hamilton, K. G. A. 1980. Aphrophorinae of Polynesia (Rhynchota: Hem- optera: Cercopidae). Pacific Insects. 22: 347-360. 44 Heffernan, T. F. 1981. Stove by a whale: Owen Chase and the Essex. Middletown, Conn.: Wesleyan University Press. Heimerl, A. 1937. Nyctaginaceae of southeastern Polynesia and other Pacific islands. Occ. Pap. Bernice P. Bishop Mus. 13(4): 27-47. Hemsley, W. B. 1885. Botany, Report on the scientific results of the voyage of H.M.S. Challenger. 1(1): i-xii, 1-75. Hooker, W. J. and Arnott, G. A. W. 1841, The botany of Captain Beechey's voyage; comprising an account of the plants collected by Messrs Lay and Collie ... in the years 1825, 26, 27, and 28. London: H., G. Bohn. 485 pp. Hutchinson, G. E. 1950. Survey of contemporary knowledge of biogeo- chemistry. 3. The biogeochemistry of vertebrate excretion. Bull. Am. Mus. Nat. Hist. 96: i-xviii, 1-554. Jackson, H. G. 1938. Terrestrial isopods of southeastern Polynesia. Occ. Pap. Bernice P. Bishop Mus. 14(10): 167-192, Kelly, C., ed. 1966. La Austrialia de Espiritu Santo. The journal of Fray Martin de Munilla O.F.M. and other documents relating to the voyage of Pedro Fernandez de Quirés to the South Sea (1605-1606) and the Franciscan missionary plan (1617-1627). Cambridge: Hakluyt Society (ser. 2), 126. WVoll.-d! i-xviia; 1-270; Voll. 22 i-xvaneaale 446. King, H. 1820. Extract from the journal of Captain Henry King of the Elizabeth. Edinb. phil. J. 3: 380-388, King, W. B. 1967. Preliminary Smithsonian identification manual: sea- birds of the tropical Pacific Ocean. Washington: Smithsonian Institution. 126 pp. Kondo, Y. 1962. The genus Tubuaia: Pulmonata, Achatinellidae. Bull. Bernice P. Bishop Mus. 224: 1-49. Labeyrie, J., Lalou, C. and Delibrias, G. 1969. Etude des transgressions marines sur l'atoll de Mururoa par la datation des différents niveaux de corail. (Cah. Pacifie 132 205-212" Lam, H. J. with Meeuse, B. J. D. 1938. Monograph of the genus Nesoluma (Sapotaceae), a primitive Polynesian endemic of supposed Antarctic origin. Occ. Pap. Bernice P. Bishop Mus. 14: 127-165. Lucas, C. P., ed. 1929. The Pitcairn Island register book. London: Society for the Propagation of Christian Knowledge. iii, 181 pp. Maiden, J. H. 1901. Notes on the botany of Pitcairn Island. Rept. Australas. Ass. Adv. Sci. 8: 262-271. 45 Malloch, J. R. 1938. Trypetidae of the Mangarevan Expedition (Diptera). Occ. Pap. Bernice P. Bishop Mus. 14(7): 111-116. Markham, C. R., ed. 1904. The voyage of Pedro Fernandez de Quirés, 1595 to 1606. London: Hakluyt Society (ser. 2) 15. Vol. 1: i-xlviii, 1-320; Vol. 2: i-viii, 321-555. Maude, H. E. 1951. Those Henderson Island mysteries. Pacif. Is. Mon. 21(10): 62-63. Maude, H. E. 1959. Spanish discoveries in the Central Pacific: a study in identification. J. Polynes. Soc. 68: 284-326. Reprinted in Of islands and men: Studies in Pacific history (Melbourne: Oxford University Press, 1968), 35-83. McLoughlin, R, 1971. Law and order on Pitcairn Island. Auckland: Office of the Governor of Pitcairn, Henderson, Ducie and Oeno Islands. McNutt, M. and Menard, H. W. 1978. Lithospheric flexure and uplifted atolls. J. geophys. Res. 83: 1206-1212. Meinicke, C. E. 1875-76. Die Inseln des Stillen Oceans: eine geogra- phische Monographie. Leipzig: Frohberg. 2 vols. Moerenhout, J.-A. 1837. Voyage aux files du Grand Océan. Paris. 2 vols. Moulton, D. 1939. Thysanoptera collected by the Mangarevan Expedition. Occ. Pap. Bernice P. Bishop Mus. 15: 141-148. Murphy, R. C. 1924a. The Whitney South Sea Expedition: a sketch of the bird life of Polynesia. Natural History, 24: 539-553. Murphy, R. C. 1924b. Birds collected during the Whitney South Sea Ex- pedition, II. Am. Mus. Novit. 124: 1-13. Murphy, R. C. 1951. The populations of the wedge-tailed shearwater (Puffinus pacificus). Am. Mus. Novit. 1512: 1-21. Murphy, R. C. and Mathews, G. M. 1929. Birds collected during the Whitney South Sea Expedition, VI. Am. Mus. Novit. 350: 1-21. Murphy, R. C. and Pennoyer, J. M. 1952. Larger petrels of the genus Pterodroma. Am. Mus. Novit. 1580: 1-43. Murray, T. B. 1854. Pitcairn: the island, the people, and the pastor; with a short account of the mutiny of the Bounty. Third edition. London: Society for the Propagation of Christian Knowledge. xiv, 342 pp. Naval Intelligence Division. 1943. Pacific Islands, Volume II. Eastern Pacific. Geographical Handbooks Series, B.R. 519B: xvi, 739 pp. 46 North, A. J. 1908. On three apparently undescribed birds from Hender- son or Elizabeth Island, Paumotu Group. Rec. Austr. Mus. 7: 29-32. Ogilvie-Grant, W. R. 1913a. On a small collection of birds from Hender- son Island, South Pacific, collected and presented to the British Museum by Messrs D. R. Tait and J. R. Jamieson. Bull. Br. Orn. Cl. 31: 58-61. Ogilvie-Grant, W. R. 1913b. On a small collection of birds from Hender- son Island, South Pacific. Ibis, (10) 1: 343-350. Ortenburger, A. I. 1923. Herpetological results of the Whitney South Sea Expedition. III. Further notes on the reptiles collected by the Whitney South Sea Expedition. Copeia, 107: 59-60. Peters, J. L. 1934. Check-list of birds of the world. Cambridge: Harvard University Press. Vol. 2. Quayle, E. H. 1922. Extract from the Journal ... Whitney South Sea Expedition. Manuscript in the Bird Division of the American Museum of Natural History, Rehder, Harald A. 1980. The marine mollusks of Easter Island (Isla de Pascua) and Sala y Gomez. Smithsonian Contributions to Zoology, No. 289: iv + 167 pp., 14 plates, 15 text figures, 1 table. Rehder, H. A. and Randall, J. E. 1975. Ducie Atoll: its) history, physiography and biota. Atoll Res. Bull. 183: 1-40. Ripley, S. D. 1977. Rails of the world: A monograph of the family Rallidae. With forty-one paintings by J. Fenwick Lansdowne and a chapter on fossil species by Storrs L. Olson. Toronto: M. F. Feheley Publishers. xx, 406 pp. Ripley, S. D. and Birckhead, H. 1942. Birds of the Whitney South Sea Expedition. 51. On the fruit pigeons of the Ptilinopus purpuratus group. Am. Mus. Novit. 1192: 1-14. Rivett-Carnac, J. R. 1937. Report on aerial and ground survey of Henderson, Oeno and Ducie Islands. Western Pacific Archives, Western Pacific High Commission (South Pacific Office), File No. 3326/1937 (Naval). [Not seen]. St John, H- 1935. See Gregory, H. B= «1935. St John, H. 1940. Itinerary of Hugh Cuming in Polynesia. Occ. Pap. Bernice P. Bishop Mus. 16: 81-90. St John, Harold & Philipson, W. R. 1962. An account of the flora of Henderson Island, South Pacific Ocean, Trans. R. Soc. N. Z. 1: 175-194. 47 Sharp, A. 1960. The discovery of the Pacific islands. Oxford: Clarendon Press. xvi, 260 pp. Sherff, E. E. 1937. Some Compositae of southeastern Polynesia (Bidens, Coreopsis, Cosmos, and Oparanthus). Occ. Pap. Bernice P. Bishop Mus. 12(19): 1-19. Sinoto, Y. H., [in press]. Analysis of Polynesian migrations based on archaeological assessments. J. Soc. Océanistes, Paris. Skottsberg, C. 1937. Liliaceae of southeastern Polynesia. Occ. Pap. Bernice P. Bishop Mus. 13(18): 233-244. Skottsberg, C. 1938. Ericaceae and Santalaceae of southeastern Poly- nesia. Occ. Pap. Bernice P. Bishop Mus. 14(4): 31-43. Smith, E. A. 1913. On a small collection of marine shells from Hender- son Island. Ann. Mag. Nat. Hist. (8) 12: 409-415. Solem, G. A. 1976. Endodontoid land snails from Pacific Islands. Part I. Family Endodontidae. Field Museum Press. 501 pp. Tait, D. R. 1912. Letter to Sir John Murray, 20 January 1913. Hydro- graphic Department, Ministry of Defence, archives. H5364/20.* Tate, G. H. H. 1935. Rodents of the genera Rattus and Mus from the Pacific islands, collected by the Whitney South Sea Expedition, with a discussion of the origin and races of the Pacific Island Rat. Bull. Am. Mus. Nat. Hist. 68: 145-178. Van Dyke, E. C. 1937. Rhyncogonus of the Mangarevan Expedition. Occ. Pap. Bernice P, Bishop Mus. 13(11): 89-129. Von Poellnitz, K. 1936. New species of Portulaca from southeastern Polynesia. Occ. Pap. Bernice P. Bishop Mus. 12(9): 1-6. Wheeler, W. M. 1936. Ants from the Society, Austral, Tuamotu, and Mangareva Islands. Occ. Pap. Bernice P. Bishop Mus. 12(18): 1-17. Williams, G. R. 1960. The birds of the Pitcairn Islands, certral Pacific Ocean. Ibis, 102: 58-70. Yuncker, T. G. 1937. Revision of the Polynesian species of Peperomia, Bull. Bernice P. Bishop Mus. 143: 1-73. Zimmerman, E. C. 1935. See Gregory, H. E. 1935. Zimmerman, E. C. 1936. Cryptorrhynchinae of Henderson, Pitcairn, and Mangareva Islands (Coleoptera, Curculionidae). Occ. Pap. Bernice P. Bishop Mus. 12(20): 1-8. Zimmerman, E. C. 1938. Anthribidae of southeastern Polynesia (Coleop- tera). Occ. Pap. Bernice P. Bishop Mus. 14(13): 219-250. North coast with low cliffs, beach,and coconut and other vegetation back of beach, from sea (Rehder photo). North coast, from sea, closer up. Pitcairn people on beach preparing to load coconuts and Thespesia wood (Rehder photo). Plate 3. Base of cliff on north coast showing small cave site of archaeological excavation by Dr. Sinoto (Rehder photo). 4. West coast, undercut cliffs (Rehder photo). Plate 5. West coast, looking north from near south end, from top of cliff (1943 photo). 6. West coast, looking north, near northwest point, from part way up cliff (Fosberg photo). Plate 7. Cliffs back of North Beach, back-beach scrub in foreground, single coconut tree on top of cliff (1943 photo). 8. Vegetation of interior plateau, from top of large Pandanus tree (Fosberg photo). A aez” Su (3 co a2 . we a .z « — . “ - Sal . | 0)" APACE. ee) . A ue i 4 ae * - ~ ma Plate 9. Interior of back-beach vegetation, north coast, showing Pandanus (Rehder photo). 10. Tangled interior of vegetation (1943 photo). Plate 11. Dissected limestone on plateau, forest in background (Fosberg photo). 12. Dissected limestone. on plateau, close-up, surrounded by forest (Fosberg photo). * U.S. GOVERNMENT PRINTING OFFICE : 1983 O - 413-333 eS Se ey ae ee Ee XS SY 2 = Ss 2 Yew =) ~ 5 way 5 NM § @ = ‘Qo S 4 = oe 5 ae = : 7) pe a ; 72) as ALILSNI NVINOSHLINS S31YVYUSIT LIBRARIES SMITHSONIAN _ INSTITUTION NOILOLILSNI NVINOSHLIWS 'S | — : wo = _ ee a NSS = a = ie Fe = = RNS w = YW. So fea = fm. = a = re SS a = Roo Ns, oz =) < = = < = Uy. = = z S \y ~ i 8 z LG. & z 5 SSX 3 5S NSW: 8 = Ii = ro) Be AYR O ve =~ WOE Oo < So fer = z EF We 2 = \S 2 = = >" = rk > S Sy > a 2 a eo ae a 2 a 2 ARI!ES SMITHSONIAN INSTITUTION NOILOALILSNI_ NVINOSHLINS S31YVYGIT LIBRARIES SMITHSONIAN INST ” = wo > wn S fe) = uu yp, = wu rr Ww a Wl = Fra, % = = : - z 4 < “Yn fof A = - 9 ~ wad z =i — 2 =3 2 JLILSNI NVINOSHLINS S31YVYUdIT LIBRARIES SMITHSONIAN INSTITUTION NOILNLILSNI NVINOSHLINS S3I¥ ry <2 te ae ie = F = = ro) == ° = ° = Ne fe) w = z= = = = = . - 2 = wy =) ay =) 2 = > E > Fe : > = > r= Bs) = ze ~ x = 2 FE m . 2 m z m = m 2 “New n = = = mi k ARI ES SMITHSONIAN INSTITUTION | NOLLCEESNINVINOSHEINS Sa 1yYvudg oul BRARI ES OMT Oe | = caer \e Z = = Baye < ~ i z SAG = it fal = = = NS Zz FS x re) NG SS si ly ro) cic os Bex = fo} NN S a WAY S LY BY 6” E WS o BG Y: 2 eF WO 2 yy, ie 2 E \. 2 = > > . 2 : Se $ : 3 7) JLILSNI_ NVINOSHLINS S3IYVYEIT_ LIBRARIES SMITHSONIAN INSTITUTION NOILOLILSNI NVINOSHLIWS S318 = ; a = > 7p) = ian 2) a CX » a Seer as = @ WW = ar = a. te Zp 2 o 7 gy So « =t AS. x .- = <> Vp 4 a < = SOS > > 2 > 2 (> i ee I= ZS = = = = X m m z o z w = w = wo AILSNI_NVINOSHLINS, Saluvugi7 _LIBRAR| ES SMITHSONIAN INSTITUTION NOILNLILSNI_ NVINOSHLINS S31} < = <= = oe = = = py, Zz = WY) > « 3 = \, = WG fy = =| PD, : wD J aN. & SNE AZ? g JY 3 ee ie Ww 7 E NO 2.77 = Z. = = = ~ SS = ee >" = ae nn ¥ ae ” oe = wo - i ARI ES SMITHSONIAN INSTITUTION NOILNLILSNI_NVINOSHLINS | Sa 1YVYGIT_LIBRAR! ES SMITHSONIAN _INSI whe ee, > ”o 2 a i z se son ee et ee A as Lad i 2. ee = ~~. faa f > ow _ ag = ied i se EGE GS) |G) 2 NP GD) (CS) FG = 8 : oat = 2 e 2 es z =i 3 : , JLILSNI NVINOSHLINS S3IuVUa! pel BRARI ES_ SMITHSONIAN _INSTITUTION 2NOLLALILSNU NVI S an & Se. z - 15 (e) a) WSON) fo} - a fo} WM G @i. 8 Ka = ARO = ‘2 EW © Kar = Ws eo Wr > NSO EF GMP) 3 LAM) s/f’ > LAM) FE Gam 7 WS Conse” oS “< @) nse) On, \L ~Y, NVIN SMIT NVIN a “Ge i WA LIBRARIES SMITHSONIAN INSTITUTION NOILNLILSNI NVINOSHLINS S3I1YVYEIT LIBRARIES SMITHSONIAN JI SMIT SMITI NVIN( SMITI NVIN a z i Zee z us 2 = ph jp * z 2 NE g = tp iif Z = < = WS iN = Ad = Vike = a SS < < a oO lyf 5 oO cal NX o =I nm Su -_ ti = fe) =— (e) = Le e) — Ze a zm o ay Zz zy Nes NOILALILSNI _NVINOSHLINS [SA1YVYAIT LIBRARIES SMITHSONIAN INSTITUTION NOILMLILSNI_NVINOSHLINS _S - ~ 5 Ss zs ie is = = 5 a : = ioe) = lip = wo 3 = 2 Neo 5 2 5 Gy, 2 E 2 Lye 5 SS 2 rR = Vip ; 5 SSO | = 9 rm ee ae: g mn IW — wn = n = no — EIBRARIES SMITHSONIAN INSTITUTION NOILNLILSNI NVINOSHLIWS LIBRARIES SMITHSONIAN _II Fe (22) x = =e = < = = < o x = =n = > : F Nay z 2 : 3 : 2) ~ ENS . W See) n o (7) fe) " = > = = ” ‘ z n Zz 2 7) NVINOSHLINS S3IYVYG!IT LIBRARIES SMITHSONIAN INSTITUTION NVINOSHLINS S za < ae (eo) wn ac E = (9) “a ; S a s A 2 i Z 2 _ & % Z i = o SJ = tippy A 3 =) S = . Ge = = yt fg fA = = (= eS c , 5 =z a 2 —) IBRARI ES. SMITHSONIAN, INSTITUTION NOILMLILSNI_NVINOSHLIWS S31yvudlT_ LIBRARIES SMITHSONIAN | A ° = S) = Ne S) wo ‘S) wo = gh Mg Ki a (S 2 Ws: = g = = 2 uy > =) zy 4 NS a >) 5 Ew YZ = > NSN = > E s > 5 if 2 i 2 = 2 i 2 2 a Z a Z a Z i NOILNALILSNI NVINOSHLINS S3IYVYEIT_ LIBRARIES SMITHSONIAN INSTITUTION NOILNLILSNI iS zZ a Z Ron Y Zz Ne i) Zz ) .& = y x = < OX = as = Zz 4 ysl fy = Si best Zz AS = Zz Sj tip f () : oP oN = 2 Viy = z = WS 2 i 2 = 5 F . 3 a = z = IBRARIES SMITHSONIAN _ INSTITUTION NOILOLILSNI_NVINOSHLIWS LIBRARIES SMITHSONIAN 1 n S = an p) = 7) = EE, Foo a o & o uw ae = i jp 2 a 2 Qk = a = “Gif c = c BW = c << c oc “Shy a a Vy = = aN = =i Ee: : ae : : : | E A OILALILSNI_NVINOSHLINS S3IYVYGIT LIBRARIES SMITHSONIAN INSTITUTION NOILONLILSNI S = * S x FS : us z im Zz ios] > — wo = fp jes} = w — = Ne 5 : = G% > E = E a Ye S 2 if : 5 2 2 XA E 2 = fe 2 = 2 = al SS NS oP) = it te oO = oD) = wo no ms = wn z n = 7) z IBRARIES SMITHSONIAN INSTITUTION NOILALILSNI NVINOSHLINS S31uvugia_ LIBRARIES SMITHSONIAN II no Za Xe ) z n Ze ie on Fe = ee = 5 = ely s Es : 2\, i B,3 : : : : a a NS b fff @ w 2) a a fe) rT WAN SG GY YY, fe) 36 (e) Ts Z E \ 2.4 E Z = = E = = WN > = > = > = 2 77 ie z oO Zz 7) 2 7) _NWVINOSHLINS S3IYVYAIT LIBRARIES SMITHSONIAN INSTITUTION _NVINOSHLIWS S z 4 Ss ¢p) > n > i We a ES oe es % = “i 4 = cc 2 oc = a = AW ce a <= Z < Se < 2 YN < = oO el = =I mi =I RN NS oO S) = o =a rs) a One Poss = 2 ay ze = 7 =i 2 = IBRARIES SMITHSONIAN INSTITUTION NOILMLILSNI NVINOSHLINS S3!uYvusit LIBRARIES SMITHSONIAN I = 3 eo Sas = ie Re z S z a i ZESON Dy ~ » Y Paice ED) 5 gi zy 2 EPR 5 PD 2 SK EGPDIG™S wy? AS) FS) SeZZe > te Wel - (z 4) > Ws rans | 2 la Sel] Se > ie ura PS ' on | | ee De | Soe ae, rs oe Bien Dope : ft ak ms : site aes o2 Dasdintats TEES se haw oe rade weed | eid los yr ¥ mar gee rah Rea * oe Pare my Ae PN py Dh, Gen att ~ rs ~ us ~ sine ¥ Ses x SSO tes revi SES . ‘ iss WAT eh erat AOR to ation tin : : OCR OLR Ta ATS tan SS ith abe it Syme eeu lveury ERENT Seu ‘