CALIFORNIA FISH-GAME "CONSERVATION OF WILDLIFE THROUGH EDUCATION" California Fish and Game is a journal devoted to the conservation of wild- life. Its contents are not copyrighted and may be produced elsewhere provided credit is given the authors and the California Department of Fish and Game. Interested persons may have their names placed on the mailing list by writ- ing to the editor. There is no charge, but subscriptions must be renewed annu- ally by returning the postcard enclosed with each October issue. Subscribers are asked to report changes in address without delay. Please direct correspondence to: Mr. Phil M. Roedel, Editor California State Fisheries Laboratory Terminal Island Station San Pedro, California u VOLUME 39 JANUARY, 1953 NUMBER 1 Published Quarterly by the CALIFORNIA DEPARTMENT OF FISH AND GAME SAN FRANCISCO STATE OF CALIFORNIA DEPARTMENT OF FISH AND GAME EARL WARREN Governor FISH AND GAME COMMISSION PAUL DENNY, President Etna LEE F. PAYNE, Commissioner HARVEY E. HASTAIN, Commissioner Los Angeles Brawley WILLIAM J. SILVA, Commissioner CARL F. WENTE, Commissioner Modesto San Francisco SETH GORDON Director of Fish and Game CALIFORNIA FISH AND GAME PHIL M. ROEDEL, Editor.. —Terminal Island Editorial Board RICHARD S. CROKER San Francisco FRANK KOZLIK San Francisco LEO SHAPOVALOV San Francisco TABLE OF CONTENTS The Fish Populations of Sail Springs Valley Reservoir, Calaveras County, California Donald B. Wohlschlag and < !hester A. Woodhull 5 The .lack Mackerel, Trachurus symmetricus : A Review of the <'ali- fornia Fishery and of Currenl Biological Knowledge Phil M. Roedel l"> EleotHs picta Added to the Fish Fauna of California Cabl L. Hi bbs 69 The Venom of Urdbatis kalleri (Cooper), The Round Stingray John E. Hollowat, Norman C. Bunkkk and Bru< i \V. II\i.-ti \i> 77 Production of the Canada Goose on Honey Lake Refuge, Lassen County, California Ai.ijkkt K. Xaylor B3 Numbers and Winter Distribution of Pacific Black Brant in North America _ A. Starker Leopold and Korert II. Suith 95 State-wide California Angling Estimates for 1951 .A. .1. Calhoun 103 California Marine and Fresh Water Sport Fishing Intensity in 1951 Frances N. Clark 1 1 5 Food of Marlin in 1951 off San Diego, California ._Carl L. IIubbs and Robert L. AVisxkk 127 An Unusual Mortality of California Yellowtail (Seriola dorsalis) in a Marine Aquarium Carl H. Oppeniikimkr 133 The Effect of Channelization on the Fishery of the Lower Colorado River Richard D. Beland 137 Age Composition of the Southern California Catch of Pacific Mackerel for the 1951-52 Season John E. Fitch 141 Notes Sleeper Shark, Somniosus pacificus, Caught off Fort Bragg, California J. B. Phillips 147 The Occurrence of Two Additional Centrarchids in the Lower Colorado River, California R. D. Beland 149 Reviews 153 Reports 157 (3; THE FISH POPULATIONS OF SALT SPRINGS VALLEY RESERVOIR, CALAVERAS COUNTY, CALIFORNIA1 By DONALD E. WOHLSCHLAG Natural History Museum, Stanford University and CHESTER A. WOODHULL Bureau of Fish Conservation, California Department of Fish and Game TABLE OF CONTENTS INTRODUCTION . ''' ACKNOWLEDGMENTS 6 DESCRIPTION AND HISTORY OF SALT SPRINGS VALLEY RESERVE IIR 7 METHODS — 9 RESULTS AND CALCULATIONS- 1 I Population of largemouth bass 1 1 Weight of the bass population 1-4 Population estimates of seined bluegills 1~> Population estimates of trapped bluegills 22 Weight of tbe bluegill population 23 Population of carp 26 Weight of carp population 20 Population of brown bullheads 30 Population of white catfish 33 Population of golden shiners •">' Populations of other species 32 SUMMARY OF POPULATION AND WEIGHT ESTIMATES- - 32 EVALUATION OF RESULTS- . 34 General 34 Differences between marked and unmarked fish 34 Random distribution of marked fish and random sampling 34 Differential vulnerability of various length groups •".•"> Recruitment 37 Effects of natural and fishing mortality 38 Evaluation of weight estimates 39 MANAGEMENT PROBLEMS IN SALT SPRINGS VALLEY RESERVOIR— 39 Largemouth bass 39 Bluegills 40 Carp . 40 Other species 41 SUGGESTED PROCEDURES FOR FISH POPULATION ESTIMATES IN LARGER BODIES OF WATER 41 SUMMARY 42 REFERENCES __. . 43 1 Submitted for publication June, 1952. (r>) 6 CALIFORNIA FISH AND GAME INTRODUCTION The purpose of this study was to estimate the numbers of fish in Salt Springs Valley Reservoir, Calaveras County, by the mark-and-recapture method, primarily to appraise the possibilities of this procedure for a large warm-water reservoir. A subsidiary purpose was to obtain informa- tion for use in managing this reservoir and similar impoundments. The field work was done during the hot months of August and September, 1951, when angling pressure was almost negligible, obviating elaborate corrections for fishing mortality. Warm-water impoundments in the Central Valley of California might be expected to yield large numbers of game fish. Yet Calhoun (1950) has presented data which indicate that the Central Valley with its many impoundments contributes rather small catches of warm-water fish com- pared with the Sacramento-San Joaquin Delta or the San Diego region. While it is true the impounded waters of the Central Valley lie near the heavily fished Sierra and delta areas, which are presently preferred by many fishermen, there is little doubt that they would be much more popular if they provided better fishing. Learning why they are so un- productive is the first step toward discovering how to improve them. The problem is largely one of population size. Are the reservoirs productive? Do they have large fish populations? Is there competition between desirable and trash species? Is there a sufficient forage popu- lation to support desirable predatory species ? A knowledge of the num- bers of the various fish present will obviously go a long way toward providing answers to questions like these. The determination of fish population estimates is by no. means a simple task. However, several well established methods are available. Of these, the mark-and-recapture technique presently seems to offer the greatest possibilities (Kennedy, 1949). Its earliest use is usually credited to Petersen (1896) [fide Ricker (1948)]. Recent modifications and refine- ments have been made by Schnabel (1938) and by Schumacher and Eschmeyer (1943). Discussions of the applications and statistical inter- pretations have been given by DeLury (1951), Schaefer (1951a and 1951b), Fredin (1950), and Ricker (1948), among others. ACKNOWLEDGMENTS This investigation was carried on in cooperation with the California Department <>!' Fish and C4ame, which provided the staff, equipment, and operatiii1.: expenses. It is a pleasure to express thanks to the many individuals whose aid and encouragement made this project possible. Particular thanks are given t" Dr. Alex Calhoun of the Department of Fish and Game for liis assistance in matters of personnel and equipment. Student biologists Richard Ilali-y ami David E. Pelgen, who helped with the field work, merit commendations for their efforts as does student biologist William E. Rowley, who assisted with compilations and computations. Thanks are due Miss < lliffa < lorson for drawing the map and lettering the figures. Greal appreciation is accorded Mr. Frank Tower, on whose property the base of field operations was established. FISH OF SALT BPRINGS \\l.l.l.'> RESERVOIB i DESCRIPTION AND HISTORY OF SALT SPRINGS VALLEY RESERVOIR Sail Springs Valley [Reservoir (Figure L) is located in Calaveras County, California. The 2,150 fool earth fill dam impounds a maximum of 10,900 acre-feel of water originating Prom aboul -1 square miles of watershed comprising the upper Rock ('reek drainage basin. The reser- voir is relatively shallow and the bottom slopes gently to a maximum depth of I- feet at the dam. The maximum area at spillway level is 900 acres. At a typical annual drawdown of 12 feet the area is reduced to 412 acres, and the volume to ahout 3,200 acre feet. Salt Springs Valley Reservoir was among the first reservoirs con- structed in California. The original dam, buill in the L860's, impounded aboul 4()() surface acres of water, which was used for placer gold min- ing operations in the Jenny Lind and Milton areas. The heavy demand for additional water led to the building of the present dam in 1882. Subsequently gold mining operations dwindled, and the impounded water has since heen used I'm- irrigation and stock watering. Little is known of the fish species which were stocked originally. Incomplete records made around 1000 indicate that largemouth black bass (Microptents salmoides) , smallmouth black bass (Micro />h r us doJomieu), bluegill (Lepomis machrochirus) , black crappie (Pomoxis nigromaculatus) , brown bullhead (Ameiurus neovlosus), white catfish (Ictalums catus), and carp (Cypriniis carpio) had been introduced. Formerly the reservoir was used as a natural rearing area from which fish were removed for stocking elsewhere. It provided excellent bass sport fishing until about 1940, when the bass fishery declined seriously. Simultaneously, the carp and stunted black crappie populations increased tremendously. In October, 1947, the reservoir was drawn down and treated heavily with rotenone to destroy fish populations. It was later restocked, between December, 1947, and March, 1948, with 635 adult largemouth bass and 1,150 adult bluegills, amounting to approximately one bluegill per surface acre and one bass per two surface acres. In the summer of 1949, only a year and a half later, a few anglers reported excellent catches of small bass. Some limit catches of 25 good- sized bluegills were reported later that summer. It may be assumed that many of the age 1-4- fish rather than the brood stock were supporting the fishery in 1949. A sampling of the juvenile fishes by rotenone treatment of a small bay during autumn, 1950, indicated a pronounced lack of suitable forage species for the abundant small bass. Consequently, 2,000 four- to six-inch golden shiners (Notemigonus crysoleucas) were introduced during October, 1950, with the hope of improving the forage situation. The 1951 spring and early summer season was quite successful for the bass fishermen and many limit catches of five bass were made. It is roughly estimated that as many as 5,000 to 8,000 bass were removed dur- ing this season. The bass caught by anglers were generally small, perhaps averaging between 10 and 11 inches in length. While some good catches of bluegills were made, the total 1951 catch seemed to be quite small. From time to time an occasional brown bullhead, white catfish, or carp appeared in the catches. 8 CALIFORNIA FISH AND GAME SALT SPRINGS VALLEY RESERVOIR CALAVERAS COUNTY, CALIFORNIA ELEVATION AT SPILLWAY 1074 FEET ABOVE M.S.L. AREA AT SPILLWAY LEVEL 899.6 ACRES AREA AT APPROX. 1062' CONTOUR 412.3 ACRES AREA AT COMPLETE DRAWDOWN 47 ACRES 1000 2000' 3000 FIGURE 1. Map of Salt Springs Valley Reservoir, Calaveras County, California « ( I'isil OF SALT SPRINGS VALLEY RESERVOIR ■ > UaHier in the L951 season, the fish appeared to be relatively Eree of worms," "grubs," and other parasites. By late summer and early autumn, however, most of the bass and bluegills were heavily parasitized by a roundworm, identified as a larval stage of Contracaecum spicuh gerum by Mr. Harold Wolf, Bureau of Fish Conservation parasitologist. Casual field observations revealed thai even heavily parasitized fish were in good eondit ion. Little is known of the other biota in Sail Springs Galley Reservoir. Though emergent shoreline vegetation is generally Lacking, tie' reservoir contains lair quantities of a pondweed I Pota/mogt ton sp.)j locally abun- dant filamentous algae, and prodigious quantities of a colonial bryozoan, Pectinatella, whose "jelly-balls" with diameters up to three feel clog many of the shallower bays. Several small bluegills, whose stomaeh con- tents were examined, were gorged with bryozoan statoblasts. Extremely dense swarms of Tendipedidae (=rChironomidae) mid-jvs during August and September, 1951, gave indirect indication of a fairly good bottom fauna at this time of the year. Otherwise there is no information on the kinds and amount of either benthos or plankton. The limnology of the reservoir has not been studied. Evidence of a temporary lack of oxygen in deeper waters was found during a pro- longed calm, hot period in mid-August. At this time fish of all species caught in traps below depths of 14 to 16 feet were dead. With the appearance of winds several days later, this condition disappeared. METHODS In this study the sizes of the fish populations were estimated by the well known mark-and-recapture technique described by Schnabel (1938). Accounts of the application of this method have been given by Ricker (1948), Schaefer (1951a, 1951b), and DeLury (1951). Essentially, the technique involves capturing successive random samples of fish ; marking and releasing those in each sample ; and noting the number of recaptures in each sample after the first.2 In this study, estimates were made of the numbers of largemouth black bass, bluegill, carp, brown bullhead, and white catfish present in the lake between August 7 and September 19, 1951, using successive samples of trapped and seined fish. 2 If each of t successive samplings is carried out over a short period of time, say for one to seven days, then Bt = the total number of fish marked and at large just before the fth sample, At = the number of fish sampled at the tth interval, and Ct = the number of recaptured fish among- those of the tth sample. If there is no difference between the marked and unmarked fish, if all sampling and dis- tribution of marked fish is random, and if the population remains unchanged during the mark-and-recapture operations, the following relationship holds where P is the size of the total population : Ct — At Bt/P = 0. 1 — Bt/P Since the equation in this form can be solved only approximately for P, and since the denominator nearly equals unity when the total number of marked fish at large is small in relation to the total population, an estimate of P, A ^ S(AtBt) P, may be given as P = 2(Ct) If a given number of marked fish, B, is released and sampling is continued ^ (B)2(At) P = 2(CO 10 CALIFORNIA FISH AND GAME Traps were constructed of one-inch mesh poultry wire, as described by Wohlschlag (1952). The seine was 200 feet long, 15 feet deep in the middle, and tapered to six feet at the ends ; it was made of No. 6 medium twine with a stretched mesh measure of 1.5 inches; it was fitted with 2.5-inch corks and number 12 leads spaced at two-foot intervals. The seining procedure was to pay the net out from a platform on the bow of a 14-foot boat which was being pulled along backwards by a reversible five-horsepower motor. In this way a large semicircle was formed with the ends of the seine in about three feet of water. It was hauled and beached by two men. while a third man remained near the center to clear snags and prevent rolling. Each individual sample covered the whole reservoir. To insure good distribution of sampling and release of marked fish, the reservoir was divided into eight areas, designated A to H in Figure 1. Two were ordinarily seined and trapped each day. Under this schedule each sam- pling took four days. The sampling in each area consisted of two seine hauls and 10 trap sets. Traps were emptied in the morning and evening each day. Within each area four traps were set at a depth of about 10 feet, four at about 15 feet, and two at about 20 feet. Trapping and seining were usually simultaneous for each sampling period, although at times there was a disparity of a day or two. The schedule of sampling periods is given in Table 1. Fish were removed immediately after capture to a tub or floating live car. Only the fork lengths to the nearest millimeter were recorded for each fish handled, because the heat made rapid handling necessary. Scale samples and weight records were obtained for small, selected samples. TABLE 1 Schedule of Seining and Trapping Operations in Salt Springs Valley Reservoir During August and September, 1951 Seining operations Trapping operations P'-riod Dates Days elapsed from period l1 Days between periods Dates Days elapsed from period l2 Days between periods 1 7-10 Aug. 13-16 Aug. 17-21 Aug. 22-25 Aug. -'7-30 Aug. 3-6 Sept. 7-n Sept. [2-14 a 17-19 Sept. 0 6 io..-, I", 20 27 35 . ■". Hi..", 6 4.5 4.5 5 7 4.5 4 5 7-11 Aug. 12-16 Aug. 16-20 Aug. 20-24 Aug. 26-30 Aug. 2-6 Sept. 6-10 Sept. 0 5 9 13 19 26 30 2 5 3 4 4 4 6 6 / 8 9 7 4 1 Calculated from middle of 7-10 Augu I period. I ted from middle of 7-11 August period. FISH OP SALT SPRINGS \ WA.lA 1:1 ! [{VOIR 11 Largemouth blael llheai Is, w bite ca1 fish, and golden ie Last periods of seining and trap bass, hi'nw n liii shiners were marked during all bul 1 1 ping. Bluegill marking was discontinued after the third period of seining and after the fourth period of trapping. All carp marking was diacoD tinned after the third period. Seined fish were marked by removing the lel'f ventral (IAr) fin; trapped fish were marked by removing the righl central (RV) fin. All fish, whether marked or not, wen- released near Hie location of their capture, except that all seined and trapped carp were removed from the lake and destroyed after the third period. RESULTS AND CALCULATIONS Population of Largemouth Bass I'.eeanse only (iS bass were taken ill traps, they ha\r ln'm included with those which were seined. 'Idie capture-recapture data witli Schnabel-type population estimates are given in Table 2. The final estimate uncorrected for recruitment (except for the partial correction implied by raising the minimum size limits of the fish handled) is 2(A.B) 2,047,596 = - =19,501. 2(C) lor, Confidence limits at the 0.95 level, calculated for the epiantity (C) by using Chapman's Table II and formula (46) (Chapman, 1948), are 15,881 to 23,347. TABLE 2 Data for Estimation of Largemouth Bass Population of Salt Springs Valley Reservoir During August and September, 1951, on Basis of Combined Seine and Trap Catches Period Days elapsed1 Minimum size handled (mm.) Total number handled U) Total number marked and released Total number marked large IB) Number of recaptures (C) 1 0 6 10.5 15 20 27 31.5 35.5 40.5 95 95 95 100 105 105 105 105 105 127 113 199 321 257 330 435 242 191 127 112 185 311 247 310 399 222 0 0 127 239 424 735 982 1,292 1,691 1,913 0 2 1 3 4 5 6 7 8 9 7 10 8 15 31 13 20 1 Computed from middle of 7-10 August period for seined fish. Fork length frequency distributions in five millimeter groupings for seined bass only are illustrated in Figure 2. Small young-of-the-year and yearling bass were observed to be feeding actively on small bluegilK and their growth rate was rapid. The breaks marked with arrows in the length frequency histograms in Figure 2 are believed to represent roughly the same group of fish in successive samples. The midpoints of the corresponding intervals have been plotted against the mid-dates of the seining Periods 3 to 9 in Figure 3. Growth was nearlv linear, and 12 CALIFORNIA FISH AND GAME FORK LENGTH (MM) FIGURE 2. Length frequency histograms of largemouth bass seined during nine periods of sampling in Salt Springs Valley Reservoir during August and September, 1951 KISI1 ok SALT SPRINGS VALLEY i:l -u:\oli: 13 TABLE 3 Data for Estimation of the Salt Springs Valley Reservoir Bass Population From Combined Trap and Seine Catches Corrected for Recruitment Period Minimum size handled (mm.) Total number handled U) Total Mllllll H'l l and relea ed L.t.il number [narked :it lurj'f- Number of l 97 102 107 109 1 12 118 121 124 128 127 ill 193 284 238 2.58 348 201 108 127 i in 181 274 229 L'l-> 316 1 86 0 1 0 L27 237 lis 692 921 1,163 1,479 1,664 1) 2 1 3 7 4 10 5 8 6 I i 7 30 8 .. .- 12 9 16 147 142 I'37 I 132- r- W 127-1 CC 122 O 117- 112 FORK PERIOD T'ME LENGTH HtKIOU(DAYS) (MM) 3 4 5 6 7 8 9 10.5 15.0 20.0 27.0 31.5 35.5 40.5 I 17 I 22 127 I 32 I 32 I 37 142 SLOPE _ -,-. MM/ 0.7 7 /DAY 20 30 ~1~ 40 TIME (DAYS) 50 FIGURE 3. Data and diagram indicating progressive increase in lengths represented by a break in length frequency histograms (Figure 2) for largemouth bass a least squares calculation of the slope of the line indicated a daily increase of 0.77 millimeters. At this rate, bass hatched by June could easily reach five to six inches by autumn. Young-of-the-year bass of this size were quite numerous by autumn in Salt Springs Valley Reservoir. One result of this rapid growth was a progressive increase in the numbers of small fish retained by the seine. This recruitment will tend to bias the population estimate upward as discussed in detail in a later section. The black bass estimate was corrected for recruitment by starting ii CALIFORNIA FISH AND GAME with a niininiuni size of 95-99 millimeters (midlength of 97 millimeters) for Period 1, gradually increasing to 128 millimeters in Period 9. The revised data are shown in Table 3. The corrected population estimate is 2(A.B) 1,162,579 P = = = 11,924. 2(C) 98 The 0.95 confidence limits are 12,139 to 18,282. The difference between the two estimates is too small to be of much concern, in view of the limita- tions of the field procedures on which they are based. Weight of the Bass Population The fork length-weight relationships for a selected sample _ of 186 largemouth bass taken in August and September are shown in Figure 4. When these data are plotted as logarithms of the weights (W) in grams FORK LENGTH (mm) 200 250 300 8 9 10 FORK LENGTH (inches) FIGURE 4. Length-weight relationships for largemouth bass taken in Salt Springs Valley Reservoir during August and September, 1951. Linear relationship is log weight in grams = —5.00462 — 3.07612 log fork length in millimeters. FISH OF SALT SPRINGS VAl.l.KY RESEBVOIB 1 5 against the logarithms of the fork Lengths I L) in millimeters they show reasonable linearity, and the straight Line equation derived by the method o!' Leasl squares describes the relationship Log W • 5.00462 | 3.07612 Log D. The bass population was considered to be adequately represented by the com I lined Length frequency distribution of Periods 1 and 2. For each five-millimeter Length group, the midclass Lengths, the percentage fre- quencies, the numerical frequencies, the calculated average weights per fish, and the gross weights of the Length group were calculated and tabulated (Table 4) For both the uncorrected and the recruitment cor- rected estimates. The relative crudeness of these calculations must be emphasized. The tola Is in Table 4 also include the weigh! of bass whose fork Lengths were 230 millimeters (nine inches) or Longer. Pish of the Larger size group are, ol' course, of greatest interest to anglers; they comprise only one-fiftli of the estimated population numbers and over half of the total estimated weight within the size-range sampled. Population Estimates of Seined Bluegills The numbers of both seined and 1 rapped bluegills which were sampled. marked, and recaptured, are given in Table 5. The length-frequency dia- grams for each of the periods are given separately for seined and trapped fish in Figure 5. From data in the first part of Table 5 for seined fish, it was impossible to calculate a sensible Schnabel estimate of the bluegill population by utilizing the simultaneous mark-and-recapture records for the first four periods. The four-period estimate, 2(A.B) 5,299,908 (C) ~ 51 is ridiculously low, because there were too many LV recaptures in the first several periods, when restricted seining within the eight major areas (Figure 1) was practiced. Later, however, seining was much more randomized, and the sampling data from Periods 5 to 9 can be considered much less biased. During these later periods, when marking was discon- tinued, the LV marked fish had also had a chance to become more widely distributed. By considering 2,646 LY marked bluegills at large during Periods 5-9, the Schnabel estimate uncorrected for recruitment or mortality would be P: — = 103,920, A (B)2(A) (2,646) (4,340) P = - -=574,182. 2(C) 20 The 0.95 confidence limits calculated from Chapman's (1948) Table I are 344,969 to 887,685. 16 CALIFORNIA FISH AND GAME S §- B O o S ±= E en -•— ccz s -^ L_> . — — a> O- ^K-^shNHNnao OCCjHt-HOOl-OCira^NCD co -c* co © O co oct^o— < ci -# ijH-OOlOILOCO^ONOONLOO) ■~^ hM^tCJONOhhh coaocioOHrtTtiHOctono TC* >> co 5 -*^ — "5: *V .*3 ■r ■g 1 **■ a) OQ ouiooo^oonOHt-M ^OrtOCDOOHdHHMO ^ C h to 00 M -< N M O i-l O LOOOLOMCONHCOO^CDO - iZ 0 »-N -hmnkhN rt CI -C O CO O UO (M LO Tf ^l IO rf -E -v u f. ~~ ^, '- r = vE J -a a — — 0 _ ^OTilnMONfSN*'*^ C. LO CI ^< LO O N N LO CO H CO O) _• >» NKOOKCN^MMIMnM TiCOClOOCOSO'. OOCON^N'* — F o 9 :■; r. XX.KSHnn ci-^oo^LOiiH^cocococi -= 0 S © T— 1 — c *3 z C 3 o z * I >. : s - c o o 1 1 a « «) o n "*MLOCONCONOON> co c c. - i: k x oo h c c co Cl O t- C. 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H CO LO N C H CO LO N co — -r -r -r -t '0 IC lO io >o 1C CDOCSCONt-NNNCOCOcOCO j: 4-3 "3 --. rcj c - ^■*, 1- ?i 1- 01 1- 01 t- 01 1- 01 1- 01 ci t^ ci t^ ci r^ ci r~ o t^ ci i^» ci <-. - r. c C oi oi co co — -r i.o CCNNXXIOOOHrtCi — — — — Cl Cl Cl Cl Cl -- u 1 > I 1 1 I 1 1 1 1 1 1 1 III 1 1 1 1 1 1 1 1 1 , c 1 1 1 1 1 1 1 E9 1 1 1 1 1 I h ~Z 1 1 I 1 1 1 1 1 1 1 1 1 1 i i i i ■ i i i i i i i • 1 I 1 1 1 1 1 1 1 1 1 1 i ■ i i i i i t ■ i ■ i — i i t i ■ i ( i i i I 1 I 1 1 1 1 1 1 1 1 t U ~ — r. — r — - — r. — ~. — r. cc oi oi co co — — '0 •rr. -rr.fOftsi'O'jcx* B 0 ■z co i~ i- mxc. ooohh ci - ■ i i • oC'OC'OC'OC'OC'OC C '0 C '0 O LO CO 1.0 CO LO O 1.0 o r. c c — — oi oi co cc — — '0 CO CO (~ t^ 00 00 OC CC O O i-i -H Cl h'ISII <>h' SALT SPRINGS VALLE1 i:i I i:\oii; 17 OJOihO^MOOOiOO 00 'f h Ol r^ W O M «-< 0>iOfitOfM^H«it5 co c 71 -r >-i I- 00 -t CI CO 00 — — ' 00 T T "5 'Q ^H rH ~H .-. -71 ^ ^ I so cr 3 7 9. 71 ->Jt CI -f CO Ol / ftMOOOSOMS — ' OI CO -ti 10 M C7 (O lO !C CI IO O CO CI CI CI CI i 3 -h ci ci co cc EG I- I — / 71 / ^ CO — i I. I. h Ol Ol N M- f h»00h ffOlOOOON CO^i-icOCNCI**i-*rt-H CI CI CI CI tO CO CD CD CI CI 71 CI CO CO to io o> h h oo n i-i m O b- •fftDOl tDONO«(NNC-tO) iOOOOl(OM01"0 0 — I -t< 00 w (DCOCO t- t^. 00 00 o -< O ci ci CI i-i 1- co H !D N lO N Tf IO n CI CD r^ co ai in HiOdOcOMM(D!DOOl NOON * Tf o m oooo oooo co -r co © m co Tf 00 o r COCOCOi.OOt~CTSTt t^ t^ 00 00 a> O O i-i co ■* 05 oooooooooo OOOO O 1-1 ,-1 lH ,—t rt oo oo oo O CO o a> " CO m t^ 03 — 77 • : t» i— ' CO m CO o CN -T CD ■* 00 Tt< 00 a> OJ 01010)0000 CN CN ci CN CO CO t~ t^Cir~Clt~Olt^Clt^OI CICOCOTfTtiinmcDCDt^ N CN CI CI CN CN CI NCI CI CI t- CI t- f^ CI 1^ CI CN CN CI oooo oi a O -H — 1 ci 'CH m Tfl CI CI CI CI CO CO CO CO CO CO ■* Gl'^05ictiOlTtiCn'^CT)icH i*05TjiOi CTlTjiOlTf cicocoTti*fioincocor~ oo oo oi oi o-^h cn CI CI CI Cl CI CI CI CI Ol CI CICICICI cocococo I I I I I I I 1 I I till I'll in o >o o »n o in © »n o o in o in in o in O cicocoTt o -d a c« o CO CI I o cd ■+* O o .a O M 18 CALIFORNIA FISH AND GAME TABLE 5 Data for the Estimation of the Bluegill Population of Salt Springs Valley Reservoir From Samples of Fish Seined and Trapped During August and September, 1951 Period Days elapsed1 Minimum size handled (mm.) Total number handled (A) Total number marked and released Total number marked at large (B) Number of re- captures (C) Seined fish only (LV clipped) 1 0 6 10.5 15 20 27 31.5 35.5 40.5 0 5 9 13 19 26 30 70 75 80 80 80 80 80 80 80 80 80 80 80 80 80 80 969 711 1,115 1,040 1,034 1,098 853 602 753 611 570 519 523 567 214 598 968 700 978 0 0 0 0 0 0 609 546 499 97 0 0 0 0 968 1,668 2,646 2,646 2,646 2,646 2,646 2,646 0 609 1,155 1,654 1,751 1,751 1,751 12 2 ... ... 10 3 20 4 21 5 3 6 -.- 6 7 8 5 2 9 .-- 4 Trapped fish only (RV clipped) 1 22 2 __ . 2 3.-. --. - 3 4. 0 5 3 6 .. ... .. 0 7 7 1 Computed from middle of 7-10 August period for seined fish and from middle of 7-11 August period for trapped fish. 2 Not counted due to nonrandom sampling immediately after release. As iu the case of bass, discussed earlier, large numbers of rapidly growing young-of-the-year bluegills were continually being recruited to the population being sampled by the seine. A corrected estimate of the sort already described was therefore made, using the breaks indicated by arrows in the length-frequency histograms of Figure 5. This ill- defined break was chosen quite subjectively, although a similar break did appear when the data were grouped in several other ways. A fairly linear increase in length is shown in Figure 6 by plotting the lengths of the fish at the respective points indicated by arrows in Figure 5 against the times to the niiddaies of the periods reckoned from Period 1. The least squares calculation of the slope of the line indicates a growth rate of 0.65 millimeters per day for the smaller bluegills during August and September. FISH OP SALT SPRINGS YAM. IV RESERVOIR 111 ■t o * in * » It in * CD •1 en 1 1 • 1 O o O o o in o o O CO Q .7, < . '1 •I • > IS PERIOD 8 01 o 01 01 Ol m 01 01 in 01 IO 01 01 CO 01 IO n lO in CM in m in in IS in in CO 01 FORK LENGTH (MM) FIGURE 5. Histograms showing length frequency distributions of seined and trapped bluegills for each period of sampling in Salt Springs Valley Reservoir during August and September, 1951. The histograms on the left are for seine catches; those on the right, trap catches. 20 CALIFORNIA FISH AND GAME X Z UJ rr 147- 142- 137 132 127" 122- FORK TIME LENGTH PERIOD (DAYS) (MM) SLOPE = 'DAY 20 TIME -< r- 30 (DAYS) "i — 40 50 FIGURE 6. Data and diagram of progressive increase in bluegill lengths represented by a break in the length frequency histograms (Figure 5) used for rate of growth calculations A good check on this growth rate can be obtained by plotting the lengths of the smallest recaptured bluegill taken in each period against the time at recapture, which had elapsed from the beginning of Period 4, when all marking had ceased. These data, shown in Figure 7, yield a slope (growth rate) by a least squares calculation of 0.72 millimeters per day — a very close agreement with 0.65 millimeters per day. Corrections for growth of the small bluegills into the range of sizes taken by the seine were made on the basis of a minimum size of 85 milli- meters fork length at Period 4. At the rate of 0.65 millimeters of growth TABLE 6 Data for the Population Estimation of Seined Bluegills in Salt Springs Valley Reservoir Corrected for Recruitment With Summations From the Fifth and Following Periods Period Minimum handled mm. Total number handled (A) Total number marked and released Total number marked at large (5) Number of recaptures (C) 1 75 79 82 85 *-s 93 95 98 101 '.Hi.-, 711 1,109 936 894 661 582 27.-, 308 964 700 975 0 0 0 0 0 0 0 964 1,664 2,639 2,639 2,639 2,639 2,639 2,639 ji 2.. 10 20 21 3~ l 6 7— 3 6 5 8 . 2 ■ 4 1 Not counted due to immediate sampling after release. [SI] OP SALT SPRINGS VAU,i;\ RE 5EKVOIH 21 PERIOD DAYS ELAPSED FROM BEGINNING OF PERIOD 4 FORK LENGTH (MM) OF SMALLEST LV REGAPTURE 4 5 6 7 8 9 3 8 15 19 23 28 85 130 92 98 105 127 130- UJ cc D h- Q. < O UJ at 2 I H O z UJ o u. 120- 10- 100- 90- 80 SLOPE = 0.72 MM /DAY 0 T 10 20 T 30 TIME CDAYS) FIGURE 7. Increase in length as indicated for a series of the smallest recaptured bluegills taken within Periods 4 to 9 of the seining operations 9,9 CALIFORNIA FISH AND GAME per day, the corresponding' minimum lengths at earlier periods were less than 85 millimeters, and the lengths for later periods were greater, as shown in Table 6. In this table capture-recapture data for seined blue- gills revised to include only fish above these minimum lengths are also given. On the basis of the revised data from Periods 5-9, A (B) 2 (A) (2,639) (2,720) P=- = 358,904. 2 (C) 20 The 0.95 confidence limits are 215,630 to 554,866. Population Estimates of Trapped Bluegills It is of considerable interest to compare the bluegill estimates derived from seining and trapping. The capture-recapture data in the bottom part of Table 5 have been used to estimate the population of fish suscep- tible to trap capture. The resulting figure, uncorrected for recruitment over all the periods, would be P = 2 (A.B) 4,226,246 2(C) 15 = 281,750, with 0.95 confidence limits 154,258 to 469,113. The numbers of recaptures among trapped RV marked fish (Table 5) indicate much more random capture-recapture sampling than for the seined fish. The relative randomness of the trap sampling was due to the setting of the traps and the releasing of RV marked fish over a much wider area than was initially possible for the seined fish. This estimate has also been corrected for recruitment, using a growth rate of 0.65 millimeters per day, and starting with a minimum size of 85 millimeters during Period 1. The revised data are shown in Table 7. TABLE 7 Data for the Population Estimation of Trapped Bluegills in Salt Springs Valley Reservoir Corrected for Recruitment Period Minimum size handled (mm.) Total number handled (A) Total number marked and released Total number marked at large Number of recaptures (C) 1 85 88 91 93 97 102 KM 611 -Mil 514 519 542 195 543 609 540 494 97 0 0 0 0 609 1,149 1,643 1,740 1,740 1,740 21 2 . - 2 3 3 4.. 0 .'. 3 6 0 7 7 1 Not counted. This revision crives a figure of X i A.B) 1,013,979 2 (C) P 267,599. risil OF SAL I'RINUS VALLKY RKS1 RVOIR 23 The 0.95 confidence limits are from 146,510 to 145,552. The resulting reduction in the estimate is negligible in contrasl with the sizeable redud ion in I lie ciise of scinn l hi negill. Weight of the Bluegill Population The fork length and weight relationships for a small, selected sample of 189 bluegills taken in Augusl ami September, L951, are diagrammed in Kigm-e s. On 1 lie ha sis of a linear relationship be1 ween the Logarithms of the fork lengths (L) in millimeters and the logarithms of the weights (W) in grams, a least squares equation of the relationship is log W = 5.33887 + 3.31138 log L. FORK LENGTH (mm) 70 80 90 100 110 120 130 140 150 160 170 180 190 200 170 i ' 1 ' 1 *- -1 1 ' 1 ' S 1 6 4 5 6 7 FORK LENGTH (inches) FIGURE 8. Length-weight relationships for bluegills taken in Salt Springs Valley Reservoir dur- ing August and September, 1951. The linear relationship is log weight in grams = —5.33887 + 3.31138 log fork length in millimeters. 24 CALIFORNIA FISH AND GAME r= a^ rs ° oo _£ -» s "o -o a> ob ■TB 03 NiOWNtOOlOHOOiOvOlCcOiHrtOOl^ON^ iffiO CN o HCT'tNOOONrtOaMNNOi'NrHCSn^mH iOO(D CO CO •^" ^lOtOOMi'tOiOOOHNOlNNOiOWN^HQOH i"*C0 oo o SB = 03 -#MlO00 00taiNWNN00rfrt00HOllOIOINra 1 CM rH CN 43 £ l-H ^H r-H I— IHHH ^HrH^Hi— I CN o" oo" o fcfl IO -r3 "S M = — 2 B = o.-S -*- — 3 | 03 03 o !DOaNOOMSOOHD'JiOOMNN«5N'KiiO'*iOD ON o co u o ctNOcoNNtffiOHOHinsocico^ocooOH i in -* nHooinKiiooojjtOMOOfHiiTiinNii iho o CM _ m fci NiotooooOMOioranncDioooio^«ra CO = 2 a e c3 >> OOWM'tWOlLO^CDiOOOlOOMiOCONOOJtNOO 'CON CO ■* o ^nHooOHHHNOoonsMH«a)HioNHH 't-.ee oo OB O o o 7-i co" rt OONOOh h o" n" oo" oo" t> !m" oo C0J CO 0 > -r» 01NOOO>ONNID'<^iOO:CSI10mnMOC-l" ■-<" i-i rH C 5 2 -5 a I— I m a * H-^oomoscocicDuiTjiMii^io^^icort^^^ eon N ■* *rt Ma >i NCOOa. hOCON^COCO^iON^SSOlOiOSN ICO O) OB d "^ C3 O COCOOONLO-HCCCONWNCD^iOOiOCOCOHiONb. 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(Ni't-Oi'NONNCO^HCOCDiOnnniONCJOHO ,"* ;- HHHOiriOICOCOTliiiracDCDNCOOlOHNCOlOCD — o COCOCOCOOI0101HHHOOOC:*01000000SSNSCOCO 1 „ d OOOOIfOOOON^COCCONCOiONOlHCOlONOlHCOlO tH CD > OlCOCOCOCOCO'l'^^^HjtoiOiOiOiOtOcOcOCDCDcONNN o a ii — - T3 c &JZ oj N oi i- oi s :i s oi s ci n « s oi mm r- m s n s oi s N s J, i-i. MooaoioOHHOioicoco^i'ioiococDSNccaioi IO IN o ~ti . — * CO ' J cc J 5 u a a O «*H T, '- CD m 2 M c: o ».o o >co o '.o o 'O o »o o »o o io o io o r- t- f. f r. ~ e o — — ' oi oi co co -f -f i-o io co co n n oo oo ob KISII OF SALT SPRINGS VALLEY RKSKKVOIR •_'•< 03 E E o o 1 <_> w o- 03 o o> lO 1- r— -o (~VJ ic_ "S o> => cu u_ O CQ o> o> -*- Q. oo oj o CD Q c i oo (D a> -f i.o ><5 cx> r- co c/> c i . — •-. c. ■"- I eo O -r •0 • - ~ i - r. r i / / -i :r> '.-. f -r 1- ti -• • > fi Jf re i- — •". -:i - — ?i i- — - C '"- '' "" i - « r — ct ■ C •• ' CO / 1 - 7- • / :'. I Si 1- c- J z 01 I-' = If O <-• "3 CI C — s is o S 3! 3 aoi(M00-r-H-> O to •» » n ffl O ci oo i- o -< t '. '" "i ': ■: ^ O k h oo moo » f o ■■: t. i- ■: -i ; ■:■; ; : '' ' i - - CI z o c '0 ■ - — u 0 O 'C c rtNOOfflNNCHONO-l-JI-T-r-rKCI-H 1- / Ph « 0) S a & MfCCI-HHri z 01 3 9 £ M -4-> oo oi o 'f n co h in -f to -c -• : - i - i- - ■; ;c ■; i-: ~ CI C CO »t N (O ci i" :i *i :i - I- »" :c i- cc -r ^- •" — r M N eo f «! oo o 3 o n co o to O •;■ C C CI -r CI c <~ Q) '"^ z • -. 00 KNOJONMSHfO': — f, ~ ~ X -z t:o • -. • '. 3 t, <=> a +* jO -r CO A 01 .£P £-■0 "© 8 S CO CO O U t-iooococ»i3:OcO"*,oocDr»co-f'Ococx)Ot-^ -r - l-t otOHN'jootOHOiHrtOieotoocicicicic CO o o *-~ ■> h co in 9 O oo r» n oj eo io i» o n c. x /. i- -• ~ -r -r '-. bi HNcNCONOSiOtS'ftSOtO-ffCOCI-'- —• r-* c3 S -M I— 1 i-H ,_' o .§2 *^»« •-1 -3 s m a) as t. .2*2 oioonoofflO^oioi-toneMMeBcsoNooaoi -. '0 15 >> soicooo)^oo^coio^HS9io*- r. r - — -r 00 3 *^ ft S 0 u. O o COClNOOtOOlOCOOOlXHCIiOOLOWCICOOl r- o *n a 4) IH ON co oo" o coo co" b-~ 00* iH iH t>T o oo" ■* io" 1>" co" ON IH — r o 4) a 3 C eoio-*0N>-i'H'-i'H i-i 00 01 at M 0 1 a) •*t c3 T^COONNaO-^OcOOOC-INiOOOCDNOD'HCO^CO o en OOCOtOf-NOOoOtOtOifCltOOlHH-HOOO o — o cr-iTi o CO u © «_ o 1 — 1 0*-*C0000C0^»0Ot-CC © T3 INCOCO^iOtDNCOOiOCNCOiOODOOOCOiOOOOCO bfl C 3 0 PL, OOOOOOOOOr-ipHi-ii-ii-irHeNeNCNCNeOCO ooooooooooooooocooooo 13 ft -3. IF cqoieoM'ioconi^NHeooeNNOiincoisoBW HiOCOLOOOlCOH^OIiOTrCOOOOOOOOCOCOON | «T|iNO'*r-0)N0100ifHOOtDiO'*OiOf-CtN 13 * ca HHHM0NCNt0W*T|iiO09!ONI»fflOH0NC0it; o 0 COCNC>^0N^H'-^^OOOClC00C00000000t^t^t>-t»0r OO _c ^OMON^rtDWOCItOiONOiHCOiONOO^CO It COCOCO'OCC0D^t^0000 ■a -r — 26 CALIFORNIA FISH AND GAME The relative numbers of fish in each five millimeter group in the popu- lation at the outset of marking operations was determined, using 968 fish seined during Period 1 and 1,183 fish trapped during Periods 1 and 2. Frequencies and weights of each length group are given in Table 8 for seined bluegills and in Table 9 for trapped bluegills. In each case total weights are given both for all sizes sampled and for fish roughly five inches or longer (125 mm. fork length). The latter are large enough to interest anglers. Population of Carp Carp data are summarized in Table 10 for seined fish plus a few trapped fish. After the fourth period, with 505 carp marked at large, marking was discontinued, and all carp sampled were removed from the lake. Using the 505 marked fish at the start of the Period 4, with correc- tions for subsequent removals of marked fish, the Schnabel estimate is „ 2 (A.B) 613,142 P = = = 68,127. 2 (C) 9 Actually this estimate is biased downward slightly since removal of fish violates the basic tenet of the Schnabel method, which assumes a constant population. The 1,087 carp removed during the last sampling period have therefore not been included in the final estimate of 68,127, which has 0.95 confidence limits from 30,351 to 133,052. The length frequency distributions of the seined carp, which com- prise practically all of the fish handled, are given in Figure 9. These data indicate that all the carp handled were fully vulnerable to the seine or traps and recruitment corrections were therefore not necessary. TABLE 10 Data for Estimation of Carp Population of Salt Springs Valley Reservoir During August and September, 1951, on Basis of Combined Seine and Trap Catches Total Total Total number Total number Number number number marked and marked at of Period handled removed released large recaptures (A) (B) (CO 1 115 0 115 0 0 2 174 0 171 115 1 3.. 223 152 0 1 52 219 0 286 505 2 4—. 1 5— . 345 345 0 504 2 6 129 129 0 502 2 7 225 225 0 500 3 S . 2.36 236 0 497 1 9—. 137 137 0 496 0 KISII OF SALT SPRINGS S ILLE1 RESERVOIR TABLE 11 Fork Length and Weight Frequency Distributions of Salt Springs Valley Reservoir Carp Population Estimate of 68,127 From Combined Data of Trapped and Seined Fish Zt Mi'lchuis length Percentage frequencj of length NllllH'l il a 1 1 1 & [uency of Lengl ii < laloulated avi weight per ii i> Gro lengl •il'lit r,f (mm.) (in.) class' class (gin (lb (kg.) (lb.) 134.5 5.30 0.200 136 17.2 0. Mil 6 i 1 1 1 144.5 5.89 0.200 L36 18.0 0. 128 7.9 17.1 234.5 9.23 0.200 136 235 . I 0.518 32 '1 70 :. 244.5 9.63 2. L96 1. 196 265.2 ii 585 396.7 874.6 254.5 10.02 6.387 4,351 297.8 0.657 1,295.7 2,856.5 2(i4 5 hi. II 11 . 178 7,615 332.9 n 734 2,535 '1 5,588.7 274.5 10.81 11). 778 7,343 370.5 ii 817 2,720.6 :,,997.9 2S-I ;, 1 1 .20 5.589 3,808 HO. 8 0.906 1,564. 3 3,448.7 294.5 11.59 3.393 2,312 154.0 I .00 1,049.6 2,31 to 304 . 5 11.99 0.998 (ISO 199.9 1 . 10 339 9 749.4 314.5 12.38 3.593 2,1 is 548.8 1.21 1,343.5 2,961 .9 324.5 12.77 N 1S1 5,576 1,1111 7 1.32 3,349.5 7.384.4 334 . 5 13.17 11.776 8,023 655 . 8 1.45 5,261 .5 11,599.6 344.5 13.56 8.184 5,576 714.0 I . 57 3,981.3 8,777 ,3 354.5 13.96 8.184 5,576 775.6 1.71 4,324.7 9,534.3 364 . 5 14.35 4.790 3,263 840.4 1.85 2,742.2 6,045.5 374.5 14.71 2.994 2,040 908.8 2.00 1,854.0 4.0K7 1 384.5 15.14 2 . 595 1,768 980.7 2.16 1,733.9 3,8i'- 6 394.5 15.53 1.597 1,088 1,056.2 2.33 1,149.1 2,533 . 3 404.5 15.93 1.397 952 1,135.3 2.50 1,080.8 2,382.8 414.5 16.32 1. 198 816 1,218.3 2.69 994.1 2,191.6 424.5 16.71 0 . 599 408 1,305.2 2.88 532.5 1,174.0 434.5 17.11 0.798 544 1,395.9 3.08 759.4 1,674.2 454.5 17.89 0.798 544 1,589.6 3.50 864.7 1,906.3 474.5 18.68 .399 272 1,800.3 3.97 489.7 1,079.6 484.5 19.07 0.200 136 1,911.9 4.22 260.0 573 . 2 504.5 19.86 0.200 136 2,148.9 4.74 292.3 644.4 534.5 21.04 0.200 136 2,539.2 5.60 345.3 701.3 554.5 21.83 0.399 272 2,823.4 6.22 768.0 1,693.1 564.5 22.22 0.200 136 2,973.0 6.55 404 . 3 891.3 604.5 23.80 0.200 136 3,623.1 7.99 492.7 1,086.2 624.5 24.59 0.200 136 3,980.1 8.77 541.3 1,193.4 654.5 25.77 0.200 136 4,557.9 10.05 619.9 1,366.6 Totals 100.004 68,131 44,132.8 97,296.1 1 Based on length frequency distribution of 501 carp seined during Periods 1, 2, and 3. 28 CALIFORNIA FISH AND GAME ff> ff> & * < *■ * 6606 o in 16 I2H 8 4 PERIOD I 16 12 8 4 20 16 12 8 4 32 28 24 20 16 12 8 4 24 20 16 ■12 8 4 36 32 28 24 20 16 12 8 4 16 12 8 4 •24 20 16 12 8 4 24 20 16 12 8 4 20- 16- 12- 8- 4- 32- 28- 24- 20- 16- 12- 8- 4- 24- 20- 16- 12- 8 4' 36 32- 28 24 20 1 16 ■ 2 12 "- 8 u. 4 O o CM o o CM en CM CM 1 o CM CM "i — i — i — i — i — i — i — r— i — i — r CD CM 1 o <*- CM cd CD CM 1 o CD CM CD CO CM i o CO CM CD o m i o o ro CD CM to I o CM to 1 — r CD I o <* ro FORK LENGTH (MM) FIGURE 11. Length frequency distribution of brown bullheads taken during August and September, 1951, in Salt Springs Valley Reservoir TABLE 12 Data for Population Estimate of Salt Springs Valley Reservoir Brown Bullheads on Basis of Combined Seine and Trap Catches Period Total number handled (A) Total number marked at large Number of recaptures (O 4 .. . 54 2.5 58 43 L6 8 75 125 150 207 248 263 4 1 6 1 7 4 8 3 g 2 PISH OF SALT SPRINGS VALLEY RESERVOIR 31 Recruitment corrections were unnecessary because of nearly complete vulnerability of the bullheads to the gear. It should be noted, however, that 20 traps lifted morning and evening caughl about twice as many bullheads as did Tour daily' seine hauls. I >ata were insufficient for making a crude weight estimate of the bullhead population. Population of White Catfish Over all periods <>l" seining and trapping only .! I white catfish were taken. A single recapture out of 127 marked catfish at large appeared among six fish handled in Period 8, indicating that p (A.B) 0-27 (C) n;i!. The confidence limits from Chapman's data are from 1_! to 3,157 ; actu- ally, the 34 fish handled in the study would provide a more appropriate lower limit. It is manifestly impossible to obtain an adequate estimate of such a small and diffuse population with the scanty capture-recapture data. The length frequency distribution of the 34 white catfish is shown in : Fig X CO ll_ Li_ O 'ure 12 1 n — A a: UJ m 4- 3- 2- 1- -3 -2 - | z> 7^ i en ro • o ro H — r CD in i o m 6 i o cd i o CD ro OJ i O ro '' C\J i o (M cd1 CD C\J i o CD CVJ CD ro i O ro en ro ro i O ro ro 'cn m ro i o in ro cn CD ro i o CD ro FORK LENGTH (MM) FIGURE 12. Length frequency distribution of white catfish taken during August and September, 1951, in Salt Springs Valley Reservoir. Population of Golden Shiners Sampling with the seine for the small golden shiners was inadequate, since only the larger fish were taken. A total of 161 was marked and released ; none were recaptured. The length frequency histogram (Figure 13) indicates that the 161 shiners were the remnants of the four to six inch fish which had been stocked less than a year earlier, plus a few of their larger progeny. The spatial distributon of the shiner population in the reservoir was quite spotty and most of the 161 fish came from only a few hauls. 32 CALIFORNIA FISH AND GAME 20 1 16- -20 co "S. o> on Z3 CO a> E o >- E ' O 3 ■ - © i ' O) X XI CO -r d ■ .£ 28 -r c« o te m i>. w - .2 3 73 *- S3- 6 i. — / / i CI .— - - '0 ' ' : n - -r •■ 3 / « I ft 5?1 — ■ i "I CI / d P— « ft > U o ft. X a ftS EC r. :' i - • / / - 1 O CO - 00 1 - ci ci'" -r ^h — CO O © © V. 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CO H X i i i < . i i ■ i i 1 T^ I s~* /: /. i • -• u • — u / — i i i i i i i i i — c 03 0 rS 0 I tO tfl 1 i | : :"* :"S ! ! : : : * ^ : s j : i : :^3 : = cS , i ' ' O 3 | 3 *> i i i loc ; — r- ■3 -1- 3 - - - _ - - - - Z i .S as ft 03 m -o CO 1 i- m ^3 -' 5 O S3 OS 1— 1 - 111 O oj 73 C3 C3 73 3 3 ' r- ., IscccOtCfsocyca'J-S cuiucucucscccofts.t: 11 3 S — ; o Hi -^ 3 3 «ci 3 ii^ol^^3 cd (3 03 t-rr cj * s — « 2— 6S841 34 CALIFORNIA FISH AND GAME EVALUATION OF RESULTS General To make satisfactory population estimates by the Schnabel (1938) capture-recapture technique it must be assumed that the populations in question are constant in number and that random sampling of both marked and unmarked members is attained. These assumptions and their ramifications are discussed in detail by Richer (1948, p. 39-52). Differences Between Marked and Unmarked Fish In this study there was no evidence to indicate any failure to recognize clipped fins on any species, nor was there any evidence to indicate that regeneration of clipped fins took place during the seven weeks of the study. So far as could be observed, there was no difference in the vulner- ability of marked and unmarked fish to the gear, although the possibilities of differences would be expected had tags or other encumbering marking devices been utilized. Although there was no satisfactory check, marked fish were believed to survive as well as unmarked fish. Random Distribution of Marked Fish and Random Sampling The random sampling of the bluegill population in Salt Springs Valley Reservoir was a complex problem. The results of nonrandom distribu- tion of seined (LV marked) bluegills and their subsequent recapture in seine hauls were especially noticeable until Period 5. During the first four periods they were seined in very restricted snag-free areas and released near the place of capture. As a result the number of recaptures in the first four periods was unusually high and population estimates were unusually low in comparison with the later periods, when seining localities and the release of seined bluegills were much more randomly distributed over the entire reservoir. By contrast, the traps, which were set in the more open waters, captured bluegills more nearly at random and the distribution of RV marked bluegills was quite broad at the outset of marking operations. The bass and carp seemed to have a greater tendency to roam than bluegills ; there was little evidence to suggest that marked fish of these -IM'cies remained long at the point of release. Some evidence for the random distribution of marked bass came from observations of 9 marked bass among 69 taken by anglers April 5-6, 1952. For the ninth period of sampling in September, 1951, when 1.664 marked bass were at large, a sample of 108 bass yielded 16 recaptures. The proportion of marked bass in the two entirely different types of sampling are remarkably alike, considering the possibilities of mortality differences. This would tend to indicate that bass sampled in September were about as randomly distributed as they ever would be. Catch data for brown bullheads and white catfish indicate that these small populations were fairly well distributed throughout the reservoir, although the capture-recapture data were too meager to indicate whether or not the marked fish were randomly distributed and resampled. Un- fortunately, for most population studies there will be no a priori knowl- c< lire of fish movements and aggregation tendencies and there will be little opportunity to have a single type of gear which samples all parts of a body of -water with equal efficiency. Even in small ponds Fredin Kisii OF salt SPRINGS vai.i,i.\ RESERVOIR 35 (.1950) notes thai nonrandom sampling of certain species can cause serious error in estimates by the capture recapture method. For Future large-scale capture-recapture operations it would be advisable to take extra precautions to insure both the random distribution of marked fisli and the random distribution of sampling. The random distribution <>r marked (isli could he assured l>y transporting and releasing them throughoul the lake or reservoir, taking due precautions to prevenl mortality from the extra handling. Differential Vulnerability of Various Length Groups Another type of nonrandom sampling bias results when different size groups of fish are taken in numbers no1 strictly proportional to the absolute abundance of the size groups. A bias of this sort appears especially when small fish which are not fully vulnerable to the gear are included in the mark-and-recapture tabulations. The effed of includ- ing' incompletely vulnerable fish is to make the population estimates too low, as pointed out by Kicker (1948, p. 47). This type of bias mighl be suspected in the bluegill estimates from trap and seine data, in which the fish above the minimum sizes after recruitment corrections were somewhat too small to be fully vulnerable. It would have been much better to consider only those bluegills large enough to be included in the right limbs of the length frequency histograms in Figure 5; for trapped and seined bluegills such minimum fork lengths would have been about 115 and 95 millimeters, respectively. The differences in Table-, 8 and 9 among the relative frequencies of the smaller length groups of bluegills taken in the two types of gear could, of course, be explained partly by mesh size differences. Differential vulnerability of various larger size groups of bluegills may have been the cause of the discrep- ancies of the numbers of fish estimated for comparable length groups, as summarized in Tables 8 and 9. Bluegills larger than 115 millimeters should have been large enough to have been taken in direct proportion to their abundance by either seine or traps. To test for discrepancies in relative frequencies of different length groups of seined and trapped bluegills, simple Chi-square tests of homogeneity were utilized. In order to have sufficient numbers of seined and trapped fish for comparisons, the fork length frequencies of fish over 115 millimeters taken during the first two periods were combined for the respective seine and trap catches. These data are set up in Table 14 with the appropriate ''ex- pected" numbers of fish which should occur if the seine and traps were nonselective over the indicated range of length groups. For the com- bined data of Periods 1 and 2, the very highly significant Chi-square of 36.33 (P<0.001) indicates that the frequency distributions for seined and trapped fish were not homogeneous; the traps caught dispropor- tionately more fish in the 115-129 and, for the most part, in the 170-194 millimeter range; and the seine was generally more efficient than the traps in the 130-159 millimeter range. It has already been pointed out that seining during the first four periods was quite restricted areally in comparison with trapping, and it is quite probable that this bias was largely responsible for the differences in gear selectivity. During the later periods, when seining was much more randomized, it would be expected that size selectivity differences between seine hauls and trap catch would diminish. That this homogeneity did actually exist later 36 Test of Homogene CALIFORNIA FISH AND GAME TABLE 14 ity of Length-frequency Distributions of Seined and Trapped Bluegills Taken in Periods 1 and 2 (7-16 August, 1951) Fork length Seined fish Trapped fish Totals (millimeters) Observed Expected Observed Expected 115-119 - - 78 43 47 43 64 50 61 36 31 15 19 9 8 7 92.3 58.0 56.4 39.0 53.9 38.0 51.8 32.8 25.7 18.0 19.0 9.7 7.7 8.7 102 70 63 33 41 24 40 28 19 20 18 10 7 10 87.7 55.0 53.6 37.0 51.1 36.0 49.2 31.2 24.3 17.0 18.0 9.3 7.3 8.3 180 120-124.. 113 125-129— - 110 130-134 - -- - 76 135-139 . -. .-- - 105 140-144. -- 74 1 15-149 - -- - 101 150-154 -- 64 155-159 50 160-164... 35 165-169 - 37 170-174.. _- 19 175-179... . 15 180-194 ... _ 17 Totals .. .. 511 485 996 Chi-square = 36.3329, df = 13, P = <0.001. TABLE 15 Test of Homogeneity of Length-frequency Distributions of Seined and Trapped Bluegills Taken in Periods 6 and 7 (2-11 September, 1951) Fork length Seined fish Trapped fish Totals (millimeters) Observed Expected Observed Expected 115-119 62 57 41 27 23 23 19 21 14 12 16 3 4 64.9 50.2 38.4 25.7 28.7 24.4 15.2 18.1 13.9 14.3 12.2 6.7 9.3 92 62 50 34 45 35 17 22 19 22 13 13 18 89.1 68.8 52.6 35.3 39.3 33.6 20.8 24.9 19.1 19.7 16.8 9.3 12.7 154 120-124 119 125-129 91 130-134 61 135-139 68 140-144 58 145-149 36 150-154 43 155-159 33 160-164.. 34 165-169 29 170-174 16 175-199 22 Totals S 22 4 42 764 Chi-square = 18.2124, df = 12, P = ca. 0.11. on may be illustrated by comparing the length frequency distributions from combined data of Periods 6 and 7, as shown in Table 15. Here the Chi-square value is nonsignificant, although a great portion of the Chi- square is derived from the 170-199 millimeter range, in which the traps again seemed to be the more efficient gear. These comparisons between trap and seine catches do not indicate, however, which gear is the more unbiased; they indicate only that the two types of gear can differ in size selectivity. A seine of somewhat larger mesh would probably be more effective in taking bluegills in the larger size groups. PISH OF SALT SPRINGS 7ALLE1 RE8EBV0IB 3*3 The discrepancies in the population estimates for bluegills of L25 millimeters and larger, shown in Tables 8 ami 9, can be attributed to nonrandom distribution of marked fish, aonrandom resampling, and non- random length selection by the two types of gear. For Bpecies other than bluegills, everything indicates thai sampling was essentially at random. The fact that the Larger bass observed in a creel cheek on April 5-G, 1952, had essentially the same proportion of marked fish as the bass of all sizes bad during September, L951, is a Eurther indication that sampling and distribution of all of the size groups were random I'or this species. II' gear selectivity had varied for different size groups of any species, it would have been necessary to divide the samples into arbitrary Bize groups and mark each differently. The sepa rate populal ion es1 imates for the different size groups could then bave been added Eor a total popula- tion estimate. Otherwise, the population estimate calculated by lumping all data would be too low (Kicker, 1948, p. 47-48 j. Recruitment During August and September there was a lar^e recruitment of bass and bluegills at the lower limit of vulnerability to the gear. Estimates from an extended mark-and-recapture procedure under these circum- stances are biased upward, because the smaller marked bass increase in vulnerability. In later samplings these small marked fish, even though now fully vulnerable, represent a disproportionately small fraction of fish in the size class compared to the proportions of marked fish in the larger size classes, which were vulnerable from the outset. The bluegill population estimates would have been less biased due to recruitment had the initial minimum sizes been of the magnitude of about 95 and 115 millimeters for seined and trapped fish, respectively. The bass population estimates similarly would have been less biased due to recruit- ment had the initial minimum length been about 120 millimeters. With but rare exceptions all of the carp, brown bullheads, and white catfish were large enough to be fully vulnerable to either seine or traps, so that recruitment corrections were considered unnecessary. The method of making the corrections for growth by following breaks in the bass and bluegill length frequency distributions (Figures 2 and 5) is admittedly arbitrary, although sufficiently accurate for the purpose. More adequate information on the magnitude of growth rates could come from detailed scale-growth studies or from studies based on growth records from individually marked fish — studies beyond the outlined scope of this investigation. The importance of recruitment corrections are strikingly illustrated by a comparison of the corrected and uncorrected population estimates of bluegills (compare Tables 5, 6, and 7). The estimate from seined blue- gill is reduced from 574,182 to 358,904, while the estimate from trapped fish is only reduced from 281,750 to only 267,599. The lesser reduction in the latter stems from the fact that the traps retained larger fish, which were not subjected to large recruitment from young-of-the-year fish as was the case with the seine samples. Had the studies continued for an- other month or so, the hordes of rapidly growing small bluegills would have grown large enough to affect the estimates from trap data also. 38 CALIFORNIA FISH AND GAME Bass recruitment in August aud September presented problems similar to those for seined bluegills, and recruitment corrections lowered the estimate from 19,501 to 14,924. Recruitment corrections could be circumvented in several ways in population estimation procedures involving rapidly growing small fish. A season of the year could be selected when the population would include only fish of sizes fully vulnerable to the gear. Wohlschlag (1952) noted that yearling bluegills, black crappies, and brown bullheads in Sears- ville Lake were, for practical purposes, fully vulnerable to the one- inch mesh wire traps during April and May. Another method of avoid- ing recruitment corrections would be to deal only with fish of fairly large sizes, say over five inches in length for bluegills and over eight or nine inches for bass; with fish of these sizes, the relative changes in vulner- ability would be slower. and population estimation could be carried out over a period of perhaps a month without recruitment corrections. Also, it might be possible to estimate populations during the winter months, when fish grow more slowly. Before making any population estimates a preliminary large sample of each species of interest should be taken with each type of gear, in order to ascertain the length (or weight) frequency distributions of fish which should be large enough to be fully vulnerable to the gear in question. Effects of Natural and Fishing Mortality In the Schnabel type of estimation procedures, the loss of fish due to natural or fishing mortality tends to make the population estimate too great. The effects of fishing mortality could be accounted for only if there were an adequate estimate of the numbers of fish taken by fisher- men during the capture-recapture operations. In Salt Springs Valley Reservoir a complete creel census would be needed only for bass caught in the spring and early summer. At other seasons, the numbers of all species taken by anglers are so small that they would be negligible com- pared to those taken in the capture-recapture operations. For this reason the estimates in this reservoir were conducted in late summer. Similar circumstances prevail in many of the warmer waters of California. The occurrence of natural mortality, on the other hand, occurs through- out the year at varying seasonal rates. In this study attempts were made to correct for bass and bluegill mortality by accounting for the decrease in numbers of the marked fish at large. They were unsuccessful because tlc-re too few capture-recapture periods to follow the trend of succes- sively increasing population estimates. In the case of the seined bluegill • lata for Periods 4 to 9, a mortality rate of about 0.8 percent per day was obtained, although the inclusion of the nonrandomly sampled Period 4 i hit a ma < le this value a purely arbitrary one. At this rate the fish would '•xperience a seasonal mortality of about 88 percent over a period of 2511 days — a rather high rate. (See Richer, 1944, for a discussion of instantaneous and seasonal mortality rates.) By adjusting the recruit- ment-corrected data so that the marked fish were removed at this arbi- trary rate of 0.8 percent per day, the estimate of 358,904 is reduced to 298,544. Similarly, the recruitment-corrected estimate for trapped blue- gills is reduced from 267,599 to 238,413. The if ruitment-corrected bass population estimates showed a general tendency to increase from period to period to the extent that a daily mortality of about 3 percent would be required to correct the tendency. I'isil OP SALT SPRINGS \\i.l.i\ i;i ERVOIB 39 At this rate, the seasonal mortality on a 250-day basis would be aboul 95 percent a most unlikely high rate, which would reduce the estimate of 1 1,924 to around 10,.r>()0 bass. The effects of more reasonable mortality rates wci'c also calculated: at a pate of about 1 percenl per day (corre- sponding to over 90 percent For a 250-day season), the I 1,924 estimate would be reduced to about 12,900; at a mortality rate of aboul <>:!~> percent per day (corresponding to 58 percenl over a 250-day season), the M, 924 estimate would be lowered to aboul 14,200. The obvious conclusion from these laborious adjustments is thai the small corrections attained are not worth the effort for capture-recapture operations Lasting five or six weeks. Evaluation of Weight Estimates The weight estimates involve a series of calculations in which propa gated errors could have occurred. The more important are errors of population estimates, errors associated with length -weight data based upon small, selected, and independent samples of fish, errors in length frequency histogram data due to sampling biases, and errors associated with recruitment corrections. It must be emphasized that the calculated weights of the various populations are only gross approximations. MANAGEMENT PROBLEMS IN SALT SPRINGS VALLEY RESERVOIR Largemouth Bass If the guesses that 5,000 to 8,000 bass were taken by anglers in the 1951 spring season were reasonable, it is obvious that the population is very heavily exploited. Assuming that about half the estimated 15,000 remain- ing after the 1951 fishing season survived to the spring of 1952 and that the fish were large enough to be taken by anglers, it is also obvious that most of the larger bass would be removed. That extensive exploitation of the larger bass during the spring of 1951 actually existed is suggested by the very common occurrence of hook wounds which were observed on most of the larger seined bass in the late summer of 1951. Since the 1951 bass population was a "young" population it could possibly increase in numbers for several more years with present mor- tality rates and with continuing spawning successes. However, it would be doubtful if very many older "lunker" bass would ever exist at the present high rate of exploitation. Furthermore, a spawning failure in any one year could cause a great decline in the fishery during the follow- ing year, because the yearling bass (9 to 10 inches long) make up a large part of a normal catch, and they would be largely absent after a spawning failure in the previous season. At the present time food relationships of the bass to their prey are not well understood, although indications are that the bluegills are the principal forage. If the young-of-the-year bluegills grow at the usual rates for warmer waters, most of them would be too large to be eaten by the smaller yearling and young-of-the-year bass by late autumn. This has been observed to be the case in autumn samplings of the fish in the reservoir. The introduction of a small species of forage minnows might well facilitate the growth of the smaller bass during the late summer through the following spring, and result in considerably more yearling bass being recruited into the population supporting the sport 40 CALIFORNIA FISH AND GAME fishery. The recently introduced golden shiners may accomplish this in Salt Springs Valley Reservoir, although this will have to be evaluated in the future in terms of increased growth rates and population numbers of their predators. Bluegills The bluegill population has grown remarkably from the original stock- ing in 1947-48. From the data of Figure 5 and Tables 8 and 9 it may be observed that there are now relatively few bluegills large enough to interest anglers. The growth rate of 0.65 millimeter per day for the small bluegills during late summer is quite high compared with many of the data compiled by Carlander (1950), but this rate itself is mis- leading. A cursory examination of bluegill scales indicated that the small fish do in fact grow rapidly. But the three- and four-year-old fish have scale annuli very close together and it is quite obvious that the larger bluegills are stunted. Which of the larger benthos and fish forage were available to the adult bluegills is not known definitely, but a few stomach examinations revealed that they ate small bottom fauna, as did the younger bluegills. Undoubt- edly the very abundant carp also compete with the bluegills for elements of the bottom fauna. Under present conditions there would be little small fish forage available to the larger bluegills except in the spring when bluegill and bass fry are present. The chief value of bluegills in Salt Springs Valley Reservoir seems to be as forage for bass and the immediate question could be raised as to whether or not species such as golden shiners or other small minnows would provide better year-round bass forage. Observations of anglers during spring and summer of 1951 revealed that bluegills were only slightly exploited, although a few fishermen made large catches. Because there is some doubt of the value of bluegills as the ideal bass forage and because the larger bluegills appear to be stunted and of little importance to anglers, the over-all desirability of stocking bluegills in a reservoir of this type should be reviewed very critically in the future. Carp The rapid build-up of the carp population of Salt Springs Valley Reservoir from supposedly no fish at the time of poisoning in 1947 has 1 ii quite phenomenal. Although the carp outweigh all of the other species combined, they are of no importance to the anglers, and because of their rapid growth to large sizes, undoubtedly they are of little value ;i- 1>;iss forage. The '-tTects of carp on bass and bluegills may only be surmised. They probably compete very successfully with bluegills for elements of the butt mil fauna, and their feeding and spawning habits probably interfere with spawning of the more desirable species. [deally the entire carp population should be replaced either with sport Species or with species which are more efficient in supporting bass pro- duction, since bass are //" -port species of the reservoir. The possibilities of carp extermination in the reservoir could be realized only if complete extermination over the entire watershed were possible and if subsequent reintroductions were prevented. PISH OF salt SPRINGS \ u.u.v BESEEVOIB 41 Commercia] carp removal could be effective in reducing the quantity of carp only if the rate of exploitation were high and continuous. While the sporadic removal of an accumulated stork of carp might be economi- cally profitable, the removal would be ineffective should the population rapidly grow back to former pro port ions. ( >n the other hand, continuous commercial operations designed to keep the population at a low Level would be less profitable than sporadic operations on a catch per unit of effort basis. Other Species The only other species of any importance to anglers at the present time in Salt Springs Valley Reservoir arc brown bullheads and white cattish. Apparently these catfishes survived the 1947 poisoning. Thai continued spawning success for these species has occurred is evident from observations of fmgerlings and good size distributions as indicated in Figures 1 1 and 12. It is possible that both species do, to some degree at least, occupy the carp niche. It is also possible that the catfishes could reach the high proportions in which they compete with centrarchids noted in Searsville Lake (Wohlschlag, 1952). They therefore warrant serious consideration in future reservoir stocking programs. The golden shiner population deserves special mention, since it is the only strictly forage population of any consequence. Because they are relatively small, their forage value should be high for predators of all sizes. While no information exists on the comparative value of the young-of-the-year of this species over bluegills as bass forage, it may be presumed that the small size of the shiners would render them more valuable forage than bluegills for the small bass during autumn and winter. There are undoubtedly other small minnows which could also fulfill bass forage requirements. If the reservoir is ever poisoned again for complete fish removal, restocking only with golden shiners and/or other small minnows with bass is recommended. Then, if the minnows support an adequate bass population, bluegills and possibly black crappies could be stocked later if there was enough surplus forage to insure their rapid growth. SUGGESTED PROCEDURE FOR FISH POPULATION ESTIMATES IN LARGER BODIES OF WATER Experience gained in this exploratory study has shown that adequate Schnabel type population estimates for the more abundant and larger species can be made in from two to four weeks with a crew of four men. The method is applicable to waters up to about 3,000 acres, with popula- tions of about three times the magnitude of those of Salt Springs Valley Reservoir, provided they are suitable for seining. Operations should coincide with a period of low angling intensity, so that populations can be considered "constant." Even with a high rate of natural mortality, corrections will have little effect on estimates based on four weeks of sampling, as mentioned earlier. Since the seine sampled all of the common species in Salt Springs Valley Reservoir as well as or better than the traps, seining is recom- mended over trapping for general use. 42 CALIFORNIA FISH AND GAME Mesh sizes should be chosen to avoid inclusion of large numbers of small, rapidly growing fish to obviate recruitment corrections. It has been pointed out that recruitment corrections for bluegill population estimates were much less for trapped fish than for seined fish, since the Larger mesh size of the traps resulted in catches of larger, slower-growing bluegills. This information suggests that a seine having about two-inch s1 retched mesh could have been used; such a seine 300 feet long, 15 feet deep in the middle, and tapered to 6 feet deep at the ends can be handled readily by four men. At the outset of sampling operations, size frequency histograms should be constructed for each species to determine the mini- mum sizes which are fully vulnerable to the gear, and only the sizes of fish included in the right limbs of the size frequency histograms should be used for the capture-recapture data. For most rapid estimates, in which only the larger sizes of fish of interest to anglers are to be included, the lower length limit of species with more compressed forms (e.g., bluegills) would be about five or six inches, while the lower length limits of more fusiform species (e.g., largemouth bass) would be about eight or nine inches. With minimum sizes like these, recruitment corrections for studies lasting a month or less would ordinarily be small enough to ignore. The same preliminary sampling of fish could also be used to provide weight data, so that the average weight of fully vulnerable fish could be computed. The results of the bluegill studies indicate that serious errors in population estimates occur when the marked fish are not randomly dis- tributed. Because there will usually be inadequate a priori information on the nature of fish distribution, marked fish should be released through- out the bodj- of water and sampling should be as random as possible. The continuous marking procedure is to be recommended over the procedure of initially releasing a large number of marked fish, since it is quite possible that the initial release may turn out to be too small and that sampling will have to be carried out over too long a period in order to obtain enough recaptures for narrow confidence limits. For studies lasting much over a month, recruitment and mortality corrections may have to be considered. Continuous marking operations have the further advantage that more marked fish are eventually released for the same amount of sampling effort and that marking operations can be discontinued for any one species as soon as an adequate estimate is obtained. SUMMARY Population estimates by the Schnabel mark-and-recapture method were obtained for the principal fish species in 900-acre Salt Springs Valley Reservoir, Calaveras County. These estimates with 0.95 confi- dence limits, crude weight estimates, and densities on areal and volume !•• summarized in detail in Table 13. The principal conclusions are : 1. The principal game species is the largemouth black bass. The late summer population, after the heavy and efficient spring exploitation, was estimated to be 15,000 fish four inches or more in length. Most of these fish which survive until the following spring and summer would be expected to be of catehable size. Of the 15,000 bass present in late summer, aboul 2,900 weighing around 2,000 pounds were estimated to be over nine inches long. PISH OF SALT SPRINGS VALLEY RESERVOIR 13 2. The best estimate of the bluegill population from seining data was about ::.">*, !)()() fish longer than approximately three inches; of these, it was estimated that around (is, Dili) weighing aboul L0,200 pounds were Longer than five inches. The besl estimate of the bluegill population From trapping data was approximately 267,600 fish Longer than aboul three and a half inches; of these, it w;is estimated thai around 85,500 weighing about 12,900 pounds were Longer than five inches. Although the smaller bluegills grow fairly rapidly lor a time, the adults grow very slowly. Presumably there is inadequate forage for the Larger fish. '.]. The carp population was estimated to include aboul 68,100 fish weighing approximately i)7,300 pounds a weighl greater than that for all of the other species combined. 4. Brown bullhead and white catfish populations arc small and unim- portant to fishermen. The catfish populations appear to be permanently established. 5. The golden shiner population has quite possibly become established within one year after the introduction of adults, judging by the presence of young-of-the-year fish. The problems of management of the fishery resources in Salt Springs Valley Reservoir have been evaluated in terms of the sizes of fish popu- lations and their value to anglers. The crux of these problems is the maintenance and, if possible, the increase of the production and yield of largemouth bass. Bluegills, the principal bass forage, are of little value to anglers due to the small size of adult bluegills ; and carp, whose forage value to bass is doubtful, are of no value to fishermen. Ideally, greater bass production could be realized if the carp were completely removed and their niche occupied by small minnows of value as bass forage. Removal of carp might also allow for an increased rate of growth for adult bluegills. A large population of small minnows might ultimately support good bluegill and black crappie populations in addition to black bass; if not, the value of stunted bluegills and black crappies is great ly to be questioned. It has been concluded that the continuous mark-and-recapture method is practicable for estimating warm-water fish populations in moderately large reservoirs or lakes at seasons when fishing pressure is negligible. It is believed that estimations of adult populations in bodies of water up to about 3,000 acres can be made by a four-man crew utilizing a large seine continuously for two to four weeks. The greatest obstacle in obtain- ing accurate estimates would appear to be nonrandom distribution and resampling of marked fish. Errors of recruitment and mortality should provide no great obstacles and can be disregarded, provided only adult fish are sampled and provided the estimation procedures lasts a month or less. REFERENCES Calhoun, Alexander J. 1950. California angling catch records from postal card surveys: 1937-194S : with an evaluation of postal card nonresponse. Calif. Fish and Game, vol. 36, no. 3, p. 117-234. Carlander, Kenneth D. 1950. Handbook of freshwater fishery biology. Dubuque, Iowa, W. C. Brown Co., 281 p. 44 CALIFORNIA FISH AND GAME Chapman, Douglas G. 1948. A mathematical study of confidence limits of salmon populations calculated from sample tag ratios. Internat. Pacific Salmon Fish. Comm., Bull. 2, p. 69-S5. DeLury, D. B. 1051. On the planning of experiments for the estimation of fish populations. Fish. Res. Bd. Canada, Jour., vol. 8, no. 4, p. 281-307. Fredin, R. A. 1050. Fish population estimates in small ponds using the marking and recovery technique. Iowa State Jour. Sci., vol. 24, no. 4, p. 363-384. Kennedy, W. A. 1949. Estimating lake populations. Canadian Fish Cult., vol. 4, no. 5, p. 3-6. Petersen, C. G. J. 1S96. The yearly immigration of young plaice into the Limfjord from the German Sea, etc. Danish Biol. Sta., Repts. for 1895, vol. 6, p. 1-48 [fide Richer (1948)]. Richer, William E. 1944. Further notes on fishing mortality and effort. Copeia, no. 1, p. 23-44. 1945. Methods of estimating vital statistics of fish populations. Indiana Univ. Publ., Sci. Ser., no. 15, 101 p. Schaefer, Milner B. 1951a. A study of the spawning populations of sockeye salmon in the Harrison River System, with special reference to the problem of enumeration by means of marked members. Internat. Pacific Salmon Fish. Comm., Bull. 4, 207 p. 1951b. Estimation of the size of animal populations by marking experiments. U. S. Fish and Wildl. Serv., Fishery Bull. 69, p. 191-203. Schnabel, Zoe E. 1938. The estimation of total fish population of a lake. Amer. Math. Mon., vol. 45, no. 6, p. 348-352. Schumacher, F. X., and R. W. Eschmeyer 1943. The estimate of fish population in lakes or ponds. Tennessee Acad. Sci., Jour., vol. 18, no. 3, p. 228-249. Wohlschlag, Donald E. 1952. Estimation of fish populations in a fluctuating reservoir. Calif. Fish and Game, vol. 38, no. 1, p. 63-72. THE JACK MACKEREL, TRACHURUS SYMMETRICUS: A REVIEW OF THE CALIFORNIA FISHERY AND OF CURRENT BIOLOGICAL KNOWLEDGE1 By PHILM. ROEDEL Bureau of Marine Fisheries, California Department of Fish and Game INTRODUCTION The jack mackerel, Traehurus symmetricus (Ayres), a member of family Carangidae, occurs along the Pacific Coasl of North America from British Columbia south at least into the southern half of Baja California, Mexico. It has been captured nearly 500 miles off the coasl of California. Despite this extensive range, the fishing grounds are con fined largely to inshore waters from central California south to 1 1n- Mexican boundary. By far the largest tonnages are taken in Southern California waters, and catches are most unusual north of Monterey Bay. Small quantities have been taken off the Oregon coast, where the fish are said to occur regularly in the summer (Cleaver, 1951, p. 29). The fishery is prosecuted almost entirely by boats using roundhaul gear, particularly purse seines. Virtually the entire catch is canned. Until 1947, this fish was of minor commercial importance. In 19-47 it emerged as a major variety, and has remained among the leaders since that year. Its sudden rise and continued high rank are attributable in a large part to the series of poor seasons experienced by the sardine and Pacific mackerel fisheries (Sardinops caerulea and Pneumatophorus diego). (The present status of these fisheries is discussed by Clark, 1952, and Fitch, 1952.) In the earlier years, the seiner fleet sought sardines primarily and Pacific mackerel when they were available or when the 1 Submitted for publication, June, 1952. FIGURE 1. The jack mackerel, Traehurus symmefricus (45) 46 CALIFORNIA FISH AND GAME sardine season was closed. Jack mackerel catches were in a large part accidental. Jacks are still less highly regarded than are the other two but they remain available on the fishing grounds. Another factor affecting the fishery's rise, the importance of which cannot be properly assessed, is the increased use of depth-sounding devices as a fishing aid. These were first installed on California seiners in 1944 (Daugherty, 1952, p. 130) and within two or three years were virtually standard equipment. The rise of the jack mackerel fishery thus occurred at the time this equipment was first widely employed and there is a certain amount of evidence to show that jack mackerel tend to school somewhat below the surface so that they are often not observed by visual scouting. If this schooling habit can be confirmed, it would help explain the low catches of the earlier years. For even though these catches were largely accidental, one would anticipate that the total tonnage caught would have been greater if the fish had been as available to the fishermen as they are at present. An alternative explanation is, of course, a rise in abundance of jack mackerel concurrent with the decline of sardines and Pacific mackerel. COMMON NAME The name "jack mackerel" dates only from 1947 and first appeared in print in 1948 (Roedel, 1948, p. 10, 57). Prior to that time, the fish was known as either "horse mackerel" or "Spanish mackerel," the former predominating in the northern part of the State and the latter in the southern. "Horse mackerel" appears most frequently in the literature and had been recognized as the official common name in Cali- fornia ("Walford, 1931, p. 81). This name was in use in San Francisco as early as 1878 (Lockington, 1880, p. 34). "Spanish mackerel" was noted by Smith (1895, p. 231) as the prevalent name in San Pedro in 1894. The official name "horse mackerel" was not subject to any criticism during the years of a minor fishery, and, whatever else may be said, did reflect popular usage. However, the industry found the name a handicap in marketing an increased pack, and in the summer of 1947 the Depart- ment (then Division) of Fish and Game undertook a survey of the industry in an attempt to select a name more suitable for labeling purposes. The concensus favored "jack mackerel" and this name was given official sanction. As a result, the United States Pure Food and Drug Administration gave its permission to use the name on labels in May, 1948 (Roedel, 1949a, p. 31; 1949b, p. 204). This coined name has entered the vernacular remarkably rapidly and appears well on the road to supplanting the old. There is an interesting postscript to the adoption of "jack mackerel." The Majr, 1950, issue of Fisheries Newsletter (p. 14), an official Austra- lian publication, carried an announcement that "scad, formerly known as horse mackerel and cowanyoung, from now on will be Jack Mackerel. The scientific name is Trachurus novaezelandiae." The change was sug- gested by the Commonwealth Director of Fisheries and accepted by the Australian states, fisheries authorities, and the canners' association be- cause the name "scad" had been found unsatisfactory for marketing purposes. "In addition," continues the notice, "a very closely related THE JACB \i A i i.i i.i l.. i i;\< in 1:1 ', \i \11.1 i:n i I i species known as Jack Mackerel was taken in California waters, and it was possible thai the Australian canned scad would be competing on the same markel as the California fish. The name 'Jack Mackerel1 would not only luive ;i greater appeal on the local market hnt would also be known on the overseas market." THE FISHERY PRIOR TO 1926 The early history of the jack mackerel fishery is a1 besl obscure. Records are scanty for the years prior to 1926 and often mention Bimply "mackerel" — meaning either jack- or Pacific or both. There are, bowe^ interesting bits of information included in some of tl arly reports on the fisheries of tin' Pacific ('oast. Among these surveys was thai con ducted by W. N. Lockington, who was employed by the California Com- missioners of Fisheries to investigate the fishes found in the San Fran- cisco markets during the period October, 1878 September, 1879. His report (1880), which, as noted, listed the common market name as horse mackerel, included these remarks (p. 35) : "This fish is only senl occa sionallv to our market, usually from Monterev, !>nt when it is presenl it is in greater abundance than any of the other Scomberoids. Oc sionallv it visits the Bay of San Francisco, for the single specimen I 17 inches long) on which Dr. Ayres founded his species, was taken there, and the dealers assure me of its occasional occurrence. Those senl from Monterey are seldom as large as Ayres' S] imen. It is not valued so highly as either of the previous species (pompano, Palometa simillima, and Spanish mackerel, S cornier omorus concolor]." In another report, also prepared for the Commissioners of Fisheries. Lockington 1881, p. 39) wrote this: "... the horse mackerel is an old friend of the Levantines who carry on here [San Francisco] the same occupations they pursue in the Mediterranean. Occasionally it strays up the const as far north as San Francisco. It is taken in large numbers in seines, and salted for bait. " Taking part in a nation-wide survey of American fisheries. Dr. 1). s. Jordan, in company with Dr. C. H. Gilbert, spent the year 1880 on the Pacific Coast. His reference to jack mackerel was brief and is here quoted from Goode (1882, p. 36) : "... In California, according to Jordan, it is an abundant species, and is there commonly known as the Horse Mackerel. He remarks: 'It reaches a length of about a fool and a weight of less than a pound. It ranges from Monterey southward, appearing in the summer, remaining- in the spawning season, and disappearing before December. It arrives at Santa Barbara in July, and at Monterey in August. In late summer it is exceedingly abundant. It forms part of the food of larger fishes, and great numbers are salted for bait. As a food-fish it is held in low esteem, but whether this is due entirely to its small size we do not know . . . .' ' Substantially the same quotation is the only reference to jack mackerel contained in the multivolume report later issued on the fishing industry of the United states (see Goode, 1884, p. 326). Collins (1892), reporting on another survey of Pacific Coast fisheries made in 1888 and 1889, listed "horse mackerel" as a commercial variety in Los Angeles and Santa Barbara Counties but gave no catch figures. He reported that, in San Luis Obispo County, jack mackerel were taken in drift nets and to a lesser degree trolling, the fishery reaching a peak 48 CALIFORNIA FISH AND GAME in the summer. Port Harford (now Port San Luis) shipped 1,500 pounds of salted jack mackerel valued at $90 in 1888. He mentioned jack mackerel as present in Monterey Bar from July to October but rarely found farther north. In discussing the fisheries of San Francisco, Collins wrote (p. 121) : "[It] averages 3 pounds in weight . . . and is in the market most of the year. The price ranges from 8 to 20 cents per pound. Professor Jordan . . . says its weight is less than a pound and in 1879 found it to be held in low esteem as a food-fish, though he did not know whether this was due entirely to its small size. The estimation of its value seems to have changed materially in the past decade." A tab- ulation of San Francisco's fresh fish trade in 1888 and 1889 shows larger sales of jack mackerel than of Pacific but at a lower retail price. Similar data for 1890-1892 are given by Wilcox (1895, p. 209) and the five years are summarized in Table 1. We note a sharp decline in jack mackerel sales with a constant average retail price ; a less marked decline with an increase in price for Pacifies. TABLE 1 Sales of Jack and Pacific Mackerel in the San Francisco Market, 1888-1892 Data From Collins, 1892, and Wilcox, 1895 Jack mackerel Pacific mackerel Year Pounds Average retail price Pounds Average retail price 1888 . - - 100,000 125,000 75,000 40,000 15,000 SO. 08 .08 .08 .09 .08 25,000 30,000 20,000 15,000 10,000 SO. 10 1889 ... .125 1890 .13 1891 .15 1892 . .._ .15 Wilcox's (1898) report on the Pacific Coast fisheries of 1895 showed a catch of "horse-mackerel" totaling 118,530 pounds valued at $1,386. (Pacific mackerel landings were 90,390 pounds valued at $2,637 this same year.) Of this, 98.530 pounds worth $986 was landed in Los Angeles County while Santa Cruz County accounted for the remaining 20,000 pound's worth $100 (p. 650, 652) . The first reference to canning is found in Smith (1895) who made a survey "for the purpose of making a study of the apparatus and methods of the fisheries of that region [the Pacific Coast] " in May and June, 1894. By way of background, in December, 1893, a sardine cannery opened in San Pedro. It was the second plant outside of the salmon industry to operate in the State, one which handled sardines and ancho- vies having o p" rated in San Francisco from June, 1889, until August, 1893 (Scofield,1951,p.26).ToquoteSmith(p.231) : "In connection with the capture and canning of sardines at San Pedro, a species of carangoid fish ... is taken and utilized to some extent for canning and salting. At San Pedro it is known as 'Spanish mackerel'; at other places on the coasl it is failed 'horse mackerel. ' . . . "At San Pedro these fish are taken in the small steam vessel used for sardine fishing. A special purse seine, 135 fathoms long and 100 feet THE JACK M \< i.i IR] I;, TRACH1 Bl J M '-ii.'i i:ICUS I't deep, with ;i two-inch mesh, is used. The fish are caught in San Pedro Bay ;iikI around the < latalina [slanda. Thej go in chools of irarj ing sizes. Some Large hauls are made; thus in the fall of L893, L50 barrels were taken at one Se1 near the ('alalina Islands. "The (ish caugh.1 arc mostly of small size According to the statements of the gentlemen connected with the California Pish Company, the largest taken in their seine are L2 it ii inches long, the smallest are about 0 inches, and the average length is aboul 9 inches. The smallest fish are packed in nil iii half-pound square cans ami in mustard, tomato sauce and souse in 2 pound oval cans. The fish too large for canning are salted. They are never fat, however, and do not make a high grade of salt fish." Later in the same report Smith mentioned that Pacific mackerel were used to a small extent for canning and that jack mackerel were "not uncommon" in the San Francisco market. This first attempt at canning was short-lived. Wilcox I 1902, p. 570 . discussing conditions in 1899, stated: "With the exception of sardines used for canning, the products of the fisheries were disposed of fresh." Croker (193:?, p. 23) said that the canned product described by Smith was not a success and that the plant concentrated on sardines after L894. Another publication by Wilcox (1907) gives considerable detail on the "Spanish mackerel" — as distinguished from "chub ! now Pacific mackerel" — fishery of 1904. Ilis data are summarized in Table 2. Of particular interest is the fact that the total catch of 354 tons was greater TABLE 2 The California Catch of Jack Mackerel for 1904 Data From Wilcox (1907) Pounds landed County Seine Gill and trammel nets Lines Totals 1,000 1,000 7,500 42,740 3 136 3,000 46,660 177,829 in, 300 Los Angeles and Orange - 426,300 515,700 181,265 Totals- .- - - -- - 1L'7,300 53,676 -'-•7,489 708,465 than that reported in any year from 1926 (the first year for which there are official state records) through 1932. Further, in only one year (1947) since 1926 has the San Diego catch surpassed the 91 tons landed there in 1904. The 1904 catch of Pacific mackerel was 67 tons. Apparently the entire Los Angeles seine catch was canned, for in Wilcox ' discussion of the sardine fishery (which, incidentally, yielded only 161 tons at Los Angeles) he stated (p. 15) : "The catch in 1904 was made with purse seines by a gasoline steamer which cruised all the season between San Mon- ico [sic] and Redondo and occasionally as far north as Santa Barbara and off the islands of Santa Catalina and Santa Cruz. Besides the sardines, the steamer took 426,300 pounds of Spanish mackerel, the latter being 50 CALIFORNIA FISH AND GAME used at the cannery to help ont the season's pack which amounted to 4,292 cases of sardines and 5,834 cases of other fish." Eecords of jack mackerel landings are virtually nonexistent from 1905 until 1926, largely because of the confusion in common names and the lack of scientific names in the reports for those years. Eecords of the State of California commence in 1916, but through 1925 did not distinguish between Pacific and jack mackerel. During this period the total catch of the two did not exceed 2,500 tons, and probably consisted mostlv of Pacifies. In 1926 and 1927, the jack mackerel catch averaged about 8% percent of the Pacific (Fry, 1930, p. 25), and the catch of jacks alone did not reach even 500 tons until 1933. Starks (1918, p. 126) discussed the pack mackerel as a commercial variety, saying: "As a food fish it is inferior to the mackerel^ being rather coarse fleshed. Little has been done in preserving it. ' ' Within a few years, however, estimates of its desirability were to change, for Scofield (1924, p. 87) wrote as follows regarding Pacifies and jacks: ' ' The other species commonly taken at Monterey is the horse mackerel (Trachurus symmetricus) , a fish that has been considered very inferior, and in past years was not taken in quantity because there was either no sale for it or the price was so low as to leave little profit in handling it. In the last two or three years there has been an unexpected development in the mackerel fishery. It has been discovered that the people of Latin races and orientals, especially Chinese, living in the state are very fond of the horse mackerel and are willing to pay an advanced price for it, so that now (Feb. 1924) the sale value of the two mackerels has been completely reversed. The choice black or zebra striped mackerel is sold by the fishermen at 4 cents per pound in the round, and the horse mackerel, formerly held in such contempt, is sold at 8 cents." CATCH TRENDS, 1926-1951 Commencing in 1926, landings of Pacific and jack mackerel were segregated in the catch statistics, which are presented by region and year in Table 3. The Los Angeles region (Los Angeles and Orange Counties) has been dominant throughout the 26-year period, though deliveries in the Monterey and Santa Barbara regions have been substantial in recent years. From 1926 through 1932 the state-wide catch did not surpass 350 tons. Croker (1929) noted in discussing the catch in 1926 and 1927 that jack mackerel then commanded a higher price than Pacifies and was more in demand in metropolitan markets. (It was not until 1928 that large-scale canning of Pacific mackerel commenced.) Croker (1933, p. 16) stated, with reference to the years prior to 1932, "The horse mackerel is not of very great importance in the fisheries of California, principally because the market for it has not been developed." Later (p. 38), in discussing the Monterey mackerel fishery, he remarked, "The price paid for this species is somewhat higher than the price of Pacific mackerel, so the horse mackerel is not relatively so unimportant as would appear at first glance. Most ... is used fresh but some is salted and dried." With regard to the Los Angeles fishery he wrote (p. 51) : "... the horse mackerel is fifth in importance of the locally caught market fish. . . . Although there is no great demand . . . the fisher- men are able to sell all they can catch. The horse mackerel seems to be hi; .1 \t IB MACKEREL, TR \< B I B1 5 M METRK I TABLE 3 Annual Landings in Tons ol Jack Mackerel :,1 I : i jion Year Ban I i ancisco Monterey Santa Bai b 1 iQ \ n [i i. 1 >i 1 • L926 28 28 I I 19 48 124 60 17 69 73 15 21 49 41 55 132 162 81 41 125 3,579 1,076 4,444 2,091 15,756 388 89 203 265 : 10 L37 i:,7 187 72K i 917 2,253 3,202 1 977 i 837 656 901 -MM 6,189 6,317 1,390 3,966 56,550 29,148 22,109 19,076 41,906 -- 117 1927 23 1 1928 269 1929 349 1930 ■ 185 L931 281 L932 1 2 1933 506 1934 1 1 31 19 ii 1 ii 28 790 1935 1,991 L936 1937 1938 .■ 067 1939 I 879 1940 717 1941 1 033 1942 2,674 1943 78 - 1 1 1 1 I -- 1945 1 515 1946 6,774 2,841 1,413 1,335 J tin:, 7,545 1947 12 1 L5 13 23 21 64,521 1948 148 19-19 .'".,626 1950 440 66,630 1951 11,920 scarcer than the Pacific mackerel and there is seldom a glut of these fish on the market. "The horse mackerel commands a higher price than the mackerel, because it does not spoil so readily and is said to have a better flavor and also because it is scarcer and therefore more desirable. . . . The price paid to the fishermen varies from 2 to 6 cents per pound." And finally (p. 134), "As a sport fish the horse mackerel is unim- portant. This species is nowhere as abundant as the Pacific mackerel and is never the subject of special fishing effort. It is taken in small numbers incidental to the capture of mackerel, bonito and other fish of similar habits. The young are often taken by pier fishermen. The horse mackerel is a fine game fish for its size and would undoubtedly be very popular if it were more abundant. Many people would rather catch and eat it than the Pacific mackerel." Landings increased in 1933 and 1934 and then rose sharply to nearly 5,000 tons in 1935, virtually all of which was delivered in the Los Angeles region. Fry (1937, pp. 22-23) wrote: "There is no special fishery for horse mackerel, they are caught inci- dentally by boats fishing for the Pacific mackerel. Most of the horse mackerel taken are mixed with the other species, though it is not at all uncommon for a boat to find an unmixed school. The fish are taken with ring nets and purse seines by boats fishing for the canneries and with set lines by the fresh fish market boats. 52 CALIFORNIA FISH AND GAME ' ' At the fresh fish markets horse mackerel are well regarded and often bring a better price than mackerel. At the canneries this does not hold true. The Pacific mackerel makes a better pack and hence brings a better price. In 1935 the cannery prices for the two species were $15 and $6 per ton, respectively. The result of this peculiar situation is that when a cannery boat brings in a load containing any great quantity of horse mackerel it will often go first to the fresh fish markets and sell what it can. The markets will seldom accept net-caught mackerel, as the rough handling usually bruises them enough so that they will not keep well. Horse mackerel withstand the bruising much better and are perfectly acceptable. "The rise in the horse mackerel catch in 1933, 1934, and 1935 was due primarily to the heavy mackerel canning which has been going on in the Los Angeles region. In 1935 there was a particularly great rise because for a period of months there was very heavy mackerel fishing going on around the Channel Islands. Horse mackerel are much more abundant in those waters than along the mainland shore, and as a result many more of them were taken by the mackerel boats. . . . "At Monterey the horse mackerel landings were about normal, even though canning activities brought the Pacific mackerel catch far above normal. ' ' 60 1 1 | 1 | 1 | 1 | .1 JACK MACKEREL 1 1 1 1 1 ' 1 A / \ 50 — ! A * \ LOS ANGELES REGION LANDINGS ' M 1 V \ 1 N £«0 o I \\ // - o z < 5* o X — f I \\ 1 II 1 20 1 1 1 ■ 0 \/ i i'T^T r— 4 — r-"l , 1 1 i 1 • 1 . I 1 •7 - 0 co O (vi ■o in i t 0t 0t low of 717 tons in 1940. During the nexl six years, <-.-i t <-Im-s were much more substantial, surpassing 6,000 tons in L943 and 1944, and 7,500 tons in 1946. h was in 1947 that the fishery experienced its tremendous expansion. Landings reached an unbelievable 61,500 Ions, of which 56,500 was delivered in the Los Angeles region. II 1i;is been of major importance since, wiih L950 the peak year with 66,630 ions, aboul 50,000 of which was delivered in the Los Angeles region. Tn terms of ions Landed, jack mackerel ranked third among the State's fisheries in 1917, 1948, and L950, and fourth in 1949 and 1951. In terms of dollar return to I he fishermen, it came fourth in 1947 and 1949, fifth in 1948 and L950, and sixth in 1951. THE LOS ANGELES REGION FISHERY The supremacy of the Los Angeles region has I a seriously challenged but twice in the period 1926-1951. In 1931, ;i year of no consequence <,, far as total landings are concerned, the Monterey region reported 124 tons as against Los Angeles' 157. Tn 1946, the lasl year of a relatively minor fishery, Monterey handled 3,579 tons compared with Los Angeles' 3,966. Since the expansion of 1947, Los Angeles' share lias been from 74 to 93 percent of the annual state wide catch. The great bulk of the catch is processed at canneries in the Los Angeles-Long Beach Harbor area. In addition, a portion of the tonnage landed in the Santa Barbara region is shipped by truck to these canneries. Gear Records of catch by gear are not available for tl arly years. Croker (1933, p. 51) stated:' "The same boats, fishing in the same places with the same gear, take both mackerel and horse mackerel for the markets. Tn addition to the hook and line boats, which really fish for mackerel in particular and take horse mackerel only incidentally, some of the ring net boats fishing for miscellaneous market fish deliver occasional fares of horse mackerel. The ring net boats fishing mackerel for the canneries sometimes encounter schools of horse mackerel, make catches and sell the fish to the wholesale markets for a much higher price than any mackerel they might catch would command at the canneries. Horse mackerel are not so easily bruised by a net as the Pacific mackerel and are in any event relatively scarce, so the fresh fish dealers are willing to accept net-caught horse mackerel." Fry (1937, p. 22) mentioned only net-caught fish in discussing the 1935 catch. Certainly the net boats took most of the fish, and records since 1947 show only a few thousand pounds each year taken by gear other than seines. Most of this is taken accidentally by Pacific mackerel scoop fishermen. Monthly Landings Monthly landings for the period 1934 (the first year of more than a nominal catch) through 1951 are presented in Table 4. During the 13 vears of a minor fishery, 1934-1946, the total catch was but 39,839 tons- less than was landed in the months of November and December, 1947. November was the best average month during these years, and about SO percent of all landings came in during the period September- January. 54 CALIFORNIA FISH AND GAME en CO. lo OS - — CO 1> CD lo t)< t)< i I i i i I ■* t «N- O ' t-_ ci c ■-_ m » i ' i i i ' cm hconh" ! 1 ! 1 ! ! • T— OS ffl*OOON«IOH^H00 W C 00 CI C) 00 M rt * 13 OS CM *NO)HBOOOioollO*» ■*" of CM lo" -*" CO" Cm" "#" ^" CO" oq" CD o OS T— 1 o W os rt^rHTfctcicoasN^Mm OB)X«!N9O»l»ffiO00 LOOOiO^QONnOO^ODC: co -tf cm co o eo •* o o n CD o Os" en 05 i— 1 C5WOQQ0CSHNOHHH MHrtOON^GOnTfO CO L0 1> CD CM COMTfNOO OS. — ,-i rn CI CI N rt OS o of CM 00 — CO — — — OOOOOhnn 0_ 00 0_ — OS oo_ o_ CI CO CD t> -*" of cm" lo" lo" oo Til Os" CI — OS i— 1 i-iONOSOSOO^CB^OS'Oci ^^MOhhOOOWlON-h O WCCN CO H CI CC C5 H CO — " T)<" i-T co" cm" Os" — " i-h CM o U0 U0 cd" LO Ol - i ICO 1 INIOOM y-4 ^11 1 1 L0 — i-H CO I i i i d N LO OS 00 CM 1 — OS — o^cd i > i> -* oo oo t^ oo co T-HiOi— I I I ONtOOS^H ,-1 II t-C ,-( CI o OS CZ ■a = o en — -# t~ CM NOCOONN^r)! —i — i CI LO -n 31 GS CI CO L0 CD 1= o OS CO o — -j> H i i N m N OS « 00 OS X i CD i i »— i CM — © — CM I CM CI CO CO — OS eo OS co oh i iNOooiowsa — CO CM i ' COt^CM LOO -co »-i cm co OS — lo — CD — — 1D00OON00M LOSi^ci'fOOfliNOfin Tj< — 1-0 CD CM — t- CM o CM co" CO CO OS — o con icmcso— icocoi-hio CO— OCICIOhO •* ' — — CM . ' — CS -* CM — © — CO HTf H 1 CI rf CO N LO N ^ 00 I o CM c I— 1 ■ ■ll'llifel^h it* o o s b g : : ! J -g n -s J §ij fe"S rt ci? w"S,3 > 8 -s^-m---C/jJ:« Hsfeg-SJgt-si-j-^CQOfZiQ o EH THE JACK MACKEREL, TEACHUB1 1 \i\ii.n:i< I 55 April was the low month. This pattern follows the Pacific mackerel and sardine seasons very closely landings high in the fall and winter when a max inn i in number of vessels were on the grounds and minimal in April when the sardine season is closed and the period of scarcity of Pacifies is at its height. Experience in the following five years, l'H< 1951, indicates thai lack of fishing rather ihan lack of lish accounted for the low spring catches. In 1947, 1948 and 1949, many boats remained in the fishery through March and into April. The Low month in 1947 was May ; in the m\t two years, June. In 1950 and 1951 monl hly Landings fluctuated considerably and the high month for 1951 was April. A sizable fleel remained on the grounds throughout both years. There are periods, erratic in their occur- rence, when jack mackerel are not to be found, but Mien' is no evidence of a seasonal occurrence similar to t hat exhibited by the Pacific mackerel. The total catch in 1948 and 1949 was held down by fishermen's strikes in October and November, 1948, and in November and December, 1949. The Fishing Season Despite the evidence of 1950 and 1951 that jack mackerel are available throughout the year, the calendar year does not comprise an ideal unit for either catch or biological studies. The fishing fleet is actually seek- ing three species, primarily sardines, and the maximum number of boats is operating during the sardine season which is limited by law to the period October lst-February 1st in Southern California. Further, as has been mentioned, Pacific mackerel are scarce in the late winter and spring with the period of scarcity usually most marked in April. The Pacific mackerel season has traditionally been regarded as opening in May and extending through the following April. (For a discussion of the Pacific mackerel fishery during this same period see Koedel, 1952. The rise in summer seiner catches of Pacific mackerel in recent seasons, noted in that paper, is explained in a large degree by the availability and marketability of jack mackerel which made it profitable for the boats to fish.) The number of active boats thus tends to be at a minimum at this time. When investigations of the jack mackerel were undertaken in 1947, the same period was selected as the fishing season, based on landing figures for the previous years and for convenience in comparing catches of the three species. It has since been found that this forms a convenient biological season as well, because completion of a year's growth is indi- cated in the spring. For these reasons, we continue to regard the jack mackerel fishing season as commencing in May. Seasonal landings appear in Table 5 and Figure 3. TABLE 5 Seasonal Landings in Tons of Jack Mackerel — Los Angeles Region, 1934-35- The Season Extends From May Through April 1951-52 Season Tons Season Tons Season Tons 1934-35.. 752 4,852 2,820 4,002 1,849 525 1940-41 1941-42 1942-43 1943-44 1944-45 1945-46 809 786 4,751 4,068 6,832 4,489 1946-47 1947-48 tots lit 1949-50 1950-51 1951-52 11,658 1935-36 62.042 1936-37 2 1 ,334 1937-38.. 29.728 1938-39 . 50,016 1939-40. .._ 34,370 56 CALIFORNIA FISH AND GAME FIGURE 3. Seasonal landings of jack mackerel in the Los Angeles region, 1934-35—1951-52. The season is defined as commencing in May and ending in April. Data from Table 5. Price The price paid to the fishermen for jack mackerel was for many years intermediate between that for Pacific mackerel and sardines, with Pacif- ies commanding the highest figure. Since 1947, prices have fluctuated considerably, and over most of the period jack mackerel brought the same as sardines. In 1935-36 and 1936-37 the price for jack mackerel was the lowest of the three : $6 per ton, compared with $8 and $10 for sardines and $15 and $18 for Pacifies. Jacks occupied the intermediate position in the ensuing seasons through 1946-47. The price was $16 from 1937-38 through 1940-41, $22.50 in 1941-42, $35 through 1945-46, and $45 for the most part in 1946-47. The prevailing price started at $45 in 1 947-48, but rose to $60 in December. In 1948-49, the price reached $67.50 in October but dropped to $50 in November, where it remained. Sardine [•rices were identical in both seasons. In 1949-50 the jack mackerel price fluctuated considerably : $50 from June through September, $25 to $40 in October, $32.50 for the next three months, and $40 thereafter. The sardine price was $32.50. In 1950-51, the prevailing price started at $40, fluctuated from $25 to $45 during the sardine season and ended at $45. Sardines brought $35 for most of the season, the price rising to $45 at the close. In 1951-52, both jacks and sardines brought $46 at the start and $60 later in the season. THE JACK MACKEREL, TRAGHT7RUS SYMMETRICA ■" Fishing Grounds In general, the fishing grounds Eor ,j;i ck mackerel are the Bame as those for Pacifies and sardines: the mainland coasl from Poinl Con ception to the Mexican boundary and offshore to include the channel islands. Kor ,-i knowledge aboul fishing localities, the Department of Fish and Came is dependenl largely on information supplied by the fisherman to t he weighmaster at the time of unloading. The coastal waters oi' California are divided into numbered blocks, each encom passing 10 minutes of latitude and 10 minutes of Longitude, and the fish receipt made out by the weighmaster contains a space in which to record the number of the block in which the catch was made. This system has been in effect since the early thirties, and now provides, on the average, reasonably accurate (judging from auxiliary information obtained through interviews with fishermen and field observations and reasonably complete records. In presenting the data which follow, catches by individual blocks have been grouped into general fishing areas as shown in Figure 4. The Santa Monica. Newport and Santa Catalina areas comprise the "local" grounds, the others the "distant." Prior to 1935, we have no data on jack mackerel fishing grounds, and records are scant for the 1935-36 and 1936-37 seasons. Pry (1937, p. 22 attributed the good fishery of 1935 to "very heavy [Pacific] mackerel fishing . . . around the Channel Islands," but actual locality records are so few as to be meaningless. For the seasons following the data are quite adequate. Catches by general area are presented in Table 6. From 1936-37 through 1942-43, catches on the distant grounds exceeded those on the local, largely because of the contribution of the northern area, where the fishery then, as now, centered at Anacapa and Santa Cruz Islands. Since 1942-43, the total contribution of local areas has been heavier than that of the distant. Fishing has tended to concentrate in the last few seasons at Anacapa Island and the east end of Santa Cruz, off Pt. Vicente, at Santa Catalina Island, particularly the west end. in the Newport Beach-Dana Point area, off Oceanside, and at San Clemente Island. The average catch per numbered block for the five seasons 1947-48 — 1951-52 is shown in Figure 5. Block number 720. Pt. Vicente, has been by far the most productive with an average seasonal catch of nearly 4800 tons. Block number 762, at the west end of Santa Catalina Island followed with about 2500 tons, and three blocks, numbers 684 (Anacapa Island), 685 (east end of Santa Cruz Island) and 738 (Newport Beach) fell in the 1500- to 2000-ton class. Some information is available as to the distance from shore at which catches are made. Commencing in 1947, routine samples have been taken from the commercial catch to determine the size and age of the fish. At the time that the sample is taken, the vessel's captain is asked to provide certain information about fishing conditions including the locality of catch. Of 396 samples taken from July, 1947, through April, 2 In the summer of 1952, the seiners extended their operations into a hitherto virtually unexploited area comprising Tanner and Cortes Banks. These banks lie, respectively, Mine 30 and 40 miles southeast of San Clemente Island. They are so far from port that in past years they were very rarely fished even though it was known that both jack and Pacific mackerel were to be found on them. However, fishing was so poor on the regular grounds that from mid-July on the fleet worked both banks and enjoyed considerable success throughout the summer. In late September, huge catches of jacks were made on these banks and fishing was still fairly good as this paper goes to press (early November). Preliminary figures for September indicate a catch of about 19,000 tons. 58 CALIFORNIA FISH AND GAME CVJ CD to CD o O tu < CO (0 CD o CD CD If) 00 CD CD J3 "D (U — 0) J3 E 3 C -a c o 0) u D E o a. -a c O o T3 C 3 o 1- C3> O) C a> c o 'c o "5 u c a) o CO o THE JACK HACKER] b, 1 BAl HI Bl 5 M Ifl TBI* I .." 1/-I o 3 to no CO o en as 2? -5 1- -H CO • 1 co ■ ■ 1- Is? — s 1 ■ 1 — 0. 1 — 00 CO - 1 - CO g M 1 • o _, 01 CO — ' i - ■ o. ^- 2? — — CO - CO ' - ^- — . _-■ CO •— • -n © CO — OS 01 . ■ i - co" ' St i/5 » 00 co i- s 01 • - 1 - MO CI — 5 — CO CO OS -r "*■ is 2T •0 CO -r CO — 1 CI CO 1- B — « 1 - t>* eo co* 10 co" co" — ' 1 CO CI 00 co i . i ■ © CO • 1 ' _ _ 2t 09 >n -r co io_ co_ r. ci i rJ ! oo" a -t -i O -r 1 CO 01 \ ^ i - OMOl 01 iO / * i r 35 s co ^ os '0 -r OS ih ic — c i 2T CN b- Oi OS co_ — ■ -r 01 CI — - l-I 01 oi co" co" - " ^- *o -^ -f co co co 3 cc ■- ^ rs ie - ■# 2 MOIN o 56 — in m CO 00 St C0_ t- OS •— • ; 1 OS q — — iH ' "<" co" -r — •*f .« C lO Tf OS -f 00 CO • - "r 00 CI 5 3 2t CJOl o_oo oo CO i- -r C-l 01 CO ■ - 1- i i-I CO >o" CO -■ CO _« os os >o co 00 t~ CO CO - 1- _ 00 ■^ 3! WON oo ■n:r; i- 00 co a 5 ^T com '-'. go m co co CI - -r ^H 1 -« CN — co' - CM «* "-< ■* CN ^ oo co oo 3 co rt ■* 2 HtJ>C OS OI OJ CO — ^" CO • c ST H'f* °i CO ^ "", ■o I- rt" -* OI CI — — CN 00 CO CO -r -r — - CI — s ** Z2 CO CO ~* IO IC o CI -.: 2T CN co CO T 1- t- o _, OS KO 00 CN CN C '~ C O CI I_; rs •* ni oo t- oo OS 00 •» CN o O St CN ^H ^^ •* l> 00 OS ,-^ io ■* w •0" tcio ^ iC o 10 CO 2 CN O CO Tf os — n O: O. — CO CO •c '0 CI 01 00 ! -1 cm" iO .-. o r-i oo OS O i OS OS 00 • CO CO CO CN ' O i t— i -1 o • -. CO IC rt ■ ', - ■* s3 i i i ■ i i ■ i i i i i i i i 1 1 1 1 1 1 1 0) c3 *3 d a 2 .a c 'S J_ ' ! 03 2 l| "S c C ! B - o9 49 OQ z. C r. pq i - ?■ o3 2. =3 c ! ~ s C o s -z -^ a 3 s E- - X. _ - : r^ "3 — 0 s /. C a c c3 ^ c3 *? e c ^ S S3 3 3 "C 0 60 CALIFORNIA FISH AND GAME THE JACK M \« 1. 1 1:1 I., 'I i; \« in i: i Mil KI< 61 1952, reasonably precise infonnatioii regarding locality •• ■ en for 27-4 catches ( Table 7 ,), almosl half of which were made in L951 52 Judg ing from these records, aboul 55 percenl of the catches were made li than three miles from the nearesi land mass and only 7.7 percenl eighl TABLE 7 Jack Mackerel Catch Localities Distance From Nearest Land as Reported by Fishing Boat Captains in Personal Interviews, 1947 48 1951-52 Seasons I i III Mil 1..- than 1 I 2 2 :: :; I 1 i .. 7 7 B Mainland, south of Los Angeles I I 3 11 6 9 16 17 9 2 7 19 15 1 5* 11 19 6 4 8 I 9 3 1 10 0 11 1 1 1 1 e i i 0 0 0 I 1 0 2 II-' Mainland, north of Los Angeles Harbor. Santa Cruz and Anacapa Islands. Santa Catalina Island San Clemente Island - - - II Totals Percentages. 16 16.8 51 18.6 54 19.7 41 15.0 23 8.4 .'1 7.7 ii 2 2 L'l 7.7 100.1 * Includes one catch at Santa Barbara Island. or more miles from land. Most of the waters within three miles of Santa Catalina Island are closed to seining, which accounts for the relatively large number of catches reported three or more miles distant from t; island. The catches reported some distance from the mainland smith of Los Angeles Harbor were made for the most part between the harbor and Santa Catalina Island. There is little evidence in the records for 1950 and 1951 to indicate that jack mackerel appear on specific grounds at specific times of the year. These are the only two years in which fishing continued on a fair scale throughout a 12-month period. In 1950, Anacapa and Santa Cruz Islands and the Pt. Vicente area were the leading producers from January through August. San Cle- mente Island led in June, a month of small landings) . In 1951 . the New- port Beach-Dana Point area was the center of an excellent fishery from March through May, with Pt. Vicente the favored ground in January and February, and Anacapa and Santa Cruz from July throngh Angnst. From September through December, 1950. records show greatest ton- nages caught along the mainland coast from Pt. Dume to Dana Point, with good catches at San Clemente Island in September. In 1951, the Pt. Vicente area led in September, San Clemente Island in October, Anacapa and San Clemente Islands and Pt. Vicente in November, and Anacapa and Santa Catalina Islands in December. Size of Fish in the Catch Most of the fish in the commercial catch measured since the sampling program was instituted have ranged from about S to about 15 inches in total length (about 185 to about 350 mm. fork length). These sizes are 62 CALIFORNIA FISH AND GAME almost identical with those given by Smith (1895) for fish taken in the initial canning venture of 1893 (see page 49). On rare occasions catches are made which consist entirely of extremely large individuals. The largest specimen so far observed was 26| inches total length and weighed 4iy pounds. THE SANTA BARBARA REGION FISHERY Landings of jack mackerel in this region (Santa Barbara, San Luis Obispo and Ventura counties) were nil until 1947. Since October, 1947, fair amounts have been delivered, particularly at Port Hueneme. Part of the catch is canned locally ; the balance is transshipped for processing elsewhere. Monthly landings for the years 1947-1951 appear in Table 8. TABLE 8 Monthly Landings in Tons of Jack Mackerel — Santa Barbara Region 1947 1948 1949 1950 1951 January _ - 693 876 875 86 387 48 124 7 41 23 344 236 83 129 176 210 108 May 79 515 577 August _ _ . 4 13 210 282 684 15 37 302 96 88 17 39 October ___ 214 2,796 3,764 421 November 362 December . - 7 Totals. -_--- 6,774 2,841 1,413 1,335 2,605 This is properly considered as an extension of the Los Angeles region fishery. Boats from the same fleet of purse seiners deliver in both regions, and the fishing grounds chiefly exploited by the Santa Barbara vessels are extremely important to the Los Angeles fishery. Almost the entire catch is reported from the northern fishing area, particularly the main- land adjacent to Port Hueneme and Anacapa and Santa Cruz Islands. Landings were concentrated in the sardine season through January, 1950. Since April, 1950, there has been a small but fairly consistent fishery based at Port Hueneme. The landing figures are deceptive, for large catches are frequently taken direct to Los Angeles Harbor can- neries, rather than being unloaded locally. THE MONTEREY REGION FISHERY By far the greatest proportion of the present-day Monterey region jack mackerel catch is made in Monterey Bay and delivered to canneries at the bay ports of Monterey and Moss Landing. The fishery predates the earliest records, for as mentioned earlier (page 47), Lockington (1880) found jack mackerel from Monterey in the San Francisco markets when he made his initial survey in 1878. Until 1946, the fishery was of very minor importance, though landings are recorded for every year since 1926 (Table 3). With the failure of the sardine fishery in Central California, landings of jack mackerel THE JACE \i \< i. ii.-i L, 'I R \< in im 1 M VI 1 .1 KI< increased tremendously, as the local canners, who until then confined their operations to sardines exclusively, were forced to i pi other varieties. Monthly Landings for the period 1946-51 appear in Tabli TABLE 9 Monthly Landings in Tons of Jack Mackerel Monterey Region 1946 IV 17 1948 1949 January 8 1 9 5 4 3 33 249 69 6 16 1 15 30 308 270 8 1 77 ■". 2 B 3.35 1 70S 1 1 12 I 7 2.IHH) February March April May June July 1 I 2 S21 670 • 7ii 7 1 August September October November 6 163 49 11 - December 3,331 80 1X2 us Totals . ... 3,579 1,076 1,111 2, IB . -- As in Southern California, this is a roundhau] fishery prosecuted by the sardine purse seiners and smaller ringnel and Lampara boats. The can nery fishery first became of significance in December, l!>4o', when, after several months of poor sardine fishing, the boats suddenly found an abundance of jacks within the bay. In the week ending December 21st, nearly 3,100 tons out of the year's total of 3,57! I were landed. Mos1 of the catches were reported from the northern half of the bay. although some came from the southern half and a few from north of the bay as far as Pt. Alio Nuevo. Catches were far smaller in 1947, but almost all of the seiner fleet left for Southern California waters within about two months of the opening of the sardine season on August 1st, (The sardine season in this area closes on January 15th and there is usually relatively little seine fishing during the months closed to sardines.) In 1948. 1949 and 1950, there was a sudden upsurge of jack mackerel landings in September August sardine fishing was fair in all three years. In 1948, jacks appeared on the grounds early in September. By early October sardine fishing had become so poor that the seiners were moving to Southern California and jack mackerel landings fell off — whether from a lack of boats, a lack of fish or both remains uncertain. In 1 !»4!>. a si/able Heet remained in Central California during the sardine season and took fair quantities of jacks through December. In 1950, because of poor sardine fishing, a large part of the sardine fleet left for the south in the last week of Sep- tember; most of those remaining left in early October. Jack mackerel fishing, however, was exceptional, with 13,673 tons landed in September and an additional 2,000 in October. Fishermen had reported jack mack- erel schools in the bay late in August. In September, all the canneries operating accepted jacks, but individual boat limits of 15 or 20 tons per night probably held down the total catch. The fish were found within the bay at the beginning and at the end of the month. The remainder of the time they were taken north of the bay and for the most parr about 64 CALIFORNIA PISH AND GAME ten miles offshore. Early in October, the demand for jacks by the can- ners decreased. In 1951, there was little seiner fishing in the area, and jack mackerel landings fell off sharply. There is a hint that jack mackerel are seasonal in the Monterey Bay area. This was mentioned in some of the earlier accounts. Goode (1882), quoting Jordan, stated that jacks reached Monterey in August. Collins (1892) said they were in the bay from July to October. The records for 1948-50 indicate arrival in quantity early in September. There was a good-sized fleet operating each year in August, and, while the processors did not want jack mackerel, the fishermen did not report their presence except in late August, 1950. "With the great fluctuations in fishing pres- sure through the year associated with the sardine season and its success, little beyond the inference can be drawn at present. BIOLOGICAL KNOWLEDGE The Department of Fish and Game undertook an investigation of the jack mackerel in early 1947, when it became apparent that this fish was to play other than a very minor role among the fisheries of California. Up to that time, there had been no biological studies of the species ; even its range and relationships with allied species on this coast were matters of some uncertainty. Koutine sampling of the commercial catch com- menced in July, 1947. This phase of the work provides information as to the sizes and ages of fish entering the commercial catch. The otoliths (ear bones) can be used to determine age, and preliminary work shows that jack mackerel may attain an age of over 20 years. Analyses of the size and age composition of the catch, and studies of the relationships of size, age and weight are in progress, concurrent with studies of ma- turity, fecundity and food habits. The relationships of the jack mackerel and its close relatives on the Pacific Coast have been studied (Roedel and Fitch, 1952) and it was found that only the one species of jack mackerel exists in this area. Further, there is no evidence to date of any separate populations along the coast. The southernmost limit of its distribution remains unknown but it becomes progressively less abundant in the southern half of Baja California. "We have not taken specimens south of San Juanico Bay (Lat. 26° 15' N.). A superficially similar fish, the Mexican scad {Decapterus hypodus), which is rather abundant off northern Baja California and has been taken at San Clemente Island, could be confused with the jack mackerel. The scad, however, has enlarged scales only along the posterior half of the lateral line whereas the jack mackerel has enlarged scales along its entire length. Further, both dorsal and anal fins in the scad are followed by a detached finlet. The last dorsal and anal rays of the jack mackerel may be finlet-like in structure but are not widely separated from the fins. The jack mackerel has an accessory lateral line (sometimes difficult to see) running along the back close to the first dorsal fin and extending usually to the second dorsal. This accessory line is lacking in the scad. No other fish within the jack mackerel's range is likely to be confused with it. The fish described as a scad, Decapterus polyaspis, from the Pacific northwest has proved to be the very large adult jack mackerel. THE JACE \i \< l.i BEL. Ti; \< in i;i , M M I I Kit FIGURE 6. Mexican scad, Decaplerus hypodus. Photograph fay Al Johm lor Vernon M. Haden, San Pedro. It has been found that the fish attains a much greater Bize than was supposed. The record specimen to date was ■_,<;1, inches i 67 cm. in total length. Schools of Large fish 16 to i'4 inches i IP to 60 cm. long have been found at considerable distances from shore, well outside the presenl limits of the fishery. On rare occasions, they have been taken commer- cially on the current grounds, and they are sometimes caughl by Bporl fishermen. Data have been and are being obtained regarding the spawning grounds and season incidental to the California Cooperative Sardine Research Program. The first report (Calif. Mar. Res. Comm., 1950, p. 41) states that the spawning season is similar to thai of the sardine (February to August), that larvae were found over a large area off California and Baja California, that larvae were very abundant, and that the center of their distribution was at a considerable distance from shore. The second report (1952, p. 38) remarks that the larvae of jack mack- erel were more abundant than those of sardines in 1951. A chari shows that jack mackerel larvae were found at most stations occupied from Central California to central Baja California, with the center of abund- ance about 150 miles off the coast of Southern California ami northern Baja California. Larvae were still being taken at the furthesl offshore stations some 350-400 miles from land, so the offshore limit of spawning remains uncertain. Information as to the abundance of jack mackerel off California and Baja California and as to their abundance relative to sardines, Pacific mackerel and anchovies (Engraulis nun-dux is being obtained in the course of young sardine surveys conducted each year by the Department in conjunction with the cooperative pro-ram. Data Eor 1950 ami 195] (Radovieh, 1952, p. 55-57) indicate thai jacks were most abundant off Southern California and northern Raja California and that they were more abundant in 1950 than in 195] except in the southern portion of Baja California. In Central and Southern California and northern Baja California jack mackerel, sardines and anchovies were found in roughly comparable numbers each year; Pacifies were less abundant. Farther south jacks were less abundant in relation to the other species. 3—68841 66 CALIFORNIA FISH AND GAME Though much remains to be learned of the jack mackerel's life history, the investigations are progressing at a satisfactory rate and should provide most of the basic biological knowledge in the immediate future. AN ESTIMATE OF THE STATUS OF THE FISHERY At the present time, the jack mackerel fishery appears to be in a healthy condition. There are serious gaps in our knowledge of the species ' biology and there is no measure of fishing effort ; given that information the estimate might be less favorable. However, in the lack of it there are several factors which seem favorable enough to justify the more opti- mistic approach. First the biological range of the species far exceeds the commercial and there is no evidence to indicate that the Central and Southern California fisheries are drawing on limited, localized popula- tions. It remains to be demonstrated that fish from all portions of the range actually do move freely within the range and ultimately contribute to the fishery. This can be shown only by a tagging program, which at present is beyond the scope of the investigations. A second factor is the existence of a reservoir of large, old fish beyond the limits of the present fishery. These fish would presumably not be exploitable by the seiner fleet. The scarcity of schools scattered over a wide area precludes economic roundhaul fishing even under favorable weather conditions. The. abund- ance of larvae is another good sign, though there is as yet, at least, no possible estimate of survival. Finally, an economic factor operating in favor of the jack mackerel is its relative undesirability compared to the sardine and the Pacific mackerel. "When either or both of these species are available, the seiners will take them in preference. It is, of course,: the very lack of sardines and Pacifies which has created the market for jacks. Parenthetically, it is the fact that the jack mackerel ranks third which renders any measure of conventional return-per-unit-of -effort vnv tually unobtainable. A great deal of additional information must be obtained before any estimates other than more or less educated guesses can be made as to the true condition of the fishery. The program now being carried out should provide much of what is required. Data on general oceanographic con- ditions now being accumulated through the Cooperative Sardine Re- search Program will be of great value. The inclusion of the jack mackerel in that broad study effective July 1, 1952, at which time the special research tax was imposed on jack mackerel in addition to sardines, will permit greater emphasis on the areas particularly important to the species and should assist materially in the gathering and analyzing of biological data, particularly with respect to spawning and the behavior of young fish. It is fortunate that much of the basic knowledge is being obtained while the fishery is relatively young and the population in no apparent straits. Although the evidence of the future may bear out the favorable estimate of today, it is well to be armed against less pleasant possibilities. It is hoped that sufficient data can be obtained in time to foresee, if not forestall, any potential danger to the fishery. THE JACK MACKER] I.. 1 i; kCHURI I I ! I 'I RI( i REFERENCES California Murine Research Committee L950. California cooperative sardine re parch pro • [' r«»port 1950 ■".( p L952. California < perative sardine pe pnrch program I' report I Januai L951 to 30 June L952, 51 p. Clark, Frances X. L952. Review of the California sardine fisher] Calil Fl b and Game, rol, mi. .*;, p. ."i(>7 380. Cleaver, F. C, (editor) L951. Fisheries statistics of Oregon. Oreg. Fi h Comm., Contrih 16, 178 p Collins, .1. W. 1892. Report on the fisheries of the Pacific const of the 1 nited State I > •■•nun. Fish., Rept. for 1888, p. 3 269. Croker, Richard S. 1929. Mackerel. In The commercial fish catch of California for the fear 1926 and 1927. Calif. Div. Fish and Ga , Fish Bull. 15, p 12 I ■ 1933. The California mackerel fishery. Calif. Div. Fish and Game, Finn Bull. 40, 14!) p. Daugherty, Anita E. 1952. Recent changes in purse seine gear in California. Calif. Fish and Game, vol.38, no. 1. p. L25-131. Fisheries Newsletter lOHO. Scad renamed jack mackerel. Australia. Fisheries Newsletter, vol. 9, no l p. 14. Fitch, John E. 1052. The decline of the Pacific mackerel fishery. Calif. Fish and Game, rol. 38, no. 3, p. 381-389. Fry, Donald II., Jr. 1930. Mackerel. In The commercial fish catch of California for the year 1928. Calif. Div. Fish and Came, Fish Bull. 20, p. 25-35. 1937. Horse mackerel, In The commercial fish catch of California for the year 1935. Calif. Div. Fish and Came, Fish Bull. 49, p. 22-23. Goode, G. Brown 1882. The carangoid fishes of the United States Pompanoes, crevalles, amber- fish, etc. U. S. Fish Comm., Bull., rol. 1. I L881 I, p. 30 13. 1884. The food fishes of the United States. Sec. 1. pi. 3, p. 163-682. I>, Fisheries and Fishery Indus. U. S., Washington. Lockington, W. N. 1880. Report upon the food fishes of San Francisco. Comm. Fish. Calif., Kept, for 1878 and 1879, p. 17-58. 1881. Report upon the edible fishes of the Pacific coast, U.S.A. Comm. Fish. Calif., Rept. for 1880, p. 16-66. Radovich, John 1952. Report on the young sardine. Sardinops caerulea, survey in California and Mexican waters. 1950 and 1951. Calif. Dept. Fish and Came. Fish BulL 88, p. 31-63. Roedel, Phil M. 1948. Common marine fishes of California. Calif. Div. Fish and Game, Fish Bull. 68, 150 p. 1949a. Jack mackerel. In The commercial fish catch of California for the year 1947 with an historical review 1916-1947. Calif. Div. Fish and Came. Fish Bull. 74, p. 31-33. 1949h. Common names. Ibid, p. 204-20G. 1952. A review of the Pacific mackerel i Pneumatophorus diego) fishery of the Los Angeles region with special reference to the years 1939-1951. Calif. Fish and Game, vol. 38, no. 2, p. 253-273. 68 CALIFORNIA FISH AND GAME Roedel, Phil M. and John E. Fitch 1952. The status of the carangid fishes Trachurus and Decapterus on the Pacific coast of Canada and the United States. Copeia, no. 1, p. 4-6. Scofield, W. L. 1924. Mackerel at Monterey. Calif. Fish and Game, vol. 10, no. 2, p. 87. 1951. Purse seines and other roundhaul nets in California. Calif. Dept. Fish and Game, Fish Bull. 81, 83 p. Smith, Hugh M. 1895. Xotes on a reconnoissance of the fisheries of the Pacific coast of the United States in 1894. U. S. Fish. Comm., Bull., vol. 14, p. 223-288. Starks, Edwin Chapin 1918. The mackerel and mackerel-like fishes of California. Calif. Fish and Game, vol. 4, no. 3, p. 118-129. Walford, Lionel A. 1931. Handbook of common commercial and game fishes of California. Calif. Div. Fish and Game, Fish Bull. 28, 181 p. Wilcox, William A. 1895. The fisheries of the Pacific coast. U. S. Comm. Fish., Rept. for 1893, p. 143-304. 1898. Xotes on the fisheries of the Pacific coast in 1895. U. S. Comm. Fish., Rept. for 1896, p. 575-659. 1902. Xotes on the fisheries of the Pacific coast in 1899. U. S. Comm. Fish., Rept. for 1901, p. 503-574. 1907. The commercial fisheries of the Pacific coast states in 1904. U. S. Bur. Fish., Rept. for 1905, Doc. 612, 74 p. ELEOTRIS PICTA ADDED TO THE FISH FAUNA OF CALIFORNIA By CARL L. HUBBS Scripps Institution of Oceanography, University of California, lo Jolla Among the numerous recenl additions to the lisl of California fishes the latest, at the time of writing, is thai of the spotted sleeper, EleoU picta K ner and Steindachner. This Large gobioid fish bas been reported occurring in coastwise waters, chiefly in the lower parts of rivers, from the regions of Cape San Lucas and Mazatlan in Mexico 1 1 1 1 - « • 1 1 <_•- 1 1 Central America to Ecuador ( Figure 1). On April 1(i, L952, Clifford Pox of [nglewood, California, canghl a specimen (Figure 2) of tli is species ;it the canal spillway between Winter- haven and the Colorado River, in Imperial County. Using shrimp for bait, he was fishing about midday on the bottom, al .1 depth "I aboul four feet, for channel catfish. He reports that the strange fish 9truck the bait and pulled like a catfish. The specimen was sent to the author for identification by Arthur V. Halloran, Manager of the Imperial National Wildlife Refuge. I' proved to be a non-breeding adult male 11' inches in total length (228 mm. in standard length). It has been deposited in the fish collection of the Cali- fornia Academy of Sciences in San Francisco I < latalog No. '_,,>~>>'-! . Mr. Halloran wrote that, so far as could be determined, m> fish of this sort had ever been seen in the region. It is highly probable, indeed, that it was a stray from the Gulf of Calif ornia or from the scarcely collected tidal reaches of the Colorado River. The specimen may have moved di- rectly from the river, a distance of about one-half mile to the spillway, or it may have come from the river through the canal that was overflow- ing here. The specimen was confidently identified as Eleotris picta because of its close correspondence with the published descripl ions and comparisons of that species referred to in the following synonymy, which I have tried to make complete : Eleotris picta. — Kner and Steindachner, in Kner, 1863, p. 223-224 (original diagnosis; questioned as new; "Rio Bayano, Siidseite von Panama"). Kner and Stein- dachner, 1865, pi. 3, fif,'. 1 (name spelled iiirlus in text |. Wagner, 1st;.", p. '.Ml (Pacific slope of Panama). Gun ther, 1868, p. 389, 111 (Pacific side of Isthmus). Regan, 1906, p. 6-8 (comparisons; diagnosis; Pacific coasts and rivers from California to Ecuador; "Cape St. Lucas"; .Mazatlan: Presidio; Colima; Rio Bayano, Panama; Ecuador). Starks, 1906, p. 762, 799 (coloration : Guayaquil, Ecuador; Panama; Gulf of California ; Lower California). Eigenmann, 1910, p. 480 ("Pacific slope, Sonora to Ecuador"). Regan, L913, p. 17- (Rio San Juan, Colombia). Meek. 1914, p. 131 (Pacific oasl rivers from California to Ecuador; Rio Grande at Orotina, and Jesus Maria, Costa Rica). Sleek and Hildebrand, 1910, p. 35(5-3r>9 i symmj my : comparisons : descripl ion : food : Wesl Contributions from the Scripps Institution of I »ceanography, New Series, No. 600. Sub- mitted for publication June, 1952. (69) 70 CALIFORNIA FISH AND GAME *tf -&■ MEXICO ^t3Z01l6n '^StAS TRES MARIAS £ABO COPRIENTES fflonzanillo 'UPPEPTON ID Jina Cruz 'l ("Rio Presidio, cerca Mazatlan. . . . Aguas dulces en San Jose del ('alio, FJ.-i.jii California. . . ."). Brock, 1943, p. 130 (Sonora to Panama ; fresh water. Cleopha Island, Tres Marias group, at Lat. 21° 17' N., Long. 106° 15' W.i. Fowler, 1944, p. 516 (Gua yaquil and Chone, Ecuador; Panama; Mazatlftn and San Jose" del Cabo, Mexico), de Buen, 1947a, p. 290 ("En Baja California (aguas dulces de San Jose: del Cabo.) Rfo Presidio") ; 1947b, p. 329 ("Cuenca del rfo Pre sidio"). Alvarez, 1950, p. 133 (characters in key. compared with /■.'. pisonis ; name misprinted pinctus; "Costa del Paclfii a America, desde Baja Cali- fornia a Centroamerica. Entra en los rlos"). Culius aequidens. — Jordan and Gilbert, 1882a, p. 161-462 (original description; near Mazatlftn, said to be from fresh water al Presidio) ; 1882c, p. .".7'J t Colima, Mexico) ; lS82d, p. 380 (fresh water near San .lose, near Cape San Lncas). Eleotris aequidens. — Eigenmann and Fordice, 1885, p. 75-76, 79-80 (comparisons; synonymy; streams about Gulf of California, south to Colima; said to be abundant in streams of Sinaloa and Lower California). Jordan, 1885a, p. 803 (tropical Pacific Coast; fresh waters of western Mexico and Lower California) ; ISSfie, p. 3S6 (Colima; Cape San Lucas). Jordan and Eigen maun, 1S86, p. 483 (streams about Gulf of California, south to Colima). Eigenmann and Eigenmann. 1888, p. 55 (comparisons; Panamft). Jordan, 1889, p. 333 (Rfo Presidio, near Mazatlftn). Eigenmann, L893, p. 60 (fresh water at Mazatlftn and Colima). Jordan, L895, p. 193 (color, etc.; rather scarce in Rfo Presidio; a few from brackish waters or muddj places about the estuary). PhUypnus lateralis (misident ilicat ion. in part see p. 72). Jordan and Gilbert. 1882b, p. 368 (in part; Cape San Lucas). Eleotris pisonis (misidentifi cations). — Eigenmann and Fordice, 1885, p. 7.V7t>. 7'.' sn (in part; E. picta regarded as a synonym; range, in part ; Rfo Bayano, Pan- ama). Jordan, 1885b, p. 386 (E. picta as a synonym ; Rio Bayano). .Ionian and Eigenmann, 1886, p. 483 (E. picta as a synonym; range, in pari : Rfo Bayano, 72 CALIFORNIA FISH AND GAME Panama). Eigenmann and Eigenmann, 1891, p. 71 (in part; Rio Bayano; E. pictus as a synonym). Eigenmann, 1893, p. 60 (Rio Bayano [with erroneous citation] ) . The published records for the spotted sleeper, duly noted in the synonymy above, and plotted on the accompanying chart (Figure 1), extend northward only to Rio Presidio near Mazatlan, Sinaloa, Mexico, near the lower end of the Gulf of California, and to Rio San Jose, near the tip of Baja California. Both localities lie just within the Tropic of Cancer. The specimen from California was taken approximately 750 miles north of the Rio San Jose record and about 860 miles north of the Rio Presidio mouth, and, therefore, constitutes a notable extension of known range. Among unpublished material I can locate no specimens from inter- vening locations. In the United States National Museum Leonard P. Schultz and Robert Kanazawa locate only four series, with definite data, from north of Panama: Nos. 2492, Cape San Lucas, John Xantus (two of the specimens reported by Jordan and Gilbert, 1882b, p. 368, as Philypnus lateralis) ; 30943, near San Jose, L. Belding (reported as Culms aequidens by Jordan and Gilbert, 1882d, p. 380) ; 37142, Rio Presidio, Sinaloa, A. Forrer (reported as E. aequidens by Jordan, 1889, p. 333) ; and 102265, Rio Tehuantepec, T. MacDougall, 1936. In the Natural History Museum of Stanford University there are, James Bohlke informs me, five series: Nos. 2907, Mazatlan, Sinaloa, Mexico, D. S. Jordan on Hopkins Expedition (reported by Jordan, 1895, p. 493) ; 6869, Panama, C. H. Gilbert and partv. January 10 to February 24, 1896 (Gilbert and Starks, 1904, p. 169)'; 8130, San Jose del Cabo, Baja Cali- fornia, GustavEisen (Rutter, 1896, p. 265) ; 37538, Puerto Utria, Colom- bia, in stream on mainland opposite tip of peninsula, G. S. Myers on Hancock Expedition, February 25, 1938 ; 37539, Watering Bay, Gorgona Island, Colombia, in freshwater stream, G. S. Myers, February 24, 1938. In the Museum of Zoology of the University of Michigan, Robert R. Miller finds no cataloged specimens and states that the species is not included in the numerous recent collections made between Mazatlan and the Colorado River by the late Ralph G. Miller. Nor have Boyd W. Walker and his students at the University of California (Los Angeles) secured any in their recent collecting along the shores of the same region. It was not obtained on the recorded collecting expeditions and surveys in the lower Colorado River (Gilbert and Scofield, 1898; Snyder, 1915; Dill, 1944), or on a collecting trip by Hubbs, Miller, and party in March, 1950, along the river from Imperial Dam in California to below the head of tidewater in Baja California. The published reports from "Lower California" and "Cape San Lucas" obviously refer to the records of Culius aequidens from near San Jose collected by Belding, and of Eleotris pictus from fresh waters at San Jose del Cabo, collected by Eisen (see synonymy). These fish were doubtless taken in Rio San Jose near its mouth, where it flows through the village of San Jose del Cabo, some miles distant from Cabo San Lucas. This is a perennial stream, with many gobies and other fishes of marine affinities. Several authors (Jordan and Evermann, 1898, p. 2202; Eigenmann, 1910, p. 480 ; Meek, 1904 p. 229 ; Beltran, 1934, p. 6 ; and Brock, 1943, p. 130) have indicated that E. picta ranges north to Sonora, but I find ELEOTRIX PICTA 73 no basis in previous literature for this extension of t be range and presume that "Sonora" was entered for "Sinaloa." Three authorities «ven1 farther instating that the range extends north to Calif ornia, bul [assume that these authors (Regan, 1906, p. 8; Meek, 1914, p. L31 ; and Meek and Hildebrand, 1916, p. 358) m is wrote "California" in place of "Baja California" or "Gulf of California." This northward extension of the recognized range of Eleotris picta adds a genus and a family (Eleotridae) to the California list and adds a species to the known fauna of the United States. The range of the genus and family is thus carried up the Wes1 Coast about as far as the genus reaches along the Atlantic Coast. E. pisowis, the Atlantic analog of E. picta, ranges northward to Texas, Florida, and Georgia and another species, variously identified as E. ab'acurus Jordan and Gilberl or as E. amblyopsis (Cope), has been reported from South Carolina, a1 about the same latitude as Imperial County, California (.Jordan, Kvermann, and Clark, 1930, p. 437, and Fowler, 1945b, p. 218). Two other large sleepers (eleotrids), Gobiomorus macula! us | Giinther) and Dormitator latifrons (Richardson), which are commonly associated with Eleotris picta, might also stray up the Colorado River into Cali- fornia. Neither, however, has yet been found as far north as the Colorado Delta. The only gobioid fish that has been reported previously from the lower Colorado River is GiUichthys detrusus, which Gilbert and Scofield de- scribed from "Horseshoe Bend, near the mouth of the Colorado River, in Mexico," and which we seined in tidal fresh water at the Ponga ferry crossing, due east of a point 8.5 miles south of El Mayor, Baja California (our specimens are all small and heavily parasitized). Incidentally, I have now checked all available specimens of GiUichthys from Salton Sea and regard all as referable to the California species, G. mirdbilis Cooper (see discussion by Miller, 1952, p. 39-40). G. mirabilis, the mudsucker, has recently been shown by Willis A. Evans and Philip A. Douglas to be well established in Salton Sea. The published literature indicates that Eleotris is relatively uniform along the margin of the Pacific Coast, not breaking up into species as the genus does along the Atlantic Coast. Two reports (Fowler, 1944b, p. 246, and 1945a, p. 135), however, appear to represent a distinct species, from the Upper Rio Jurubida at Nuqui, in the Province of Choco, northwestern Colombia, at an elevation of about 3,000 feet, It seems to be characterized by the small number of scales (in only 51 rows along the axis, according to Fowler). Doubts that now seem resolved have been raised regarding both the pertinence and the gender of the name Eleotris. The name has been added to the Official List of generic names, with fixed application to the gobioids of the E. pisonis sort. That the name should be regarded as feminine seems clear. It was so treated by the original describers (Bloch and Schneider), and by most subsequent authors, including Cuvier, Bleeker. and Giinther. According to current discussions names not occurring in Greek or Latin, with terminations like -is that are normal to the third declension, take the gender normal to such words. Such words were either masculine or feminine in classical Latin. The original feminine usage would therefore seem acceptable and is here adopted. 74 CALIFORNIA FISH AND GAME The following color notes were made on the specimen, when fresh, by Arthur F. Halloran and his assistant, Gerald E. Duncan: "Dark brown on dorsal surface. Yellowish-brown on sides mixed with small yellow spots. Light gray to white, mixed with yellow in spots, on ventral surface forward of anal fin. Dorsal fins dark, with 3^ellow spots. Caudal fin red- dish-brown with light streaks on the end. Other fins reddish with dark spots. ' ' As shown in Figure 2 the lower anterior parts are conspicuously light-spotted. The spotted sleeper can hardly be regarded as a desirable intrusion into the California fauna and it is hoped that it will not follow the striped mullet (Mugil cephalus) and the Pacific ten-pounder (Elops affinis) in dispersal from the Colorado River into Salton Sea. It has a low rating as a food or game fish, as Hildebrand (1938, p. 346-347) noted in Panama. Furthermore, its large, well-toothed mouth, with projecting lower jaw, suggests predatory habits. Several authors (see annotated synonymy) have found that the species eats fish. REFERENCES Alvarez, Jose 1950. Claves para la determinacion de especies en los peces de las aguas conti- nentales mexicanas. Secretaria de Marina, Mexico, p. 1-144, figs. 1-16. Beltran, Enrique 1934. Lista de peces mexicanos. Tornado del catalogo de peces en preparacion. Mexico, p. 1-13 (processed). Breder, C. M., Jr. 1927. The fishes of the Rio Chucunaque drainage, eastern Panama. Amer. Mus. Nat. Hist., Bull., vol. 57, art. 3. p. 91-176, figs. 1-9. Brock, Vernon E. 1943. Distributional notes on the fishes of Lower California and the west coast of Mexico. Copeia, no. 2, p. 130-131. de Buen, Fernando 1940. Lista de peces de agua dulce de Mexico. En preparacion de su catalogo. Estaeion Limnologica de Patzcuaro [IV], p. 51-65 (processed). 1947a. Investigaciones sobre ictiologia mexicana. I. Catalogo de los peces de la region nearctica en suelo mexicano. Inst. Biol. Mexico, Anal., vol. 18, no. 1, p. 257-292. 1947b. Investigaciones sobre ictiologia mexicana. III. Zoogeografia de los peces de agua dulce, con estudio especial de la region nearctica. Inst. Biol. Mexico, Anal., vol. 18, no. 1, p. 304-348. Cuesta Terron, Carlos 1932. Lista de los peces de las costas de la Baja California. Inst. Biol. Mexico, Anal., vol. 3, no. 1, p. 75-80. Dill, William A. 1944. The fisherv of the lower Colorado River. Calif. Fish and Game, vol. 30, no. 2, p. 109-211, 37 figs. Eigenmann, Carl H. 1893. Catalogue of the fresh-water fishes of Central America and southern Mexico. U. S. Nat. Mus., Proc, vol. 16, no. 925, p. 53-60. 1909. The fresh water fishes of Patagonia and an examination of the Archiplata- Archhelenis theory. Princeton Univ. Expeds. to Patagonia, Repts., 1896- L899, vol. 3, pt. 3, p. 295-374, 34 maps, pis. 30-37. 1910. Catalogue and bibliography of the fresh water fishes of the Americas south of the Tropic of Cancer. Princeton Univ. Expeds. to Patagonia, Repts., 1S«)6-1S!)9, vol. 3, pt. 4, p. 375-511. 1922. The fishes of western South America, part I. The fresh-water fishes of northwestern South America, including Colombia, Panama, and the Pacific slopes of Ecuador and Peru, together with an appendix on the fishes of the Rio Meta in Colombia. Cam. Mus., Mem., vol. 9, no. 1, p.. 1-346, figs. 1-21, pis. 1-38. I II ill |;|- ni | \ ,.i Eigenmann, Carl EI., and Rosa Smith Eigenmann L888. A list of the American Bpecic of Oobiidae and Cullionymidae, with Dot on the specimens contained in the VIu oum of Compai ■ / I in bridge, Massachusetts. Calif. Acad Scl Pro< ■ ■■ '-'. rol I, p 51 7- L891. A catalogue of the fresh water ii he ol South Amerii i I M Proc, vol. I I. no. 842, p. I 81. EJigenmann, Carl II.. and Morton W. Fordice L885. A review of the American Eleotridinue, Acnd Nat. Sci Phila . Proc., 1885, p. c.t; 80. Evermann, Barton Warren L908. Descriptions of ;i new species of trout (Salmo nel oni) and :i new cyprino ilout (Fundulus meeki) with notes ther fishei from Lower California. Biol. Soc. Wash., Proc, vol. 21, p. 19 30. Fowler. Henry W. L944a. Results of the Fifth George Vanderbill Expedition (1041) (Bahama*, Carib- bean Sea, Panama, Galapagos Archipelago ond Mexican Pacific island I. Acad. Nat. Sri. Phila., Monog. 6, p. 57-520, figt I 268, pi 1 20 1944b. Fresh-water fishes from northwestern Colombia. Acad. Nat. Sri. Phila., Proc, vol. 96, p. 227-248, figs. I 25. 1945a. Colombian Zoological Survey. Pari I. The fresh water Babes obtained in 1945. Acad. Nat. Sri. Phila., Proc, vol. 97, p. 93 135, figs. 1 IT. 1945b. A study of the fishes of the Southern Piedmont and Coastal Plain. Acad. Nat. Sci. Phila., .Mono-. 7. p. i vi, I 108, Bgs. I 313. Gilbert, Charles Henry, and Norman Bishop Scofield 1898. Notes on a collection of fishes from the Colorado basin in Arizona. D. S. Nat. Mus., Proc, vol. lit), p. 487 199, I pis. Gilbert , Charles II.. and Edwin C. Starks 11)04. The fishes of Panama Bay. Calif. Acad. Sci., Mem., vol. I. p. 3 304, pis. 1 33. Giinther, Albert 1868. An account of the fishes of the states of Central America, based on collec tions made by Capt. .7. M. Dow. F. (iodman. Esq., and < >. Salvin, Esq. ZooL Soc. London* Trans., vol. (5, art. 14, p. 377-494, pis. 63 B7. Hildebrand, Samuel F. 19.">S. A new catalogue of the fresh-water fishes of Panama. Field Mus. Nat. Ili-t.. Zool. Ser., vol. 22, uo. 4 (publ. 42.". I . p. 217-359, 13 figs. 1939. The Panama Canal as a passageway for fishes, with lists ond remarks on the fishes and invertebrates observed. Zoologica, vol. 24, no. •">. p. 15-45. pis. 1-2. Hubbs, Carl L. 1932. Studies of the fishes of the order Cyprinodontes. XI. Zoogont ticva zoniatium. a new species from Colima, Mexico. Copeia, m>. 2, p. 68 71. In Press. Geographic and systematic status of the fishes described by Kner and Steindachner in 1863 and L865 from fresh waters in Panama" and Ecuador. Copeia 1953, no. 1. Jordan, David Starr 1885a. A catalogue of the fislies known to inhabit the water- of North America, north of the Tropic of Cancer, with notes on the species discovered in 1883 and 1884. U. S. Comm. Fish and Fish., Ann. Rept. no. 13, p. 787-973 (1-185, sep.). lS85b. A list of the fishes known from the Pacific Coast of tropical America, from the Tropic of Cancer to Panama. U. S. Nat. Mus.. Pro.-., vol. 8, p. .••.»''! 394 1SS9. List of fishes collected by Alphonse Forrer about Mazatlan, with descriptions of two new species — items beani and Poecilia butleri. D. S. Nat. Mus., Proc, vol. 11, 1888, p. 329-334. 1895. The fishes of Sinaloa. Calif. Acad. Sri.. Proc, ser. 2, vol. 5, p. 377-514, pis. 27-55. 1896. Notes on fishes little known or new to science. Calif. Acad. Sci., Proc. ser. 2, vol. 6, p. 201-244, 1 pi. + pis. 2ii I-:. Jordan, David S.. and Carl II. Eigenmann 1886. A review of the Gobiidae of North America. I'. S. Nat. Mus.. Proc, vol. '••. p. 477-518. Jordan, David Starr, and Barton Warren Evermann 1898. The fishes of North and Middle America .... P. S. Nat. Mus., Bull. no. 47, pt. 3, p. i-xxiv, 2183a-3136. 76 CALIFORNIA FISH AND GAME Jordan, David Starr, Barton Warren Bvermann, and Howard Walton Clark 1930. Check list of the fishes and fishlike vertebrates of North and Middle America north of the northern boundary of Venezuela and Colombia. U. S. Comm. Fish., Rept. 1928, pt. 2, p. i-iv, 1-670. Jordan, David S., and Charles H. Gilbert 1882a. Description of five new species of fishes from Mazatlan, Mexico. U. S. Nat. Mus., Proc, vol. 4, 1881, p. 458-463. 1882b. Catalogue of the fishes collected by Mr. John Xantus at Cape San Lucas, which are now in the United States National Museum, with descriptions of eight new species. U. S. Nat. Mus., Proc, vol. 5, p. 353-371. 18S2c. List of fishes collected by John Xantus at Colima, Mexico. U. S. Nat. Mus., Proc, vol. 5, p. 371-372. 1882d. List of a collection of fishes made by Mr. L. Belding near Cape San Lucas, Lower California. U. S. Nat. Mus., Proc, vol. 5, p. 378-381. Kner, Rudolf 1863. Eine Uebersicht der ichthyologischen Ausbeute des Herrn Professors Dr. Mor. Wagner in Central Amerika. Konigl. Bayer. Akad. Wissensch. Miinchen, 1863, vol. 2, p. 220-230 (attributed in text to Kner and Stein- dachner) . Kner, Rudolf, and Franz Steindachner "1864" (1865)2. Neue Gattungen und Arten von Fischen aus Central-Amerika ; gesammelt von Prof. Moritz Wagner. Konigl. Bayer. Akad. Wissensch. Miinchen, Abb., vol. 10, pt. 1, p. 1-61, pis. 1-6. Meek, Seth Eugene 1904. The fresh-water fishes of Mexico north of the Isthmus of Tehuantepec Field Mus. Nat. Hist., Publ. 93, zool. ser., vol. 5, p. i-lxii, 1-252, figs. 1-72, pis. 1-17, 1 map. 1914. An annotated list of the fishes known to occur in the fresh waters of Costa Rica. Field Mus. Nat. Hist., Publ. 174 (Zool. Ser., vol. 10, no. 10) , p. 101-134. Meek, Seth E., and Samuel F. Hildebrand 1916. The fishes of the fresh waters of Panama. Field Mus. Nat. Hist., Publ. 191 (Zool. Ser., vol. 10, no. 15), p. 217-374, figs. 1-10, pis. 6-32. Miller, Robert Rush 1952. Bait fishes of the lower Colorado River from Lake Mead, Nevada, to Yuma, Arizona, with a key for their identification. Calif. Fish and Game, vol. 38, no. 1, p. 7-42, 32 figs. Regan, C. Tate 1906-1908. Pisces. Biologia Centrali-Americana, p. i-xxxiii, 1-203, 26 pis., 7 maps, lfig. 1913. The fishes of the San Juan River, Colombia. Ann. and Mag. Nat. Hist., ser. 8, vol. 12, p. 462-473. Rutter, Cloudsley 1896. Notes on fresh water fishes of the Pacific Slope of North America. Calif. Acad. Sci., Proc, ser. 2, vol. 6, p. 245-267. Snyder, John Otterbein 1915. Notes on a collection of fishes made by Dr. Edgar A. Mearns from rivers tributary to the Gulf of California. U. S. Nat. Mus., Proc, vol. 49, no. 2125, p. 573-586, 1 fig., pis. 76-77. Starks. Edwin Chapin 1906. On a collection of fishes made by P. O. Simons in Ecuador and Peru. U. S. Nat. Mus., Proc, vol. 30, no. 1468, p. 761-S00, pis. 65-66. T'lrey, Albert B. 1929. A check-list of the fishes of southern California and Lower California. Pan- Pac Res. Inst., Jour., vol. 4, no. 4 (printed in Mid-Pac. Mag., vol. 38, no. 4), p. 2-11. Warner, Moritz "1864" (1865) 2 Leber die hydrographischen Yerhaltnisse und das Vorkommen der Siisswasserfische in den Staaten Panama und Ecuador. Ein Beitrag zur Zoogeographie Amerika's. Konigl. Baver. Akad. Wissensch. Miinchen, Abb.., vol. 10. i>i. 1. ].. 6.3-113. 2 Listed as of 1804 but actually not published until 1865, according to Giinther, Zoological Record, 2, 1865 (1866), p. 173; listed in Dean's Bibliography of Fishes as of 1870. THE VENOM OF UROBATIS HALLERI (COOPER), THE ROUND STINGRAY JOHN E. HOLLOWAY, NORMAN C. BUNKER and BRUCE W. HALSIEAD School of Tropical and Preventive Mml College of Medical Evangelists, Lomu Linda, California The literature dealing with stingray venom appears to be the product of a single worker, Vellard (1931, 1932), and deals with the South Ameri- can freshwater stingray, Paratrygon motoro (Miiller and Henle \ Lard obtained crude extracts by scraping the ventrolateral-glandular grooves of the sting with a scalpel and triturating the material in both distilled water and physiological saline solution. Tests were made with crude extracts and by stabbing the animals with intacl stings. The venom was tested on dogs, rabbits, mice, pigeons, reptiles and batrachians. I toil- ing, strong aeids and aleoliol were said to desl roy the acl ii E the \ enom. Solutions of the venom stored at 5 degrees < '. were reported to I"--'- their potency with in a few days. The present report concerns one of a series of investigations which deal with the venom apparatus of stingrays. The purpose of this particu- lar study was to attempt to determine more exactly the site of venom production in the caudal appendage of Urobatis kalleri Cooper Fig. 1), the round stingray. Urobatis halleri i^ a common inhabitant of the 1 This investigation was supported by a research mam from the National [nstil Health, Public Health Service, and a contrail with the Office of Naval Research partment of the Navy (NONR-205(OO) ). Submitted for publication August, -The two species Taeniura dumerili and T. miilleri as mentioned by Vellard lib now considered synonymous with Paratrygon motoro (Mttller and Henle) according toGarman (1913) and Fowler (1948). FIGURE 1. Urobafis halleri (Cooper), the round stingray (77) 78 CALIFORNIA PISH AND GAME shallow bays and sloughs of Southern California and the causative agent for numerous stingray attacks each year. SPECIMENS USED One series of 125 specimens of Urobatis halleri averaging 25 cm. in total length was obtained by seine from the lagoon shore opposite Seal Beach, California. A second series of 12 specimens of the same species was similarly obtained from Mission Bay, San Diego. All specimens were iced at the time of collection. METHODS Sixty of the first series of 125 specimens were placed on ice for 42 hours prior to preparation of extracts ; the remaining 65 were frozen three hours after collection and maintained at — 7 degrees C. for 40 hours pending extraction. Extracts from the second series were prepared within 18 hours after collection. Material for extracts was obtained by scraping or sharp dissection from the following regions of the caudal appendage : (1) integumentary tissue from ventrolateral-glandular grooves of the spine; (2) cuneiform area (Halstead and Modglin, 1950) ; (3) caudal integument from other than the cuneiform area; and (4) slime associated with the sting. Material of these separate fractions was pooled and weighed. Table 1 lists the yields. The aggregate samples were then macerated by mortar and pestle and transferred to graduated cylinders. Sufficient distilled water was TABLE 1 Extract Yields From Various Caudal Portions of U. halleri Source Total weight (grams) Average amount per specimen (mg.) 60 specimens, iced 42 hours: Glandular tissue - _ _ 0.9 0.55 0.54 0.83 0.58 0.41 0.83 0.21 0.11 15 9 Caudal integument. . _ _ 9 Slime__ _ - 65 specimens, iced 12 hours, then frozen 30 hours: Glandular tissue _ __ __ _ _____ 14 9 Cuneiform tissue _ _ _ 6.8 Slime __ _- 10 specimens, iced 12 hours: Glandular tissue. _______ 13 21 Cuneiform tissue _ ____ 11 added to make 1 ml. of stock extract contain material from 10 average original specimens. Resulting solutions were centrifuged at 2,000 r.p.m. for 15 minutes. The slightly translucent supernatant stock extracts were then decanted. Dilutions of 1 :5 of the stock extracts were also prepared with distilled water. Then 1 ml. portions of stock extracts and their 1 :5 dilutions were injected intraperitoneally into white mice (strain CCi) weighing from 19 to 23 gm. each. VENOM "i ROI rD STINGRAY "'' RESULTS Alnidst invariably mice exhibil a combination of responses which may be termed an "intraperitoneal Injection syndrome," which nhould be distinguished from the toxic symptoms resulting from the injection 01 venom. The injection syndrome maj be observed when 1 ml. of distilled water or 0.9 percenl saline is used, immediately following the injection respiration rate and, usually, depth are increased, and the animal re mains normally crouched for a fevi moments. This is followed by alter nate stretching of the hind legs and restlessness. In Bome mice there is an opisthotonoid arching of 1 h«' back Lasting less thi le minute and which may bo concomitanl with any other responses. Toxic symptoms appear to consist initially of markedly increa abdominal breathing and motor hyperactivity which al firsl Beems an exaggeration of purposeful movements, bu1 later reflects an apparenl inhibit ion of self-control. Motor ataxia follows and the i ise may exhibil running motions for a few moments while lying incapacitated on its side. Dyspnea becomes marked and paradoxical breathing is often seen with ultimately complete paralysis of the intercostal muscles. The tail ami ears exhibit varying degrees of cyanosis. Violenl convulsions ^> — o 5 O + + ++ + + o m 'p.— - 3 fl g -5-0 < a + + + + + + + s£! ++ ++ ++ o 1—1 + + + + >> Q IN + + + + + -H ffl + + + - >. ^ 1 + + + + + + + + + + + + ++++++++++++++++ ++++++++++++++++ + + + + + ■*«MraTfrfnn-*i-ific<)ii <-> c-i a X H r 1. ■- 2 ■ - 2 o — - _ ea 3 © to . c — — - ^ S.2 • ft* S-i X -^ c — - _ X o c 3 o 3 C5 3 o a 53 o ■■ 1 — ' 'a? o c a .3 ;°S2 GO VENOM <>| ROl SD 11 S'GRA\ -1 3 C to M a '>. 3* a * » I ~~- B o. o 1. ¥ \ avulsion. Violent agonal convulsion. Preagona srion in hinJ- ith. 1 1 1 II 1 1 1 2 I re =£ £ H> C O — 3 c *-■ w tx c Si O -C 3 0) :3 I|l 2 = 3 o a, c £» © ■- I- a s « s c i c s~- » S 3 _ s ■= B8 » 8 - c: s = — - = - i g J S3 o c = -= c », M ' S ' S|S2c u S *> §.*" _ -. z _ •^ -: 82 CALIFOKNIA FISH AND GAME REFERENCES Fowler, H. W. 1948. Os peixes de aqua doce do Brasil, Arq. Zool. Sao Paulo, vol. 6, p. 1-204, 237 figs. Garman, S. 1913. The plagiostomia (sharks, skates and rays), Mus. Comp. Zool., Mem., vol. 36, p. 1-515, 77 pis. Halstead, B. W., and F. R. Modglin 1950. A preliminary report on the venom apparatus of the bat-ray, Holorhinus calif ornicus. Copeia, no. 3, p. 165-175. Vellard, J. 1931. Yenin des raies {Taeniura) du Rio Araguaya (Bresil) . Compt. Rend. Acad. Sci. Paris, no. 192, p. 1279-1281. 1932. Scientific Mission to Goyaz and Rio Araguaya. I. Venomous fish of the Rio Araguava. A. Venom of rays (Taeniura) . Sop. Zool. France, Mem., vol. 29, p. 513-539. PRODUCTION OF THE CANADA GOOSE OH HONEY LAKE REFUGE, LASSEN COUNTY, CALIFORNIA By ALBERT E. NAYLOR Bureau of Game Conservation California Department of Fiih and Game INTRODUCTION The (J real Basin Canada goose i Branta canadi nsis mojfitti as listed by Musgrove (1047) is known by caanj differenl names. Some of the * i • * ► r- • - common local names are honker, ( 'anada honker, wild goose, black i ked goose and brant (Kort.right, 1!)43). Of lie' many species of geese in California this is the only one thai remains in the spring t" nest, and then only in the northeastern part of the State. Bone} Lake Valley is one of the most productive areas for Canada geese in California. Other areas with high production are Tule Lake ami Lower Klamath National Wildlife Refuses and Goose Lake Another center utilized by the Canada goose is found along the Pit River in Modoc * lounty. There has been a lack of recent information on the waterfowl of tie' Great Basin area of California. Moffitt, I 193] I madeastudyon tie static of the Canada goose in California and Dow < I'M.; completed ;i two-year nesting study in the Honey Lake Valley. Pari of the area ased by Dow included the present study area; therefore, several comparisons will be made to his paper. The spring migrants arrive in Honey Lake Valley in late February and early March. During mild winters many of the geese remain in the valley as residents. They begin to establish territories and their nesting starts by the first week in March. I '.cut 1!»25 states that the older geese are mated for life and many of the younger birds, pairing For the first time, court and select mates while still on the wintering ground or just before spring migration. This possibly explains the absence of courtship of the breeding geese on the Honey bake Refuge during this study. LOCALE OF THE STUDY Northeastern California, the only pari of the state where the Canada goose nests in any number, has many reservoirs, swamps and marshes which provide ideal nesting conditions in the spring. Moffitt L933 states that Canada geese breed commonly throughout the elevated lake. of Lassen and Modoc Counties, in the vicinity of bake Almanor. Plumas County, and south to Lake Tahoe, El Dorado County. Lassen County lies south of Modoc County and is bounded on the east by Nevada (Figure 1). ' Submitted for publication June, 1952. Federal Aid in Wildlife Restoration A.ct, 1': California W30R. The writer wishes to thank the following California I '• partment of Fish and Game personnel for their cooperation, assistance and information: John R. LeDonne ; M. E. Foster, refuge manager ; A. W. Miller, project leader ; and « Una E. Corson, who prepared the map. Dr. Fred A. Glover, Humboldt State College sisted with the preparation of the manuscript. { s:1. i 84 CALIFORNIA FISH AND GAME FIGURE 1. Map of Southeastern Lassen County, California, showing location of study area Honey Lake Refuge is located about 23 miles east of the City of Susan- ville in the southeastern part of the county. The refuge lies on the floor of the valley and is on the north shore of Honey Lake. This lake usually becomes dry in the summer, but was full during the time of this study and contained water throughout 1951. The Honey Lake Valley is typical of the Upper Sonoran life zone and is of the Great Basin sagebrush type described by Jensen (1947). The altitude of the refuge is approximately 4,000 feet. The average annual rainfall is about eight inches, with the largest part of the rain PRODUCTION in i in CANADA 00061 falling between October and February. However, an abnormal rainfall occurred in November and December of 1950 to bring the water leveln higher than they had been for manj years, Thus, conditions were similar to those thai occurred when Dovt made his study. The water supply feeding the vallej comes from the ftusan River, Willow ('rock. Secret Creek, and many other Bmall Btreams. Common plants found in the area are alkali \\ I, si brush, willows, greasewood. and rabbil brush. Emergenl marsh vegetation includes bul rushes, rushes, sedges and some of the smartweeds. Aquatic vegetation includes sago pondweed, water milfoil and water buttercup. The most common grasses are salt grass, foxtail, rye grass and beard grass. The common mammals present on the study area are the Rocky Mountain mule deer, coyote, striped skunk. Oregon ground squirrel and t he black-tailed jackrabbit. In addition to the Canada goose, waterfowl commonly nesting on the refuge are the mallard, pintail, cinnamon teal, shoveller, gadwall, red head and ruddy duck. The more common wading birds are the western willet, avocet, black-necked stilt. Long-billed em-lew. killdeer, Wilson snipe and the Wilson phalarope. The main agriculture of the valley is the production of meadow grasses and alfalfa which are cut, stored and used for winter f Iin<_r of cattle. A small amount of cereal crops is also grown. The study area of Honey Lake Refuge consisted mainly of two large ranches : the Fleming Ranch of 2, TOO acres of farmed area, artificial ponds and undisturbed land, and the Dakin Ranch of 1.4'_'o acres of chiefly undisturbed land, a total of 3,525 acres. The total acreage of the refuge, however, is over 5,000 acres, hut approximately tin percent of the land is unsuitable as nesting cover and was not considered in the study. Of the 3,525 acres in the study area, approximately 2,000 acres were classified as nesting cover. The Dakin Ranch includes a large body of water called the Hartson Reservoir, and nearly all the nesting on the ranch is in the immediate vicinity of that reservoir. The complete area is managed for waterfowl and controlled public hunting of wa1 fowl and pheasants is allowed. METHODS For the purpose of this study the refuge was broken down into arbi- trary units; i.e., a fenced-in field or a piece of land surrounded by a slough would constitute a unit. These units were searched systematically by two men walking a short distance apart. The distance between the men was determined by the type of cover on the unit. As a nest was located it was given a number and the data were recorded on a nesting card with the same number. The nesting card was used to record all new information on return visits to the nests. A marker — a willow stake inserted in the ground near the nest, bearing the nest number — was used to facilitate the finding of the nest on return visits. The type of marker used in this study proved very satisfactory for use in relocation of nests and may be of help to others working on nest- ing studies. Voting willows of about one inch in diameter were the best, their length determined by the type of cover in which they were to be used (four or five feet was ideal for this study'*. The top of the stake 86 CALIFORNIA FISH AND GAME NEST NO. BARK CUT OFF FIGURE 2. Willow stake used as nest marker, front and side views I'kniHi Tlo.\ OP Till CANADA nooSK was ciii (in an angle and the nesl number written the length of the cul wit 1 1 a Presdon ball poinl pen I Figure 2 This ink is very pennanenl and survived three different rains and the complete nesting Beason with ou1 fading. Ahoni five inches below the top of the Btake the bark was scraped off, exposing aboul six inches of the white sapwood underneath. This fa cilitated Locating the slake a1 a disti Even after the white wood darkened or turned a lighl brown, the stake could be located easil) Some biologists are of the opinion thai stakes with tags Bashing in Un- wind tend to attract predators to the site. This type of marker blends well with the surrounding vegetation, bu1 because of the lighl colored portion is readily visible without the movemenl which would atti predators. The stakes were placed aboul 15 Peel from the nesl and in line with prominent local landmarks. NESTING DATES The spring of 1!).")] was mild and about two weeks earlier than usual. The first nest was found on March 18th, containing seven eggs, and hatched 18 days later. The nest, then, was actually started during the first week of March. Nests with e\ QOO -!• TABLE 1 General Cover Types -Used as Nesting Sites by Canada Geese < lover typo Numbei • •< Pen Island Bulrush over water [Scri/mx m-uhix) 1 >i( i-lihank 124 7fl 12 17 is la B 7 ■ > . » 1 1 a :; : -• 11 7 1 7 1 -' 1 '. 1 t 1 1 1 1 1 1 ii B Bulrush over land (Scirpus acutut I Levee Sagebrush (Artemisia tridentata) < )pen field .. Willow (Sub's sp.) . . . Dirt mound.- Black Greasewood (.Sarcobatus vermiculattu 1 Salt Grass (DistichUs sp.) Alkali Bulrush (Srir/ius puliiilnsiix) California Wild Rose (Rosa californica) Bur-reed (Sparniiniiuii citn/ttiriittiii) Fence row Muskrat house. -. ii \ Common Cattail (Typha latifolia) ii ., Totals 360 LOO 0 types. Open field cover type refers to undisturbed areas, such as iin- grazed pastures or uncultivated land. In one pond dirt mounds had been pushed up by bulldozer to accommodate loafing waterfowl. These mounds were not surrounded by water at the time of this study and are referred to as dirt mound cover type. Tlie remainder of the cover types listed should be self-explanatory. It is interesting to note that six nests were found [mill over old aests. Kossack (1950) found that many pairs used the previous year's uesl site or nested within 100 feet of an old nest site. There has been a noticeable change in agricultural practices since 1!»4<> when Dow made his study. Alfalfa and meadow grasses are not cut and piled in loose stacks scattered about the valley as they were formerly. Now with modern machinery the hay is cut, haled and hauled to the stackyards and cattle feeding areas. This explains the contrast with Dow's finding 16 nests atop such haystacks while there were no aests located in that cover type in this study. Also, hay crops are not utilized or cultivated on the refuge. EGG LAYING AND HATCHING During the course of the study 369 nests were Located and recorded. Seven nests had hatched when found and nesting cards of two nests were misplaced or lost, leaving a total of 360 nests with histories complete. With such a large number of nests, the interval of 18 days between visits was the shortest time in which the entire area could be searched. This proved to be sufficient time, however, to record any new data occur- ring on a nest. Since the object of this study was mainly to obtain data on produc- tion, no effort was made to determine egg-laying intervals, incubation time or other similar information. A total of 1,904 eggs was produced from the 360 nests. This figure constitutes the total number of eggs laid during the study. A nest was 90 CALIFORNIA FISH AND GAME considered as having a full clutch if there was some stage of incubation present in a deserted nest, or if the nest hatched successfully. Full clutch nests totaled 330 and produced 1,828 eggs. The average size of the clutch was 5.53 eggs. This average was slightly higher than Dow (1943) found in 1939 (5.09) and in 1940 (5.10) on the same general area. The average clutch also compared closely to Kossack (1950) in Illinois where he found the average clutch of 73 nests to be 5.4 in 1947. Williams and Marshall (1937) recorded an average clutch of 4.8 for 84 nests. The clutch size varied from 2 to 12 eggs. Nine nests had nine eggs each and two nests had 11 eggs each. The two with 11 eggs each hatched 10. One nest had 12 eggs and was incubated for 17 days before being broken up by a mammal. Three eggs were crushed and eaten and nine were scattered about the nest platform. On examination of the remaining eggs all seemed to be in the same stage of incubation. The writer believes that all these abnormally large clutches were the products of individual females and that no parasitism occurred. Of the 360 nests, a total of 246 was hatched, or 68.3 percent were successful. This was better success than Dow found in 1939 (52.5 per- cent) and 1940 (60 percent). The successful nests produced 1,360 eggs, and of these 1,127 hatched, for an 82.6 percent hatching success. This compared favorably with the data Williams and Marshall obtained at Bear River where they recorded 81 percent hatching success. Kossack recorded a much lower success in 1945 (41 percent) and 1946 (73 percent). Dow recorded a high success of 93 percent in 1940. These data seemed to indicate that the hatching success varied with the locality and other factors. UNSUCCESSFUL NESTS Unsuccessful nests were classified as being caused by either desertion or destruction. Desertion was approximately three times greater than destruction, with 28 nests or 7.8 percent destroyed as compared to 86 or 23.9 percent of the nests deserted (Table 2). Dow (1943) found 6.5 percent of the nests deserted in 1939 and 7.3 percent in 1940. The cause for such a large increase in desertion has not been definitely ascertained. One factor could be that the nesting population has increased as the development of the refuge increased, but the preferred nesting cover has not increased proportionately. Another possibility is that the gradual drying of Honey Lake during the last several years has forced the geese to nest away from the shore of the lake. This has made it necessary for the nesting pairs to nest in fairly close groups where the preferred cover occurs. The instinct to defend the territory is never forgotten and when nesting pairs are grouped together in a limited area many fights, quarrels and much loud calling occur among the pairs. This evidently results in many desertions. As an example, the writer cites one island approximately 75 yards long and 30 yards wide, equal to about 0.5 acre. This island had a total of 31 nests. The greatest distance between any two nests was 30 yards and the shortest distance between any two was six feet. Eleven hatched, four were destroyed and 16 were deserted due to crowded conditions or unknown causes. It was on this island that the males stayed close to the females on the nest. The pairs very seldom left the area and then only to feed. There was always a great deal of calling and noise in the vicinity. I'KOIHH'TION ill I III i \\ \|.\ OOO I '•1 TABLE 2 Fate of Unsuccessful Nests Cause Number • i,i Destruction Bird.. Flooded 10 '■ - 21 i 21 i ■_'i I Totals 100 'i Cause \ 1 1 1 1 1 1 ■ • i de erted Desertion Crowded conditions. 2 27 16 I Human activity ■ Ants Unknown i ; n Totals v. LOO 0 The pairs were nervous and fighting resulted upon intrusion in tin- small territories. The writer believes that the overcrowded conditions caused most of the desertions on this particular island. Those pairs thai did bring off young often left the nest with the hatching <>l the firsl two or three young and deserted the remaining eggs. Two nests were con- structed over anthills and were under incubation. Bowever, the arrival of warmer weather brought out the ants and the nests were quickly deserted. Due to the difficulty in determining the predator of a destroyed nest, the broad classification of bird or mammal was used. Mammalian preda- tors known to destroy nests on the area were the coyote and striped skunk. The black-billed magpie, crow, and ring-billed and California gulls were the birds taking their toll of eggs. Destruction by mammals may have been held to a minimum by an intensive trapping program by a state trapper prior to the nesting season. It is the opinion of some field men that if mammals are trapped heavily, predation by birds increases and vice versa. If this is true, it mav explain the high amount of predation bv birds in this study ( Table 2). EGG FERTILITY A sample of 59 hatched nests was taken to determine fertility. The eggs remaining in the nest w'ere classed as infertile if the yolks were still suspended and the nest had hatched. These nests produced 350 eggs of which 110 eggs wrere left in the nest after hatching. Of these 1 in eggs, 7 or 2.0 percent of total eggs in the sample were infertile. MISCELLANEOUS INFORMATION In the course of this study various abnormalities were recorded. Two nests were recorded as having a small egg or so-called pullet egg in the 92 CALIFORNIA FISH AND GAME clutch. In one nest the eggs hatched but the pullet egg remained with the yolk suspended and proved to be infertile. The other nest was destroyed. Thus the chance to determine the possibility of fertility in the small eggs and to observe the product of such an egg was lost. A single mallard egg was found in two of the nests. Both nests hatched, leaving the cluck eggs in the nest. In both instances no development occurred in the duck eggs. Since the deposition of the eggs in the goose nests occurred early in the season, the nests apparently served as dump nests for the dropped duck eggs. A dead muskrat was found in a goose nest which had four eggs under incubation. The cause of the muskrat 's death was not determined but the writer feels that this intrusion caused the hen to desert her nest. The habits of the nonbreeding geese are not well understood. The general consensus is that the nonbreeders remain in small groups on the nesting ground throughout the breeding season without pairing. Observation of the small groups of nonbreeders during this study, how- ever, leads the writer to believe that some of the nonbreeders pair in their second year of life but do not breed until the third year. The middle of the nesting season found the small groups loafing and feeding in the same general area every day. They showed no nesting behavior at all, but when flushed they repeatedly broke into pairs to fly away or remained in pairs away from the other groups of geese. This phenomenon occurred throughout the study and the number of geese involved was too large to assume they were all pairs from broken nests. MANAGEMENT Possible avenues of management practices which might increase the number of Canada geese produced at Honey Lake Refuge are discussed below. This study seems to indicate that there is a definite need for island type nesting cover — a raised mound surrounded by water and containing some type of vegetation suitable for nest construction and cover. Table 3 shows the nesting success for the preferred cover types. Since all islands had large numbers of geese nesting, the rate of desertion was high even excluding the one island with an unusual high concentra- tion of nests, and hatching success fell below that noted for bulrush over water and ditchbank cover types. Evidently the high rate of de- sertion was caused by overcrowding on the existing islands that had suitable nesting cover. The construction of islands would relieve the crowded nesting conditions by spreading the existing nesting population over a larger area, and more geese would be produced by a greater number of nests hatching successfully. The manner of construction, the type and number of islands built should be left to the discrimination of the refuge manager. Prenesting season predator control may be a useful management practice. Prior to the nesting season of 1951 a state trapper was head- quartered on the refuge. He concentrated mainly on trapping nest predators and it is believed that his efforts contributed to the low num- ber of nests destroyed by mammals. A study of waterfowl nesting in the Sacramento Valley also found that decreased nest success resulted from decreased local predator control (C. S. Williams and others, 1950). I'laiUM Tln\ ni Till I VNADA I TABLE 3 Nesting Success of the Three Main Cover Types I lands* 1 lit. LI. ink No. "i ae i Pi i cent \ . . ■ . Batched 1 (eserted 1 leetroyed 59 24 10 26 Hi 87 i 1 6 76 17 • 7 7 17 17 Totals 93 Hill 100 11' too ■ Exclusive ni' island wiili abnormally liiuh desertion rate Bee text, The opening of dense vegetative growth on the levees of some of the artificial ponds would provide oesting pairs with greater visibility. Tin- visibility factor seems to have a definite influence on the choice of a nest site. During the fall of L950 the writer posted the refuge for the pheasant and duck hunting seasons. The closed area boundary followed along a levee which had a \r\-y heavy vegetative growth of alkali weed. A pickup truck was used to do the posting and as a result some of the levee vegetation was smashed down by the truck. The following Bpring the geese utilized the section of the levee the truck 1 1 ail ieen through, but levees adjacent with identical growth still standing were QOl used at all as nesting cover. SUMMARY The nesting season of 1951 was about two weeks earlier than in 1950. Most nests were under incubation by April 7th. The peak of egg Laying came between March 25th and April 10th. The peak of the batch came between April 15th and April 30th. Seventeen different cover types were used for oesting. Hardstem bul- rush, islands and ditchbanks comprised 75 percent of the total next sites. The high water level made available much more oesting cover than usual. A total of 360 nests produced 1,904 eggs. The average clutch size was 5.53 eggs. Of the 360 nests, 68.3 percent were successful. The hatching success of the eggs was 82.6 percent. Desertion accounted for 23.9 percent of the nnsiu ssful nests and destroyed nests accounted for 7.8 percent. A sample of 59 nests showed 2 percent of the eggs were infertile. It is believed possible to increase the number of geese produced annually on Honey Lake Refuge by preseason predator control, con- struction of islands and control of vegetation. REFERENCES Bent, Arthur Cleveland 1925. Life histories of North American wild fowl. U. S. Nat. Mus.. Bull. 130, 311 p. Dow, Jay S. 1943. A study of nesting Canada geese in Honey Lake Valley, California. Calif. Fish and Game, vol. 29, no. 1, p. 3-18. 94 CALIFORNIA PISH AND GAME Jensen, Herbert A. 1947. A system for classifying vegetation in California. Calif. Fish and Game, vol. 33, no. 4, p. 199-266. Kortright, Francis H. 1943. The ducks, geese and swans of North America. Amer. Wildl. Inst., Wash- ington, D. C, 476 p. Kossack, Charles W. 1950. Breeding habits of Canada geese under refuge conditions. Amer. Midi. Nat., vol. 43, no. 3, p. 627-649. Moffitt, James 1931. The status of the Canada goose in California. Calif. Fish and Game, vol. 17, no. 1, p. 20-26. Musgrove, Jack W. and Mary R. Musgrove 1947. Waterfowl in Iowa. Des Moines, State of Iowa, 124 p. Williams, Cecil S. and William H. Marshall 1937. Goose nesting studies on Bear River Migratory Waterfowl Refuge. Journ. Wildl. Mangt., vol. 1, no. 3-4, p. 77-86. Williams, C. S. and others 1950. Waterfowl populations and breeding conditions — summer 1950, with notes on woodcock and Wilson snipe. U. S. Fish and Wildl. Serv., and Canadian Dept. Res. and Devlpmt., Canadian Wildl. Serv., Spec. Sci. Rept. : Wildl. no. 8, 256 p. NUMBERS AND WINTER DISTRIBUTION OF PACIFIC BLACK BRANT IN NORTH AMERICA By A. STARKER LEOPOLD and ROBERT H. SMITH Museum of Vertebrate Zoology, Univer'.ity of California, Borkoloy, and U. S. Fish and Wildlife Service, Medford. Oregon The Pacific black branl (Branta nigricans) br Is on the Bering and Arctic coasts of North America and In northeastern Siberia. One segment of the population, presumably composed largely or entirely of birds br I ing in Alaska (Spencer et al., 1951 l and northwestern Canada, (nigral in winter to Pacific shores of this continent, from southern Alaska to Baja California. The winter distribution of black branl in North America was made the subject of exhaustive study by the Late James Moffitt, whose animal brant census reports for the years 1931 to 1 943 accurately desig- nate all the major wintering areas in the continenl and many of the minor ones. However, Momtt's census data, which were taken regularly only in California, include incomplete and at besl sporadic notes on branl numbers wintering to the north and south. At no I hne was an integrated survey made of the whole winter range which would yield a reliable figure for the population in North America. In the course of the 1952 winter inventory of North American water fowl, conducted under the auspices oi the U. S. Fish and Wildlife Service with the cooperation of state and pro- vincial wildlife agencies, a reasonably complete count of Pacific black brant was obtained. It is our purpose here to record this in format ion. Small numbers of brant winter on the Pacific coast of Asia presum- ably the same birds that breed in northeastern Siberia, though this assumption has not been verified. Dresser (1903) characterizes the Asiatic winter range as ''from Kamchatka ... to .Japan." Austin (1949) cites 12 specimen records from Japan and states that the species "was formerly a common winter visitor to Japan but is now exceedingly scarce. " The same author (1948) designates the brant as "an uncommon winter visitor" in Korea. La Touche (1931-34) writes as follows of the brant on the coast of China : "A single bird wassenl to me from FoochoM which had been shot on the 4th of February. The Pacific Brenl Goose, which winters in Japan and down to California, therefore extends its winter range to the China coast as far south as Pohkien. It must, how- ever, be extremely rare in the Formosa Channel, as neither Ricketl nor 1 ever heard of the bird's occurrence during the time that we were stationed at Foochow." Likewise Thayer and Bangs 191 1 state that the black brant is an uncommon breeder on the Siberian Arctic coast. Our immediate concern is with the brant population that winters in North America, but the above records are cited to indicate the apparent scarcity of the bird in Asia and the fact that we probably have in North America the vast majority of the population of B. nigricans. 1 Submitted for publication July, 1952. ( 95 ) 96 CALIFORNIA FISH AND GAME SOURCES OF DATA During the period January 6 to 13, 1952, the authors in company with Wynn G. Freeman of Montana Fish and Game Commission, made a detailed aerial count of brant along virtually the whole coast from Humboldt Bay in Northern California to San Ignacio Bay in southern Baja California. The coast from San Ignacio Bay south to Magdalena Bay was not covered in 1952 but had been flown by Smith in 1950, so the brant figure for that year was used to complete the count for the southern wintering range. Two areas in California, where small numbers of brant are known to winter, were not eensused in 1952, namely, San. Diego and Mission Bays in the south and the north coast from Humboldt Bay to the Oregon line. Doubtless a few birds were missed in these areas. Xo allowance was made for the omission. In the area which we did census, approximately 88 percent of the continental population of black brant was found to winter. Our counts were all visual estimates, taken from an airplane flying at elevations of 150 to 200 feet, Brant lend themselves exceptionally well to aerial census for the following reasons : ( 1 ) Flocks usually are small (50 to 500 birds) and tend to be well deployed along the shores of suitable bays and estuaries. (2) When disturbed the birds normally fly toward open water and can be counted more or less accurately as they pass in front of the airplane. (3) They do not return immediately to the shallow feeding areas, where they could be confused with birds not yet counted, but instead usually settle in open water. Thus, in census- ing the brant on a big bay like Scammon Lagoon one simply flies the full shoreline in all its indentations and counts the birds as they pass at right angles in front of the airplane. At the end of the census virtually all the brant are gathered in the middle of the bay. It is probable, of course, that some flocks are missed and it is equally probable that others quarter into unworked ground where they are counted a second time. But these two errors would tend to be compensating, and it is our per- sonal feeling that the counts are much more accurate than most visual estimates of waterfowl numbers. Simultaneously with our survey of the California and Mexican coasts, counts of waterfowl including brant were being taken in Oregon, Wash- ington. British Columbia and Alaska. Summaries of these data were supplied by Joseph P. Linduska of the U. S. Fish and Wildlife Service and by David A. Munro of the Canadian AYildlife Service. We are grate- ful to these colleagues - and to the many state and provincial wildlife officers who actuallv made the counts in the field, for allowing us thus to complete our report on total black brant numbers in the continent. Some of the supplementary counts from northern areas were taken from the air but others were ground or boat counts of unknown accuracy. Certain localities in British Columbia, where a few brant have been known to winter hi the past, could not be visited at all. However, the number of birds wintering along northern shores is so small compared to the population found farther south that no appreciable error could be involved in the total figures as given below. - The senior author likewise is indebted to the Duck Hunters Association of California for sponsoring his participation in the 1952 survey. DISTRIBUTION OP PAl II n HLAI K HH \ ''7 FIGURE 1. Winter distribution of Pacific black brant in North America, as determined in January, 1952. 4—68841 98 CALIFORNIA FISH AND GAME BRANT NUMBERS IN 1952 Table 1 summarizes by locality, and by state or province, the 1952 winter inventory figures for black brant in North America. Figure 1 presents the same data on a map which encompasses all but a few minor wintering areas in the extreme north. The total population was deter- mined to be 174,740, of which 109,545 (63 percent of the birds) were found in Baja California, 43,840 (25 percent) were in California, 16,575 (9 percent) were in "Washington, and the remaining 4,780 birds (3 per- cent) were scattered along the coasts of Oregon, British Columbia and southern Alaska. The importance of Baja California as a brant wintering area was recognized by Nelson (1921), who stated that some of the bays on the Pacific side of the peninsula were the ' ' main winter home ' ' of the species. TABLE 1 Numbers and Locations of Black Brant Inventoried in January, 1952, by the U. S. Fish and Wildlife Service and Cooperating State and Provincial Wildlife Agencies Area Local numbers of brant State or provincial totals Southeastern Alaska British Columbia Masset, Queen Charlotte Islands Boundary Bay * Washington f Birch and Boundary Bays I Samish and Padillo Bays Puget i Washington Harbor and Dungeness Spit Sound I Hood Canal [Nisqually Flats Grays Harbor Willapa Bay Oregon Tillamook and Netarts Bays California Humboldt Bay f Bodega Bay Marin County J Drakes Bay Bays Tomales Bay ' Bolinas Bay Morro Bay Baja California Ensenada Bay San Quintin Bay and nearby coast Rosario Bay Scammon Lagoon San Ignacio Bay Magdalena Bay and nearby coast (1950 figure) Total black brant wintering in western North America 80 1,000 500 550 10,000 2,000 1,650 500 640 1,235 3,200 25,000 235 2,170 7,900 535 8,000 465 13,650 580 46,500 41,750 6,600 80 1,500 16,575 3,200 43,840 109,545 174,740 DISTRIBUTION OF PACIFIC BLA< B BRANT The figures in Table 1 verify this observation, Scammon Lagoon and nearby San [gnacio Bay actually containing between them 88,250 birds or slightly over half the continental population. Both of these bays in- clude greal areas of shallow water, covered w it li extensive beds of vegeta t ion which from the air appears to be eelgrass Zo ti ra mm ina , the main winter Pood of sr;i brants (Cottam et al . I'M I Smaller bays of like character ;ii San Quintin to the north and near Cape San Lazaro north ol* Magdalena Bay) to the south were upied by another 20,000 brant, with a few hundred additional birds scattered along the peninsula in coves or Lagoons. Fortunately none of the importanl branl bays in Baja California are being developed or altered in any way. in fad only a handful of fisherman live on these shores. We foresee every prospect, therefore, of perpetuation of the branl wintering grounds in Baja Cali- fornia, assuming of course thai there is no outbreak of disease Laby until iihi ) in the eelgrass beds such as occurred on the coast of California in 1940-41 (Moffitt, 1941 and 1943). The important brant wintering grounds in California are Humboldt Bay, the several bays in Marin County (especially Drakes and Tomales and Morro Kay. Formerly San Diego and adjoining .Mission Bays in the south were fairly important, but pollution, dredging and other develop- ments, plus continual disturbance by boats ami airplanes, have rendered this area of less use to brant. Some other California bays have been affected to a minor extent by similar developments I especially I [umboldt Bay) but not to the point where the brant are driven away. The only other area of any importance to wintering brant is Puget Sound, which furnishes favorable winter range for about 15,000 birds. When the brant begin their slow northward drift in early spring they frequent many other localities along the Pacific Coast not mentioned in the above paragraphs. However the January distribution as we have described it probably accounts for all but a few scattered (locks. DISCUSSION A species represented by a continental population of only 174.740, or perhaps slightly more individuals, certainly cannot be construed as abundant, Yet because of their oceanic habits and inaccessibility to hunters, black brant do not suffer an excessively heavy kill. Such at least was the opinion of Moffitt (1040'), and we have no evidence to the con- trary. Since Moffitt's time, shooting restrictions have been somewhat altered in favor of the brant hunter (later seasons, earlier shooting hours, increase in the daily bag from two to three birds in 1951 and the kill doubtless has increased. The computed kill in California for the years 1948 through 1051, for example, was in the neighborhood of l(i. 000 birds per year according to information obtained from a question- naire of hunters (data supplied by J. E. Chattin, California Dept. of Fish and Game). A similarly computed kill in British Columbia was 6,200 birds bagged in 1950-51 (letter from 1). A. Munro). Although these figures almost certainly are exaggerated, as is usually the case with hunter questionnaires, they indicate that the kill is by no means negligi- ble. However, there is no clear indication of any general decrease in brant numbers. The 1952 total for California (43,840 birds) is materially lower than Moffitt's 11-year average count of 57,365, but this may be 100 CALIFORNIA FISH AND GAME happenstance since the year-to-year winter brant figures for any given locality were found by Moffitt to vary enormously with irregularities in weather and migration. In the past winter (1951-52) there has been a sudden increase of brant damage to crops in California. According to Clinton Lostetter, U. S. Fish and Wildlife Service, Berkeley, pastures and winter grain- fields near Humboldt and Tomales Bays were invaded by large flocks of the birds, and near Morro Bay the brant caused local damage to truck crops (especially peas) as well as to pasture and grains. This curious inva- sion of crop lands by brant is precisely parallel to what occurred in 1940- 41 when the eelgrass beds were attacked by the disease organism Labyrin- thnla (Moffitt, 1941). To our knowledge no one is currently checking on the status of Pacific Coast beds of eelgrass, but this certainly should be done as background for future brant hunting regulations. Crop damage by black brant may signify a loss of carrying capacity in the natural feeding areas rather than any increase in brant numbers. SUMMARY The 1952 winter inventory of North American waterfowl yielded a reasonably complete census of Pacific black brant. The total observed population of 174,740 birds was distributed as follows : 63 percent in Baja California, mostly in Scammon Lagoon and San Ignacio Bay; 25 percent in California, mostly in Humboldt Bay, Marin County bays and Morro Bay ; 9 percent in Washington, nearly all in Puget Sound. The remaining 3 percent were scattered along the coasts of Oregon, British Columbia and southeastern Alaska. All of the principal wintering areas in Baja California and most of those along United States and Canadian coasts are remaining essentially habitable to brant, with little apparent alteration or serious destruction of necessary habitat. However, a sharp increase in crop damage by brant may signify a decrease in normal supplies of eelgrass, which situation should be studied as a guide to future brant hunting regulations. There is a suggestion of increasing hunting pressure on the species but no evidence as yet of overshooting. REFERENCES Austin, O. L., Jr. 1948. The birds of Korea. Mus. Comp. Zool. Bull., vol. 101, no. 1, 301 p. 1949. Waterfowl of Japan. Supreme Commander Allied Powers, Nat. Res. Sect. Rept. 118, 106 p., Tokyo. Cottam, C, J. J. Lynch, and A. L. Nelson 1944. Food habits and management of American sea brant. Jour. Wildl. Mangt., vol. 8, no. 1, p. 36-56. Dresser, H. E. 1903. A manual of Palaearctic birds. Publ. by the author, London. Part 2, p. 499- 922. La Touche, J. D. D. 1931-34. A handbook of the birds of Eastern China. Taylor and Francis, LondoD vol. 2, 566 p. DISTRIBUTION OF PA( II [I i:l.\< I. 1:1: \\T n i, -i. < ', : 1 1 1 1 1 ■ Same \a mi' Sa me i;i me la me i.i mi' lame Sa me Same i:i me ulif. 1 1, . n. 1 ( . vol 18, ii. 1. | M.I 19, ii> 1 | M.I -< K >i. 1 . M.I 21, ii. 1 M.I ■ »•» ii. . M.I ' '"'. in Mil 24, ii. Mil 25, Q< vol 26, Ii. vol •_'T. in . M.I 29, II' < Same, vol. Moffitt, J. 1931. First annual blach sea branl census in Cnlifoi 17. ii... I. p. 396-401. 1932. Second Calif. Fish and 1933. Third Calif. Fi h and 1934. Fourth Calif. Fish and 1935. Fifth Calif Fish and 1936. Sixth Calif. Fish and L937. Seventh Calif. Fish and 1938. Eighth Calif. Fish and 1939. Ninth Calif Fi h and 1940. Tenth Calif. Fish and 1941. Eleventh Calif. Fish and I'M:?. Twelfth Calif. Fish and Nelson, E. \Y. 1921. Lower California and its natural resources Vn Acad Sci Mem vol 16, 194 p. Spencer, 1>. L., U. C. Nelson, and W. A. Elkins 1951. America's greatest goose-brant nesting area. Trans. 16th North Amer. rVildl. Conf., p. 290-295. Thayer, J. E., and < >. Bangs 1914. Notes mi the birds and mammals of the Arctic coast of east Siberia. New Eng. Zool. Club, Proc, vol. 5, p. t-66. 310 263 ::<;i . 295 :;n. i , 290 . .'.11 :;h; 342 • 381 :>'.' . 216 233 1'. i _•- STATE-WIDE CALIFORNIA ANGLING ESTIMATES FOR 1951' By A. J. CALHOUN ' Bureau of Fish Conservation California Department of Fish and Game It is the practice in California to make periodic Btate-wide angling surveys, using postal card questionnaires. They provide estimates of sport fish catches and angling pressure, principally for fresh water and anadromous species. Questionnaires are sent to 8 random sample of all licensees. Methods have been described earlier 1 1 lalhoun, 1950 Table 1 summarizes the characteristics of the 1951 survey. It resembled the 1949 one (Calhoun, 1951 I in most respects. The principal difference was an unusually Large response in 1951: •'{•">.!» percent instead of the usual 30 percent. This may well reflect an improvement in the depart- ment's public relations. The results of the 1951 survey are summarized in Table 2, and dis- cussed briefly below by kinds of fish and by departmental administrative regions. It must be emphasized that these figures are only rough estimates. Their reliability is discussed at some Length in the earlier reporl already mentioned (Calhoun, 1950). 1951 CATCH RECORDS BY KIND OF FISH Trout Anglers caught an estimated 18,600,000 trout in California in 1951. This figure has remained relatively static since l!i-Mi. The number of anglers catching trout in 1951 was 429.000. Their mean annual catch 1 Submitted for publication August, 1952. 2 The assistance of Terrence Merkel and William Rowley with calculations Is gratefully acknowledged. TABLE I Characteristics of the 1951 Sample 1951 angling license sales 1,015,246 Questionnaires mailed2 7,01*8 Sampling level desired 0 . 8 Sampling level attained 0 . 7'.'' , Questionnaires returned 2,870 35 9 Conversion factor (1,015,246 -=-2,870) __ 353 7 Respondents who caught something 2,209 (80. 1' Respondents who fished unsuccessfully iiiU (12.7 Unsuccessful, may or may not have fished 97 (3.4 Did not fish 110 (3.8 Average fishing days per licensee 15 1 Not the final figure, hut believed correct within about tun. - The tenth license stuh in each fifth honk of 25 was selected. (103) 104 CALIFORNIA FISH AND GAME ca ro E c= -a >2 0 i^ o o tH -* 00 ro 10 0 0 i — i O "* 0 0 o i— i OS cn •* r-i 05 0 ■* e i-H ro" i-H i-H 10 cn" _0 ■* t^ Is 10 s. < ro 00 ro o o oo CNN'S ro 0 0 CN o r- 0 0 . CN o q NCCO 0 i> o oi" lO tt" 00" t>. CO 10 2 IO c3 CQ Ttl ■* O O t^ 10 00 10 CN O 0 oo O O i-l T-H O 0 ■* O iH l> LO CN O q ~ h'n CN US O" lo" cG t^ i-H t~ -^> i-H lr~ T« c3 O ■* OS 00 o o o Hcsa 0 O 0 oo O OJ rH CN O 0 IN o to I~ ^H O O o_ 02 of "O th O O" t~" t£ o O O i-H 00 O ~ Tj<" CO O O © t^ co 00 oq CN O O i-H O OS i-H O O 2 a CN O C3S -H CN Tt< O O COt)T ro 0 O" a I> 00 10 CO ro o3 CN 6 • CO W O O -h aeon CO 0 0 CO o OTfH 0 0 CO ro O 00 rt O >H 0 o_ c3 oo" in •-H CN 0" CN o 00 ■* ■^ i-H CN i-H o <3 3 O CO CO-* T« CN 00 IO O O co CO c3 o O O -h O O Tfl o co OOO O q .fl ■* to" i-H i-H O Tf" X) CD "# OS CO i-H •* i-H a i-H -*3 m CD "tf O O tN ro t> 00 O O 0 OOf CN O 0 CN 0_ CO n* h O 0 -^ . i-T OS Os" ■* CO O" lo" CN O OS o ■* CO X H 00 i-H ' ! c 08 ! CO i ' 0) 1 1 c» 1 1 CO 1 1 a 1 , CD 1 CD 1 , C3 1 , CD ' a S 1 0 _ — ■ - 0 43 0 -*n to ' •** 0 "S 4j n ^ o3 •Z t- — • CD o3 u O CD 0 ^ C3 "5 O 0 a CD "S £ "a 0 £ £ "3 e iH fc- 0 »^H -T3 CD = -s -a 7 a O -e =3 T- O C c 03 -a FH U ^ CJ h h u 03 ~ a c rH 03 c3 03 C C C C3 cS o3 03 oj "3 *£ "9 a> m h p *> s Si c 0 T3 a 03 tip » 03 +H *H ■3 -»H CO 2 00 Ph CD GO 02 CD W o 02 3 § CALIFORNIA ANGLING I - I I \i \ I I i OR 1951 10") w;is I.'! fish. The median catch, more descriptive of h •_'() fish. These estimates are much like those for 1948 and 1949 a will be seen from Table 3. Addition of anglers who fished for troul but caughl none would have reduced the medii atch from 20 to aboul 12, judgii from the 1948 persona] interview survej TABLE 3 Trends in California Trout Anghnj Total catch .-11,,, Ftil , ! Vnn Y"ear \ mill n- 1 Pel • ' m llll- li, , 1 Mi 1936 11137 1938 1939„ 12,000,000 1 1,1100,000 12,900,000 12,800,000 15,700,000 16,400,000 15,700, 17,(1(10,000 18.400, 16,700,000 IS, (100,00(1 I 10,000 151 ,000 160,000 179,000 238,000 234 000 213,000 357,000 115,000 431,000 421i,(i(H) .11 Is 16 19 :,i IS 17 i 1 l:: 12 SO 79 71 70 75 II (7 1941.. lo 1942.. 1943 nun 1948. . 1949 1951 20 20 Striped Bass The 1951 striped bass figure was 1,490,000 fish. This estimate has remained quite stable since 1!»42, as will be sen from Table 1. The 144,000 anglers catching stripers in 1 !).">] represent a slight decline from 1949. The average annual catch of 10 fish and the median catch of five fish are typical of the post-war period. TABLE 4 Trends in California Striped Bass Angling Successful anglers Annual catch per .1 angler Total catch Year Percent of Numbei angling I icensees Mian Median 1936.... 2,1 10.000 84.100 28 25 1937 2,040,000 81,1)00 2(1 25 1938 1, It 10, 000 112,, son 27 21 1939 1,880.000 89,300 2 1 21 12 1941 1,940,000 106,000 23 is 10 1942 1. (ISO, 000 88.200 20 19 1943 1 ,680.000 7. -i.OOO 17 ■ 1944 1,420,000 1946 1,380,000 1 13,000 15 12 1948 1,650,000 1(11.000 17 10 ■ 1949 1 ,750,000 165,000 17 11 ! 1951 1.41(0,000 144,000 14 10 5 106 CALIFORNIA FISH AND GAME Black Bass There lias recently been a slump in black bass fishing. The 1951 catch was only 1,280,000 ; compared with 1,890,000 in 1948. Past records are summarized in Table 5. Anglers catching black bass and average catches have also declined. The recent series of abnormally dry years has prob- ably been largely responsible. This drought seriously reduced many Southern California reservoirs, which produce a large part of the bass catch. TABLE 5 Trends in California Black Bass Angling Total catch Successful anglers Annual catch per successful angler Year Number Percent of angling licensees Mean Median 1936 1937 1938 1939 1941 1942 1943 1946 1948 1949 1951 930,000 849,000 1,190,000 1,340,000 1,530,000 1,340,000 1,570,000 1,700,000 1,890,000 1,160.000 1,280,000 34,000 33,000 46,000 67,000 75,000 66,000 79,000 104,000 128,000 116,000 108,000 11 11 13 18 17 15 18 14 13 12 11 27 26 26 20 20 20 20 16 15 10 12 6 5 6 Crappie Crappie fishing has also declined, as will be seen from Table 6. Only 7 percent of all respondents reported catches in 1951, compared with 11 to 17 percent in earlier surveys. The total catch of 2,380,000 was taken by 76,000 anglers who averaged 31 fish per year. The crappie catch is even more sharply localized in Southern Cali- fornia than black bass, and this decline is also largely attributable to the drought conditions already mentioned. TABLE 6 Trends in California Crappie Angling Total catch Successful anglers Annual catch per successful angler Year Number Percent of angling licensees Mean Median 1939 1,720,000 2,180,000 2,620,000 2,670,000 3 040,000 2,760,000 2,430,000 2,380,000 52,000 70,000 66,000 76,000 106,000 116,000 105,000 76,000 14 15 15 17 14 12 11 7 33 31 40 35 29 24 23 31 1941 1942 1943 1946 1948 12 1949 10 1951— 12 CALIFORNIA ANGLING I i i M \ I I i OH 1951 107 Sunfish There was little change in the sunfish picture in 1951, A total of 4,800,000 fish was eaughl by 102,000 anglers, who averaged IT sunfish per year. However, only 1" percenl of all licensees eaughl these fish. This is the lowest percentage on record, as shown in Table 7. TABLE 7 Trends in California Sunfish Anqhnq Total catch Sui lei Vnn i"T Year Number Percent ol angl licen I I 1 1 13 15 16 12 1 1 10 Mean ll ti 54 r, 35 ll 17 Mi 1 1939- 2. 09(1. 000 2,770,000 3,060,000 3,040,000 4,320,000 4,820.000 4,020,000 4,800,000 51,000 63, 57.000 68,000 122.000 i is. ooo I 14,000 102,000 1941 1942 1943 1946 1948 1949 20 1951 20 Catfish There was some improvement in the catfish situation in 1951. An esti- mated 171,000 anglers caught 4,71().ooo fish. Pas1 catfish records are summarized in Table 8. TABLE 8 Trends in California laffish Angling Total catch Successful anglers Vnnual BUI tatch per ler Year Number Percent of angling Licensees Mean Me lian 1936 2,940,000 2,810,000 3,480,000 4,330,000 6,100,000 8,250,000 7,060,000 6,530,000 5,560,000 3,930,000 4,710.000 38,000 43,000 48.000 75.000 97.00(1 110,000 101.000 1 19.000 182,000 161,000 171,000 13 1 I I I 20 21 25 23 19 19 16 17 78 65 72 58 75 70 11 31 2 1 28 1937 1938 1939. _ 1941 1942-_ 1943- 1946 . 1948 15 1949 12 1951 12 Salmon Interesting changes are occurring in the salmon sporl fishery. The 1951 catch of 564,000 fish is the largesl on record, as will be seen from Table 9. The 79,000 successful anglers is also a new record, and the average catch of seven fish per year is high for the postwar period. Both 108 CALIFORNIA FISH AND GAME river and ocean fishing for salmon were involved in these changes, judging from the regional analysis which follows. TABLE 9 Trends in California Salmon Angling Total catch Successful anglers Annual catch per successful angler Year Number Percent of angling licensees Mean Median 1936 1937 196,000 160,000 178,000 215,000 253,000 180,000 274,000 291,000 321,000 298,000 564,000 25,000 20,000 22,000 31,000 38,000 32,000 31,000 50,000 65,000 67,000 79,000 8 6 6 8 8 7 7 7 7 7 8 8 8 8 7 7 6 9 6 5 4 7 -- 1938 1939 1941 1942 1943 1946 ! 1948 1949 1951 2 2 3 Abalone Abalone were added to the postal card questionnaire for the first time in 1951. The department now has a special investigation of these mollusks under way. An estimated 41,000 individuals took 515,000 abalone for an average of 12 per year. Abalone records from a 1948 personal interview survey, hitherto unpublished, are included in Table 10 for comparison. There may have been a decline of some magnitude in this fishery since 1948. However, these estimates are based on relatively few reports, and with only two years of records available it will be well to reserve judgment. TABLE 10 Abalone Catch Records Total catch Successful anglers Annual catch per successful angler Year Number Percent of angling licensees Mean Median 19481 1951 1,400,000 515,000 65,000 41,000 7 4 22 12 9.5 1 Based on 85 reports. 1951 CATCH RECORDS BY ADMINISTRATIVE REGIONS Northern Region (1) This covers the extreme northern portion of California, as shown in Figure 1. It provided about half of the state salmon catch and about one-fifth of the trout in 1951. Many of the latter were large steelhead. CALIF0RN1 \ ANGLING E8TIMATI FOU 109 OREGON f ■ ■- J ■•..;. • / | S 1 Northern / ^ Region ■ -i ;■ 1 i ( I i 1 i t j t . i —..*._. »,IJW,T«. _,__ COUNTIES COMPRISING THE ADMINISTRATIVE REGIONS SHOWN IN FIGURE t Del Norte Humboldt Lassen Alpine Amador Butte Calaveras Colusa El Dorado Northern Region Countiei Modoc Tehama Shasta Trinity Siskiyou Sacramento Region Countiei Sierra SoUno Sutter Yolo Yuba Alameda Contra Costa Lake Marin Mendocino Glenn Nevada Placer Plumas Sacramento San Joaquin Bay Region Counties Monterey Napa San Benito San Francisco San Luis Obispo San Joaquin Region Counties San Mateo Santa Clara Santa Cru/ Sonoma Madera Mariposa Merced Stanislaus Tulare Tuolumne Southern Region Counties Mono Orange Riverside San Bernardino San Diego Santa Barbara Ventura FAEX»CO FIGURE 1. Department of Fish and Game administrative regions. 110 CALIFORNIA FISH AND GAME The average catch of 45 trout per year topped any other region. Other fisheries are of negligible importance, as will be seen from Table 11. An estimated 11,170 anglers (4.4 percent) lived here 3 in 1951. TABLE 11 1951 Angling in Region 1 Number of reports Regional catch Successful anglers for indicated fish Mean catch Total1 Percent of State catch Number in region Percent of State total successful angler in region Salmon 84 244 10 5 15 2 236,000 3,900,000 80,000 21.000 120,000 6,000 46.4 21.8 6.4 0.5 2.7 1.2 30,000 86,000 4,000 2,000 5,000 1,000 39.7 17.3 4.3 1.9 2.8 2.2 7.9 Trout . . Black bass 45.2 25.0 Sunfish _ __ _ Catfish Abalone ■ - 12.0 22.6 8.0 1 The combined regional totals are ordinarily less than the state total because a few reports fail to specify county of catch. Sacramento Region (2) This includes the Sacramento Valley and the northern Sierra Nevada. It provided half of the 1951 striped bass catch and a sixth of the trout. It was also an important warm-water area, contributing half the catfish catch, a fourth of the black bass, and about a fifth of the crappie and sunfish. (For further details see Table 12.) An estimated 129,730 anglers (12.8 percent) lived here in 1951. TABLE 12 1951 Angling in Region 2 Number of reports Regional catch Total Percent of State catch Successful anglers for indicated fish Numter in region Percent of State total Mean catch per successful angler in region Salmon Trout Black bass.. Crappie Sunfish..:.. Striped bass Catfish 17 251 81 38 73 200 190 18,000 3,135,000 300,000 435,000 842,000 700.000 2,178,000 3.5 17.5 23.8 18.7 17.9 47.3 50.7 6,000 89,000 29,090 13,000 26,000 73,000 67,000 7.9 17.1 31.8 16.6 25.0 49.6 38.5 3.0 35.3 11.0 32.3 32.6 9.9 32.4 Bay Region (3) This extends over the central coastal portion of the State from Mendo- cino County to San Luis Obispo County. Its sport fisheries are highly diversified, as will be apparent from Table 13. Significant catches in all eight categories were made in 1951, including half or more of the :t Based on the number of regional residents in the sample of 7,998 licensees to whom questionnaires were sent. There were 0.9 percent out-of-state anglers in our sample. CALIFORNIA ANGLING ESTIMATE KOR 1951 111 TABLE 13 1951 Angling in Region 3 N mill mi of re] ".i i Hi fni inclii M< ["otal Pi i . itch Nun in total in ri Salmon Trout Black bass 108 1 53 52 32 IS 194 113 7:. 254,000 1,767,00 1 170,000 177.(Hil( 541 i N II 1 770.1)11(1 709,000 270,000 8 9 7 6 1 1 5 0 16 5 • 000 ooo is IMM' 1 1.000 17.000 70,000 in in m • MM) ,1 7 10 H 19 7 1 1 1 17 8 11.'. 7 - Striped buss 1 1 2 17 7 Abalone - in 1 salmon, striped bass and abalone. The salmon catch comes principally from the Pacific Ocean off the Golden Gate. The troul catch include many large steelhead. Region '5 is also producing some warm-water fish. An estimated .'{01,610 anglers (2!*. 7 percenl I live in Region 3. San Joaquin Region (4) This region covers the San Joaquin Valley and the southern Sierra Nevada. It yielded a fifth of the state troul catch in 1951, and a lik • proportion of black bass, sunfish and crappie. These data are summarized in Table 14. Salmon have been much more important here in the past than they were in 1951. The agricultural development of this region, with ever- increasing water diversions for irrigation and growing water pollution from food processing plants is clearly having serious repercussions. An estimated 115,640 anglers (11.4 percenl I live in this region. TABLE 14 1951 Angling in Region 4 Number of reports Regional catch Sui for indii d anglers ated fish Mean catch Total Percenl of State catch Number in region Percent of State total angler m region Sahnon_ . 1 320 69 36 57 10 70 1,000 3,560,000 230.IHH' 1ST. (II III 1,000,000 12.000 734,000 0.1 19 9 18.3 8.0 21.4 0.8 17.1 pin 113.000 24.000 13,000 20,000 1 27.000 n .-, - 7 1 2 . .'. 19.2 2 7 1 5 - 5 3.0 Trout Black bass Crappie __ - 3 1 . 5 1 Sunfish l'| 7 Striped bass_ 3 . 5 Catfish 27 . 3 112 CALIFORNIA FISH AND GAME Southern Region (5) This includes Southern California and the Mono-Inyo area ; as shown in Figure 1. Trout are of primary importance, as will be seen from Table 15. Some 150,000 anglers fished for them in Region 5 during 1951 and caught an estimated 5,500,000. This was about one-third of the state total. TABLE 15 1951 Angling in Region 5 Trout_ __ Black bass Crappie Sunfish Catfish Abalone Regional catch Successful anglers for indicated fish Number of i reports Percent Number Percent Total of State in of State catch region total 435 5,508,000 30.8 154,000 31.0 46 480,000 38.1 16,000 17.5 11.5 1,516,000 65.6 41,000 52.5 110 2,280,000 48.7 39,000 37.5 98 558,000 13.0 35,000 20.1 46 240,000 46.5 16,000 36.3 Mean catch per successful angler in region 35.8 30.9 37.3 58.6 16.1 14.8 Southern California proper and Mono-Inyo are very distinct areas ; so the trout data for the two were separated as shown in Table 16. There were more anglers and the level of success was higher in Mono-Inyo. It is almost exclusively a trout area, so separations were not made for other fish. Warm-water fish are also very important in Southern California, which accounted for two-thirds of the 1951 crappie catch, half the sun- fish and more than a third of the black bass. Details will be found in Table 15. Under normal rainfall conditions this region ordinarily yields even higher proportions of warm-water fish. (Curtis, 1949). Almost half of the total abalone were taken in the Southern Region. Other marine sport fisheries not covered by the survey are also of great importance there. An estimated 415,350 anglers (40.9 percent) live in Region 5. TABLE 16 Trout Angling in Southern California and Mono-Inyo Number of reports Sub-regional catch Successful anglers Mean catch per successful angler Total Percent of State catch Number in sub-region Percent of State total Mono-Inyo - - 262 199 3,690,000 1,810,000 20.6 10.1 93,000 70,000 19.0 14.3 39.5 25.7 CALIFORNIA ANGLING I riMATl i OH 1951 1 1 :; SUMMARY A survey of 195] angling in California was made bj sending question naires to ;i sample of licensees. Trout angling has no1 changed appreciably since 1946 An estimated 429,000 successful troul anglers caughl 18,600,000 fish during 1951 Striped l>;iss angling has also remained quite stable in recenl ye An estimated 144,000 successful anglers caughl 1,490,000 striped l>as> in 1951. Warm-water fisheries have declined recently, probably because ol i prolonged drought in Southern California. It is estimated thai 108,000 successful anglers look 1,280,000 black bass; 76,000 anglers took 2,380 000 crappie ; and 102,000 anglers took 1,800,000 sunfish in 1951. Catfish angling took a slighl upward trend, with 171,000 successful anglers catching 4,710,000 catfish. The salmon spori fishery showed a large increase in 1951, with 79,000 anglers catching 564,000 salmon. These data are also analyzed by administrative regions. REFERENCES Calhoun, A. J. 1950. California angling catch records from postal card surveys: 1936-1948; with an evaluat ion of postal card nun response. ( 'a lit. Pish ami Game, rol. 36, no. .".. p. 177-2:!4. 1951. California state wide angling catch estimates for 1949. Ibid., vol. 37, DO. I. p. <)!>-7:>. Curtis, Brian 1949. The warm-water game fishes of California. I hid., vol. 35, no. 1. p. 255-273. CALIFORNIA MARINE AND FRESH WATER SPORT FISHING INTENSITY IN 1951 By FRANCES N. CLARK Bureau of Marine Fisheries, California Department of Fi»h and Game CONTENTS INTRODUCTION 11.1 METHOD 116 Questionnaire Form 116 Select ion of Sample 117 FISHING INTENSITY I Is Total Returns I Is Intensity l.y Are;i 1 19 Comparison with Other Measures 126 Comparison with Smaller Samples 121 Number of Fishermen per Area 1-1 SUMMARY — l-'t REFERENCES 125 INTRODUCTION Increased interest in marine sport fishing lias resulted in need tot- a better understanding of the biology of marine" game fishes and of methods for maintaining and if possible improving such fisheries. There have been many statements by marine sports fishermen ami marine sport- fishermen's organizations that they are not receiving their money's worth when they buy their angler's license because most of the license money is spent on fresh water investigations. Fresh water fishermen, on the other hand, naturally oppose any diversion of such monies from fresh water studies. In li)4cS two types of surveys were made in California to determine where and how the sportsman expends his fishing effort (Calhoun, 1950 One survey was based on a postal card questionnaire sent to a random sample of sport fishermen. Such questionnaires produce about 30 percent usable returns and this raises the point that respondents may have different fishing habits than do nonrespondents. To analyze this possi- bility, the Opinion Research Center of the University of Denver eon- ducted a personal interview survey. Comparison of these two survey results indicated that respondents and mm respondents had similar tish- ing habits and that a postal card survey will give a reliable measure of sport fishing intensity. The personal interview survey obtained some information about the proportion of the fisherman's time spent in salt water fishing and re- sulted in an estimate of 25 percent (Opinion Research Center, 1949 , 1 Submitted for publication August, 1952. (115) 116 CALIFORNIA FISH AND GAME Since this was the only figure available it was accepted as the unit for apportioning monies available to California from federal aid to fisheries funds raised from a tax on fishing tackle, usually referred to as Dingell- Johnson funds. Salt water anglers have felt that marine fishing intensity is greater than 25 percent and that the personal interview survey, based on 1,250 interviews, was not a large enough sample to give a reliable measure. Such anglers have urged that every fisherman, when buying a license, fill out a questionnaire which would tell where he fished in the previous year. Such questionnaires have been tried by the California Department of Fish and Game and found impractical because most fishermen buy their licenses through dealers who do not have the time to see that the questions are completely and thoughtfully answered. A postal card mailed to the fisherman can be filled out in his home where he has the time to consider each question and answer as accurately as his memory permits. To meet the demand for new and more complete information, the Bureau of Marine Fisheries devised a relatively simple postal card questionnaire and mailed it, during April and May, 1952, to approxi- mately 3 percent of all 1951 angling license buyers. By the end of June this survey resulted in 8633 usable returns and indicated that in 1951 California sports fishermen spent their total fishing days as follows : 32 percent on the ocean and coastal bays, excluding San Francisco Bay and the Sacramento-San Joaquin Delta, 12 percent on San Francisco Bay and Delta, and 56 percent on fresh waters. These results, however, do not necessarily invalidate former surveys. They may merely reflect a rapid upsurge in salt water fishing which has taken place in recent years. Part of this change in fishing interest may have resulted from the recent dry years which impaired fresh water fishing on Southern California inland lakes. Having learned the enjoyment and recreation inherent in salt water fishing, the anglers will, however, con- tinue this activity and pressure on marine waters will presumably con- tinue to increase. METHOD Questionnaire Form The postal card survey, here discussed, was designed to measure fishing intensity in four localities : fresh water, San Francisco Bay and Delta area, ocean and bays north of Santa Barbara, and ocean and bays south of Santa Barbara. Since San Francisco Bay and Delta constitutes a locality which gradually changes from salt to fresh water with no clear cut boundary and supports a type of fishery largely unique to that area, it was treated as a unit distinct from fresh or salt water. Ocean fishing off Northern California differs considerably from that off Southern California and Santa Barbara was chosen as the best well-known division point between these two regions. The postal card, carrying a stamped self addressed return card, ex- plained that the questionnaire was designed to determine where and how fishing effort was expended in 1951 (Figure 1). The return card risked that the recipient estimate, as accurately as possible, the number of days lie spent fishing in each of the areas. MARINE AND FRESH WATEB P0RTFI8HIN0 INTEN in 117 Will You Help Improve Fishing ill California? California faces the problem of deciding how much «>1 the money available for sport fish studies should be spent on fresh water projects .ind how much on salt water. A wise decision depends on knowing how much time anglers spend fishing in fresh and in s.ilt water. The California Department of Fish and dame is attempting to ^t-'t this information by asking a selected number of anglers where they fished in 1951. You arc one of them. You can help by filling in the squares on the return card as accurately as you can. Be sure to include in your total the number of days you dug for shellfish and also the number of clays on winch you fished but caught nothing. You do not need to sign the card for this is not a personal check-up, hut please return it and help us determine how the money you contribute should best be spent. California Department of Fish and Game 5637'J 1-52 30M © SPO Please help the California Department of Fish and Game in its efforts to improve fishing by filling out and mailing this card. How many days in 1951 did you fish or gather shellfish in California} Include the days on which you caught nothing. Number of dayi FRESH WATER SALT WATER San Francisco Bay and Delta Ocean and other bays North of Santa Barbara . South of Santa Barbara FIGURE 1. Postal card questionnaire used in the 1951 survey Selection of Sample Surveys made by the Bureau of Fish Conservation (Calhoun, 1950, 1951 ) have indicated thai a sample of 1,000-2,000 respondents will give reliable measures of fishing effort. Because the present survey was planned not only to measure fishing intensity on fresh and salt water but also to measure intensity in the three salt water areas, a sample Large enough to yield about 2.000 returns from marine fishermen was needed. The former surveys indicated that 25 percent of fishing effort would be expended in marine fishing and it was estimated that 8,000 returns would be required. Other surveys also demonstrated that about one third of the recipients of cards would respond. Based on these two figures a 118 CALIFORNIA FISH AND GAME sample of about 30,000 cards was planned. California license sales in 1951 totaled approximately 1,000,000 and to select a random sample of 30,000 it was necessary to send the questionnaire to three out of every 100 license buyers. In 1951 California had four types of sport fishing licenses : an annual $3 license sold to residents of California, a $3 license good for ten days sold to fishermen who were not California residents, a $10 annual license sold to fishermen who were not California residents, and a $25 annual license sold to fishermen who were not United States citizens. Children under 16 years do not need a license and, therefore, are not included in this survey. The $3 annual licenses are bound in books of 25. On the stub of each license, which remains in the book, is recorded the name and address of each license buyer. To obtain a random sample of three from each 100 of these licenses, four books were picked at random and the third stub from each of the first three books was selected as the recipient of the questionnaire. No selection was made from the fourth book. This process was continued until all $3 license books issued throughout the entire State had been used. License stubs for the remaining three types of licenses were grouped at random in lots of 100 and the thirty-third, sixty-sixth and ninety-ninth stub selected. For all licenses, if the tenth stub bore a nonlegible or incomplete address, the first following complete stub was substituted. This method of selecting recipients resulted in mailing out 29,464 postal cards. Mailing was begun in March, 1952, and completed by April 20. FISHING INTENSITY Total Returns By June 20, 1952, a total of 9,168 cards had been returned and the survey was terminated. This sum, 31 percent of the total mailed, com- prised 8,633 usable cards, or 29 percent, 181 from respondents who TABLE 1 Returns From Cards Used in the 1951 Survey Resident citizen $3 Type of license Tc >tal Nonresident Non- citizen annual $25 Number 10-day $3 Annual $10 Percent Mailed 29,098 264 70 32 29,464 Returned Unclaimec' . 266 5 79 176 8,523 2 268 5 81 181 8,633 0.91 0.02 0.27 0 61 Deceased -- _. Not usable 2 3 82 No fishing -- - 2 22 Usable 6 29.30 Total returned 9,049 31.10 89 33.71 24 34.29 6 18.75 9,168 31.12 Percent returned . \i \Kl\l<; A.\D FRESH WATKR SI'OKTKI IIIN(J INTKN in 1 !'• boughl licenses I > 1 1 1 did qoI fish, 8] from personH who replied l>nt did not give complete information, five returned bj relatives stating the recipient had died during the year, and 268 returned bj the p<>st office because the recipient had moved with n<> forwarding address <>r could not be Located a1 the address given (Table 1 ►. Intensity by Area Respondents who returned the 8,633 usable cards reported b total of 218,963 fishing days, or these, 56 percenl was spenl fishing in fresh water, \~ percenl in San Francisco Bay and Delta, 1" percenl in tie- ocean and bays north of Santa Barbara and 22 percenl in the ocean and bays south of Santa Barbara (Table 2).2 Thus 32 percenl of the 1951 fishing effort was on California's ocean ami coastal bays and -")ii percenl on her fresh waters. 'The L2 percenl of fishing time spenl on S;m Fran cisco Hay and Delta cannot be classified as either fresh or Ball water - The standard n-rors of these percentages were calculated from thi formula SE = V p x Q X n , where p is the ratio of Ashing days, q the ratio of no fl hlng das and n the total "i all fishing days. TABLE 2 Distribution of Fishing Intensity Based on 8,633 Usable Returns Fishing area Number reporting1 Fishing days lard error Tol ing daj - per n&hei i Number Percenl Fresh water 6,714 56 22 6 121,956 288 412 116 10-dav nonresident Annual nonresident Noncitizen Totals 6.798 1,875 7 2 1 122.772 26,537 11 2 6 56 . 07 0. 11 1 1.2-M.IKHI is <»; San Francisco Bay and Delta Resident citizen __ _ 10-dav nonresident - Annual nonresident - Noncitizen _ _ Totals _ 1,885 2,151 15 1 2 26,556 22,283 Id 1 54 12. 13 0.07 :ui77 <> 0 14.09 Ocean and Bays North of Santa Barbara Annual nonresident Noncitizen ._ Totals _ 2,169 2,996 18 2 22,378 47,118 46 93 10.22 0.06 2,592,000 10.32 Ocean and Bays South of Santa Barbara Noncitizen . Totals- 3,016 47.257 2 1 . 58 0.09 j 17 1,000 15.67 8,633 218,963 100.00 25,363.000' 25.363' 1 The sum of these numbers exceeds 8.633 because many fishermen reported fishing in more than one area. 2 218,963/8,633 = 25.363 X 1,000,000 licenses = 25,363,000. 120 CALIFORNIA FISH AND GAME and should be considered as a distinct and special type of fishing, catch- ing mainly anadromous fish, salmon and striped bass, but including some catfish, perch and smelt. Since the chief object of this survey was to determine proper alloca- tion of revenue, consideration should be given to the value of the license. To do this the number of fishing days per license type for each area was weighted by the value of the license and new percentages calculated. The results differed from the unweighted percentages by 0.1 percent or less and the unweighted values are used throughout this report. The number of $3 licenses far exceeds all other types and determines where and how fishing effort will be expended and what will be the total income from license sales. The average number of days per fisherman in fresh water was 18, in San Francisco Bay and Delta 14, in northern ocean and bays 10, in southern ocean and bays 16, and the average for all types 25. The average for all types exceeds any one area because many fishermen fished in more than one region. This average multiplied by 1,000,000 3 licenses gave over 25,000,000 fishing days in all California waters in 1951. Comparison With Other Measures Calhoun. (1950) calculated the average number of days per fisherman and the total number of fishing days for the three war years, 1941-43, and for 1946 and 1948. For 1941 through 1946 the average days per fisherman varied from 13 to 14 and for 1948 increased to 15.4 but dropped to 13 in 1949 (personal communication). Calhoun (1953, Table 1) also made a survey in 1951 and again had an average of 15 days. These figures are considerably less than the 25-day average obtained in this survey. 3 License sales in 1951 totaled approximately 1,015,250 but the rounded figure of 1,000,000 has been used in these calculations, and obviates a correction for license buyers who did not fish. This small percentage of licenses is not included in any of the calculations of average days per fisherman. FIGURE 2. Total fishing days in California waters from Calhoun (1950) and from 1951 survey. Line fitted to Calhoun data by least squares. MARINE AND FRESH WATER 8P0RTFI HINO INTENSITY l-l Such differences have a materia] effeel on the measures of total fishing intensity and the reason for the discrepancj is no1 apparent. During the war years the dumber of license sales and b finhing days remained relatively constanl and the producl of these t\\" figures gave a total of approximately 6,000,000 fishing days In 1946 increased license sales broughl the total up to 10,000, and additional license sales with an increase to 1 r> average days per fisherman broughl the l'1 1 - total to 15,000,000 days. A trend line fitted to Calhoun's data for 1949 1946 and 1948 and extrapolated to 1951 givesa value of 26,1 10,000 fishing days for the 1951 season (Figure 2). This is remarkably close to the 25,363,000 obtained from this 1951 survey (Table 1 based on an average of 25. 363 days per fisherman. The total license Bales have shown little increase in the Inst three or four years, however, ami this 25,000,000 total is dependent on the increase in average days per fisherman; not on greater license sales. If ( 'a I hon n 's average of 15 days were used the total would be 15,000,000 and no greater than in 1948. Perhaps our questionnaire asking the respondenl to lisl the number oi fishing days by area resulted in a more careful enumeral ion of his fishing effort or it may have tended toward exaggeration. Calhoun's question- naire, on the other hand, may have resulted in an understatement. Pre- sumably the true value lies somewhere between 15 and 2.~> days per fisher- man and present sport tishing pressure on California's fresh and salt water fishery resources is between 15 and 25 million man-days per year. Comparison With Smaller Samples To send out and tabulate the returns from 30,000 postal cards is an expensive and time consuming undertaking. To determine what per- centages would have been obtained if a smaller sample had been used. all usable returns were thoroughly mixed and five random samples of 1.000 cards each were drawn and tabulated. The results I Table 3 gave percentages for any fishing area which did not differ by more than 2.5 percent from the total sample. The sum of the five samples yielded per- centages within less than 0.3 percent of the total values. The greatest difference between the average number of fishing days for each of the 1,000-card samples and the total average was 1.5 days. Calcu- lations of the total number of fishing days differed, therefore, by aboul H million and for any given area from 100. 000 to 800,000. Statistical tests of the differences in the percentage and total fishing day values indicated significance 4 and the differences cannot be attributed to chance sampling errors. For practical purposes, however, such minor variations are of little importance and the test shows that returns of 1,000-2,000 cards would give sufficiently accurate information to estimate tishing intensity and localities of greatest fishing pressure. Number of Fishermen per Area Although the number of fishing days expended in each fishing area is of major importance in determining allocation of funds, it is also of interest to know fishermen preferences. For flu- five samples i>\' 1.000 cards, records were compiled of the number of fishermen reporting tish- ing in one area or in any combination of more than one area. There are 15 different classifications in this type of tabulation (Table 4). p values of less than .01 by chi square tests. 122 CALIFORNIA PISH AND GAME CO «o od CD ,-h O! 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PQ PO = B - r. - _' X X B u_ _ 33 C C DO b 3 h £ r 2 O +3 eg - : - >. >■ -S a a o o 03 33 5 2 T", T*. .- - A 3 03 o3 sec ^ - - 5> X X Q - — C 0 -^ - 5 ;■ a ! ■^- nn v: BO "a """ >- >• C 2 33 3 u §«« o ■- — « — 1 •4— - - - -3 C G 2 S g 53 * afa H fl "7 93 - « C 1 1 — C3 - - ixOC r. : ? — -= = = t - - ■e-s i |s . 93 03 OS o] PO - g -Z-- oj 03 33 ~ -r zz X X _ _ 53 53 X o o B = _ 33 - ; PQ ■£ o § a a ~ ~ ~ - - _= - " 53 a c 33 - E} u vja . . s - 3 $ * i '-■ '-■ : a 33 33 . X — 53 ' a 33 03 03 SB Sf ~ = a >. >. - 33 33 33 33 - :. z -^ ~- / i i >> - : c r 33 - - o a £0 - 3. a ••* _ r a / { ~ - '•' ^ £ ^ 33 33 i; ^ ^- ^- X /. _ 53 53 — j; X X - _ l : - ' - - - - - eg eg = as x fc 124 CALIFORNIA FISH AND GAME TABLE 5 Number and Percentage of Fishermen Fishing in Combined Areas — Based on the 5,000 Sample Number Percent Fishing In: 1,638 2,301 32.76 Fresh water and all other areas - 46.02 Total fresh water __ _______ Ocean only _ -- 3,939 790 2,081 78.78 15.80 Ocean and all other areas _ _ _ 41.62 Total ocean . _ _ _ _ 2,871 150 906 57.42 San Francisco Bay and Delta only _ _ Bav and Delta and all other areas. 3.00 18.12 Total San Francisco Bay and Delta- . 1 ,056 21.12 Of the 5,000 fishermen, 33 percent reported fishing in fresh water only, 3 percent in San Francisco Bar and Delta only, 4 percent in the northern ocean and bays only, and 11 percent in the southern ocean and bays only. The second highest percentage, 19, was reported by fishermen fishing in fresh water and in ocean and bays south of Santa Barbara. Slightly less than 1 percent reported fishing in all four of the areas. Approximately a third of California anglers fish only in fresh water and about one-sixth in ocean waters only. Nearly half of the fishermen are more versatile in their interests and fish in two or more types of waters. This diversity of interest is somewhat clarified in Table 5. In this table the numbers and percentages of fishermen fishing in only one of the three major areas or in that area and all other areas are summarized. The tab- ulations show that 33 percent of the fishermen fished in fresh water only and 46 percent in fresh water and in one or more of the other areas ; 16 percent fished in the ocean only and 42 percent in the ocean and one or more of the other areas ; 3 percent in San Francisco Bay and Delta only and 18 percent in the Bay and Delta and one or more of the other areas. SUMMARY The 1951 postal card survey was designed to measure the sport fishing effort in four areas. From the 29,464 cards mailed, 8,633 usable returns (29 percent) were received. Of the total number of fishing days reported, 56 percent was spent on fresh waters, 12 percent in the San Francisco Bay and Delta area, 10 percent on the ocean and bays north of Santa Barbara and 22 percent on the ocean and bays south of Santa Barbara. The average number of days per fisherman was 25, for a total of ap- proximately 25,000,000 fishing days on California waters in 1951. Of these, 14,000,000 were spent on fresh waters and 8,000,000 on the ocean and bays excepting San Francisco Bay. In the San Francisco Bay and Delta area fisherman spent 3,000,000 fishing days. MARINE AND FRESH WATER RPORTFISIIINfl INTI II'. 1 2fj Thirty-three percenl of the fishermen reported t i ^ 1 1 i 1 1 •_• in fresh water only, 3 percenl in S;m Francisco Baj and Delta onlj and 16 percenl in the ocean and oilier bays only. Samples of 1,000 ranis gave practically the Bame results aa did the 8,633 cards. REFERENCES •:ii<-h records from poHtal cards surveys IKW IH4S; if postal card ires] ■ ('alii Pish and Game, vol. angling catch estimate* for I'.ii'.i Calif. Pish and Game, Calhoun, A. .1. L950. California angling wit h an evalual ion ::<;, no. :'.. p. 177-234 1951. California state-wid vol. ^T. no. 1 . p. (>!)- !!)."»:?. Slate-wide angling estimates I'm- 1951. Calif, Pish and <^ no. 1. p. L03 113. ( (pinion Research Center l!)4i». Angling in California 1948. Pari I: Pishing Buccess and attitudes of an gling licensees. Opinion Res. Center, Univ. Denver, 15 p. (Mimeo rept.). FOOD OF MARLIN IN 1951 OFF SAN DIEGO, CALIFORNIA By CARL L. HUBBS and ROBERT L. WISNER Scripps Institution of Oceanography University of California, La Jolla The unusual numbers of marlin, Makaira mitsukurii (Jordan and Snyder) thai were taken by anglers off San Diego in 1950 and 1951 - provided an opportunity for the determination of its food and other characteristics. Advantage was no1 taken of this opportunity until I in the 195] season, when the stomachs of •!'_' specimens were obtained through the cooperation of .Mr. Luther II. Barber, Jr., of the Frosty Freezer in La Jolla and of S. Howard Minor, Jr. and the II and M Sport- fishers of San Diego. A. A. Allanson assisted in the procurement of tin- material. The marlins were all caught on spurt gear near San I ) i .• <_•-<» . All or nearly all came from an are extending Erom a lew miles wesl of Point Loma to about five miles southwest of Los Coronados Islands. They were medium-sized adults in the striped phase or of the striped species (we are inclined to the belief that "black marlin" are tl Ider, hut not always larger adults of the same species, with thicker bodies ami rela- tively smaller fins and beaks, comparable to the pudgy, dark, unspotted. short-finned adults of the channel catfish. Ictalurus punctatus • Kafi- nesque), that long- rated specific recognition — see Hubbs ami Allen. 1943, p. 118). The marlin weighed on the average 1 35 to 140 pounds. < Ine each was caught on August 20 and August 21, 1951 ; most or all of the others. from October 1 to 26, 1951. The minimal numbers of individuals of each food item were estimated, usually from counts of the tail ends, which are most persistent. The volumes were roughly measured by water displacement in graduate cylinders. There were rather large sources of error in all these deter- minations and only close approximations were attempted. Even the rough quantifications, however, are regarded as superior to mere guess- work or verbal statements from visual comparisons. NTo attempt was made to reconstruct the volumes of largely digested specimens. Except for small fragments of tlesh the food remains, with few ex- ceptions, were identified with little doubt. Clothier's 1950 contribution on the vertebral characters of Southern California tishes was particularly helpful. Incomplete and largely defleshed skeletons were recognized by comparison with the corresponding parts, laid bare, of more complete, readilv identifiable remains. 1 Contributions from the Scripps Institution of Oceanography, New Series, X". 601. Sub- mitted for publication July, 1952. 2 S. Howard Minor, Jr., who keeps the local marlin records, reports thai at Last 585 were caught in 1950 and at least 3S1 in 1951, in the area from off La Jolla to about Los Coronados Islands. (127 ) 128 CALIFORNIA FISH AND GAME In both numbers of individuals eaten (907) and volume of food re- mains (14,656 cc.) the saury, Cololahis saira (Brevoort) vastly pre- dominated (Table 1), just as it did in the food of albacore, Germo ala- lunga (Gmelin) of the Pacific Coast, as recently reported by McHugh (1952). The albacore examined by McHugh, however, fed on sauries to the extent of only 30 percent during the period when we find sauries comprising about 75 percent of the food of marlin. The sauries may have been eaten so predominantly merely because they are the most abundant fish of appropriate size in the area just off the close-inshore waters of Southern California. Had the marlin stayed closer to the shore, northern anchovies, En- graulis mordax (Girard), might well have formed the bulk of the food. One marlin, caught rather close to shore, 9 miles southwest of Point Loma on August 20, contained more than half (1,395 ccT) of the total volume of anchovy remains removed from all 32 stomachs ( in addition, this fish contained only one saury head, measuring 2 cc. ) . The northern TABLE 1 Food Contents of 32 Marlin Caught Near San Diego in 1951 Species of food1 Estimated number Total Ave. per marlin Percent of fish food Volume of remains, cc. Total Ave. per marlin Percent of fish food Saury Northern anchovy Pacific sardine Jack mackerel r Pacific mackerel Half moon Bonito (?) Unidentified fish fragments. Total fish Squid 907 249 21 20 2 1 1 ? 28.3 7.8 0.7 0.6 0.1 trace trace ? 75.5 20 1. 1 0 0.1 0.1 14,656 2,362 1,742 591 153 6 trace 745 1,201 + 3-6 37.5 0.9-1.9 100 20,255 + trace 458 74 54 18 5 trace trace 23 633 trace 72.4 11.7 8.6 2.9 0.8 trace trace 3.7 100 1 For scientific names, see text. BY NUMBER SAURY ANCHOVY ■ | SARDINE ■ ■ JACK ■ 1 MACKEREL ■ I PACIFIC i I MACKEREL ■ | HALFMOON tr. I ALBACORE tr. ? UNIDENT. ■ BY VOLUME 80 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 FIGURE 1. Percentage composition of fish food of 32 marlin POOD 01 MARLIN 129 anchovy was definitely second in numbers (249, or aboul '_'l percent of the fish eaten) and volume (2,362 cc, or aboul 1 2 percent Sardines, Sardinops caerulea (Girard , and jach mackerel, Traehunu symmetricus l A.yres), Hollowed and were close in numbers respectivi 21 and 20), bu1 the large sardines, which were mostly fresh ami whole, much exceeded the more digested jack mackerel in volume (1,742 cc. versus 59] cc). Two partly digested Pacific mackerel measured 153 cc. A large young halfmoon, about hair complete, measured 6 cc (young halfmoons long retain a surface-pelagic habital A Bingle bone, a pi l temporal, almost surely represented a small tuna or tuna-like fish, definitely not an albacore, almost surely a California bonito, Sarda h olata (Girard), aboul our Eoo1 Long. The only other recognizable food item comprised sis squid beaks, repre- senting three to six individuals of at least two s| ies. In 19 stomachs of marl in caughl during the first week of October, the percentage of stomachs containing each recognizable t' I item was; Saury, 9.") percent Anchovy, 32 percent Sardine, 37 percent .lack Mackerel, 11 percent Halfmoon, 5 percent It is clear from this examination that the striped marl in feeds on fish of moderate size. Except for the one young halfmoon, Medialuna californiensis (Steindaclmer) — a deep-bodied fish— and the single small bonito, all fish that had been eaten by the marlin examined were half- grown to adult specimens of medium-sized species. No fish eaten, so far as could be determined, was less than three inches long. No trace was seen of larvae or very young' juveniles. In this regard the striped marlin seems to contrast sharply with tuna, including albacore McHugn, 1952 . Nor were any of the fish eaten more than about one foot long. It is known, however, that large marlin are capable of eating Large tuna, at le those caught on a line (June, 1951). None of the fish eaten showed obvious signs of having I n impaled, cut in two, slashed, or otherwise injured by tin1 marlin 's sword, though the marlins, like the swordfish. are said to stun their prey by striking or impaling them with their sword (Norman, 1938, p. Kit'; Gudger, 1940, p. 225). No flyingfish were included in the food examined, though Cypselurus californicus (Cooper) was common in the region at the time the marlin were caught. Nor were any found in the marlin stomachs analyzed by Wallace and Wallace (1942) and by .Morrow (1952). Flyingfish, how- ever, are a favored bait for marlin and were listed as one of their food items by Norman (1938, p. 160). Very similar results were obtained by Wallace and Wallace 1942 in the study of the food of the "white marlin. T< trapturus nlhi. I 88, fig I 22, pi I 28. Gudger.E. W. 1940. The alleged pii^ii.-icii v of the swordfisfa and the pearfi hi their attacks on vessels hi si in I \ of their behavior and structure* which make 1 1 attacks possible]. Roy. Asiatic Soc. Bengal, Mem , vol, 12, no. 2, p 21S-315, figs. 1-22, pis. 3-9. Ilubhs, Curl L., and E. Ross Allen 1943. Fishes of Silver Springs, Florida. Fla. Acad. Sci . Proc, vol. 6, p 110 180, figs. 1-4. June, Fred C. 1951. Note on the feeding habits of the gianl while marlin of the Pacific Pac Sci., vol. 5, no. 3, p. 287. LaMonte, Francesca, and Donald E. Marcj 1941. Swordfish, sailfish, marlin, and Bpearfish. tnternat. Game Fish A Ichthyol. Contribs., vol. 1. no. 1!, p. 1 24, fig. I. pis. 1 5. McHugh, .T. L. 1952. The food of albacore (Germo alalunga) off California and Baja California. Scripps Inst. Oceanog., Bull., vol. 6, no. 1. p. 161 172, figs. 1 I. Morrow, James E. 1952. Food of the striped marlin, Makaira mitsukurii, from New Zealand. Copeia, no. 3, p. 143-14,5. Xorman, J. R. 1938. Giant fishes. Part I of Giant fishes whales and dolphins, by J. R. Norman and F. C. Fraser. New York. \Y. \Y. Norton and Co.. 361 p.. illus. (repub- lished in 1949 by G. P. Putnam's Suns, New York, under the in< tplete title. Field book of giant fishes) . Wallace, David H., and Elizabeth M. Wallace 1942. Observations on the feeding habits of the white marlin Tetrapturus albidut Poey. Maryland Dept. Res. and Educ, no. 50, p. 110, 1 fig. AN UNUSUAL MORTALITY OF CALIFORNIA YELLOWTAIL (SERIOLA DORSALIS) IN A MARINE AQUARIUM' By CARL H. OPPENHEIMER Division of Marine Microbiology Scripps Institution of Oceanography, University of California, La Jolla Sometime 1>H ween the hours of 9 p.m. June 18th and 7 a.m. June 19 1952, an unusual phenomenon resulted in the death of all the California yellowtail held in captivity a1 the marine aquarium of the Scripps Institution of Oceanography, La Jolla, California. The 1 I fish li;i\\ of approxi- mately 150 gallons per hour. Although it is difficult to calculate the water exchange, it is estimated that a complete change would require from two to three days. The prevailing temperature of the aquarium water at the time of the incident was approximately IT degrees C. or that of the adjacent ocean water. On June 18th the yellowtail, apparently in a healthy condition, were fed their semiweekly rations of beef liver which had been thawed from the frozen state. Although the same food was provided to the animals in several of the other aquaria, the yellowtail tank at this time, contrary to usual procedure, was supplied with an excess of beef liver in an attempt to induce the sea turtles to eat. Asa result a considerable aim unit of liver residue was left in the tank, both in fine suspension and in Larger pieces on the bottom. At 9 o'clock that nmht the aquarium curator made his rounds and reported that the fish were apparently in a healthy con- dition and had a normal appearance. On the morning following their feeding all the fish were Pound lying dead at the bottom of the tank, while the tour sea turtles were still alive. The water appeared somewhat cloudy and there was a considerable amount of decomposing residue at the bottom of the tank. While the fish were beinc removed from the tank, much more debris was noticed on the bottom of the tank than could be accounted for by the overfeeding of the fish the previous day. The outward appearance of the fish was normal except that the skin was covered with a heavy mucous coat which was thick and white in appearance with small dark granules. Dissection of the fish revealed a normal appearance of the internal organs except for the fact that the stomachs contained no food. Therefore it was con- cluded that the fish had regurgitated most or all of the food that had been 1 Contribution from the Scripps Institution of Oceanography. New Series X. 597. Sub- mitted for publication August, 1952. (133) 134 CALIFORNIA FISH AND GAME eaten the previous day. Any remaining food in the stomachs had been digested during the interim. Cheeking over the history of the fish it was noted that regurgitation had occurred before at infrequent intervals during their captivity. Parts of the slime were removed and taken into the laboratory, where they were examined in wet preparation by phase microscopy. The exam- ination showed an oily substance which contained innumerable bacteria of various types. The predominating type appeared to be a rather plump rod approximately one and a half by three microns in length. Many of the bacteria were highly motile, and to all outward appearances the slime was literally filled with bacteria. Phase microscopic examinations were also made of various other parts of the fish and of the water in the aquarium tank. The results of these examinations showed that the aquarium water contained approximately 10 million bacteria per ml which is considered a very heavy concentration. An unusual quantity of mucus had gathered on the surfaces of the gills rendering them some- what opaque and with only a slightly pinkish tinge instead of the normal bright color. There were many bacteria present on the gill surfaces. Also small rod and coccus types of bacteria were seen among the red and white cells of the blood. On the same date the other aquaria were examined for bacteria and for their outward appearance. It was noted that all were fairly clear except for one tank which contained the elasmobranchs. A bacteriological examination of the water in these tanks showed the normal numbers of bacteria. A conference with the aquarium maintenance men indicated that the normal flow of water had continued throughout the night. This report was supported by the fact that the water in the aquarium contain- ing the yellowtail had the same temperature as that in the other aquaria. In the other aquaria the fish were all in an apparently normal, healthy condition. Considering the very rapid and approximately simultaneous death of the yellowtail, it seems improbable that the cause was a specific bacterial or virus disease. There were no outward lesions on the fish and there was no evidence that the fish had struck themselves against the aquarium walls. The animals were apparently normal except for the mucus cover- ing their outer surface and the lack of food in their stomachs. As no previous mortality of this nature is known to the author, a con- clusion as to the cause of the present phenomenon cannot be based on former experiences. However, it is possible to derive a set of tentative conclusions based upon the results obtained by visual and microscopical examinations. It is well known that beef liver provides an excellent medium for the growth of many bacteria. Therefore, the knowledge that the fish had been overfed the day previous to their death leaving excess liver in the tank would suggest that conditions may have strongly favored the growth of bacteria. This feature, combined with the elevated temperature, would augment the conditions favorable to bacterial growth. Bacteria present in large enough concentration to cause an irritation to the intestinal tract of the fish may have initiated the regurgitation. Acting to increase the supply of readily available organic material in the water of the aquarium, the regurgitated matter would provide a still better medium of growth for bacteria. This may well have accounted for the extremely MORTALITY OF JTELLOWTAIL l'- I '■ \'i[ ^BS\ M 135 large 11 1 1 n i her of ]o m ill Ion bacteria per ml as demonstrated the following morning. It is assumed thai the increased number of bacteria may bave acceler- ated the production of the protective slime over the surface and on the gills of the fish. As this happened the oxygen absorbing properties of the gills would become reduced and al the same time tin- numbers of bacteria in the tank, increasing to ;i poinl where they could utilize mosl of the available oxygen iu the water, would create partially anaerobic conditions. The observed absence of hydrogen sulfide gas eliminated the possibilities of poisoning by this substance in an anaerobic environment. Combined with the tendency of the mucus to exclude oxygen Prom tie- gills, the conditions could certainly cause asphyxiation. One mighl sup port these conclusions by the knowledge that bacteria were found in tie- blood stream of the fish after deal h. This could coi ivably have occurred by the increased numbers of bacteria on the surface of the gills actually penetrating into the small capillaries and invading the blood Btream itself while the fish were still living. It seems questionable whether the bacteria were in large enough concentrations in the blood to have been directly responsible for the fatalities. THE EFFECT OF CHANNELIZATION ON THE FISHERY OF THE LOWER COLORADO RIVER By RICHARD D. BELAND Bureau of Fish Conservation California Department of Fish and Game During the period of 1936 to 1938, Hoover, Parker, and [mperial Dams were completed on the lower Colorado River. As a result, rapid changes in the ecology of the river, expansion of the game fish populations, and subsequent establishment of valuable soorl fisheries tooh place. Dill (1044) described the characteristics of this river-reservoir system as it existed in 19-42, and both he and Stevens I 1938) predicted some of the ultimate changes. Since that time many altera! ions in the ecology, both natural and man- made, have occurred in these waters. This report is concerned with the man-made changes brought about by river channelization. Under Public Daw MY.), dune 28, 1946, the Bureau of Reclamation is authorized to carry out a program of "controlling the Colorado River and modifying, straightening and rectifying the channel thereof." In short, this means river channel dredging. To date the Bureau of Rec- lamation has dredged the river Prom Needles to Topoek, has also dredg a section of the river in the Palo Verde area, is now in the process of dredging from Needles to Davis Dam, and has completed its plans for extensive operations in the Lake Cibola area. It is a distinct possibility that the entire channel from Headgate Rock Dam downstream to Im- perial Reservoir will eventually be dredged. The undesirable effect of dredging on the fishery in the Needles-Topock section is a preview of what, may be expected to result from operations in other portions of the river. Prior to this channelization, there existed at the lower end of Mohave Valley, between the towns of Needles and Topoek, a large marsh con- taining many lakes and sloughs, through which the Colorado River mean- dered. The total area of still water" maintaining fish populations was esti- mated at 4,300 surface acres. In addition, the main channel of the riv sr supported a healthy population of fishes (see Dill, 1D44. For a complete list). Largemouth black bass (Micropti rus salmoides), bluegill I /.' poi macrochirus) , and black crappie (Pomoxis nigromaculatus) predomi- nated in the lake environment, while channel cattish (Ictalurus punc- tatus) and to a lesser extent largemouth bass supported the fishery in the river habitat. Although no creel census data were obtained, fishing quality was known to be high. The I\ S. Fish and Wildlife Service, Office of River Basin Studies, Region 2, carried out field investigations in 1948-49 and estimated the annual fishery recreation value at $37,800. This figure is derived from a curve based on the area of fishable water. 1 Submitted for publication September, 1 ! » r> 2 . liased in part <>n data collected by the 1". S. Fish and Wildlife Service, Office of River Basin Studies, Ue.u'ion -• (137) 138 CALIFORNIA FISH AND GAME type of fishery, and value of similar types of lakes and streams through- out the United States. It was estimated that the California river bank in the project area received a use of 1,200 fisherman-days per mile per year. While the California Department of Fish and Game does not use the same system of evaluation, these figures do give some indication of the value of the fishery. In 1951 the Bureau of Reclamation completed a program of channel dredging and marsh drainage in this area, purportedly for flood pro- tection for the Town of Needles and the reduction of water losses through LAKE MOHAVE DAVIS DAM NOW BEING DREDGED PARKER DAM MAY EVENTUALLY BE DREDGED ARIZONA MPERIAL DAM LAGUNA DAM CALIFORNIA MEXICO cfST LOWER COLORADO RIVER SCALE OF MILES NEEDLES TO YUMA - 215 RIVER MILES FIGURE 1. The lower Colorado River bordering the State of California. A sketch showing the sections of the river that have been, or will be, channelized. CHANNELIZATION OF LOWER COLORADO RIVER 139 evaporation. This project confined the full Bom of the river to a ne dredged channel extending from Needles 10 miles wuth to Topock. This channel is 17 feel in depth, 250 Peel in width, and is designed to cai 75,000 second-feel of water a1 maximum capacity. It has e ilope feet per mile. A levee borders its Arizona Bide and effective! oft* the adjoining lakes ami sloughs from the river. The project has drained a large percentage of the lake and slough habitat that supported must of the fishery. The main channel has been changed from a meandering stream containing man) eddies ami •■ holt productive of fish life to a straight dredged sluice whose waters high in turbidity and Lacking in cover ami food. Wherever an adjoining backwater has been drained the h>>> in ti-i value has been 1oo percent. The changes to the river channel as a result of dredging are not so easily measured. However, it is believed that the damages to the river habitat in terms of fishery value are quite Bevere, The Fish and "Wildlife Service estimated the presenl fishery to be valued annually at approximately $f>,. qo. 3, p. 109-211. Stevens, J. C. 1938. The effect of silt-removal and flow-regulation en the regimen of Hie Grande and Colorado Rivers. Amer. Geophys. Union, Trans.. 1938, pt. 11. p. 653-659. AGE COMPOSITION OF THE SOUTHERN CALIFORNIA CATCH OF PACIFIC MACKEREL FOR THE 1951-52 SEASON1 By JOHN E. FITCH Bureau of Marine Fisheries, California Department of Fish and Game This is t lie second report on the age composition of the Pacific mackerel (Pneumatophorus diego) catch for L951-52 in which some :>l million pounds of mackerel were landed. The methods of sampling, age deter- mination and estimation of numbers of fish are the same as those nsed in the first report ( Pitch, 1951 I which covered the period 1939 K) through 1950-51. Table 1 presents the length frequency at each age for the 1951 52 season. Lengths of the fish from which otoliths were taken are given in quarter-centimeters. Of the 91 1 fish in age groups 0 through IX. only 28 were of age group V and older. Table 2 presents the calculated number of fish landed for each age group 0 through VI-4- together with the percentage each comprises the total number. Nearly 80 percent of the ^J'-' million fish eaughl during this season were contributed by but two year classes, 1947 and 1948. Table 3 gives the number offish landed by year class at each age group, 0 through V, for the seasons 1939-40 through 1951-52 and Table 4 pre- sents the same information in pounds. REFERENCES Fitch, John E. 1951. Age composition of the Southern California catch of Pacific mackerel 1839 M) through 1950-51. Calif. Dept. Fish and Game, Pish Bull. 83, 7.". p. 1952. The decline of the Pacific mackerel fishery. Calif. Fish and Game, vol. 38, no. 3, p. 381-389. 1 Submitted for publication September, 1952. (141) 142 CALIFORNIA PISH AND GAME TABLE 1 Length of Fish in Quarter Centimeters at Each Age for the 1951-52 Season, Based on Otoliths Read Age group Mem 0 I II III IV V VI VII VIII 89 1 1 90 1 2 3 3 2 1 4 95 6 4 3 1 4 2 7 8 9 100 1 1 1 1 2 1 3 5 3 3 2 .3 1 4 105 6 10 4 5 7 4 7 1 1 1 6 8 9 « 110 1 5 9 8 10 8 2 6 3 6 5 2 3 4 1 3 115 6 5 3 4 3 8 12 6 10 11 1 3 9 4 10 7 8 9 120 1 10 5 12 21 12 6 9 13 17 16 2 3 4 125 1 6 4 4 8 9 1 11 8 14 21 32 1 3 4 2 4 7 8 9 130 1 4 1 1 2 19 23 15 14 15 2 5 6 9 7 2 3 4 135 6 9 10 2 2 19 25 18 16 19 7 8 9 1 140 V.I ill I'M II l< \l.\i Kl 1:1 I. 1 1 : TABLE I— Continued Length of Fish in Quarter Centimeters at Each Age for the 195152 Season. Based on Otoliths Read igt group 1 (.'III 0 I II III l\ V \l VII VIII 1 1 2 3 1 7 15 8 2 3 1 1 1 4 1 1", 6 20 a 12 3 1 1 2 1 1 7 g 1 q 150 1 1 1 2 2 1 1 2 3 4 1 1 1 155 2 1 g 7 1 g 1 9 160 1 1 I 2 3 4 165 1 1 g 7 8 169 1 Sum 26 101 173 298 285 17 7 -' - 344 CALIFORNIA FISH AND GAME r^j ro uo t=> LO r> k-i o ■ 10 0 0 > CD 0 0 t~ I OS 00 CM 0 ' O O t» co CD > ■* t> CO CM ■* j— 1 CO 3 O O O 1— 1 00 O ^ CD 1— 1 M 03 f~ CO M 1— i 00 ■* <| co" T— 1 0 0 03 0 00 1— 1 00" CM CO O O 0 o_ M 10 Oi CO 00 0 , 1 0 O lO cq TJH a> 05 CD 1> CM CO M _fl A -3 CO CI cp J5 «4-l co O co O 03 h cu -^> 'o ,Q c 03 a CP 0 a; 3 Fh 1 1 1 >H S3 \ ai ■ o ■ ^r o >- I 0 H c, o be a; ' © co . i , / T -r i - I < . , / i IO — MHMWM O— < — — 'K:i:i- r - • / i . i - i-'-'Ni-rc : / / , "9 K5 — ci — i- :■- j J -. — ©' M US •- I - r - - •• . - — . — ' O O O O O © O O O O O O w . o o_ O © O © O i OrHi-ToOCDlOCOWCC C 39 CO — M tD (O Oi 'OO tt I- - '" r- "I l.- ^i CN CO CO ~ C CI/ -|--|/ / ic ic o ci d co d »h o tONMH«n-i«H -r ■•: co ©oo©©©o©©©©©© ooo©©©©©©©©©© o o o_ o_ c c o ©_ ©_ o © c c ©" cn ■* rr to r~ i~-" to ©* us io ad od t :i i: c c t ci ?i f. i- ■-: ci ci us wi;c(hom»o a. — ci - 1 — CD Os" CO Os" -f* 33 O IO IN P0 " 3 -- CN CO CN lOrt-nlN ■* iH OOOpQQQQOOOOC ©OOoOOOOOOOOO o ©_ ©_ qqSSqqoooi o" co" I--" co cm" co" cn" o* i--" o" 00 ■*" CO o»ONcD«ionsn-'iooo cn r» io_ co ■* o ro co co co oo oo io ■O O" CN Os" CN CD" 1<" Os" i-T CO" r-t Co" i-J CN CN —i CN i ii i COCN o o o o o o o o o © - © o co oo co i-i as as co co CO co 00 ©OS©©©© ©©©©©©© ©_ ©_ ©_ ©_ © ©_ ©_ co ©" ^i ^i co" co" as i-0 © oo CO co co lc >.o •— © ~i r- o Tt >o i-J 00 0" " — ~ 00" os 1 .nOHNONOiOTfiSN^ IS i 1 1 if-.^.^.o *> to ""i ct os os i> i> , , 0 1 0* 00 — " 00" -*" cs" 10 10 00 0" m" 10 1 ' H o>Li*o*e<3"*H os co ' ' T— 1 1 1 OOOOOCOOOOOOO 1 1 1 ' 1 OOOOOOOOCOOOO 1 1 1 1 1 0 c_ o_ ©_ o_ o_ o_ o_ ©_ 0_ G_ ©_ 0_ 1 1 ' 1 i — " >o ■* 00" cs" •*" os to co 00" oi 0" 0" ! isoo^h^cscoOcocccoooos > OOOO'^'-'fl'COOOtMOOCOCO^lM ; ©■-i.-iT-i,-ia r-T 00" 0: 10 10 00 ■*" os 00" os" ! to , -# 0. *-J O O CO O OJ f-H X OS t- 1-1 , 0^ ,HW)OOOHOnNf05O00 , * > tl^NCEOMOtDH i-l(M 1 1 1 1 t— — 1 1— 1 t— 1 1— ( 1— 1 T— i 1 1 1 1 en Z3 O h— OOOOOOOOOOOOO 1 1 1 1 'OOOOOOOOOOOOO ' ' 1 o-> 1 OOOOOOOOO O' OOO ' 1 ro ; to" CO" OS 00" Co" t-" Co" O" U5 t-" O" Csf t~T ! e^ ^fflTfOSifiMi-OOOnCNClN 1 *— iOrtNOONCi'NCOOOOn J K »— ' 'HNSMOIOhnm Tf-*CO 1 ' ' => t— i 'COIMCNl^^HCC---*'— 1-1 1-1 1 *— 01 a 2 0 0 3 •^ iOOOOOOOOOOOOO 1 1 0 to 1 1 iOOOOOOOOOOOOO ' 1 < ' 1 ©_ o_ o_ o_ ©_ o_ c_ o_ o_ ©_ o_ o_ C_ 1 1 =3 ^ 2 ! to" of t~" 0" --0" 00" —" 0" i-T i_o" 0" ■-< t--" ! lOOfOSOflBOONO* , .. 1 CO t~- t> DO ©_ o)_ oj_ o_ O CO_ CO U5 LO UJ ° 1 OS — 1 OS OS -<" 0" 0" 0" 0" of iC of of Co" CO 1 ' ' ti^N ■* 1-1 " i-o co" t-T i-T i>" lo" t>-" os" ^ 0" i-f os 00" of ro rt rt rt (N 09 >- >- 09 'OOO iO iOOOOOOO 1 1 1 1 iOOO iO iOOOOOOO ro • o_ 0 o_ ' o_ < 0 o_ c__ c_ c_ o_ o_ ! i-J" co co" ! rji" ! 00" os" t~" 00" t>." r-T cm" ,_ tDLOH tt* .OCNt^"^-^ LO i/l O O00H |CX| ,rHrtTj>_CS (N U_ T— 1 ., O iyt -a c 3 0 a. 0: in a "S ■*iflON000lOr-tNM^iO(DN000)OH COCOCOCOCOCO^JI'^'^'^^'r-^'^^J'^lO^ OSOSOSOSCSCSOSOSOSCSOSOSOSOSOSOiCSOS o be O B 2; t NOTES SLEEPER SHARK, SOMNIOSUS PACIFICUS, CAUGHT OFF FORT BRAGG, CALIFORNIA A male sleeper shark, Somniosus pacificus, L3 feel long, was taken by the drag boal Mart La Rocca, Captain Prank Davi, in a drag nel towed on the bottom, at a depth of 245 fathoms I 1,470 feel . wesl o£ Fori Bra California, May 12, 1952. It was not possible to obtain the weighl of this animal, but the tan-colored Liver weighed just 200 pounds. The largesl individual previously recorded was 11 \ feel long, though the species is reputed to reach as much as 25 feet . The sleeper shark is found in the North Pacific, from Southern Cali- fornia to Japan. Reports of this shark along the < lalifornia eoasl are not FIGURE 1. Sleeper shark, Somniosus pacificus, 13 feet long, caught in a drag net in 245 fathoms, west of Fort Bragg, California, May 12, 1952. Phofograph by J. B. Phillips. (147) 148 CALIFORNIA FISH AND GAME common. The first record in California waters was of a seven-foot speci- men taken in a drag net off Pt. Reyes, February 26, 1920 (Scofield, Calif. Fish and Game, 1920, vol. 6, no. 2, p. 80). This shark, a very sluggish animal, feeds on almost any animal life of suitable size and on carrion. It dwells on the bottom of the ocean, but is known to come to the surface at times. The present specimen disgorged several large rockfish, Sehasto- lobus alascanus, a species found in deeper water than are most other rockfishes. Because detailed descriptions of the Pacific form are meager, the following description and measurements are given. FIGURE 2. Sections of jaws showing teeth of a 13-foot sleeper shark, Somniosus pacificus, taken off Fort Bragg, California, May 12, 1952. Left, upper section, outside of upper jaw; left, lower section, outside of lower jaw; right, upper section, inside of upper jaw; right, lower sec- tion, inside of lower jaw. Note the several rows of reserve teeth on the inside of jaws; also the reinforcing row of teeth, below the biting edge, in the outside of lower jaw. The numbers on ruler shown represent inches. Photograph by J. B. Phillips. General Description Color, slate-gray, with darker, streak-like mottling on back. Body elongate, stout and rounded, deep anteriorly. Head large ; snout blunt ; mouth ventral. Gill slits short, low on side of body ; the length of the openings hardly more than 2\ times the diameter of eye. Spiracle opening a short distance behind eye, at least one-half as large as eye. Anal fin absent. Dorsal fins two, about equal in size and shape, rather small and some- what oblong ; no spines. Distance between the dorsals, about equal to greatest body depth. A low median, dermal ridge in front of first dorsal, but absent between the dorsals. Anterior margin of base of second dorsal about over, or slightly posterior to, the posterior margin of base of pelvic fins. Length of pectoral fin 1| times its base. Upper lobe of caudal moderately larger than lower lobe. Length and height of caudal fin only a little greater than greatest body depth. Middle of base of first dorsal fin approximately one-half the distance between the posterior base of pectoral and the \t;il length Greatest body depth (approximate) 28 Depth at caudal peduncle , 8 End of snout to eye 1 1 J End of snout to nostrils, on underside of head '■'• Length of each nostril slit End of snout to anterior margin of base of pectoral tin 12 End of snout to anterior margin of base of first dorsal fin 87 Diameter of eye Rear margin of eye to spiracle 8 Spiracle opening l"\ \' Length of gill -slits 1 Distance between first and fifth gill slits 12 \\'i$ Length of pelvic fins including claspers IT Extension of ends of claspers behind pelvic fin, proper Length of base of first dorsal fin In Length of base of second dorsal fin 8 Normal height of first and second dorsal fins Length of anterior side of first dorsal fin, and the posterior sides of the first and second dorsal fins 6 Length of the anterior side of the second dorsal fin I Distance between the first and second dorsal fins 28 Distance from posterior margin of base of second dorsal fin to end of caudal fin 12 Distance from anterior margin of base of pelvic fins, to end of caudal fin 57 Distance from posterior margin of base of pelvic fins to juncture of lower lobe of caudal fin Distance, posteriorly of juncture of lower lobe of caudal fin, to juncture of upper lobe of caudal, f Horizontal measurement i 4 Length of upper lobe of caudal fin Length of lower lobe of caudal fin 19 Distance from juncture of lower lobe of caudal to the concavity between the upper and lower lobes of caudal fin Distance between eyes 16 ■ — J. B. Phillips, Bureau of Marine FisJu ries, California l>> partnu ni of Fish and Game, June, 1952. THE OCCURRENCE OF TWO ADDITIONAL CENTRARCHIDS IN THE LOWER COLORADO RIVER, CALIFORNIA The capture of the red-ear sunfish, Lepomis microlophus i Giinther . in the Colorado River establishes this fish as part of the California fresh- water fish fauna and is an addition to the fishes recorded by Shapovalov and Dill (1950) in their "A check list of t he fresh-water and anadromous fishes of California." Red-ear sunfish were seined by the writer from the river four miles below Parker Dam and from a small oxbow lake immediately below Headgate Rock Dam on April 27, 1951. No specimens larger than four inches in length were captured nor has this species yet been observed in the anglers' catch. 1 2— 150 CALIFORNIA FISH AND GAME The red-ear is distributed throughout the eastern half of the United States and into the southwest as far as Arizona. It probably became established in the Colorado River in 1948 or 1949, since the Arizona Department of Game and Fish made several plants of this species in the Headgate Rock Dam area at that time. It is a desirable pan fish and in Indiana is considered to be superior to the bluegill for stocking in ponds in combination with the larger piscivorous game fishes (Krumholz, 1950). With the addition of the red-ear sunfish there are now four species of the genus Lepomis present in California waters. The following key, taken in part from "Fishes of the Great Lakes Region" (Hubbs and Lagler, 1947), will aid in their identification. /Anal spines 3 ; scales large, 53 or fewer in lateral line ; body depth usually 1 ) about one-half standard length ; no teeth on tongue ; supramaxilla re- duced, its length when present less than greatest width of maxilla (Lepomis) 2 Upper jaw extending to (or even beyond) middle of eye ; pectoral fins short and rounded, contained about four times in standard length. Green Sunfish, Lepomis cyanellus Rafinesque. Upper jaw not extending nearly to middle of eye ; pectoral fins long and pointed, contained a little less to a little more than three times in standard length 3 /Opercular bone flexible posteriorly ; gill rakers long and slender. 3 — \ Bluegill, Lepomis macrochirus Rafinesque. (Opercular bone stiff behind ; gill rakers short and stout— 4 Opercle with definite scarlet spot ; cheeks with prominent blue and orange stripes in life ; pectoral fins less than one-third standard length in adult ; body outlines gibbous. Pumpkinseed, Lepomis giboosus (Linne). I Opercle with broad scarlet margin ; cheeks without conspicuous orange and blue streaks ; pectoral fins more than one-third standard length in adult ; form more rhomboidal. Red-ear sunfish, Lepomis microlophus (Gunther). Dr. Carl L. Hubbs identified the sunfish new to California. Not new to California, but new to the lower Colorado, is the smallmouth black bass, Micropterus dolomieu Lacepede. In August, 1950, 3,200 finger- ling smallmouth bass obtained from the California Department of Fish and Game's Central Valley Hatchery at Elk Grove were stocked in the Colorado River at a point four miles downstream from Parker Dam. To date 12 specimens have been observed in the anglers' catch. One smallmouth taken on December 1, 1951 at a point approximately 10 miles below the planting site measured 11^ inches in fork length. This fish was approximately 18 months old at the time of capture. For growth rate comparison, smallmouth black bass of a similar age from Norris Reservoir, Tennessee averaged 8.9 inches in total length (Stroud, 1948). Since no record of smallmouth bass spawning in the Colorado River has as yet been obtained, this species cannot yet be considered an estab- lished part of the fish fauna. However, the excellent growth and condition of those specimens captured indicates that the smallmouth bass may do well in portions of the Colorado River. I 1 .". I REFERENCES Huhhs, C.irl I.., .iikI Karl l'. Lagler 1947. Fishes of the Greal Lakes Region. Cranbrook In t. 8d., Bull 26, i Krumholz, I .miis A. 1950. New fish stocking policies for Indiana pond I teentfa No Am«*r Wild). Con!'., Trans., i». 251 U7<). Shapovalov, Leo, and William A. Dill L950. A check list of the fresh water and anadromou l Calif. Fisli and Game, rol. 36, ao. I, p. 382-391. Stroud, Kicli.ml II. L948. Growth oi the basses and black crappie in Norri IV IV i tteelfool Lake Biol. Sta., Kept., \<<\. 12, p. 31 99 — R. D. Behind, Hunan of Fish Conservation, California Departmt ni Fish and Game, September, 1952. REVIEWS Land for Tomorrow By Dr. L. Dudley Stamp; [ndiana University Pre . BloominKton, 1052, '-'•"•'» | ; This book presents ;i very careful analysis of the world' population and Its f I needs and presents a method of solving the problem thai Is the mos1 promising proposed. Dr. Stamp is an English geographer and Professor of Land Use ;it the London School of Economics. This book is based on a series of lectures given .it the l nivci of Indiana in 1950 while the author was a visiting professor. The I I. joe into i siderable detail in defining the problem, particular!] population trends. Some rather startling facts are developed which will be of considerable interest i" li I" i ■ For example, Dr. Stamp shows thai the rate of increase of the middle latitude "white" races actually exceeds the increase of the tropical races. In fad the "white" incT( is in the order of four times as rapid as the total population increase. Dr. Stamp scrutinizes the so-called "point Four" rather careful]] and reaches the conclusion that there are severe technical handicaps that must be solved before its aims can be realized. Instead he proposes that we devpte our immediate attention t.. the lands we know how to manage, namely the middle latitude lands such as the United States where staggering results can he achieved if wc can only reach the presenl [in- duction per acre of European lands. With the removal of man-made trade barriers this country alone can go a long ways toward feeding the world. This book can be highly recommended as an extremely interesting and provocative discussion of our food needs. It seems that I>r. Stamp's conclusions can applj equall] well to marine as well as land resources in many cases. < me thing thai is advocated is a world-wide survey of land use including tropical cultivation. It is hoped thai Bomeone will point out in as good a fashion that our marine resources can also be ut ilized t" bring the peace that is not likely in a hungry world. — R. 1/ . Paul, Department of Fith ■ through dealers i" thiscounl rj . Actually, this is Mr. Roughley's sec M I \.u tralla' fl h< ed on the first, which was published in 1 - » 1 * 5 and has long been oul of prinl The text I fully revised and expanded ; a few of the original color plat* are omitted and a f< ■■ new unes have been added. I feci thai the revision wenl a itep I ar ha thai rysten descriptions of the species have I □ omitted. This limn- the usefulne i of the !■■ at least so far as the potential technical purchaser is concerned. Bui tb volume designed for him, though ii does include much which will interesi the I investigator particularly. Approximately half of the text is devoted to descriptions of the common fl marine and fresh water. These descriptions, with \cr.\ few exceptions, do DOl include any aids to identification and, as noted, in this respect the new booh Buffers in comp son with the old. They do tell of genera] relationships, distribution, Bize, habits and habitat, and of sporting and commercial qualities. The chapters on fisheries and angling range from aboriginal fishing to underwater spear fishing (using a face plate; the aqua-lung had apparentlj aol appeared on the Australian scene when Mr. Roughlej wrote). There is a chapter on troul both the brown and rainbow have been introduced with success. < it her fresh water fisheries, pond culture, big game angling, sharks, commercial fishing and canning, all receive their just due. Fish canning is still a young industry in Australia and the pelagic fisheries remain practically unexploited. The inshore and bottom fisheries, to the contrary, are in the author's opinion already overexploited. — Phil 1/ . Roedel, California 1>>\>les pole Carp: No license Clam: Pismos: Overlimit; undersize; no license; in refuge; closed season; failure to bury undersize; digging in state preserve; possession out of shell. Cockles: overlimit; closed season and undersize. Big necks: overlimit Commercial: No license; selling undersize tuna; possessing abalone out of shell prior to delivery; working on commercial abalone boat without permit; selling live fish without license; failure to procure party boat permit; Btriped bass on commercial boat; taking undersize abalones commercially; selling undersize albacore; unloading yellowtail caught in Mexico without permit; bringing fish ashore to sell without commercial license; failure to register fishing vessel; sale striped bass; overlimit frogs; market owners possessing spiny lobsters in closed season and marking without supervision; fish dealers failing to keep records; failure to make out correct fish receipts; possessing untagged catfish; possession of untagged trout by market; possession of abalone commercially without permit; overlimit and undersize barracuda and sale of undersize; selling undersize yellowtail; using net to take salmon between sunrise Saturday and sunset Sunday... Crab: Taking females Frog: Overlimit; closed season Lobster: Closed season Perch: Overlimit Pollution: Mill refuse; oil; discharging saniclor into state waters; sawdust in creek; liquids from log pond in creek Rockfish: Overlimit Salmon: Undersize; overlimit; no license; snagging; 2 poles Smelt: Dipping without license Sunfish: Overlimit and failure to show license; closed season; no license Trout: Closed season; overlimit; closed stream; 2 poles; no license; using more than one outfit; chumming with corn; no license; using borrowed license; closed waters; set lines; 3 poles Total Sale of seized fish . Grand total Number ■ it .irr. ' IS 757 84 9 2 41 115 1 4 2 3 10 2 17 1 16 97 1.209 11,230 'hi 10,984 -_■ oo .ill (Ml 15 00 9,725 00 25 00 225 (Hi 50 00 - 1 1,600 00 35 00 455 00 10 00 550 00 3,785 00 $32.7 - 736 30 15 10 27' $33,474 80 (157) 158 CALIFORNIA FISH AND GAME GAME CASES July, August, September, 1952 Offense Number of arrests Fines imposed Jail sentences (days) Beaver: Taking closed district . Deer: Failure to carry tags; taking spotted fawn; night hunting and taking doe; possession untagged deer and failure to retain hide; failure to fill out tags; taking spike buck; taking closed season; carrying another's tags; shooting within 150 yards of dwelling; shooting from road; failure to tag; hunting in refuge; using A tag in B tag district; hunting closed district; taking 2 does and using spotlight; failure to retain horns and hides; no license; failure to have tags punched and countersigned; taking forked horn in refuge; transferring tag; taking with .22 rifle ---- Deer meat: Possessing unstamped meat; illegal possession; selling; possession without license, tags or transport permit — Dove: Closed season; overlimit; no license; taking from auto; early shooting; unplugged gun; shooting within 150 yards of dwelling; shooting from public road — Duck: Closed season; no license Goose: Closed season; selling Hunting: Loaded gun in car; trespassing; spotlight in game area; shooting from car; night hunting; shooting from public road; no license; late shooting; shooting within 150 yards of dwelling; discharging gun in refuge Nongame birds: Taking blue heron, grouse, kingbird, monkey-faced owl, sea- gull, avocet Pheasant: Illegal possession from out of State; shooting in closed season, possess- ing hen; no license, loaded gun in car; shooting from car; taking without tags Pigeon: Overlimit; taking bandtails, closed season Quail: Taking in closed season Rabbit: Taking in closed season, at night; spotlighting; no license; loaded gun in car; shooting from car; hunting with .22 rifles; using unplugged gun Sagehen: Taking protected game bird Squirrel; gray: Taking in closed season Sheep: Taking young ram Totals S250 00 227 34 94 13 2 631 31 2 11 131 1 1 1 18,651 50 3,575 00 3,680 00 1,195 00 50 00 14,278 00 260 00 2,450 00 125 00 745 00 4,860 00 50 00 25 00 250 00 1,085 245 13 12}^ 1,188 150,444 00 1,363^ SEIZURES OF FISH AND GAME July, August, September, 1952 Number Pounds Fish: 464 512 455 225 731 121 1 58 111 1 312 46 32 666 1,686 135 Clam Carp - Catfish 475 Frog - ... . - _ _- .- . 20 920 Perch -- Trout - _ 90 437,474 1,226 Game: 1 1 94 682 501 151 6 9 41 16 41 226 2 1 Duck - Quail Rabbit 68841 9-52 7500 printed in California state printing office ■:-----mm;.,- Notice is hereby given that the Fish and Game Commis- sion shall meet on January 2, 1953, in the California State Building, Los Angeles, California, to receive recommenda- tions from its own officers and employees, from public agen- cies, from organizations of private citizens, and from any interested party as to what, if any, orders should be made relating to fish, mollusks, crustaceans, amphibia, reptiles, birds, and mammals or any species or variety thereof. Notice is hereby given that the Fish and Game Commis- sion shall meet on January 30, 1953, in the State Building, San Francisco, to hear and consider any objections to its determinations and proposed orders in accordance with Section 14.2 of the Fish and Game Code, such determina- tions and orders resulting from hearing held on January 2, 1953.