';"?0STGR.^DUATE SCHOOL " yi, CALIF. 939-1-
DUDLEY KNOX LIBRARY NAVAL POSTGRADUATE SCMOO; MOWTFREY CA 93943-5101
67^
MARINE FOULING ORGANISMS
IN MONTEREY HARBOR, CALIFORNIA
JUNE THROUGH SEPTEMBER, 1966
by
Thomas Leroy Miller Lieutenant, United^States Navy B.S., Pennsylvania State University, 1960
Submitted in partial fulfillment for the degree of
MASTER OF SCIENCE IN OCEANOGRAPHY
from the
UNITED STATES NAVAL POSTGRADUATE SCHOOL October 1966
Marine fouling organisms occurring on test panels of various substances and at several locations and depths in the Monterey Harbor, California, were studied for identi- fication and significance.
Some panels were immersed for the entire length of the study-- June 10 to September 16, 1966; others, mainly plywood, were immersed only for month-long periods through- out the study.
Barnacles, bryozoans , and serpulids were the major fouling organisms in the inner harbor, while hydroids were most significant in the outer harbor. The barnacles reached maximum attachment in June and July, but were covered later by bryozoans. Phoronid worms were abundant in August and September on the shallow panels in the inner harbor.
Fouling increased with depth and distance away from direct sunlight. Fibrous masonite and wood panels were the best collecting surfaces and stainless steel the worst.
LIBRARY
NAVAL POSTGRADUATE SCHOOL
K0NT2REY, CALIF. 95340
TABLE OF CONTENTS
Section Page
1. Introduction 7
2. Equipment 10
3. Procedures 15
4. The Fouling Organisms 17
5. Factors Affecting the Type and Rate of Fouling 27
6. Conclusions 45
7. Acknowledgments 47
8. Bibliography ^ 48
LIST OF TABLES Table Page
I. Fouling Organisms Recorded on Test Panels in Monterey Harbor, June through September, 1966. 18
II. Results of First Observations on Long-term Panels. 28
III. Results of Final Observations on Long-term Panels. 29
LIST OF ILLUSTRATIONS Figure Page
1. Location of Test Sites 8
2. Relationship of Racks to Sea Surface under
Wharf #2 11
3. Relationship of Panels to Sea Surface under
Buoy #4 12
4. Photograph of Fouling on Wood Panel from Shallow Rack after 47 Days' Exposure 30
5. Photograph of Fouling on Wood Panel from Shallow Rack after 93 Days' Exposure 30
6. Photograph of Deep Long-term Wood Panel
after 46 Days' Exposure 31
7. Photograph of Deep Long-term Wood Panel
after 95 Days' Exposure 31
8. Short-term Panel Exposure Times 33
9. Variation of Major Fouling Organisms with
Time on Shallow Wood Panels 34
10. Photograph of Fouling on Wood Panel in Deep
Rack Exposed between June 10 and August 8 35
11. Photograph of Fouling on Wood Panel in Deep
Rack Exposed between June 24 and August 22. 35
12. Weekly Mean Temperatures and Salinities 37
13. Photograph of Fouling on Steel Panel in Floating Rack Exposed for 93 Days 40
14. Photograph of Fouling on Steel Panel in
Deep Rack Exposed for 90 Days 40
1. Introduction.
The primary objective of this study was to continue the type of research begun earlier in the year ^.lOJ, so as to obtain by systematic test panel experiments a more com- plete seasonal analysis of the fouling organisms under Monterey Municipal Wharf #2. Data for this study were gathered from June 10 to September 16, 1966.
It has been pointed out by othersl^, 12, 16] that a fouling community will vary not only seasonally but year- ly. Thus, even though there is now fairly complete sea- sonal data, it cannot be said that the community will re- main unchanged from year to year. However, the fluctua- tions will most likely be in the relative numbers and not in the species of animals present.
Several other secondary experiments were added to determine such features as: ecological succession; the effect of direct sunlight; and the effect of open, less polluted water on the fouling community. Also, several types of test panel surfaces were used to determine which type was best suited to collection and analysis of fouling organisms. Some panels covered with antifouling compound were used to determine if their surface coating had any effect on nearby panels.
Finally, a comparison was made of the fouling com- munity with temperature and salinity data.
Three sites were chosen for the experiments. The primary site, which had five racks at varying depths and various types of panels, was located approximately 1000 yards from the shoreline under Monterey Municipal Wharf #2 (see Figure 1). No direct sunlight reached the speci- mens here, and water motion was mostly from tidal action.
CHART OF MONTEREY HARBOR
//
Wharf No.l
Scale 1:50,000
^^..
<— USNPGS
Figure 1* Location of Test Sites (denoted by arrows).
The two secondary sites were principally used for compari- son purposes. To investigate the direct sunlight effect, a rack was hung exposed on the west side of the wharf at the same distance from the shore. The third site was Navigation Buoy #4, approximately 1800 yards due north of the west end of the Coast Guard Breakwater. This loca- tion was 800 yards from the nearest land, but in more open water than were the two wharf sites.
2. Equipment.
Except for the buoy site, the same types of racks were used in all locations as in the previous study [l^J*
Four stainless steel racks and two pine wood racks were placed under the wharf at various locations (see Figure 2). Henceforth, the racks under the wharf will be referred to as follows: floating rack--the wooden rack which always remained at the surface; intertidal rack--that metal rack suspended five feet above mean low tide so that it was in the water half of the time and out of the water the other half; shallow rack--that metal rack suspended one foot below mean low tide; deep rack--the metal rack suspended 14 feet below mean low tide; antifouling rack-- that wooden rack containing two antifouling paint-coated panels and a glass control panel suspended 14 feet below mean low tide; light rack--that rack suspended from the western side of the wharf to one foot below mean low tide. Each rack was capable of holding six 8X10 inch panels with a three inch space between them (see Figure 2 for a diagram of each rack).
All racks were originally held in location by 3/32 inch stainless steel Bathythermograph wire. However, after about three weeks' exposure, the 5/16 inch hot gal- vanized steel "U" clamps used to secure the wire to the racks were corroded severely and an additional \ inch ny- lon line had to be added to each rack for extra security.
At first, it was planned to have six kinds of col- lecting panels, all 8X10X3/16 inches, with glass, stain- less steel, and plywood being used as the main collecting surfaces. To give surface variety and to test fouling
10
*k
0 _
-1
-I*
SEA SURFACE
RANGE - OF TIDE
>iMEAN LOW TIDE
Wood
LIGHT RACK
Wood
Steel
Glass
ANTIFOULING RACK
-21 BOTTOM
Steel Glass
Masonite Wood
Steel Glass Masonite Wood
Wood
Steel
Glass
Wood
Steel
Glass
FLOATING RACK
INTERTIDAL RACK
SHALLOW RACK
DEEP
RACK
Figure 2« Relationship of Racks to Sea Svirface under Wharf #2 and Types of 8X10 Panels Contained in Each.
11
SEA SURFACE
-11 FEET
-15 FEET
NAVIGATION BUOY #^
WOOD
STEEL
-132 FEET
BOTTOM
Figure J>» Relationship of Wooden Panel under Navigation Buoy #^ to Sea Surface.
12
qualities, other secondary materials were used--niasonite, and aluminum coated with Teflon. In this last case, the aluminum reacted electrolytically with the steel racks and dissolved within the first month, thus rendering these panels useless. All of the other panels were uncoated except for ball point pen lines which were drawn on the panels to divide the surfaces into one inch squares. Lastly, on July 7, 1966, both a pljrwood and a steel panel were coated with the U.S. Navy's Formula 105 antifouling hot plastic and then placed in the study area for observa- tion.
The panels suspended from the buoy also were hung originally with the wire. However, the panels were lost and had to be replaced, and in the replacement nylon line was substituted for the wire. The wood panel was sus- pended 11 feet below the surface and the metal panel 15 feet (see Figure 3).
There were four primary racks. Each contained a glass panel, a plywood panel, and a steel panel which re- mained in the rack the entire test period of 93 days. In addition, a new plywood panel was added to each rack every two weeks and removed after a month's exposure. Because of the weight of the stainless steel panel, it was neces- sary to use a counterweight pulley arrangement to keep the floating rack continually at the surface.
Under the wharf, in addition to the above-mentioned racks, there was one wooden rack which contained a wood panel and a stainless steel panel coated with antifouling compound, as well as an uncoated glass control panel. Also, in order to investigate the effect of light on
13
settling fouling organisms, one metal rack was exposed to the maximum afternoon sunlight on the western side of the wharf. This rack originally contained glass, stainless steel, masonite, and three plywood panels. Because of its unprotected location, though, it fell prey to several pilferages and all that could be salvaged was the long- term wood panel; even this panel was lost at the end of 40 days' exposure.
14
3. Procedures.
Two basic procedures were followed in analyzing the test surfaces under the wharf.
First, to determine any ecological succession within the fouling community and to test the effect of various surfaces on the attachment of fouling organisms, a set of glass, stainless steel, wood, and in some cases masonite panels were placed in each rack and allowed to remain the entire test period of approximately 93 days. For analysis of the organisms, these panels were withdrawn from their racks at the half-way point of the study (or, after 47 days) and again at the end of the study period, but were kept immersed in sea water in order to approximate in situ conditions. The panels were examined thoroughly with the aid of a 30X Binocular Microscope. Since the panels had been divided into one inch squares before placement in the water, it was possible to count and record the aver- age number of each species per square inch. Furthermore, each panel was photographed with a Polaroid Model 100 Land Camera with a close-up lens. The purpose of the photographs was to make possible accurate counts of the larger fouling organisms, and to enable accurate compari- sons with later photographs taken of the panels at the end of the study. Since the panels were returned to their racks within two to three hours after removal, and since they were continually immersed in sea water during analysis, it is believed that no ill effects befell any of the organisms. All analyses were done at the new aquarium building on the beach of the U. S. Naval Post- graduate School. Since all panels except a plywood one
15
were stolen at the beginning of the study period from the light-exposed rack on the side of the wharf, only that one panel could be examined. As of August 20, even that last panel was lost. Under the wharf, the plywood and stainless steel panels coated with antifouling compound and the glass control panel in the same rack were examined only at the end of their 65-day exposure.
Second, to determine periods and rates of attachment, additional plywood panels were introduced to each rack every two weeks and were withdrawn after one month's ex- posure. These panels were examined in the same manner as were the long-term panels but, in addition, some were allowed to dry and then each of these was scrutinized carefully. Others were placed in aquaria with fresh but filtered sea water continually bathing them. The purpose here was to try to obtain some estimate of the rates of growth of the organisms without the introduction of new species or individuals.
Similar methods of examination were used in checking the buoy panels of plywood and steel for fouling in the outer harbor. These panels were left in the water for a period of 65 days.
Finally, temperature measurements using a standard Navy bucket thermometer, and salinity measurements using a Kahlisco salinity hydrometer were made at two to three day intervals during the entire period of study. The purpose of this analysis was to determine a possible cor- relation between the fouling community and the water con- ditions .
16
4. The Fouling Organisms.
Essentially the same techniques employed by Mommsen QlOjwere employed in examining the fouling organisms of this study. All test panels were examined initially while immersed in a pan of sea water, so that an in situ environment could be maintained for easier identification and for ecological observations.
Identification was carried as far as possible using the keys C 5, 8, 14J, but many of the immature specimens would have necessitated observation by an experienced biologist for complete analysis.
Non-attached animals which appeared to be an integral part of the fouling community were also described in this s tudy .
Limnoria lignorum, a marine borer, was found in sev- eral wood panels throughout the period of this investiga- tion. The abundance was about the same as that found earlier in the year [_10j, thereby adding evidence to the observation that Limnoria lignorum is as continually pre- sent in Monterey Harbor as it was at Friday Harbor £ 7 J , and at Oakland [^ 4j.
There was no evidence of Teredo infection in this s tudy .
The fouling organisms observed are listed in Table 1.
Bacteria At first, a slime always appeared on the test panels and was especially noticeable on the glass. The slime was undoubtedly due mainly to bacteria J7l4j , although this feature was not examined specifically. According to
17
TABLE I
FOULING ORGANISMS RECORDED ON TEST PANELS IN MONTEREY HAR30R, JUNE THROUGH SEPTEMBER, I966
Plants
Phylum ThaJLlophyta
Subphylum Algae
Glass Chrysophyta - Diatoms (unidentified) Class Phaeophyta - Brown Algae (unidentified) Class Rhodophyta - Red Algae, Corallina sp. Class Chlorophyta - Green Algae (unidentified)
Animals
Phylum Protozoa
Foraminifera (unidentified) Zoothamnium sp. Folliculina sp.
Phylum Porifera
One species (unidentified; numerous spicules)
Phylum Coelenterata - Class Hydrozoa Obelia gracilis
Phylum Platyhelminthes (Flatworms)
' Leptoplana sp. /
Phyltim Nemertea
Tetrastemma nigrifrons *
Phylum Aschelminthes
Nematodes (unidentified)
Phylum Annelida (Segmented Worms) Nereis vexillosa Laeospira sp. Dexiospira sp. Spionids (unidentified)
Phylum Arthropoda - Class Crustacea
Balanus crenatus Balanus glandula Caprella sp. Copepoda (unidentified) Amphipods (unidentified) Limnoria lignorum
Phylum Mollusc a
Snalla (some unidentified; some Littorina spp.
18
TABLE I (continued)
Phylum Mollusca (continued)
Hermissenda crassicornis . Dendronotus subramosus Do to varians Duraucelia festiva Triopha grandis Austrodoris odhneri Mytilus edulis Pododesmus macroschisma Clams (unidentified)
Phylum Entroprocta
Pedicellina cernua
Phylum Bryozoa
Tubulipora sp. Membranipora membranacea -Hippodiplosia insculpta Parasmittina collifera Hippothoa hyalina Tricellaria sp. Bugula californica Bugula neritina Crisia sp.
Phylum Phoronidea
Phoronis sp.
Phylum Echinodermata / ^
Pisaster sp. Strong:ylocentrotus sp.
Phylum Chordata
One species of Tunicate (unidentified)
1 o
Zobell [[17J, this slime not only is always present, but it is also necessary for the subsequent growth of the macroscopic fouling organisms in a marine environment.
Plants
Diatoms were observed adhering to projections on all of the panels, but they were most obvious on the panels exposed to direct sunlight. None were identified.
Algae were observed only on the light panel and on the long-term panels located under the wharf. Three forms of algae were only identified to major group: red, brown, and green. All forms occurred on the light panels; however, only the red algae, Coral lina sp. was found under the wharf and, then, it was found at all depths and on all surfaces.
Animals Discussion of the numerous animals will be by phyla.
Phylum Protozoa Several of the panels had the dark bottle-shaped protozoans, Folliculina, but these were not as evident as they had been during the first three months of the year LlOj. However Zoothamnium, the colonial vorticellid, was present throughout the period on almost all the panels. They appeared to grow best on the deep glass and steel panels.
Phylum Porifera (Sponges) The most common evidence of sponges was the numerous tiny needle-like siliceous spicules. Some live specimens
20
were seen on the long-term glass panels at various depths, but they were so limited and so poorly developed that they could not be identified easily. They probably belonged to the class Demospongiae .
Phylum Coelenterata - Class Hydrozoa The hydroid, Obelia gracilis , did not appear under the wharf in any significant numbers until the fourth monthly set of panels (July 22 - August 18) was examined; then, it occurred only on the bottom half of the floating and intertidal panels, i.e., not more than a few feet under the surface. The most abundant growth of Obelia gracilis was on the steel and wood panels exposed under Buoy #4. At the end of the 65 days' exposure, this hy- droid had developed colonies which were six inches thick on both sides of the panels. When comparing these obser- vations with earlier ones LlQJ , it appears that there are at least two "blooms" of hydroids in the area: one in February and March, and another in July and August. In both periods, the number and size of the nudibranchs (which apparently grazed on the hydroids) increased with the increase in the hydroids.
Phylum Platyhelminthes (Flatworms) Several flatworms were observed on early panels containing many barnacles, but no relationship between the flatworms and the barnacles was found L-'-QJ • The flatworms did not appear again until the long-term panels were examined, and then they were quite common at all depths. The majority were Leptoplana sp.
21
Phylum Aschelminthes The small transparent nematodes described in Light etal. [8J were found on all panels throughout the study- period. They were not identified further.
Phylum Nemertea (Ribbon Worms) Only one species, Tetrastemma nigrif rons , was ob- served during the study period. The several specimens that were found occurred on the long-term intertidal masonite panels.
Phylum Annelida (Segmented Worms) On almost all panels, several species of polychaetes without tubes were observed. One common variety was Nereis vexillosa. Other tubeless annelids were not iden- tified further.
Of the tube-building annelids, the white calcareous tubes of the Serpulidae were the most common. Unlike earlier in the year QlOj , they were found on all panels except the ones in the floating rack and the intertidal rack. Three different tube designs were observed: the sinistrally-coiled Laeospira, the dextrally-coiled Dexiospira, and a straight or uncoiled species of ser- pulid f 8j . All were equally abundant and became most numerous in September.
Finally, on the long-term panels, several annelids with transparent membranous tubes were observed but were not specifically identified.
Phylum Arthropoda - Class Crustacea Several species of free-moving amphipods and cope- pods were observed on the panels; however, they were not
22
identified further.
The tube-building amphipods were observed only once on the deep panel during the monthly period of July 22 to August 18. No particular pattern was observed.
The gribble, Limnoria lignorum, was seen occasionally at various depths on wood panels throughout the study period.
Balanus crenatus was the most significant fouling organism and the only barnacle (except for two specimens of Balanus glandula) which settled on the panels during the entire test period. Figure 10 shows how the barnacles had settled in great numbers during the first monthly period of June 10 to August 8; Figure 11, a photograph of the second monthly period of June 24 to July 22, shows fewer barnacles, but ones which have grown much larger. The crowded barnacles of the first period, which numbered 40 to 50 per square inch, probably could not get enough food to maintain the large population; Figure 11 shows that the population was reduced to equilibrium with the environment, or, to three or four barnacles per square inch. This finding is in accord with those of Coe QlJ. This extreme crowding also was observed on the deep panels at the halfway point of the study. These panels had been covered completely with barnacles in the pre- ceding 49 days but, at observation time, only half of the original barnacles remained. It must be pointed out that some of the missing barnacles might have been removed by grazing starfish rather than by crowded conditions. Very few Balanus crenatus attached after the end of July and, at the end of the study, almost all of the barnacles were covered by bryozoans.
23
The barnacles grew in basal diameter at the rate of
about one millimeter per ten days. This rate agrees with growth measurements taken on Balanus crenatus in the White Sea [15] and elsewhere. The barnacles' attachment rate varied with regard to water depth in the following ways: it increased with depth on all surfaces--that is, there was less barnacle fouling on the shallow, floating, and intertidal racks (except the rough side of the masonite) than on the same surfaces on the deep panels; there were no variations in the surfaces on the deep panels--all were solidly covered; and, later in the study when fewer bar- nacles were settling, it was noticed that they preferred the sides of the wood panels which were darkest in color and away from the light.
Phylum Mollusca
Pelecypods were quite numerous throughout the study period and occurred on almost all panels and at all depths. The most common forms were immature specimens of the mussel, Mytilus edulis, which numbered approximately one per square inch. None were attached and most were about one millimeter long. The next most common pele- cypod was the rock oyster, Pododesmus macrochisma, which was usually unattached and averaged about half a milli- meter in diameter. Later in the season, it was observed that numerous specimens were attached firmly on the long- term shallow and deep panels and that, by the end of the 93 days, some had grown to a diameter of eight millimeters, Several unidentified clams were also observed.
A small snail (one-half to one millimeter) with a greenish translucent shell was seen on several occasions,
24
but could not be identified with the available keys. The same situation occurred regarding a specimen which was white with brown spots and which appeared late in the study period.
The most colorful animals seen during this study were the nudibranchs. Hermissenda crassicornis was the most prevalent and was found on almost all panels and at all depths. Although these nudibranchs were present through- out the test period, they became much larger and more numerous when the hydroids, Obelia gracilis , became abun- dant near the first week in August--literally thousands of nudibranch eggs were found on the hydroid-inf ested buoy panels at the end of the study. Another nudibranch, Dendronotus subramosus , was noted on an intertidal panel after 48 days of exposure. During the fifth monthly period (August 5 to September 2), several specimens of a third species, Doto varians , were observed on the floating panel. Finally, the long-term panels yielded three other species, Duvaucelia f estiva, Triopha grand is , and Austro- doris odhneri .
Phylum Bryozoa
One of the most plentiful bryozoans was the en- crusting form, Membranipora membranacea. It was found at all depths and on all panels, and the largest grew to about four millimeters across in a month.
The next most common encrusting species was Tubulipora sp. . It was found everywhere, but preferred steel panels. It did not develop as fast as the other encrusting bryozoans.
All long-term panels from under the wharf were 75%
25
covered with Hippodiplosia insculpta by the end of the study period (see Figure 5). These yellowish, circular, encrusting bryozoan colonies averaged 30.0mm across and were seen covering all previous fouling organisms. They became abundant only in August and September; yet, since they were found only on the long-term panels, other fouling organisms might have to be present on a surface before the Hippodiplosia insculpta will attach. They were particularly heavy where the growth of phoronid worms was most intense.
Other encrusting forms seen occasionally were Tricellaria sp. and Parasmittina collif era.
Finally, there were several bryozoans which were on stalks and were not encrusting. It is believed that these were the early stages in the development of Hippothoa hyalina. These animals preferred attachment along the cracks made by the ball point pen lines on the wood panels. Other stalked bryozoans were Bugula calif ornica and Bugula neritina. These last two species were found only on the long-term panels.
Phylum Echinodermata Two small (a half millimeter) immature starfish, Pisaster sp. , were observed during the fourth monthly analysis (July 22 to August 19) and were seen on the long- term panels at the end of the study. Also toward the end of this test period, several sea urchins, Strongylocentro- tus sp. , were observed.
Phylum Chordata One species of tunicate was seen but not identified. It was found on the deep panel of the third monthly analy- sis (July 8 to August 5).
26
5. Factors Affecting the Type and Rate of Fouling.
The factors which, influenced fouling on the test panels in this study were: length of exposure; season of exposure; type of surface; depth; amount of light; edge effect; and geographic location. These factors differ slightly from those examined by others [9, 10, 14j], because of the limited scope of this study.
Length of Exposure As in observations made earlier in the year at this same location LlOj^i^d, indeed, as has been found at many other locations Ll^J > the fouling increased with the length of exposure at all test sites. This point is illustrated in Table II, which summarizes the results of the examination of three macroscopic foulers from the wood, glass, and stainless steel panels in the floating rack, the shallow rack, and the deep rack, re- spectively; this examination was made at the halfway period of the study, which was approximately the same length of time as the final observations in the earlier study [^lOJ . Table III is a comparison of the same pan- els at the end of the test period. Care must be exer- cised in interpreting the number of bryozoans, especially those on the shallow rack, because even though the number of colonies did not increase significantly, the size of the colonies did. For example, the bryozoan Hippodiplosia insculpta covered up to 75% of the surface in the case of the wood panel and yet it was not as numerous as the Tubulipora sp, and other stalked bryozoans found on the deep panels. Even though this examination was spaced over several days, it is believed that the results will
27
TABLE II
RESULTS OF FIRST OBSERVATIONS ON LONG-TERM PANELS
(Barnacles and serpulids are indicated by the average number of individuals per side of panel--80 square inches; bryozoans are indicated by the average number of discrete colonies per side of panel. )
FLOATING RACK (^8 Days' Exposure)
Stainless
Steel Glass Wood
Barnacles 6 12 SO
Serpulids 0 0 0
Bryozoans 0 0 10
SHALLOW RACK (^7 Days' Exposure )
Stainless
Steel Glass . Wood
Baurnacles L 3 6
Serpulids 0 0 , 70
Bryozoans * 0 50 4o
DEEP RACK (^9 Days' Exposure)/'
Stainless
Steel Glass
Barnacles 30 1200
Serpulids 23 6
Bryozoans 20 80
28
V--'- •'■•'
TABLE III RESULTS OF FINAL OBSERVATION ON LONG-TERM PANELS
(Barnacles and serpulids are indicated by the average number of individuals per side of panel--80 square inches; bryozoans are indicated by the average number of discrete colonies per side of panel. )
Barnacles Serpulids Bryozoans
FLOATING RACK (9^ Days' Exposure)
Stainless Steel
100
0
10
Glass
ho
0
10
Wood
60
0
30
Barnacles Serpulids Bryozoans
SHALLOW RACK (93 Days' Exposure)
Glass Wood
Stainless Steel
1 80 50
80 50
6 20' 80
y
Barnacles Serpulids Bryozoans
DEEP RACK (95 Days' Exposure)
Stainless
Steel
300
"2000 350
Glass'
1000 350 150
Wood
^00 150 200
29
Figure 4, Photograph of Fouling on Wood Painel from Shallow Rack after 4? Days Exposure.
Figure 5« Photograph of Fouling on Wood Panel from Shallow Rack after 93 Days Exposure.
30
Figure 6. Photograph of Deep Long-Term iVood Panel after 46 Days* Exposure.
Figure ?• Photograph of Deep Long-Terra .Vood Panel after 95 Days' Exposure,
31
be accurate.
Figure 4 shows a photograph of the plywood panel in the shallow rack after 46 days of exposure; Figure 5 shows the same panel after 93 days' exposure. These figures il- lustrate the point that the encrusting forms of fouling organisms, such as bryozoansj, eventually assume an in- creasingly dominant role. This result agrees with that which was found in Biscayne Bay Ll2j . However, the evi- dence is not conclusive and further seasonal studies are required. (The same results can be seen in Figures 6 and 7 which show the wood panel in the deep rack after 46 and after 95 days' exposure respectively.)
Season of Exposure
Every two weeks, a new panel was placed in each of the racks under the wharf. Each was allowed to remain for a period of one month, then it was examined. The periods of exposure are shown in Figure 8. The variation of the major fouling organisms on the shallow panel during these periods is illustrated in Figure 9.
As shown in Figure 9, barnacles are by far the major foulers early in July and then they drop off rapidly in abundance. Balanus crenatus was the only barnacle found in significant numbers during July and August, and, there- fore, the peak barnacle attachment earlier in the year L -^Oj must have been caused by Balanus glandula. It remains to be seen if there might be a second maximum attachment in November as was found at Friday Harbor [^7].
Figures 10 and 11 are photographs of the deep panels during the first two monthly exposures and they show the sharp decrease in the number of barnacles as the season
32
:2
3 P3
n> ft)
OQ
fD
00
CO
o f^
(T
I
H fD fi 3
nd
fD
X
o
c
fD
H
3
fD CA
|
crv |
in |
-C |
a> |
^ |
I-* |
n f-" |
|||||
|
•. |
• |
1^^ 1^-* |
|||||||||
|
\ \ |
o |
||||||||||
|
^ |
r N> |
\ |
|||||||||
|
\ |
P- |
\ |
|||||||||
|
\ |
\i |
00 |
|||||||||
|
^ |
» |
1 |
c |
||||||||
|
r — |
\J |
\ |
|||||||||
|
\ |
^i |
\ |
|||||||||
|
\ |
V\ |
||||||||||
|
r- |
Ln |
\ |
\] |
-n |
/ |
> |
|||||
|
• |
\ |
\ |
c |
||||||||
|
\l |
\\ |
c |
|||||||||
|
\ |
I-' |
\\ |
â– ^^ |
||||||||
|
^ |
vO |
^ |
^. |
||||||||
|
\ |
u_i |
NJ |
|||||||||
|
\ N |
CO |
||||||||||
|
\ |
m |
||||||||||
|
, \ |
•XI |
||||||||||
|
V\ |
H |
||||||||||
|
\^ |
M |
||||||||||
|
\ |
y-' |
s |
|||||||||
|
' w • |
m , ^ |
33
300
200
100
Figure 9« Variation of Major Fouling Organisms with Time on Shallow Wood Panels. (BcLrnacles and serpulids are indicated by the average number of individuals per side of panel — 80 square inches; bryozoans are indicated by the average number of colonies per side of panel. )
34
Figure 10, Photograph of Fouling on Wood Panel in Deep Rack Exposed between June 10 and August 8.
Figure llo Photograph of Fouling on Wood Panel in Deep Rack Exposed between June 24 and August 22.
35
progressed.
Serpulid worms and bryozoans increased in number constantly throughout the test period.
Hydroids, which were not present during the early part of the study, suddenly became quite common on the August panels and then, just as suddenly, disappeared from under the wharf in September. Hydroids, though, were very abundant on the buoy panels in September. From data earlier in the year LlQJ , it is seen that there are at least two strong periods of hydroid growth: the first in February and March; the second in August and September.
Maximum fouling at La Jo 11a [ij occurred in May and June; at Oakland Harbor, it occurred during July and August ^4J . Thus, it could be expected that June and July would be most significant at Monterey, and yet this expectation is true only as far as one species of barnacle is concerned. Serpulid worms and bryozoan colonies became more numerous even later in the season. The abundance of these last two fouling organisms could be due to ecological succession processes rather than to seasonal variations.
Figure 12 shows the weekly m„ean surface temperatures and salinities. No correlation between the attaching fouling organisms and either of these factors was readily apparent. However, the sudden appearance and disappear- ance of the hydroids in August could have been caused by the rise in temperature during that month. More evidence would be necessary to confirm this inference though.
36
o
OP
c
ft)
N)
fD
fD ^
H
fD B
fD
rt n
fD CO
;::3
cyi pj
I— ' rt
fD CO
00
o
O
O
o
cr>
CO G
>
o
>
r
|
X |
|||||||
|
71 |
|||||||
|
> |
|||||||
|
u |
z; |
||||||
|
• |
w |
• / |
3 |
||||
|
• |
• |
TI |
|||||
|
\ |
> |
||||||
|
i â– IHIIII * â– ' |
• |
71 |
|||||
|
• |
/ |
||||||
|
/ |
\. |
||||||
|
\ |
/ |
7d |
|||||
|
9 • |
G 5 |
• / |
> H G |
||||
|
• |
W |
||||||
|
• |
|||||||
|
1 |
• 1 |
||||||
|
• 1 |
1 |
||||||
|
1 • |
• |
> |
/ \. |
||||
|
• 1 |
C I |
) |
|||||
|
J. • \ |
G CO H |
/ |
\ > |
||||
|
9 |
• |
||||||
|
f ft |
.1 |
||||||
|
{ |
â–º |
C/5 |
\ |
||||
|
1 |
•X) |
1 |
|||||
|
1 |
1 |
Ul
o
37
Type of Surface
Various types of surfaces were used for the same reasons as given in the earlier study- -namely 5 to give a greater variety of surfaces for attachment and to attempt to gain some insight into the fouling organisms' method of attachment and surface preference.
DePalma [[Sj and others have discovered that the best collecting surface for fouling organisms is one which is rough, fibrous, and comparatively soft. Asbes- tos fits these qualifications and is being used at sev- eral locations. However, since asbestos is seldom found on submerged surfaces, it is believed that untreated marine plywood, stainless steel, and glass are somewhat more representative of materials likely to be fouled in a marine environment. It must be noted that several masonite panels, which have both a smooth side and a rough side similar to asbestos, were employed with the result that the rough fibrous side collected significantly more fouling organisms.
As mentioned previously. Teflon-faced aluminum panels were used to test a "non-stick," non-toxic surface; how- ever, the electrolytic action dissolved the panels.
As another sidelight, two panels (plywood and stain- less steel) were coated with hot plastic antifouling paint. In the same rack but three inches away, a glass panel was inserted to test whether the antifouling paint had any effect on fouling in the immediate vicinity. The result was a confirmation of the earlier results from Biscayne Bay L^2j in which it was determined that antifouling paint is effectual when applied to test surfaces, but does not
38
affect "unpainted" surfaces nearby. The painted panels were completely unfouled, but it was noted that the paint on the steel panel chipped off easily after two months' exposure.
Regarding the major part of this study and the evi- dence from Tables II and III, wood was generally the best all-around collector and stainless steel the worst (com- pare Figures 5 and 7 with Figures 11 and 12). However, at depth where the fouling was heaviest, it did not matter what the surface was since the majority of the fouling organ ism.s found were represented on all three types of surfaces. Several anomalies were noted: on the deep racks, serpulid worms and the bryozoan Tubulipora sp. preferred the steel panels, and barnacles preferred the glass panels; on the shallow and floating panels, phoronid and nemertean worms were common only on the fibrous mason- ite and wood panels, while sponges were found only on glass panels.
Depth
As illustrated in Tables II and III and in Figures 13 and l4, the number of fouling organisms attaching to the surfaces definitely varied with depth.
Two striking features were noted regarding the occur- rence of serpulid worms: first, they increased in numbers with depth; second, they never occurred on the panels in the intertidal or floating racks.
The significant fouling barnacles consisted of Balanus crenatus . The occurrence of this barnacle was greatest at depth and then decreased upward until, near the surface on the intertidal and floating panels, it
39
I
«l
I *
irittiil
Figure 13. Photograph of Fouling on Steel Panel in Floating Rack Exposed for 93 Days.
Figure ih , Photograph of Fouling on Steel Panel in Deep pack Exposed for 90 Days.
40
increased again. The exact minimum point of occurrence could not be determined from this study.
All species of bryozoans occurred at all depths; Membranipora membranacea and Hippodiplosia insculpta were most common near the surface, while Tubulipora sp. was the major bryozoan at depth.
One significant point is that the intertidal rack and the floating rack were not very different in the num- ber or the species of observed fouling organisms.
Although the species varied seasonally, the conclu- sion Ij-Oj remained unchanged that the amount of fouling increased with depth.
However, the fact that a masonite panel in the shal- low rack had almost the same amount of fouling as the wood panel at depth indicates that the type of surface may be as important as the depth.
Light
One of the primary objectives of this study was to compare the fouling organisms attaching to panels exposed to direct sunlight with the relatively sheltered panels under the wharf. The most significant result was that algae grew on the exposed panels and not on the ones under the wharf, and this lack of algae on the latter is attrib- uted to the absence of direct sunlight ^12, 14j . (Some red algae, Corallina sp., did occur sparsely under the wharf, however, since it did not require direct sunlight for growth.)
According to some observers [b , II, 13J, the lack of algae on the panels under the wharf would alter or reduce the number of organisms which would settle later on the
41
panels. Moreover, DePalma states [Sj that the lack of direct sunlight might make data from the panels under the wharf useless. It must be noted, though, that the major- ity of fouling organisms are found occurring naturally on the bottom of boats and on wharf pilings where there is no direct sunlight.
It was found in this study that fouling increased with depth and was greatest on the deep rack under the wharf where there was only a small amount of diffused light. Even on the light panels, it was noticed that bar- nacle fouling was heaviest at the bottom of the panel, furthest away from the light. Thus, it appears that the lack of direct sunlight and the subsequent lack of growth of algae did not inhibit the abundance of other foulers, particularly of barnacles. This result supports the ob- servation flAj that the settling larvae are negatively phototropic and prefer areas with diffused light. It should be noted that the observations on the panels ex- posed to direct sunlight and the conclusions drawn from them pertained only to the first half of the study, since shortly afterward the exposed rack was lost. It is pos- sible that with longer exposure and with the absence of so many barnacle larvae in the water, the panels exposed to direct sunlight could have obtained more overall fouling .
In the earlier study LlOj , it was shown that the side of the panels away from the light was most heavily fouled. Since some of the racks in this study were hung so that they could turn freely with the water movements, this light feature could not be investigated in all cases.
42
However, it was noticed in all cases that, if a wood panel had one side darker than the other, it would show a 25% increase in barnacle fouling over the side lighter in color. It was noted further that, if one side received more light than the other 3 barnacle fouling was heaviest on the side away from the light regardless of the coloring. On the other hand, bryozoan colonies preferred the side to- ward the light regardless of the shading in the wood.
Edge Effect
In general 5 fouling appeared heaviest within an area one inch from the edge of the panels. However, this dis- tribution was evident only in a few cases and, in these cases, it was caused by one or two species of animals.
Algae grew densest near the edge on the panels ex- posed to direct sunlight, Hydroids, which became prevalent during August 5 preferred the edges as a starting point of attachment and also were densest there. This same distri- bution was true for the bryozoans Hippothoa hyalina and Membranipora membranacea.
Another type of preference for position was shown by barnacles. They preferred to settle along the etched lines on the glass panels and along the indentations made by a ball point pen when lining the wood panels.
Geographic Location
There was an attempt to show how the fouling organisms in Monterey Harbor varied at two geographic locations.
The first location, which has been described already in detail, was under the municipal wharf and the second was under the Navigation Buoy #4. What was deduced was that the entire fouling community at the buoy location consisted
43
of hydroids, while hydroids were of no significance under the wharf and many other organisms were common. The evidence is too limited to be conclusive, but it is indicative of the fact that the fouling communities will vary markedly from one location to another even though the actual geographic separation is not great.
44
6. Conclusions.
Table 1 lists the fouling organisms present in Monterey Harbor during the period of June 10 to August 16, 1966.
The intensity of fouling was influenced by season of exposure^ type of surface, depth, light, edge effect, and geographic location.
The barnacle Balanus crenatus was the most signifi- cant fouling organism at all depths during the first half of the study, with the maximum abundance of larvae in early July, The specimens grew at the rate of one millimeter per ten days. Bryozoans and serpulid worms became dominant during the last half of the study (August and September), However, phoronid worms were quite common on the near-surface panels in August and September; hydroids had a minor bloom in August under the wharf but were continually dominant on the buoy panels. Limnoria lignorum was found boring into the wood panels throughout the test period.
On surfaces of the same composition, attached fouling organisms increased with depth and with distance away from direct sunlight.
No fouling was observed on the antifouling panels during their 6 5 days in the water; the antifouling paint did not influence fouling on nearby surfaces.
At any given depth, fouling was heaviest on the rough fibrous sides of the masonite panels and lightest on the stainless steel panels. An all-around collecting surface was plywood--the fouling intensity here was between those found on the steel and on the rough masonite.
45
Seasonal succession appeared to be the dominant force which controlled fouling in Monterey Harbor, and yet certain ecological successions also might be signif- icant. (A prime example of the latter was the late bloom of the encrusting bryozoan, Hippodiplosia insculpta, which covered all previous foulers and whose appearance seemed strongly influenced by the presence or absence of phoronid worms . )
Temperature and salinity variations were not con- sidered important factors in fouling attachment.
For further study, the following subjects are suggested: a more complete seasonal, yearly, and geo- graphic record of the fouling community; a more detailed study of algae and of the "microfilm" which precede the settlement of the macrofouling organisms; and a study of the interrelationship of the members of the fouling community.
46
7. Acknowledgments.
Grateful acknowledgment is given to Dr. Eugene C. Haderlie for his kind criticism, counsel, and outright instruction, without which this study would not have been possible. Appreciation is also extended to Commander Donald A. Still, U.S. Navy, for providing necessary equipment and facilities.
47
BIBLIOGRAPHY
1. Coe, Wesley R. Season of Attachment and Rate of
Growth of Sedentary Marine Organisms at the Pier of the Scripps Institution of Oceanography, La Jolla, California. Bull. Scripps Inst. Oceanogr. tech. ser. v. 3:3, 1932: 38-87. Four-year study of fouling organisms on wooden and cement blocks.
2. Coe, W. R. and W. E. Allen. Growth of Sedentary
Marine Organisms on Experimental Blocks and
Plates for Nine Successive Years at the Pier of
Scripps Institution of Oceanography. Bull.
Scripps Inst. Oceanogr. tech. ser. v. 4:4, 1937:
101-136.
Nine-year study using cement blocks and glass
plates .
3. DePalma, John R. A Study of the Marine Fouling and
Boring Organisms at Admiralty Inlet, Washington. U.S. Naval Oceanographic Office Informal Manu- script Report No. 0-6-66. May 1966: 1-23. Unpublished manuscript. Two-year study using asbestos and wood test panels
4. Graham, H. W. and H. Gay. Season of Attachment and
Growth of Sedentary Marine Organisms at Oakland, California. Ecol. 26:4. October 1945: 375-386. A fourteen-month study using wood panels.
5. Hedgepeth, J. W. Introduction to Seashore Life.
Univ. of Calif. Press. 1962.
Descriptions of most common marine organisms along
California coast.
6. Hewatt, W. G. Ecological Succession in Mvtilus
calif ornianus Habitat as Observed in Monterey Bay, California. Ecol. 16. 1936: 244-251. Classic methodology for ecological succession studies .
48
Johnson, M. W. and R. C. Miller. The Seasonal
Settlement of Shipworms , Barnacles, and Other Wharf -pile Organisms at Friday Harbor, Washington, Univ. of Wash. Publ. Oceanogr. v. 2, No. 7. March 1935: 1-18. Ten-year study using wooden blocks.
8. Light, S, V. rev. by R. I. Smith, F. A. Pitelka,
D. P. Abbott and F. M. Weesner. Intertidal Invertebrates of the Central California Coast. Univ. of Calif. Press. 1954. The primary key for identification of marine organisms in this study area.
9. Marine Corrosion and Fouling. Arthur D. Little, Inc. Dept. of the Navy. Project Trident Technical Report. July 1962: 1-32.
General analysis of fouling and related problems.
10. Mommsen, D.. B. A Study of Marine Fouling in
Monterey Harbor. Master's Thesis, U.S. Naval Postgraduate School. May 1965.
Initial Monterey Harbor fouling study for period of January through April, 1966.
11. Scheer, Bo T. The Development of Marine Fouling
Communities. Biol. Bull. 89:1, 1948: 103-121. Study of fouling communities on submerged objects in Newport Harbor, California.
12. Weiss, C. M. The Seasonal Occurrence of Sedentary
Marine Organisms in Biscayne Bay, Florida. Ecol. V. 29:2, April 1948: 153-172. Four-year study using glass panels.
13. Wilson, Oo T, Some Experimental Observations of
Marine Algal Successions. Ecol. 6, 1925: 303-
311.
Five-month study on various surfaces at La Jolla,
California.
49
14. Woods Hole Oceanographic Institution. Marine
Fouling and its Prevention. U.S. Naval Institute
1952.
A basic text on all phases of marine fouling.
15. Zevina, G. B. Marine Fouling in the White Sea.
U.S. Naval Oceanographic Office Translation 221 of Trans, of Trudy Instituta Okeanologii, Moscow. 1963: 70/52-100/70. Six-month study of organisms on buoys.
16. Zinn, D. J., R. D. Wood and H. Berkowitz. Fouling
Project, Final Report. Office of Naval Research, NR 163-312. June 1957.
Two-year study in Rhode Island water with glass slides .
17. Zobell, C. E., The Role of Bacteria in the Fouling
of Submerged Surfaces. Biol. Bull. 77(2). 1939:
302.
Analysis of significance of bacteria.
50
INITIAL DISTRIBUTION LIST
No. Copies
1. Defense Documentation Center 20 Cameron Station
Alexandria, Virginia 22314
2 . Library 2 U.S. Naval Postgraduate School
Monterey, California 93940
3. Dept. of Meteorology and Oceanography 1 U.S. Naval Postgraduate School
Monterey, California 93940
4. Professor Eugene C. Haderlie 1 Dept. of Meteorology and Oceanography
U.S. Naval Postgraduate School Monterey, California 93940
5. LT Durward B. Mommsen Jr., USN 1 20 East Humbird Street
Rice Lake, Wisconsin 54868
6. LT Thomas L. Miller 1 205 West Fifth Street
Oil City, Pennsylvania 16301
7. Commanding Officer and Director 1 Naval Electronics Laboratory
Attn: Code 2230
San Diego, California 92152
8. Environmental Sciences Service Administration 2 UoSo Department of Commerce
Washington, D.C. 20390
9. U.S. Naval Oceanographic Office Attn: Division of Oceanography Washington, D.C. 20390
10. Superintendent
United States Naval Academy Annapolis, Maryland 21402
51
11. Office of Naval Research
Attn: Biology Branch (Code 446) Department of the Navy Washington, D.C. 20360
12. Director
Woods Hole Oceanographic Institution Woods Hole, Massachusetts 02543
13. Dr. James S. Muraoka Materials Division
U.S. Naval Civil Engineering Laboratory Port Hueneme, California 93041
14. Director
Scripps Institution of Oceanography University of California, San Diego La Jolla, California
15. Chairman, Department of Oceanography Oregon State University Corvallis, Oregon 97331
16. Executive Officer Department of Oceanography University of Washington Seattle, Washington 98105
52
Security Classification
DOCUMENT CONTROL DATA - R&D
(Security claasitication ot title, body of abstract and indexing annotation muat be entered when the overall report ia claaaiiied)
1 ORIGINATING ACTI\/|TY (Corporate author)
Environmental Sciences Programs U.S. Naval Postgraduate School Montgr^v, — California
2a. REPORT SECURITY C 1. ASSI FIC A TION
Unclassified
26 GROUP
3. REPORT TITLE
Marine Fouling Organisms in Monterey Harbor, California June through September, 1966
4 DESCRIPTIVE NOTES (Type ot report and inolualve datea)
Thesis
5 AUTHORCS; (Laat name. Hrat name, initial)
MILLER, Thomas Leroy
6 REPORT DATE
October 1966
7a- TOTAL NO. OF PAGES
53
7b. NO. OF REFS
17
8a. CONTRACT OR GRANT NO.
b. PROJECT NO.
9a. ORIGINATOR'S REPORT NUMBCRCSJ
9b. OTHKR REPORT HO(S) (A rxy othat numbera that mtmy be mmaitnad
thia report)
s^^i\^^^ ^^iHl'^j
10 AVA ILABILITY/LIMITATION NOTICES
This document has been approved for public i^lease and sale; its dlGtribitir- ^s unliiDi+-'
11. SUPPLEMENTARY NOTES
12 SPONSORING MILITARY ACTIVITY
U.S. Naval Oceanographic Office Washington, D.C.
13. ABSTRACT . ^ ^ . , . , ^ .
Marine fouling organisms occurring on test panels of various substances and at several locations and depths in the Monterey Har^ bor, California, were studied for identification and significance.
Some panels were immersed for the entire length of the study-- June 10 to September 16, 1966; others, mainly plywood, were immersed only for month- long periods throughout the study.
Barnacles, bryozoans, and serpulids were the major fouling organisms in the inner harbor, while hydroids were most signifi- cant in the outer harbor. The barnacles reached maximum attach- ment in June and July, but were covered later by bryozoans. Phoronid worms were abundant in August and September on the shallow panels in the inner harbor.
Fouling increased with depth and distance away from direct sunlight. Fibrous masonite and wood panels were the best collect- ing surfaces and stainless steel the worst.
DO
FORM
1 JAN 64
1473
53
Security Classification
Security Classification
u-
KEY WORDS
LINK A
ROLE WT
LINK B
ROLE
WT
LINK C
ROLE
Marine fouling
Fouling
Biology
INSTRUCTIONS
1. ORIGINATING ACTIVITY: Enter the name and address of the contractor, subcontractor, grantee. Department of De- fense activity or other organization (corporate author) issuing the report.
2a. REPORT SECUHTY CLASSIFICATION: Enter the ovei- all security classification of the report. Indicate whether "Restricted Data" is included. Marking is to be in accord- ance with appropriate security regulations.
2b. GROUP: Automatic downgrading is specified in DoD Di- rective 5200. 10 and Armed Forces Industrial Manual. Enter the group number. Also, when applicable, show that optional markings have been used for Group 3 and Group 4 as author- ized.
3. REPORT TITLE: Enter the con^lete report title in all capital letters. Titles in all cases should be unclassified. If a meaningful title cannot be selected without classifica- tion, show title classification in all capitals in parenthesis immediately following the title.
4. DESCRIPTIVE NOTES: If appropriate, enter the type of report, e.g., interim, progress, summary, annual, or final. Give the inclusive dates when a specific reporting period is covered.
5. AUTHOR(S): Enter the name<s) of authot<s) as shown on or in the report. Enter last name, first name, middle initial. If military, show rank and branch of service. The name of the principal author is an absolute minimum requirement.
6. REPORT DATE: Enter the date of the report as day, month, yean or month, year. If more than one date appears on the report, use date of publication.
7a. TOTAL NUMBER OF PAGES: The total page count should follow normal pagination procedures, Le., enter the number of pages containing information.
76. NUMBER OF REFERENCES: Enter the total number of references cited in the report.
8a. CONTRACT OR GRANT NUMBER: If appropriate, enter the applicable number of the contract or grant under which the report was written.
86, 8c, flc 8d. PROJECT NUMBER: Enter the appropriate military department identification, such as project number, Bubproject number, system numbers, task number, etc
9a. ORIGINATOR'S REPORT NUMBER(S): Enter the offi- cial report number by which the document will be identified and controlled by the originating activity. This number must be unique to this report.
96. OTHER REPORT NUMBER(S): If the report has been assigned any other report numbers (either by the originator or by the sponsor), also enter this number(8).
10. AVAILABILITY/LIMITATION NOTICES: Enter any lim- itations on further dissemination of the report, other than those
imposed by secxirity classification, using standard statements such as:
(1) "Qualified requesters may obtain copies of this report from DDC"
(2) "Foreign announcement and dissemination of this report by DDC is not authorized. "
(3) "U. S. Government agencies may obtain copies of this report directly from DDC. Other qualified DDC users shall request through
(4) "U. S. military agencies may obtain copies of this report directly from DDC Other qualified users shall request through
(5) "All distribution of this report is controlled. Qual- ified DDC users shall request through
If the report has been furnished to the Office of Technical Services, Department of Commerce, for sale to the public, indi- cate this fact and enter the price, if known.
IL SUPPLEMENTARY NOTES: Use for additional explana- tory notes.
12. SPONSORING MILITARY ACTIVITY: Enter the name of the departmental project office or laboratory sponsoring (pay- ing for) the research and development. Include address.
13. ABSTRACT: Enter an abstract giving a brief and factual summary of the document indicative of the report, even though it may also appear elsewhere in the body of the technical re- port. If additional space is required, a continuation sheet shall be attached.
It is highly desirable that the abstract of classified reports be unclassified. Each paragraph of the abstract shall end with an indication of the military security classification of the in- formation in the paragraph, represented as (TS), (S), (C), or (U).
There is no limitation on the length of the abstract. How- ever, the suggested length is from 150 to 225 words.
14. KEY WORDS: Key words are technically meaningful terms or short phrases that characterize a report and may be used as index entries for cataloging the report. Key words must be selected so that no security classification is required. Identi- fiers, such as equipment model designation, trade name, military project code name, geographic location, may be used as key words but will be followed by an indication of technical con- text. The assignment of links, roles, and weights is optional.
DD
FORM
1 JAN e4
1473 (BACK)
54
Security Classification
thesM592
Marine fouling organisms in Monterey Har
3 2768 001 89066 8
DUDLEY KNOX LIBRARY