TABLE 17. TEMPORAL CHANGE IN COMMUNITY STRUCTURE OF MACROSCOPIC INFAUNA

AT SHIMMEY BEACH.

For discussion, see text.

Average Number/m*

august 21 December 19 April 13 August

TAXA 1969 @ 1970 19715 19716
Ancinus brasiliensis 80.25 6.3 32.9 10.8
Excirolana salvadorensis 67.88 17.5 13.8 1.2
Cyclaspis sp. 44.75 0.8 -- --
Scolelepis agilis 20.00 7.5 52.1 19.5
Donax Spp. 7.75 0.8 1.7 0.4
Exosphaeroma diminutum 2.63 -- -- --
Lepidopa spp. 1.25 -- -- --
Atylus minikot 1.25 -- -- --
Microprotopus Sp. 1.00 - -- --
Emerita braziliensis 0.50 -- 7 0.4
nemertean 0.50 -- -- --
Dispto sp. 0.13 -- -- --
Trichophoxus floridenus 0.13 -- -- --
amphipod -- 1.2 -- --
magelonid polychaete -- 0.8 -- 0.4
polychaete sp. 3 -- -- 7.5 --
polychaete sp. 4 -- -~ 0.4 0.8
polychaete sp. 5 - = - 0.4
Hippa sp. -- -- 0.4 --
sipunculan -- -- -- 0.8
ophiuroid -- -- -- 0.8

a Average of 80 samples, 0.1 m* each, taken by Dexter (1972).

b Average of 24 samples, 0.12 m* each, taken by FWQA staff.

48


£
wv oO oa 2
= a) 3 GD o
5 S s 3 S
o — S - i=
~ 3 oO oO oo
3 Ss NI = <
Ischnochiton 12/24 14/24 8/20 1/20 3/20
(Ischnoplax) 1-2-3 1-3-4 2-4-6 1 1-1-1
peetinatus (9,740.4) (18.340.7) (13.240.6) (0.4) (1,2)
14.9 12.3 27.7
3.044 2.844 2.765
Ischnochtton 3/24 3/24 2/20 3/20 2/20
(Stenoplax) 1-1-4 1-1-3 1-1 1-1-1 1-1
purpurascens (2.0) (1.7) (0.8) (1.2) (0.8)
Isehnochiton 11/24 12/24 12/20 10/20 4/20
(Ischnochiton) 1-2-2 1-2-2 1-1-2 1-2-2 1-1-2
papillosus (6,040.2)  (8.0+0.3) (6.8#0.2)  (6.8+0.2) (2.8)
9.3 5.4 14.3 51.5
1,255 1.913 0.735 1.176
Chiton viridis 2/24 1/24
1-1 1
(0.7) (0.3)
Acanthopleura +
granulata
GASTROPODA
Emarginula 1/16
phrixodes 1
(0.5
Emarginula 2/20
pumila 1-1
(0.8)
Hemi toma +
octoradiata
Hemitoma sp. 1/20
1
(0.4)
Diodora minuta 9/20 1/20
1-2-2 1
(7,642.9) (0.4)
10.5
2.922
Diodora 2/20
variegata 1-1
(0.8)
Diodora 3/20 1/20 2/16 V16
dysoni 1-1-1 1 1-1 2
(1.2) (0.4) (1.0) (1.0)

112


TABLE 3. NUMBER OF SPECIES NECESSARY TO MAKE UP 50% OF THE INDIVIDUALS
IN EACH ZONE FOR EACH OF 11 CATEGORIES OF MACROINVERTEBRATES UN THE
INTERTIDAL CARIBBEAN REEF FLAT AT GALETA MARINE LABORATORY.

g

°

g 2 P 2 3

= cs) Sa n °o

co —7 ss n =

3 2 2 2 2

Ss o os os

° oO } = 9

Oo a N e 4

ACTINIARIA 2 1 1
OPHIUROIDEA 3 2 1 1

ECHINOIDEA 1 2 1 1 2

AMPHINEURA 2 ] 2 1 3

GASTROPODA 3 3 4 2 4

BIVALVIA 2 1 2 2 2

SIPUNCULA 4 4 3 2 2

POLY CHAETA 3 1 2 2 2

PYCNOGONIDA 2 3 2 2 2

NATANTIA 2 2 2 2 2

REPTANTIA 2 2 3 2 2

14


APPENDIX C

Occurrence of two species of Barbatia in 0.06 m* quadrats on the intertidal
reef flat of Galeta. The survey presented in Appendix B was made before it
was realized that some of the B. dominigensis were actually B. tenera. The
three statistics are as follows, from top to bottom in each unit:

1. Frequency (0.06 m? samples): no. of samples in which species were
present/total no. of samples sorted for these species.

2. Abundance (0.06 m* samples): median plus quartiles of abundance
counts.

3. Abundance (calculated mean and standard error per 1 m?).

oO
LS
°
2 = a < 6
—_ [s} Ss n °o
Lad i= = wn =
‘Ss 2 £ < e
S a o o oO
8 Ss a = Ed
Barbatta 15/18 12/24 12/16 1/16 9/16
dominigensis 1-3-4 1-2-3 1-2-3 1 1-1-3
(41.8#9.8) (16.044.5) (26.0+5.2) (1.0) (16.044.6)
Barbatia 7/18 4/24 7/16 1/16 1/16
tenera 1-1-2 1-1-3 1-1-2 1 1
(8.943.2) (4.0) (10.03.2) (1.0) (1.0)

143


Hippolytidae
Hippolyte
euracacensis

Lysmata
intermedia

Thor
manningt

Processidae
Ambidexter
symmetricus

Processa
bermudensis

Processa
finbriata

CRUSTACEA: DECAPODA:

Porcel lanidae
Petrolisthes
gugosus

Petrolisthes
galathinus

Petrolisthes
armatus

Petrolisthes
sp.

Pachycheles
serratus

138

£
o oO o 2
c — n — a
— cs) S Ww fo}
- i— a— n —
3 2 € < <
S a 8 2 3
=) — N Re 4
1/16
6
(3.0)
1/20
1
(0.4)

1/20 2/20 16 1/16
1 1-1 2 2
(0.4) (0.8) (1.0) (1.0)

1/16
3
(1.5)
1/16
2
(1.0)
1/16 2/16
1 1-2
(0.5) (1.5)
REPTANTIA
9/20 2/20
2-3-5 1-1
(12.4+4.0) (0.8)
2.6
2.366
2/20 1/16 2/16
1-2 2 y-1
(1.2) (1.0) (1.0)
1/20 1/16
1 3
(0.4) (1.5)
1/20
1
(0.4)
17/20 1/20
5-7-11 1
(52.0+7.7) (0.4)
11.0
1.276


RESEARCH REPORTING SERIES

Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into five series These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:

1 Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research

4 Environmental Monitoring

5. Socioeconomic Environmental Studies

This report has been assigned to the ECOLOGICAL RESEARCH series. This series
describes research on the effects of pollution on humans, plant and animal
species, and materials. Problems are assessed for their long- and short-term
influences. Investigations include formation, transport, and pathway studies to
determine the fate of pollutants and their effects. This work provides the technical
basis for setting standards to minimize undesirable changes in living organisms
in the aquatic, terrestrial, and atmospheric environments.

This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161


ASTEROIDEA
Oreaster
reticulatus

Ophidiaster
guildingit
OPHIUROIDEA
Ophiolepis
pauctspina

Ophiocoma
echinata

Ophiocoma
pumila

Ophiocoma
wendtt

Ophionereis
reticulata

Ophioderma
appressum

Ophioderma
brevicaudum

Ophtoderma
brevispinun

Ophioderma

einereum

Ophiodermatid
sp.

£
o
g 4 a 2 5
-_ cS) J wn co}
= S S 3 S
oO £ = - i=
S a J o oO
8 8 a = 2
+
+
8/24 6/24 6/20 5/20 8/20
1-1-2 1-2-2 1-1-2 ]-1-2 2-2-3
(4,321.6) (3,341.4) (3,241.2) (2.841.2) (7.62.4)
1.3 2.0 1.1 5.4 2.4
2.462 2.667 1.429 1.905 1.988
18/24 7/24 2/20 1/20 4/20
2-3-4 1-1-3 1-1 1 1-1-1
(20.344.0)  (3.741.4) (0.8) (0.4) (1.6)
6.1 2.2
1,522 2.618
7/24 1/24 2/20
1-1-4 1 1-1
(6,743.5) (0.3) (0.8)
2.0
6.568
+
3/24 1/24 1/20 1/20
1-1-1 4 2 1
(1.0) (1.3) (0.8) (0.4)
1/24 2/24
1 1-1
(0.3) (0.7)
3/24 3/24
1-1-1 q-1-1
(1.0) (1.0)
1/20
1
(0.4)
2/24 3/20 3/20
1-1 1-3-3 2-2-2
(0.7) (2.8) (2.4)
2/24 1/24
q-1 1
(0.7) (0.3)

108


TABLE 22. SUMMARY AND COMPARISON OF SOME OF THE CHARACTERISTICS OF THE
COMMUNITIES OF ORGANISMS FOULING PLEXIGLAS PLATES ON THE PACIFIC AND
CARIBBEAN SIDES OF THE ISTHMUS OF PANAMA,

Taboguilla Galeta

(Pacific) (Caribbean)
Total No. animal spp. 83 117
Ave. No. animal spp. per month? 27,038.43 S.D. 23.9412.6 S.D.
Total No. tunicate spp. 13 28
Ave. No. tunicate spp. per month? 2.8+1.3 S.D. 4.4+3.8 S.D.
Total No. bryozoan spp. 22 15
Ave. No. bryozoan spp. per month® 8.143.1 S.D. 2,842.9 S.D.

94 = 0,085 with 36 d.f.: not significant

5 c = 0.909 with 36 d.f.: not significant
Fail to reject Ho: the number of animal species seen on any single
monthly or bimonthly collection of settling plates does not differ
significantly between the Taboguilla and Galeta sites.

4 = 11.28 with 36 d.f.: P<0.01
Reject H): conclude that the number of bryozoan species seen on

any single monthly or bimonthly collection of settling plates differs
significantly between the Taboguilla and Galeta sites.

57


Pilwmus sp.

Eriphia gonagra

Domecia
acanthophora

Xanthid sp. F

Pinnotheridae
Pinnotherid sp.

Grapsidae
Pachygrapsus
transversus

Pachygrapsus
marmoratus

Majidae
Acanthonyx
petivertt

Epialtus sp.

Thoe puella

Pitho aculeata

Mithrax (Mithraz)
spinossissimus

£
ov oO oO 2
= CS $ a Ss
an 5 6 a $
g 5 5 S 5
8 Ss a = 2
1/20 16
1 1
(0.4) (0.5)
2/20 1/20 1/16
1-2 1 1
(1.2) (0.4) (0.5)
3/20 16
1-1-1 1
(1.2) (0.5)
2/20 1/16
1-1 1
(0.8) (0.5)
1/20
1
(0.4)

5/20 16/20 6/16 1/16 9/16
1-3-9 3-5-16 1-2-4 1 1-1-4
(9.2#6.2) (54.8412.5) (7.042.9) (0.5)  (13.0+6.1)
1.9 35.9 15.4 16.5
7.194 1.853 2.637 3.889

1/20
1
(0.4)
2/20
1-1
(0.8)
1/20 1/16
1 2
(0.4) (1.0)
3/20
1-1-1
(1.2)
2/16 1/16
1-1 2
(1.0) (1.0)

141


air tube

water level

upper side

branch without
oil oily

branch lower side

branches not ex- tissue

posed to oi] Sy lead by
& July 9
branch
branch exposed
exposed > to oil,
to oil, lower side
upper side

tissue dead at
\ original date

Figure 4. Exszerimental methods for investigating the effects of cil 2

Poeillovora cf, damicornis in the laboratory. For exctanation
see text, exrerizent 3.

68


drift up against the solid outer bands of stilt roots of the forest and
stop, not doing any apparent damage to the standing forest itself.

14. The Caribbean sand beach faunae varied greatly between wet and dry
seasons in terms of species composition and abundances. This was probably
due to changes in substratum composition and/or grinding action of the
sand brought about by heavier wave action during the windy dry season.

15. Animals settle on plexiglass plates in a pattern indicating that re-
cruitment is seasonal in different ways in the two oceans. A larger por-
tion of the Caribbean species were restricted to a specific portion of the
year, but the total dry weight of the fouling community on each plate
varied less obviously with season than it did in the Pacific.


oO
i
i=}
g £ P 2 3
- oO a un °o
= 5 5 2 5
oO £ = _ i=
‘= a oO oO os
fog os °o = 5)
oO od MN e 4
Coralliophila 1/20 4/16
eartbaea 1 1-1-1
(0.4) (2.0)
Anachis catenata 2/20
1-1
(0.8)
Anachis sp. 1 1/20 1/20
1 1
(0.4) (0.5)
Anachis sp. 2 1/20
1
(0.4)
Nitidella nittda 1/16
1
(0.5)
Nitidella sp. 2 1/20 2/20
1 1-4
(0.4) (2.0)
Psarostota 2/20 1/20
moni lifera 2-3 1
(2.0) (0.4)
Cantharus 1/20
tinetus 1
(0.4)
Bailya intricata 1/16
1
(0.5)
Fasctolaria + + +
tulipa
Latirus V6
carintfera 1
(0.5)
Leucozonta 1/20
ocetlata 1
(0.4)
Vasum murteatum + +
Mitra sp. 1/16
1
(0.5)

117


5
2 id aw = a
-_ cS) J n ce}
= 5 s 3 Ss
g 5 5 = 5
8 & 8 = 2
POLYCHAETES
(Families presented
in alphabetical
order)
Ampharetidae
Melinna Nn. Sp. 3/20
1-1-1
(1.2)
Amphinomidae
Eurytho& 17/24 16/24 16/20 5/20 14/20
comp lanata 1-2-7 1-2-4] 1-3-16 1-1-2 1-3-27
(16.3#3.6) (37.3415.1) (27.6+7.0) (2.8) (39.6413.6)
0.6 0.6 0 2.7
1.653 4.575 2.159 3.073
Hermodice 1/24
earunculata 1
(0.3)
Amphinomid 2/20
sp. 1 1-1
(0.8)
Amphinomid 1/20
sp. 2 6
(2.4)
Aphroditidae
Aphrodita 4/24 5/24 5/20 1/20 1/20
n. sp. 1-1-3 1-1-2 1-1-16 1 1
(2.0) (2.3) (8.0) (0.4) (0.4)
Arabel lidae
Arabella 10/24 18/24 10/20 12/20 9/20
mutans 1-3-14 1-8-22 1-4-12 1-2-12 1-5-13
(11,344.9) (45.649.5) (16.845.3) (19.625.7) (18.8+6.5)
0.4 0.8 1.3 2.9 1.3
4.705 1.834 2.497 2,244 2.941
Oenone fulgida 1/24
1
(0.3)
Capitellidae
Dasybranchus 1/24 1/20
lumbricotdes 1 1
(0.3) (0.4)

123




APPENDIX G

Names and present addresses of the authors of each section are given below.
Questions, requests for further details or for general information would
be most efficiently addressed directly to the person responsible for the

specific section.

It is suggested that specific taxonomic questions be

referred to the authority on the subject cited in the Acknowledgments

section.

Sections IV, VIII, IX, XIII:

Sections V, VI, X:

Other Sections:

Charles Birkeland
Marine Laboratory
University of Guam
P.O. Box EK

Agana, Guam 96910

Amada A. Reimer

Department of Biology, Zoology Section
208 Life Sciences Bldg I

Pennsylvania State University
University Park, Pennsylvania 16802

Address questions to either Birkeland or Reimer

All questions concerning Algae:

Joyce Redemske Young
Department of Botany
University of Massachusetts
Amherst, Massachusetts 01002

167


Results and Discussion

The effects of Bunker C oil on the hermatypic coral Porites furcata were
especially interesting in view of the lack of apparent damage upon casual
observation. In brief, the Porites subjected to Bunker C for 1 or 2-1/2
hours appeared quite healthy during the next 61 days, but the difference

in growth increments between corals subjected to Bunker C and controls was
significant (Tables 25 and 26) and there was a significantly greater pro-
portion of branches which failed to grow at all (Table 27). Thus, although
exposure to Bunker C oil was not fatal to the Porites, it had some negative
effect on its physiology which was reflected in its growth. As was previ-
ously mentioned, much of a sessile organism's success in a community, e.g.,
its strength in competition with other sessile species or its ability to
tolerate grazing or predation, depends in part upon its rate of growth.

It is quite conceivable that a decrease in growth rate of the predominant
corals could affect the reef community as a whole.

A comparison of the growth increments of Porites furcata treated with Bunker
C oil and of those used as controls is given in Table 25. The branch tips
that did not grow at all were not included in this analysis but were treated
separately (Table 27). When combined, these analyses amplify the signifi-
cance of our conclusion (Table 26) that the growth rate of Porites was im-
paired by contact with Bunker C oil. When the corals were collected each
time after 61 days' growth and cleaned, they appeared to have not differed
in their growth rates. In fact, the single branch which increased in length
the most (12.4 mm) was on a Porites subjected to Bunker C oil. It was only
through statistical treatment that the reduced rate of growth of corals
treated with oil became apparent. Because of the subtleness of the effect
of oil on coral to the casual observer, the experiment was repeated a second
time in spite of the significant results of the first trial. However, this
is an example of how the minimal effects of an oil spill cannot be adequate-
ly judged on the basis of mortality or apparent condition of the resident
populations.

Each Porites head consisted of several branches. An analysis of variance
was made on the differences in mean growth increments on different heads
between the 5 controls and also between the 10 experimentals in the first
trial. The mean growth of control Porites heads did not differ signifi-
cantly (F = 1.96 with 4, 55 d.f£.; P >0.10). The mean growth rate of
Porites heads subjected to Bunker C did differ significantly (F = 5.51
with 9, 108 d.f.; P <0.005). Since controls and experimentals were treated
at the same time in the same manner except for the treatment with Bunker C,
it would appear that there is much individual variation in susceptibility
to oil pollution.

Although no difference in growth increments was found between the branches
of controls growing in the same areas during the same periods, the growth

63


The lowest numbers of species that constitute over 50 percent of the indi-
viduals in each zone are summarized in Table 3 for each of 11 classes of
animals. Curiously, no matter how many species are in the area and no
matter how abundant or numerous the total class is in the area, there seems
to be most often 1 "relatively abundant" species making up 50 percent of
the total. For invertebrate communities in general, some as remote as
those in decaying oak logs in an English forest (Fager, 1968), at least
half the individuals are made up of about 2 species. The calculated diver-
sity indices (Table 4) correlate with the number of "relatively abundant"
species in a rather imprecise manner. This may lead us to wonder whether
nearly all communities (or zones) are organized around a similar pattern
of common species while certain areas or classes with higher diversity
have only additional rare species. For instance, compare pycnogonids and
polychaetes. The polychaetes are represented by about 4 to 18 times as
many species (Table 2), usually over 100 times as many individuals as pyc-
nogonids (Table 5) and usually a higher diversity (Table 4), but over 50
percent of the individuals in both classes are usually made up by about

2 species.

A vague correlation does exist between diversity and the number of species
required to make up 50 percent of the individuals in a class. Gastropods
and sipunculans are the only classes that sometimes require 4 species
(Table 3) and aré usually the 2 classes with the highest diversities (Table
4). Sipunculans are a particularly "crowded" group of species on the
Caribbean intertidal reef flat whether considering species "packing" (Table
2), the number of "relatively abundant" species (Table 3) or species di-
versity (Table 4).

Tables 2, 3, and 4 are concerned with summarizing relative abundances;
Tables 5 and 6 with absolut abundances. Table 5 compares the average
number of individuals per m“ for twelve taxonomic categories of animals

in each of the zones. On the intertidal reef flat, polychaetes are clearly
the numerically predominant class of motile animals and the Laurencia Zone
is the most heavily populated region. However, the greatest number of
“common” species is found in the Coralline Zone (Table 6) when we arbitrar-
ily define "common" in the absolute sense as having an abundance greater
than 1/m2.

The spatial pattern of the reef flat biota at Galeta is summarized in
Table 1 for sessile species and in Figure 1 for the abundance and variety
of motile animals in relation to sessile species. Spatial heterogeneity
of different zones of the reef flat is defined and measured as diversity
of surface coverage by sessile species, and categories of substrata. The
numbers of common animal species (>1/m2) and the mean diversities of the
10 major categories of motile animals have the same general comparative
relationships in magnitude between zones as do the measurements of spatial
heterogeneity. However, the numbers of algal species and of animal species
differ from the other trends and correlate with each other in that they
reach their lowest values in the Zoanthus Zone. This may be because of

21


Two experiments were set out in the Caribbean in 1972 on 14 April and left
for 59 and 92 days, respectively. In 1972, experiments were set out in the
Pacific on 4 April and left for 59 and 126 days. The Caribbean experiment
was repeated in 1973. The plates were set out on 9 April and left for 60
days.

The surface coverage counts and dry weights were taken by the same proce~
dures as described in Section VIII. The surface coverage counts consisted
of 104 points per side (208 per plate) and 4 plates per line. Each control
average is based on 8 plates from 2 lines and each experimental average is
based on 4 plates.

Results and Discussion

The upper surfaces of Galeta settling plates which were coated with Bunker
C oil had a significantly greater percent coverage of algae than did the
controls (Table 39). This corroborates the tendency for algae to increase
in the presence of Bunker C oil more than in controls which was found in
the Galeta reef flat field experiments (Section XI) and noted in laboratory
aquaria experiments (Section X). Two factors are possibly involved with
the Bunker C effect on algae, viscosity and nutrient supply. In the field
experiments on the Laurencia Zone which is washed by surf and on the sub-
tidal settling plates, animal larvae and algal spores may have a difficult
time attaching to smooth surfaces in surging water. The viscosity of Bunker
C oil may facilitate the attachment of algal spores. However, the same
benefits of Bunker C oil to algae appear to occur in the still water in
aquaria, which implies some aspect other than viscosity. The most unex-
pected result of all was the significantly greater coverage of algae on the
undersides of the Bunker C-treated plates than on the undersides of the
control plates. The coating of the plates with the thick black, tarry
Bunker C oil must have reduced light to a much lower level than that avail-
able to the algae on the undersides of the translucent control plates.

Increased algal growth is not so clearly associated with Bunker C oil on
the Pacific plates. The much more rapid productivity of Pacific Fouling
communities (Section VIII) implies that nutrients may be more limiting to
algal growth in the Caribbean and so additional nutrients from Bunker C
oil may have a greater effect. Secondarily derived carbohydrates or hydro-
carbons may be a possible source of nutrients for organisms. This hypo-
thesis, of course, needs further testing, but it seems to be the best ex-
planation to fit the results to date.

Unlike Bunker C oil, marine diesel oil appears to have a toxic effect on
fouling communities. Dry weight measurements of production showed that
neighboring lines of plates coated with marine diesel oil had significantly
less (about half) biomass of fouling organisms than the nearby controls
(Table 38). If the error of oil added to the measured weight of the com-
munity could be corrected, it would further increase the differences. We
did not attempt to measure the weights of the fouling communities from

92


average of 284 barnacles per m2, Of these, 51 or 18 percent were dead and

harbored a rich fauna of some 32 species of mollusks, 37 species of poly-
chaetes, 3 species of sea anemones, 2 species of sipunculans and several
species of crustaceans, nemerteans and turbellarians (Appendix E). Live
and dead Tetraclita together occupy an average 28 percent of the surface
area available in the zone (Table 8). The rest of the surface area is
mostly bare rock except for a few anemones, patches of Membranipora
tuberculata, M. hastingsae and sponges. The algae present in the zone
(Appendix E) are very small and densely packed and grow close to the sub-
stratum. At first sight the zone appears almost barren at low tide. Aside
from the barnacles and some crabs (Pachygrapsus transversus) which move
about in and out of dead Tetraclita tests or crevices in the rocks, there
are apparently no other animals in the zone. If a collection is taken and
examined with care, over 4,000 specimens belonging to about 90 different
species can be found in an 1 m2 area (Appendix E).

Table 9 shows the number and abundance of taxa, their distribution among
live and dead barnacles, and their physical position with reference to the
barnacles. The first number gives the density or number in a taxon found
per test of dead or live Tetraclita. The second number represents the per-
centage of the specimens of a particular taxon that are found in any par-
ticular niche. In the case of Balanus, 34 percent are associated with the
external surface of live barnacles, 37 percent with the external surface
of dead barnacles and 29 percent with the internal surface of dead barna-
cles. The third number in the table indicates the importance of each taxon
on every niche relative to the total number of specimens of all species
found in the samples. The last number in the table indicates the number
of species found in each niche.

Dead Tetraclita offer several space niches to associated invertebrates:
the external surface of the test; the base of the parapet or largest cir-
cumference of the barnacle where the test is attached to the substratum;
the internal surface of the empty test; the parietal canals, which start
with a large diameter at the base of the test and taper off to a point at
the upper end. Most niches are occupied by a very diverse and abundant
fauna which includes over 50 species. On dead barnacles the number of
specimens associated with a particular niche is greatest on the internal
surface. In order of decreasing importance, other niches are the external
surface and the parietal canals. The number of species, however, is lar-
gest in parietal canals and decreases in the internal surface. The most
important animals in terms of abundance and frequency of occurrence are
three species of Balanus: 8B. tintinnabulum, B. inexpectatus and B. amphi-
trite which were not distinguished to species but counted together. They
are found preferentially on the external surface (Table 9) where they rep-
resent 17.3 percent of the entire fauna associated with dead barnacles.
They are also found on the internal surface of dead barnacles and there
they make up 14 percent of the faunal associates.

28


Patota sp. indet.

Hes ionidae
Ophiodromus pugettensis

Lumbrineridae
Lumbrinereis inflata

Nereidae
Eurinereis n. Sp.

Neanthes pseudonoodti

Nereis callaona

Perinerets elenacasoi

Perinereis sp. indet.

Platynereis dumeri lit

Pseudonerets gallapagensis

nereid indet.

Palmyridae
Bhawania goodet

o
Fi 2 2 g
i= oO - -
= € (a) o
s 5 5 z
2 & 2 a
1/8
1
0.1
1/8
1
0.1
3/8
24
2.8
2/8
2
0.2
1/2 2/12
32 10.8
33.2 0.9
8/8 + 9/12
56 126.6
6.7 11.4
2/8 2/12
50 66.0
6.0 5.9
1/8
1
0.1
1/8 2/12
1 16.8
0.1 1.5
5/8 2 WW/12
15 16 223.2
1.8 16.6 20.0
+ 4/8
5.4
0.5
2/8 2/12
2 1.2
0.2 0.9

153


and tallied into the categories in Table 19 by assuming only one period per
year for each species. The longest possible period for each species in
which no recruitment was observed during the year was subtracted from 12
months and the remainder was considered the recruitment period. If the
longest break was only three months, recruitment was considered to be con-
tinuous throughout the year. The greatest possible break was always used
in the calculations, e.g., records from a single set of l-month settling
plates and a single set of 2-month settling plates would each be considered
as one month of recruitment since we could not be certain that recruitment
had occurred during both months on plates left out for two months. The
presence of a species is, of course, a solid observation while its absence
may be due to sampling error.

The eastern tropical Pacific is a more "seasonal" environment in terms of
magnitude of yearly (and other) fluctuations in several physical parameters
of the environment (temperature, salinity, nutrients, tide levels) and
plankton productivity than is the Caribbean. In view of this, it is most
interesting to compare the degree to which the recruitment of benthic or-
ganisms in these two environments differ in uniformity, "seasonality" and
"unpredictability." In order to do this we first need operational defi-
nitions of these terms. So, for the purpose of these comparisons alone
and in order that workers in other latitudes may compare their organisms
with ours, we make the following ad hoc definitions:

Where n,; = the number of species recruiting to plates in a given month
of one year (Mj) but not on the same month in the next year

(Mo),
Ny = the number of species recruiting to plates in My but not M),

n, = the number of species recruiting to plates in both My and Mp,

= the number of species recruiting to plates in a given month
(M,) but not in the sixth month following (Mg),

Ng = the number of species recruiting to plates in Mg but not My,

and
n= the number of species recruiting to plates in both My and Me>
n,n,
"seasonality" = __i+ f£ and
. +
ny ng + ny

; By t+ 92
"year-to-year variation" =
ny + No tm

These comparisons are given in Table 20 and analyzed statistically in
Table 21.

53


Metalpheus
rostratipes

Salmoneus
ortmannt

Synalpheus
anasimus

Synalpheus
fritamellert

Synalpheus
herricki

Synalpheus
minus

Synalpheus
pandionis

Synalpheus
sp.

Synalpheus
tenutspina

Synalpheus
townsendi

Thunor
rathbunae

£
o o oO 2
= S s "7 o
= 5 s 8 §
g 5 3S s 5S
8 s g = 2
6/20
1-2-4
(4,841.0)
17
3.030
1/20 2/20 4/16 1/16 3/16
1 q-1 1-1-1 1 1-1-3
(0.4) (0.8) (2.0) (0.5) (2.5)
2/20 1/20
1-1 1
(0.8) (0.4)

20/20 3/20 2/16
2-10-36 1-1-2 1-1
(92.8#18.6) (1.6) (1.0)

32.5
1.519
1/20
1
(0.4)
16/20 1/20
1-6-15 1
(42.048.9) (0.4)
14,7
1.512
4/20 1/20
q-1-1 1
(1.6) (0.4)
1/20
1
(0.4)
3/20 1/16
2-2-5 1
(3.6) (0.5)
14/20 1/20
1-4-11 1
(3.2#1.0) (0.4)
9.6
1.005
10/20
1-6-13
(18. 746.4)
7.0
2.646

137


All the Laurencia and Halimeda present within the 0.06 m? frame was picked
up by hand or by using a paring knife. Samples were placed in bottles iden-
tified with their placement numbers. In the laboratory, Halimeda and
Laurencia were separated and washed in running seawater over a screen to
removed any sediment or organisms caught in the blades. The algae were
fixed in 5 percent formalin in seawater for 2 days, dried to constant weight
and weighed in a Mettler balance.

Results and Discussion

Four collections were made (Table 7); the first collection was taken after
a period of continuous coverage of seawater at high tide levels for at least
1 week previous to the sampling, the other three after a period of at least
1 week of prolonged midday exposures. An analysis of variance on the bio-~
mass of Laurencia found in the four collections showed that there was a
significant difference in biomass (Table 7). For some reason the Laurencia
biomass to the left of the transect line seemed more sparce than the lush
growth to the right of the line. A test applied to the 36 samples of the
May 2nd collection showed the difference to be insignificant (t = 1.57,

P >0.05).

Although the changes in biomass of Laurencia papillosa were statistically
significant, the changes would not be obvious without careful quantitative
sampling. Our results are in striking contrast to those of Thompson (1969)
and Bernatowicz (1952) who found marked seasonal changes in biomass and
surface coverage of many algal species in Florida and Bermuda. Although
technically the Florida and Bermuda studies were in the temperate zone
(above the Tropic of Cancer) while ours were done in the tropics, most of
the species are common to our studies. It suggests that the same commu-
nity may have different dynamic properties in different regions. A part
of this difference may also be due to our studies not being comparable
with theirs. Casual observations on species outside our transect (e.g.,
Padina sp.) suggest that other species show more temporal change than those
we studied. Further, the data of Croley and Dawes (1970) indicate much
less seasonal change in Florida than those of Thompson (1969).

Other aspects of the biology of organisms in our studies, such as reproduc—
tion and larval settlement, often show more periodicity than biomass or
surface coverage (Section VIII). The Caribbean fouling organisms were
found to be significantly more "seasonal" than those in the Pacific by

this comparison.

24


It can be seen that when using our definition of seasonality, there is much
less seasonality in the Pacific. It is surprising in view of the greater
amplitude of seasonal fluctuations of physical parameters in the Pacific.
But these differences between Pacific and Caribbean seasonality are shown
to be statistically significant in Table 21 and this conclusion is also
corroborated by the significantly greater proportion of animal species
which recruit throughout the year in the Pacific (Table 19) and by the
comparisons in Table 22 which indicate a greater total number of animal
species, but no more in any given month, in the Caribbean. Although the
total number of animal species recorded on settling plates is 41 percent
greater in the Caribbean, the average number of animals recorded in any
given comparable settling plate collection or on any given month is not
significantly different (Table 22). There tends to be more "repeats" from
month to month in the Pacific. A significantly greater proportion of
Pacific species than Caribbean species can be found recruiting throughout
the year.

A confounding factor exists in this analysis. Rather than being more sea-
sonal, individual species could merely be more common at Taboguilla. Since
observed presence is hard data, while absence of a species could be due to
sampling error, common species would be recorded more regularly than rare
species and would thus be less likely to be regarded as "seasonal." While
we cannot disregard this possibility, a number of species do appear to be
seasonal. Even those species which are found to be present throughout the
year in our qualitative analysis appear to have definite quantitative sea-
sonal trends in abundance of recruitment. Balanus trigonus is thus found
to recruit throughout the year but shows a tremendous increase in abundance
each late dry season (February through April). The quantitative patterns
of other presumably continuous settlers do not show evidence of such a
regular pattern.

In a few instances, we have what appear to be identical species on the
settling plates in both oceans. In these cases, they appear to have simi-
lar reproductive periods in spite of the great differences in their physical
environments. As examples, the brachiopod Discinisca strigata appears to
set only in December through February in both oceans, while the tunicate
Diplosoma macdonaldi sets throughout the year. There is a statistically
significant predominance of bryozoan species on the Pacific settling plates
and ascidian species on the Caribbean settling plates (Table 23). This
reflects the clear prevalence of this pattern in the surrounding community.

While recruitment is restricted to certain times of the year for a larger
portion of the species in the Caribbean than in the eastern Pacific, the
total dry weight production does not show a significant change with season
(Table 24). In contrast, there are extreme seasonal changes in dry weight
production of the fouling community on the Pacific plates (Table 24), but
the predominant species are present throughout the year. Thus, recruitment
is seasonal in the benthic communities in both oceans, but in opposite ways:
seasonal in organization or quality in the Caribbean in contrast with pro-
duction or quantity in the eastern Pacific.

56


TABLE 38. COMPARISON OF THE DRY WEIGHTS OF CARIBBEAN FOULING ORGANISMS
WHICH GREW OVER A 60-DAY PERIOD ON CONTROL PLEXIGLAS PLATES AND PLEXI-
GLAS PLATES COATED WITH MARINE DIESEL OIL. 4

Dry weight
Treatment (gms/plate) t d.f. P
Control 1.03 + 0.17
2.79 14 <0.02
Marine Diesel 0.55 + 0.04

a Each sample is composed of four plates on each
of two lines.

93


Serpulid sp. 4

Serpulid sp. 5

Serpulid sp. 6

Serpulid sp. 7

Serpulid sp. 8

Serpulid sp. 9

Serpulid sp. 11

Spionidae
Boeeardia proboscidea

Boceardia tricuspa

Syllidae
Autolytus cf. magnus

Haplosyllis spongicola

Odontosyllis sp. indet.

Opisthosyllis brunnea

oO
= g 5 s
< S = =
= = fe) <
p S s 3
o s s Pp
= p ey et)
2 & & 3
3/8
12
1.4
V/8
13
1.5
1/8
1
0.1
4/8 §/12
93 9.0
11.2 0.8
V/8
1
0.1
1/8 7/12
4 13.8
0.5 1.2
2/12
1.2
0.1
2/8 1/2 5/12
8 48 58.8
0.9 16.3 5.3
9/12
24.6
2.2
2/12
18.0
1.6
2/16
5.4
0.5
1/8 1/12
1 1
0.1 0.1
1/8 12/12
21 42.0
2.5 3.8

156


£
fo}
co oo o c—
= a) g a s
- i= rms n 4
— o o— oO —
oO LS <7 _ i
LS a o oo ci]
o oC is) = 9
(=) aT nN e <=
Cerithiun 1/16
litteratum 3
(1.5)
Bitttum vartun 1/16
1
(0.5)
Opalia erenata 1/16
1
(0.5)
Opalia pumilo 1/16
1
(0.5)
Epitontum 2/20
candeanum 1-1
(0.8)
Epttonium +
lamellosum
Epitonium 1/20
occidentale 1
(0.4)
Epitonium sp. 1 1/20 W16
1 1
(0.4) (0.5)
Baleis 1/16
intermedia 1
(0.5)
Baleis sp. 1 1/16
1
(0.5)
Cheila 1/16
equestris 1
(0.5)
Hipponia 8/20 14/20 9/16 4/16
antiquatus 1-1-3 2-3-4 1-1-4 1-1-2
(6,843.0) (22.846.6) (9.043.0) (2.0)
9.4 38.2 41.9
3.676 2.254 1.882
Hipponia 2/20
subrufus 3-4
(2.8)

115


TABLE 71. RELATIVE IMPORTANCE OF DIFFERENT SPACE NICHES FOR COMMON
SPECIES ASSOCIATED WITH rETRACLITA STALACTIFERA PANAMENSIS. Calcu-
lations are based on Table 10.

Per cent of” Per cent of
Per cent total fauna common
of total (Balanus species
Niche fauna excluded) _present
live 25 6 79
External surface
dead 32 15 42
live 0.2 0 21
Internal surface
dead 25.8 43 80
live 0 0 37
Parietal canals
dead 7 36 71
live 26 6 92
All niches
dead 74 94 87

34


All corals used in these experiments had filamentous algae associated with
them around the bases of the colonies and branches at the time the experi-
ments were begun. In the five control aquaria not subjected to Bunker C
oil, the algae maintained itself at about the same levels. In each of the
five aquaria previously treated with marine diesel oil, the algae grew more
lush. The five aquaria previously containing Bunker C oil each grew strands
of algae, especially blue-green algae (Cyanophyta), three to five times as

lush as any of the control aquaria or aquaria previously containing marine
diesel oil.

76


15

16

17

18

19

20

21

22

23

24

25

26

27

Characteristics of mangrove samples from Galeta. A description
of the degree of spatial heterogeneity.

Size estimates of probable habitats available to plants and
animals in mangrove samples.

The mean frequency of occurrence of plant phyla and animal
classes in 0.125 m* intertidal quadrats taken at the edge
of a mangrove forest.

Temporal change in community structure of macroscopic in~
fauna at Shimmey Beach.

Abundances of macroscopic organisms found in three zones
of a sandy beach.

A comparison of lengths of recruitment periods for benthic
animals on the Pacific versus the Caribbean as estimated
from animals settling on Plexiglas plates.

Degree of "seasonality" and “year-to-year variation" in
recruitment of animals to settling plates.

Chi-square test of the significance of differences between
Taboguilla and Galeta settling plate communities in terms
of the categories in Table 20.

Summary and comparison of some of the characteristics of the
communities of organisms fouling plexiglas plates on the
Pacific and Caribbean sides of the Isthmus of Panama.

Comparisons of predominance of certain bryozoans and tuni-
cates in Pacific and Caribbean fouling communities.

Rates of increase in dry weight of the communities of fouling
organisms on Plexiglas plates.

The effect of exposure to Bunker C fuel oil on the growth
rate of Porites furcata.

A comparison of mean growth increments in Table 25 showing
statistical significance of physiological stress.

A comparison between controls and experimentals of the

proportion of live branch tips that failed to grow during
61 days following initiation of the experiment.

xi

Page

43

44

48

49

54

55

55

57

58

59

64

65

66


PREFACE

This report presents the results of a three-year study on the intertidal
marine communities near the Galeta Point Laboratory following the spill
of approximately 20,000 barrels of Bunker C and marine diesel oil during
the breakup of an oil tanker about three miles from the laboratory.

Since the laboratory was new and still unoccupied at the time of the
spill, no baseline data on marine organisms were available for comparison
so the damage caused by the spill on the local marine communities could
not be evaluated precisely. It was apparent from the literature that
adequate data were not available for any Caribbean intertidal reef flats.
We accordingly had to devote the first two years of the study primarily
to compiling baseline data for the marine community on the reef flat to
provide background information for experimental tests of effects of oil.
This base of information is presented in the appendices and is discussed
in the first half of the report. The second half of the report is con-
cerned with the experiments testing the effects of oil.

Throughout the study, we often observed patches of oil about 15 to 60 cm
in diameter wash up against the foundation of the laboratory at high tide
or during onshore winds and other patches which stuck to the algae and
animals in the reef community at low tide and during calm seas. These
oil patches presumably were coming from ships clearing ballast tanks or
perhaps sometimes from accidents in operations at the nearby refinery or
Panama Canal fuel piers. Visitors to the laboratory from other parts of
the world would sometimes comment on these irregular but not infrequent
oil patches or "blobs" as being of more immediate and personal concern
to them than were the less frequent major oil spills. They would ask
whether these small patches had significant effect on the intertidal mar-
ine communities. Because the small patches of oil were of more frequent
concern and yet perhaps have received less attention in previous studies
than the massive oil spills, our field studies were set up as experiments
with controls using one meter square quadrats as the size of the repli-
cates. We also used one meter square quadrats rather than larger ones

in order to prevent undue damage to the reef from our experimental pro-
cedures and to protect other on-going research projects.

Therefore, because of the frequent occurrence of small oil patches, the
widespread interests in their effects, the agreement with authorities to
release only a small amount of oil into the environment, and for the
general condition of the study sites near the laboratory, our field was
restricted to experimental quadrats of one square meter in size as was
outlined in the contracted program.

In addition to the field studies on entire communities, experiments were
performed which were designed to concentrate on specific effects of oil,

ili


139

¢
io}
g g Ps 2 &
-_ [} Ss wn ro}
load i—? Pm Yn =
@ 2 < ~ €
5 F 3 2 3
3 a N - <
Pachyche les 8/20
chacet 4-5-6
(16.845.2)
3.6
2.369
Pachychetles 12/20
susanae 1-3-4
(15.6#4.4)
3.3
2.078
Pachy che les 3/20
eristobalensis 1-1-2
(1.6)
Clastotoechus 1/20
nodosus 1
(0.4)
Megatlobrachtum 7/20
roseun 2-3-4
(8,843.2)
1.9
2.684
Megalobrachiun 5/20
poeyt 1-1-2
(2,841.2)
0.6
1.905
Megalobrachium 3/20
soriatum J-1-1
(1.2)
Leucosiidae
Uhltas limbatus 2/20 2/16
1-1 2-2
(0.8) (2.0)
Xanthidae
Paraltomera 20/20 2/20 2/16
dispar 6-21-40 1-9 1-1
(23.744.2) (4.0) (1.0)
40.3
1,556
Platypodia 5/20 1/20 7/16
spectabi lis y=-1-1 1 1-2-2
(2,440.6) (0.4) (7,042.9)
0.5 15.4
1.333 1.758


Live Tetraclita also have an important number of species associated with
the external surface of the test. With the exception of the mollusks
Hipponix panamensis (only found on dead barnacles) and Siphonaria maura
(only found on live barnacles), the same species are found associated with
live and dead Tetraclita (Table 10). However, the variety of the fauna
associated with each dead barnacle is far greater than that of the fauna
associated with each live one (Table 10). In terms of abundance of speci-
mens, the tests of dead Tetraclita support 74 percent of the animals (Table
11) although only 18 percent of the tests are of dead Tetraclita (Table 8).

SUCCESSION OF INVERTEBRATES IN TESTS OF DEAD TETRACLITA

The first animals to invade and occupy the empty tests of dead Tetraclita
were the crabs, Pachygrapsus transversus. No other animals colonized the
spaces during the first 14 days after the barnacles were killed.

Colonization of empty tests started within 32 days and the abundance of the
fauna increased steadily for about 6 months. From then on it fluctuated
slightly. If some of the more abundant species are considered separately,
each had a different pattern of change with time (Figure 2). The polychaete
Pseudonereis gallapagensis showed sharp fluctuations in abundance. The
mollusk Sphenia fragilis increased slowly, reaching a maximum abundance
after 9.8 months, then decreased but maintained itself for the rest of

the period for which data is available. Serpulid polychaetes appeared in
the collections at the same time as Sphenia, but their abundance increased
at a more rapid rate, then decreased more dramatically. The Balanus spe-
cies were the first to achieve dense populations, but their abundances
fluctuated from then on.

The number of species found in each collection is given at the bottom of
Table 12 and in Figure 3. The diversity was quite low initially, but it
increased rapidly to reach a peak after 9.8 months. The diversity dropped
considerably in the next collection taken during the same month. The lat-
ter collection gave the largest number of species and the drop in diversity
was due to a drastic change in the relative abundance of the species, mostly
because of a predominance of Balanus spp. The diversity increased again
and reached a maximum after 13 months and at this point it also approached
the theoretical maximum. If only the number of different species was taken
into account (Figure 3), the highest diversity was reached after 9.8 morths
and then there was a drop. From Table 12 it can be seen that the species
that drop out are the rare ones, with relative abundances below 1 percent.

After Tetraclita tests are heavily colonized by a mixed fauna, they are
structurally weakened by the burrowing animals, especially by the bivalve
Lithophaga aristata, and are broken by wave shock and washed away. Space
is thereby cleared for settlement of new Tetraclita. Boring organisms
force a pattern of repeated succession or cyclic changes in the communi-
ties dominated by barnacles. The data in Table 13 demonstrate that the

31


Abietinaria

Chthamalus

Littorina

Anach s lyrata

Anachts boivini

Anachis fluctuata
Anachis fulva
Anachis rugosa

Anachis varia
Anachis diminuta
Nassarius exilis
Opeatostoma pseudodon
Mitra lens

Conus purpurascens
Conus fergusoni
Crassispira discors
Onchidella (?binneyi)

Onchidella (?hildae)

Siphonaria maura

BIVALVIA
Arca mutabilis

Brachidontes puntarenensis

Brachidontes semilaevis

+ + + t+ He +

150

+

wy Tetraclita

Nn

n
=-a~N ons]
_o

won FN

.

3/12
27.0
8.6

7/12
21.0
6.7

10/12
70.8
22.7

9/12
88.8
28.5

wie
0.02
3/12

6.6
0.3

10/12
830.4
37.3


were left with Bunker C oil for 1 hour, four in the other two buckets were
left with Bunker C oil for 2.5 hours and the remaining four corals were
left in two buckets with pure seawater as controls for 2.5 hours. Since
no significant difference was found between the growth of corals exposed
for 1 hour and 2.5 hours, all corals were exposed for 2.5 hours during the
second experiment.

When removed from the buckets, the corals were replaced in the Porites bed
at a depth of 4.6 m near the laboratory. In order to distinguish between
the experimentals and controls, wire bag fasteners were twisted about the
base of each coral head, 1 on each of those from 1 hour in oil, 2 on each
from 2.5 hours in oil, and 3 on each of the controls. Except for the last
step in the entire process, the corals were transferred between containers
within water, never breaking the surface. In the last step, however, the
oil was poured off and the corals, coated with a film of oil, were placed
in buckets of seawater by being lifted through air. The controls were also
transferred through air.

Twenty-four hours later, the corals were observed in their field location.
All corals appeared quite healthy, including those treated with Bunker C.
All polyps were expanded to the same degree as those of the surrounding
natural population. Effects of oil treatment were not apparent upon casual
observation.

After 61 days in the field, both controls and experimentally treated Porites
were collected and sprayed with water to remove the living tissue. The tips
of the branches were filed by hand down to the center to that a flat, lon-
gitudinal section was provided for growth measurement. The measurement was
made with vernier calipers to the nearest 0.1 mm of the distance between
the apex of the pink-stained portion and the tip of the branch.

Before designing the experiment to test the effects of Bunker C oil on
Porites furcata, we had already anticipated that growth increments of coral
would vary greatly from location to location and from month to month. This
variability could not be separated from the differences due to the effects
of oil if all the data from controls were lumped together and compared with
the data from all corals treated with Bunker C oil. Therefore, the statis-
tical design of the growth experiment was a simple randomized block design
and the data were analyzed by a paired difference test. A comparison of
growth increments between corals used as controls and corals treated with
Bunker C oil were made for each location and time period to eliminate the
effects of variations between time periods and locations and to yield more
accurate information on the mean difference in growth due to stress from
treatment with Bunker C oil. Three difference measurements were utilized
to test the null hypothesis that the average difference is equal to zero, |
This is equivalent to stating that the mean growth increments are the same.

62 . .


colonies. Colony 1 in marine diesel oil, for instance, showed a 2.94 per-
cent increase between.27 April and 10 June, and this represents a growth of
tissue to cover 64 mm“ of surface.

Several colonies in the third experiment showed extensive "bleaching" (loss
of their characteristic brown color) due to a massive loss of symbiotic
zooxanthellae. Most bleaching occurred within 5 to 13 days of the experi-
mental setup and, except for colony 3 in marine diesel oil and which was
bleached towards the end of the experiment, all the others recovered by the
third observation time, 27 days after experiments were initiated. Colony 3
in marine diesel oil was also unusual in that bleaching disappeared in the
lower oil-treated side by the second observation, but it recurred by the
fifth observation and then it affected both sides and all the branches of
the colony. Although bleached polyps seemed to regress in size (evident
especially in the smaller tentacles) there was only one instance where
previously bleached tissue was dead at the next observation.

Table 29 details the percentages of live and bleached tissue remaining on
upper and lower branches which were exposed to oil and on upper and lower
branches not exposed to oil. The purpose of this table is to permit sev-
eral analyses to find the effects of, and interactions between, the factors
of oil and light in their effect on corals. Seventy-one days after being
exposed to oil for 0.5 minutes, corals do not display a significant differ-
ence in living tissue left on upper and lower branches (t = 1.33, d.f. 16,
P >0.05) or on oily and nonoily branches (t = 0.14, d.f. 13, P >0.05).

If an analysis of variance (Table 30) is conducted on the percentage of
tissue bleached within five days after 0.5 minutes exposure to marine diesel
or Bunker C oils, it becomes clear that the variation between the colonies
is greater than the differences due to treatment. The factors analyzed are
the presence or absence of oil and the different amount of light received
by upper and lower surfaces of the branches. The variance ratios are smller
than expected for both colonies and treatments and therefore the percentage
of tissue bleached is not significantly different (P >0.05) between colo-
nies or between treatments. The same analysis applied to the percentage

of live tissue present on the coral after 109 days of the oil application
(Table 30) produces similar results.

The results of similar experiments performed on other species of hermatypic
corals are given in Table 31. Psammocora stellata is not clearly affected
by Bunker C or marine diesel oils, but physiological stress or unseen damage
was not measured by growth increments in comparison with controls. The
effects of Bunker C and marine diesel oils on Pavona gigantea and Porites
furcata did not appear until after a period of about two weeks following
the exposure to the oil. After 93 days, both Bunker C and marine diesel
oils were seen to have detrimental effects on both Pavona and Porites. As
with Pocillopora, both Pavona and Porites were more severely harmed by
Bunker C oil than by marine diesel oil.

771


ENVIRGNMENTA|
PROTECTION

AGENCY
EPA-600/3-76-028 DALLAS, TEXAS
May 1976 Ecological Reseapipaaiay

SURVEY OF MARINE COMMUNITIES IN
PANAMA AND EXPERIMENTS WITH i

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V AGENCY

©,

Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Narragansett, Rhode Island 02882


SECTION XIV
REFERENCES

Anonymous. 1970. Navoceano biologists study marine fouling; use foulers
to detect water pollution. U.S. Naval Oceanographic Office Bulletin No.
5-71:1-3.

Bernatowicz, A. J. 1952. Seasonal aspects of the Bermuda algal flora.
Papers of the Michigan Academy of Science, Arts and Letters. XXXVI:3-8.

Birkeland, C., F.-S. Chia and R. R. Strathmann. 1971. Development, sub-
stratum selction, delay of metamorphosis and growth in the seastar, Medi-
aster aequalis Stimpson. Biol. Bull. 141(1):99-108.

Blumer, M., G. Souza and J. Sass. 1970. Hydrocarbon pollution of edible
shellfish by an oil spill. Woods Hole Oceanographic Institution Reference
No. 70-1, Unpublished Manuscript. 14 pp.

Brongersma-Sanders, M. 1957. Mass mortality in the sea. In: J. W.
Hedgpeth (ed.), Treatise on Marine Ecology and Paleoecology. Vol. I,
Ecology. Geol. Soc. Amer. Mem. 67:941-1010.

Carthy, J. D. and D. R. Arthur (eds.). 1968. The biological effects of
oil pollution on littoral communities. Supplement of Vol. 2 of Field
Studies, Field Studies Council, London. 198 pp.

Croley, F. C. and C. J. Dawes. 1970. Ecology of the algae of a Florida
Key. I. A preliminary checklist, zonation, and seasonality. Bull. of
Mar. Sci. 20(1):165-185.

Dayton, P. K. 1971. Competition, disturbance, and community organization:
The provision and subsequent utilization of space in a rocky intertidal
community. Ecol. Monogr. 41:351-389.

Dexter, D. M. 1972. Comparison of the community structures in a Pacific
and an Atlantic Panamanian sandy beach. Bull. Mar. Sci. 22(2):449-462.

Fager, E. W. 1963. Zooplankton species groups in the north Pacific.
Science 140(3566) :453-460.

Fager, E. W. 1968. The community of invertebrates in decaying oak wood.
J. of Animal Ecol. 37(1):121-142.

Glynn, P. W. 1968. Mass mortalities of echinoids and other reef flat

organisms coincident with midday, low water exposures in Puerto Rico.
Mar. Biol. 1(3):226-243.

97


minuta, 112
vartegata, 112
Diplodonta punetata, 120, 166
Diplosoma maecdonaldt, 56
Discinisea strigata, 56, 107, 15]
Dispio sp., 48
Dodecacerta concharum, 124, 152
Domecia acanthophora, 141
Donax spp., 48, 49
Dorvillea cerasina, 152
rubrovittata, 124
Drupa nodulosa, 116, 145
Dynamenella aff. acutitelson, 159
n. sp. A, 159
setosa, 159
sp. 1, 159
sp. 2, 159

echinoderms, 18

Emarginula phrimodes, 112
pumila, 112

Emerita braziltensis, 48, 49

Enteromorpha flexuosa, 146
sp., 102

Epialtus sp., 141

Eptphellia n. sp., 106

Epttontwn candeanum, 115
lamellosum, 115
nitidisca, 148
occidentale, 115
sp. 1, 115

Eriphia gonagra, 141
squamata, 161

Erycina emmonsi, 120
periscoptana, 120

Erythropodium cartbaeorum, 11, 105

Eteone sp., 154

Eucheuma echinocarpum, 103

Eulalta myriacyelum, 154, 164
viridis, 37, 154

Eumida bifoliata, 154

Eunice afra, 125, 164
antennata aedificatrix, 125
aphroditois, 125, 164
caribaea, 85, 86, 125, 164
filamentosa, 125
sp., 125, 152
websteri, 125

171

Eupleura nitida, 149
Eupleurodon trifurcatus, 160
Eupolymnia nebulosa, 132, 157, 164
Eurinerets n. sp., 153
Eurycyde raphiaster, 133

sp., 133
Eurythoé complanata, 123, 163
Exetrolana slavadorensis, 47, 48, 49
Excorallana aff. tricornis, 159
Exosphaeroma diminutun, 48

Fartulum sp., 148
Fasciolaria tulipa, 117
Favia fragum, 107
Fissurella angusta, 113
barbadensis, 113
mierotrema, 37, 148
rugosa, 148
virescens, 36, 148
Fostella sp., 104, 147
Fossarus atratus, 37, 149
Fossarus megasoma, 149

Gastrochaena hians, 121
gastropods, 2, 21, 165, xi
gelidiale, 162
Geltdiella acerosa,
sp., 147
Gelidiwn pusillun, 104
Geodia sp., 163
Giffordia indica, 102
Glycera omycephala, 126, 164
sp., 126
tesselata, 126
Gnathophyllum americanum, 135
panamense, 160
Golfingia, 41

12, 104

sp., 12]

sp. 1, 163
sp. 2, 163
sp. 3, 163
sp. 4, 163

Gontada acicula, 126
Gontotrichium alsidit, 104
Gonodactylus austrinus, 134

bredini, 134

cerstedii, 134

sp., 134


120

£
g 2 ¥ 2 2
-_ V8 J n fe]
- i= = wn 4
: 2 = 8 2
S a oO o oS
° oO Oo = 9
Oo a N e 4
Diplodonta 7/20 7/16 1/16 3/16
punetata 1-1-1 1-1-2 2 1-2-3
(3,241.1) (5.0£1.7) (1.0) (3.0)
1.1 3.3
0.714 1.600
Lueina 1/16
pensylvanica 1
(0.5)
Phacoides 1/20
pectinatus 1
(0.4)
Codakia 2/20 3/20 1/16 2/16
orbiecularis 1-1 1-1-2 2 1-1
(0.8) (1.6) (1.0) (1.0)
_.«Codakia costata 2/16
1-3
(2.0)
Codakia 1/20 1/16 1/16
orbiculata 1 1 1
(0.4) (0.5) (0.5)
Chama 1/20 1/20
macerophy lla 1 1
(0.4) (0.4)
Pseudochama arcinella +
Erycina 1/20
pertscoptana 1
(0.4)
Erycina emmonst V/ “0
(0.4)
Tellina fausta 1/16 1/16
1 1
(0.5) (0.5)
Strigilla sp. 1/20
1
(0.4)
Macoma tenta V wo
(0.4)


Abietinaria
Chthamalus
Tetraclita

Littorina

GASTROPODA

Fissurella microtrema ie
0.6
0.2

Fissurella rugosa +

Fissurella virescens

Notoaemea filosa + 1/12
0.6
0.2

Patelloida semirubida A 12
on6

Tegula panamensis +

Tricolia phastanella ane
1.3

Nerita scabricosta

Nerita funiculata + + 5/12
3:0

Littorina aspera

Littorina dubiosa +

Aorotrema Sp. +

Cyclostremiscus panamensis +

Fartulum sp. +

Caecum spp. + +

Modulus disculus + +

Tripsycha tulipa

Cerithium stercusmuscarum +

Cerithium gemmatum +

Epitontum nitidisea

Hippontx grayanus + +

Hipponiz panamensis + 10/12
26.0
8.3

Hippontx pilosus +

148


DISCLAIMER

This report has been reviewed by the Environmental Research Laboratory,
U.S. Environmental Protection Agency, and approved for publication.
Approval does not signify that the contents necessarily reflect the
views and policies of the U.S. Environmental Protection Agency, nor does
mention of trade names or commercial products constitute endorsement or
recommendation for use.

li


Glynn, P. W., R. H. Stewart and J. E. McCosker. 1972. Pacific coral reefs
of Panama: structure, distribution and predators. Sonderdruck aus der
Geologischen Rundschau Band 61(2):483-519.

Johannes, R. E., J. Maragos and S. L. Coles. 1972. Oil damages corals
exposed to air. Marine Pollution Bulletin 3(2):29-30.

Lane, F. W. 1924. Effect of oil pollution of coast and other waters on
public health. Publ. Health Rept. 39:1657.

Lane, F. W. 1925. The effect of oil pollution on marine wildlife. Rept.
U.S. Commiss. Fish. 1925, App. 5.

Loosanoff, V. I. 1964. Variations in time and density of settling of the
starfish, Asterias forbesi, in Long Island Sound during a twenty-five year
period. Biol. Bull. 126:423-439.

MacNae, W. 1968. A general account of the fauna and flora of mangrove
swamps and forests in the Indo-West Pacific Region. In: F. S. Russell
and M. Yonge (eds.), Advances in Marine Biology, Academic Press, New York,
pp. 73-270.

Murphy, G. I. 1968. Pattern in life history and the environment. Am.
Nat. 102(927):391-403.

Nelson-Smith, A. 1968. Biological consequences of oil pollution and shore
cleansing. In: Carthy, J. D. and D. R. Arthur (eds.), The Biological
Effects of 0il Pollution on Littoral Communities. Supplement of Vol. 2 of
Field Studies, Field Studies Council, London, pp. 73-80.

Nicholson, A. J. 1933. The balance of animal populations. J. Animal
Ecology 2:132-178.

North, W. J., M. Neushul and K. A. Clendenning. 1965. Successive biologi-
cal changes in a marine cove exposed to a large spillage of mineral oil.
Symp. Poll. mas. Micro-org. Prod. petrol. Monaco 1964:335-354.

Orton, J. H. 1925. Possible effects on marine organisms of oil discharged
at sea. Nature 115:910-911.

Rutzler, K. and W. Sterrer. 1970. Oil pollution damage observed in trop-
ical communities along the Atlantic seaboard of Panama. BioScience 20(4):
222-224.

Sanders, H. 1970. Testimony of Howard Sanders before the Antitrust and
Monopoly Subcommittee, United States Senate, August 11-13, 1970.

98


criticism against this tabular presentation of descriptive statistics may
be that the pile of 5 numbers in each species-zone unit is bulky. But
having it in one location is more efficient that in 5 sets of tables. The
table is basically similar to that of E. W. Fager on the invertebrates in
decaying oak wood (1968) or plankton (1963). The 5 statistics are briefly
discussed from top to bottom in order of their organization in Appendices
B, C, and D.

The first line in each set of statistics refers to frequency, the number
of samples in which collections of the species were obtained over the total
number of samples sorted for this species. Frequency is a very important
index with which to judge the spread of the species within the zone, to
evaluate its significance in the zone and to evaluate the reliability of
other statistics such as "fidelity."

"Fidelity" is a measure of the degree to which a species is confined to one
zone. This is not presented directly as an additional line to the unit of
statistics because it can be easily observed by comparing the frequency fig~
ures of the species through the zones. For instance, note that Paraliomera
is quite restricted to the Coralline Zone, each polychaete species is dis-
tributed through all zones but each is particularly abundant in one zone
and Arca is fairly uniformly distributed through all zones. Fidelity is an
indication of an ecological characteristic of each species which is very
important for both the baseline and pollution studies. For most species,
each zone is a physically and biologically different environment. If a
species is generally restricted to one zone it may be regarded as a special-
ist, while if found fairly uniformly throughout most zones it may be regard-
ed as adapted to a wide range of conditions. It may be hypothesized that
wide-ranging species may be more tolerant to oil pollution than highly
localized species. This definition of degree of generalization of a species
based on fidelity to a zone is also of particular interest to our baseline
studies. The baseline studies are, in part, a comparison of the structure
of intertidal communities in mild but unpredictable environments (Caribbean,
Galeta) with those in harsh but predictable environments (Pacific, Paitilla).
The degree to which the predominant species are generalists or the propor-
tion of species which are of restricted range in the communities occupying
these environments of opposite physical characteristics is of theoretical
interest for several reasons. Further, these same comparisons will be ex-
tended to inspect the species characteristics between the zones within each
of the intertidal ranges under study.

Abundance is described in the second and third lines in two manners, in
median plus quartiles (second line) and in mean plus standard error of the
mean (third line). Since most intertidal invertebrates are quite aggregated
in their dispersion, the abundance count data do not resemble a normal dis-
tribution. Thus the mean plus standard error is not an appropriate abun-
dance statistic and the median plus quartiles is much more informative be-
cause it provides a more precise record of aggregation. Examples demonstra-
ting the definitive superiority of the median and quartiles in terms of

19


a few meters from the first triplet, and also places at 1 meter intervals,
were used to study the effects of oil on the recruitment of invertebrates
to empty Tetraclita tests. For the latter study, all the barnacles in a
quadrat were killed and the tests were washed thoroughly with seawater to
clean out the remains of the animal. In each triplet one quadrat was
sprayed with a 1:1 mixture of Bunker C:marine diesel, one was sprayed with
marine diesel and one was left as control. In order to have an idea of

the flgra and fauna present in the study site at the time of pollution, two
0.10 m“ samples were scraped from the rock, and two clumps of Tetraclita

(7 barnacles each) were collected in the neighborhood of the experimental
quadrats. The experiments were carried out at low tide. The area remained
exposed for about 5 hours. Examination of the area on the next day showed
no visible traces of oil on the surface of rocks or Tetraclita tests. Peri-
odic samples were taken in order to evaluate long-term changes in the quad-
rats.

The experiments ig the Laurencia Zone on the Galeta reef were set up as
follows. Six 1 m* quadrats, 100 meters northwest from the Laurencia Zone
marker of our transect zone, were staked with railroad spikes at 1 meter
intervals. The two extreme quadrats (1 and 6) were controls; quadrats 2
and 4 were sprayed with a 1:1 mixture of Bunker C and marine diesel oils;
quadrats 3 and 5 were sprayed with marine diesel oil. Three days previous
to the experimental pollution a series of twelve 0.10 m2 samples (2 from
each quadrat) were collected and sorted. The quadrats were obgerved con-
tinuously for 1 hour after pollution. A series of four 0.10 m“ samples

(1 each from quadrats 2 to 5) were taken after 1-1/2 hours. Another series
of twelve 0.10 m2 samples (2 from each quadrat) were collected after 48
hours of the pollution experiment. The experiment was carried out at low
tide. The pollution quadrats were completely exposed for 2 hours. Monthly
collections were taken to detect any long-term changes.

Results and Discussion

The number of species of algae in the Laurencia Zone quadrats underwent a
significant increase following pollution with Bunker C:marine diesel oil
mixutre (Table 32). The four 0.01 m* samples each contained fewer than
the four samples taken one week following treatment with the oil (P = 0.014,
Mann-Whitney U test). During the following three weeks, the number of
algal species increased significantly further (P = 0.029, Mann-Whitney U
test). The samples taken in control quadrats and quadrats treated with
straight marine diesel oil varied greatly and in no particular pattern
(Table 32). The small number of samples and the variation in the control
quadrats cast a warning of caution on acceptance of the significance of
the Bunker C effects. However, a similar pattern of effects of Bunker C
oil on algae is found in the significant results of increased algal pro-
duction on settling plates coated with Bunker C oil to a much greater ex-
tent than in the aquaria not exposed to oil (Section X).

78


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73


A MAP OF PANAMA,
INDICATING THE
MAJOR STUDY SITES
DISCUSSED IN
THIS REPORT.

1 = STRI MARINE
LABORATORY,
GALETA POINT

2 = ISLA TABO-
GUILLA

3 = PUNTA PAITILLA

4 = SHIMMEY BEACH

COLOMBIA

PACIFIC OCEAN

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CRUSTACEA: DECAPODA: NATANTIA
Gnathophyllum panamense 1/8
1
0.05
Synalpheus sp. 1/8
1
0.05
Thor Sp. 1/8
1
0.05
other shrimps (species 2/8 3/12
unknown) 2 12.6
0.1
CRUSTACEA: DECAPODA: REPTANTIA
Diogenidae
Caleinus obscurus 1/12
0.6
Clibanarius albidigitus 1/12
0.6
Porcel lanidae
Neoptsosoma mexicanun 1/12
1.8
Pachycheles calculosus Wie
1.2
Paguridae
pagurid (juvenile) 1/8
3
0.2
Grapsidae
Pachygrapsus transversus 5/8 9/12
47 25.2
2.3
Majidae
Eupleurodon trifurcatus 2/8
2
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Inachoides laevis 2/8
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Pelta pacifiea 4/8
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2.0

160


or compare with oils involved in other situations.

Perhaps the most important single criterion for judging the effects of an
oil spill is comparative data from control quadrats. If no change occurs
with respect to extensive background data for the area, this does not nec-
essarily imply a lack of effect of oil. As an example, consider the changes
in Eunice caribaea populations in the three quadrat sets (Figure 5). Eunice
caribaea was previously regarded as the polychaete species most accurately
evaluated in our pollution experiments because of its relatively regular,
nonclumped, consistently abundant distribution (Appendix B). Although the
populations in quadrats treated with Bunker C oil underwent a significant
decrease between the period before the oil spray and 28 days after (P <0.05,
t-test or P = 0.057, Mann-Whitney U test), during the same period popula-
tions in both the control quadrats and quadrats sprayed with marine diesel
oil increased significantly in abundance (P <0.01, t-test or P = 0.01,
Mann-Whitney U test). The increase in control quadrats and quadrats sub-
jected to marine diesel oil alone did not differ significantly. Thus,
marine diesel oil apparently had no effect on Eunice caribaea populations,
while Bunker C oil had a significant effect. From baseline data the Eunice
caribaea populations would not have been expected to undergo an increase.
The decrease in Bunker C oil populations would have been far less notice-
able and it may even have been hypothesized that marine diesel oil encour-
aged the increase in Eunice caribaea. This implies that, even though no
gross changes in diversity or abundance are apparent, subtle changes in
certain populations do occur and may in the end have significant effects
on the ecology of the area. This points to the need of extensive controls
for a reliable interpretation of the effects of an oil spill on a marine
community.

85


Ophiolepis paucispina, 108, 166
Ophionerets reticulata, 108
Ophiozonoida sp., 109
ophiuroid, 48, 49, xi
Ophiuroid sp., 166
sp. B, 109
Opisthosyllis brunnea, 33, 36,
131, 156, 164
sp., 157
Oreaster reticulatus, 108
Ostrea conchaphila, 36, 151
tridescens, 36, 151
palmula, 37, 151
tubulifera, 37
Quenta collaris, 128

Pachycheles caleculosus, 160
chacet, 139
eristobalensis, 139
serratus, 138
susannae, 139

Pachygrapsus marmoratus, 141
sp. 1, 165

transversus, 28, 31, 37, 141, 160

Padina sp., 24, 146
pagurid, 160
Palola stciltensis, 126, 152
sp., 126, 153
Palythoa cartbaeorun, 11, 105
variabilis, 106
Panopeus bermudensis, 140, 161
sp., 140
sp. 1, 165
sp. 2, 165
sp. 3, 165
Paracerceis sp. 1, 159
Paraliomera, 19
dispar, 139
Parasptdosiphon fishert, 121, 163
sp. 4, 163
spectosus, 121
sptnoso-scoutatus, 122, 163
spp.» 122
steenstrupt, 122, 163
Pasiphaeid sp. 1, 164
Patelloida semirubida, 37, 148
Pavona, 69, 71, 75
gigantea, 1, 67, 71, 75

Pelta paetfieca, 160
Penicillus capitatus, 12, 102
Periclimenes americanus, 135
Perineris, 20
elenacasoi, 33, 127, 153, 164
sp., 153
sp. A, 127
sp. B, 127
Petrolisthes armatus, 138
galathinus, 138
jugosus, 138
sp., 138
Peyssonnelta amorica, 104, 162
nordstedtii, 12, 104
rubra, 104, 147
Phacoides pectinatus, 120, 166
Phascolosoma antillarwn, 122, 163
perlucens, 37, 122, 163
sp. 3, 163
sp. 4, 163
spp., 122
vartans, 122
Pherusa inflata, 124, 152
Phragmatopoma sp., 129, 155
Phyllactis flocultfera, 11, 106
Phyllodocid sp., 154
sp. 1, 37
Phymanthus cructfer, 106
Pigrogramitus timsanus, 134, 158
Pilumus dasypodus, 140
holosericus, 140
lacteus, 140
rettculatus, 140, 161
sp., 141
Pinetada vadiata, 119, 166
Pinnotherid sp., 141
Piromis americana, 152
Pista brevtbranchiata, 157
fasciata, 132
Pitho aculeata, 141
Planaxis lineatus, 145, 165
nucleus, 145, 165
Platynereis dunertlit, 33, 36,
127, 153, 164
sp., 127
Platypodia sp., 161
spectabilis, 139

174


sphaeromatid juvenile 1/8
1

0.05

159

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oS = - <
z g 3 t
3 5 5 2
2 & & a
CRUSTACEA: ISOPODA
Aleirona insularts 3/8
28
1.4
Dynamenella aff. 4/8 2/12
acutttelson 213 34.2
10.6 4.7
Dynamenella josepht 1/2
192
65.2
Dynamenella setosa 1/8 3/12
1 30.6
0.05 4.2
Dynamenella n. sp. A 4/8
198
9.9
Dynamenella sp. 1 7/12
49.2
6.8
Dynamenetla sp. 2 1/8 3/12
1 4.2
0.05 0.6
Excorallana aff. tricornis 4/8
53
2.6
Jaeropsis rathbunae 3/8
6
0.3
Mesanthura (?) 2/12
7.2
1.0
Paracerceis sp. 1 4/8
9
0.4
Sphaeromatid sp. 1 12
0.6
0.08


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64


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25


vartabile, 114, 145 Crepidula aculeata, 149

Chaetomorpha antennina, 146 ineurva, 149
brachygona, 42, 101, 162 lessonti, 149
elavata, 42, 162 marginalis, 149
sp., 101, 146 onyx, 149
Chaetozone sp., 124 plana, 116
Chama echinata, 151 strtolata, 36, 149
macerophylla, 120 crustaceans, 2, 18, 28, 41, 80
Champia parvula, 103 Crustose coralline, multipored, 147
Charonia vartegata, 116 Crustose coralline, one pore level, 147
Chetla equestris, 115 Crustose coralline, one pore raised,147
chiton, 37, xii Crustose coralline sp. B, 103
Chiton viridis, 112 Crustose coralline sp. C, 103
Chondria floridana, 103 Crustose coralline sp. D, 103
tenutssima, 103 Crustose coralline sp. E, 103
Chone sp., 129 Crustose coralline sp. F, 103
Choneplax Lata, 111 Crustose coralline sp. G, 103
Chthamalus panamensis, 26, 158 Crustose coralline sp. H, 103
Cirratulid sp., 124, 152 crustose coralline spp., 103
Cirratulus cirratulus, 124 crustose red coralline, 162
Cirriformia lucuriosa, 36, 124, 152 Cumingia antillarum, 121
punetata, 124 lamellosa, 150
tentaculata, 37, 152 Cyathodonta semirugosa, 166
Cittariun pica, 113 Cyelapsts sp., 47, 48
Cladophora sp., 101, 162 Cyclostremiscus beaut, 114
Cladophoropsis, 42 panamensis, 148
membranacea, 101, 162 Cymatiwn gibbosun, 149
rubusta, 146 nicabaricum, 116
Clastotoechus nodusus, 139 ptleare, 116
Clibanarius, 41 Cypraea arabicula, 149
albidigitus, 160 eervinetta, 149
sp., 165 zebra, 116
Codakia costata, 120 Cypraecassis testiculus, 116
orbicularts, 120, 166
orbiculata, 120, 166 Daphnella lymneiformis, 118
Codiun isthmocladium, 101 Dasybranchus lumbricotdes, 123
santamartae, 146 decapod, 105
Conus fergusoni, 150 Demonax Sp., 129
mus, 118 Dendrostomum sp., 121
purpurascens, 150 Derbesia sp., 101
Coralliophaga coralliophaga, 119 Diadumene leucolena, 33, 36
Coralliophila aberrans, 116 Dichocoenia stokestt, 32, 107
caribaea, 117 Dietyopteris delicatula, 102
squamosa, 149 Dietyosphaerta cavernosa, 12, 101
Corbula eontracta, 121 vanbosseae, 101
Craniella sp., 12 Dietyota conerescens, 146
Crassispira discors, 150 sp., 102
sp., 118 Diodora eayenensis, 112
Crassostrea sp., 40, 45 dysoni, 112

170


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- - - - - - - - 20 - - p1002buods 8127 Asojdoy (dq)
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“SHLINOW SL 40 GOIYSd VY Y3A0
SNOILI31109 JAISSIIONS NI SISNAWWNYd WATITLOWIWES WLTTOVYLEL HIM GALVIIOSSV S3II3dS *(panutquos) z1 A18VL

37


£
°
ovo oO oO =
= es) $s a Ey
= 5 é Z $
oS S — _ i=
S = oO oO oO
fo} os ° — 9
Co a N ke ad
Palythoa 5/24 3/24
caribaeorun —_~1=2063 1-5-12
(784) (6.0)
Isaurus
duchassaingt + *
Zoanthus 3/24 20/20 6/20 1/20
soctatus 1-2-44 1847-4305-7492 1-2-103 82
(15.7) (481241364) (45.2#41.0) (32.8)
99.9 89.2
1.012 16.627
Zoanthus 19/24 19/24
solanderi 13-247-2333 1-91-2155
(32124963) (13344694)
67.5 80.0
3.059 7.196
Order Actiniaria
Aiptasia 11/24 9/24 10/20 8/20 8/20
tagetes 1-6-15 1-4-10 1-7-63 1-1-19 1-3-41
(30.0#10.3) (13.744.8) (55.2428.9) (16.0+8.2)  (24.8+16.0)
22.5 17.2 49.6 13.6 68.8
3.481 3.307 5.141 5.717 9.032
Anthopleura 3/24 5/24 8/20 1/20 1/20
krebst 1-3-4 2-2-3 1-3-4 4 1
(2.6) (4.0) (8.4+1.8) (1.6) (0.4)
Anthopleura sp. 12/24 10/24 6/20
1-3-13 1-3-8 1-1-5
(20.044.1)  (12.343.9) (5.62.5)
15.0 15.5 5.0
2.922 2.378 3.736
Epiphellia 1/24 1/20 15/20 7/20
n. sp. 7 1 1-7-91 1-2-8
(1.7) (0.4) (97.2438.5) (7.6+0.8)
82.6 21.1
3.916 4.093
Phyllactis 8/24 12/24 11/20 2/20
floeulifera 1-3-91 1-4-12 2-6-18 1-2
(59.6432.3) (16.345.2) (33.648.8) (1.2)
44.8 21.4 30.2
7.630 2.837 2.088
Phymanthus 4/24 1/24 1/20
erucifer 1-3-4 1 1
(4.0) (0.3) (0.4)

106


TABLE 14. CHARACTERISTICS OF THE MANGROVE SAMPLES FROM GALETA POINT, A
description of the degree of spatial heterogeneity which is too large for

our sampling program to cope with capably. a Ss
° S$ 3 - 28
>o a S 7 nn
=o Wmi se Oo
et - &S2 3 3Oo
Sample Ground coverage as Z-se = £90
number, algal Coral ot Ss 2P5 5 eo
location a mat frag- 3 oe . PES . =
and date ments = 2288 2 3s
1 (?) Cladophoropsis
23 Nov 70 (abundant) none none 2 --- 13 870
Caulerpa few with Bostrychia-
2 (38-4) fastigiata some Catenella
24 Nov 70 (abundant) Laurencta (abundant) - 11.12 11 105
papillosa
3 (84-4) no prop _
20 Apr 71 none none roots 0 - 4 6
4 (49-1) Cladophoropsis Bostrychia-
21 Apr 71 ~~ (common to none Catenella 4 1.90 16 365
abundant) (common to
abundant )
few with Bostrychia-
5 (55-4) none no fleshy Catenella 8 19.02 25 341
21 Apr 71 algae (abundant)
6 (77-2) Filamentous Catenella aoe
22 Apr 71 blue-green few (sparse) 5 24 336
Cladophoropsis, few with Bostrychia-
7 (25-1) Caule sparse but Catenella
29 Jul 71 (some typical coral (abundant) 10 2.96 12 73
u reef algae
( ) oraaepnonepets Bostrychia-
8 (65-1 common to Catenella
11 Aug 71 abundant) none (common to 4 4.36 15 99
abundant)
9 (75-1) Filamentous no aerial .
23 Aug 71 blue-green few roots Poo 44 1500
few with Bostrychta-
10 (61-3) | Cladophoropsis some Caterella
25 Aug 71 (abundant Laurencia (abundant) 6 4.90 22 = 335
papillosa

4 Location is given in parenthesis, the first number representing paces along
the shore, the second representing paces into the mangrove forest perpen-
dicular to the shore.

> The Bostrychta-CateneLla association includes some or all of the following
algae: Bostrychia binderi, Catenella repens, Caloglossa leprieurii,
Murrayella periclados, Chaetomorpha brachygona and Chaetomorpha clavata.

42


Nereidae
Ceratonereis
mirabilis

Neanthes n.
sp. 1

Neanthes sp.
indet.

Nereis
callaona

Nereis n.
sp. A

Nereis risett

Perinerets
elenacasot

Perinereis Sp.
indet. A

Perinerets sp.
indet. B

Platynereis

duneri Lit

Platynereis
sp. indet.

so
L
°
g 2 g £ 5
= E 2 g 8
3 2 2 2 2
S J oS o o
5 5 & = 2
18/24 23/24 20/20 17/20 14/20
1-8-45 1+12-48 1-16-70 4-18-68 1-15-62
69.6420.0 121.0#23.1 178.4+36.3 218.4#38.9 118.4432.3
2.5 2.0 13.4 32.7 7.8
2.791 1.774 1,748 1.570 2.358
2/24 2/20 1/20
6-46 1-1 1
17.3 0.8 0.4
1/24
1
0.3
14/24 9/24 8/20 6/20 1/20
1-3-25 1-2-6 13-28 1-2-4 3
33,6411.8 7,322.6 16.4211.2 5.642.4 1.2
1.2 0.1 1.2 0.8
3.630 2.909 9.658 3.296
6/24 5/24
1-7-19 2-5-12
17.647.8 10.6
0.6
5.190
1/24 2/20 1/20
1 1-1 1
0.3 0.8 0.4
21/24 23/24 15/20 14/20 16/20
2-9-23 1-9-106 1-7-17 1-3-20 1-5-148
67.0411.3 100.3#42.5  36.4410.3 30.449.4 102.8462.6
1/24
1
0.3
1/20 2/20
i 1-2
0.4 1.?
15/24 14/24 4/20 5/20 3/20
2-7~102 1-4-22 1-1-4 1-1-2 1-1-4
86.3+36.6  29,049.6 2.8 2.4 2.4
3.1 0.5
5.048 3.297
1/20
4
1.6

127


UZ, -AN1 species
Polychaete spp. 80

Cl Mollusk spp.

r60

Wn

No. species

20

25 Mar 71
12 Apr 71
27 Apr 71
9 Aug 71
7 Sep 71
7 Oct 71
4 Jan 72
31 Jan 72
7 Mar 72
13 Apr 72
13 Jun 72

Figure 3. Number of species in collections of invertebrates associated
with Tetraclita stalactifera panamensis over a period of 15
months.


SECTION X
LABORATORY EXPERIMENTS WITH THE EFFECTS OF OIL ON HERMATYPIC
CORALS FROM THE EASTERN PACIFIC AND FROM THE CARIBBEAN

To compare the effects of different oils on several species of hermatypic.
corals, controlled experiments were performed in aquaria. The species
used were: Pocillopora cf. damicornis, collected at a depth of 9 meters
off Saboga, Perlas Islands, Pacific Panama; Pavona gigantea and Psammocora
(Stephanaria) stellata, collected at a depth of 9 meters off Isla Chapera,
Perlas Islands, Pacific Panama; Porites furcata, collected in intertidal
open pools at Galeta Point, Caribbean Panama.

Methods

Experiments with Pocillopora cf. damicornis.—Two colonies of Pocillopora
ef. damicornis were placed in a dish without water. The size range of the
first colony was 6.0 cm (largest height) by 3.6 cm (largest width), and
the second colony was 5.9 cm by 3.1 cm. Marine diesel oil was poured into
the dish to cover them for 30 minutes. After 30 minutes, the colonies were
rinsed in several changes of seawater and then placed in a well~aerated
5-gallon aquarium. Control colonies were subjected to the same manipula-
tions, using seawater to replace oil, and were placed in a different well-
aerated 5-gallon aquarium.

Next, two colonies of P. cf. damicornis were submerged in marine diesel oil
(size ranges of the colonies were 2.5 by 3.0 cm and 5.5 by 4.5 cm), three
colonies in Bunker C oil (size ranges of 2.9 by 2.2 cm to 4.0 by 4.2 cm)
and three controls (size ranges of 4.5 by 3.7 cm to 4.5 by 4.2 cm) in sea-
water, all for 1l-minute exposures to the test substance.

A third experiment was performed as follows. Colonies of Pocillopora with
two distinct branches (Figure 4) were used for experiments in which 1 branch
was exposed for 0.5 minutes to marine diesel oil in three colonies ranging
in size between 4.0 by 2.5 cm and 4.0 by 4.0 cm, or to Bunker C oil for

0.5 minutes in three colonies ranging in size between 4.5 by 6.9 cm and

6.8 by 6.8 cm; the second branch in each colony was left untouched by oil.
Three control colonies ranging in size between 4.0 by 4.6 cm and 5.0 by

5.2 cm were handled in the same manner but were exposed to seawater instead
of oil.

In all of the experiments oil was removed from the colonies by submerging
them in seawater and allowing the oil to float to the surface, from where
it was removed by soaking it into Kimwipes. Next, the colonies were placed
in a different container and exposed to running seawater for one-half hour.

67


SECTION XI
FIELD EXPERIMENTS WITH THE EFFECTS OF OIL POLLUTION ON
CARIBBEAN AND EASTERN PACIFIC INTERTIDAL COMMUNITIES

On the basis of the baseline data presented in Part I of this report on
intertidal communities of the Caribbean and Pacific coasts of Panama, two
zones, one on each coast, were selected for the tests of the long-term
effects of an oil spill on the fauna and flora. These zones were selected
for several reasons: they were the most easily sampled zones on each coast,
they were relatively high in the intertidal zone so that the oil could be
applied safely, they were characterized by a diversity of species so that
we could obtain data on the effects of oil on a variety of organisms, they
were relatively uniform in composition in comparison with other zones so
that our replicates and controls would have some validity and, perhaps
most importantly, they were zones selected for special studies in addition
to our regular sampling program. These additional studies are hoped to
provide further insight in interpreting any effects or lack of effects of
the oil pollution. The zones selected were the Tetraclita Zone, Pacific
side, at Paitilla Beach, and the Laurencia Zone, Caribbean side, on the
Galeta Point reef flat.

Methods

Since Bunker C and marine diesel are the oils most commonly spilled in the
areas under study, we conducted experiments with each of them. Bunker C
and marine diesel oils were mixed in a 1:1 ratio while marine diesel was
used pure. They were applied to the substratum during low tide, while the
area was exposed, with an X-Pert 2-gallon professional sprayer (D-Hudson
Manufacturing Company, Illinois). The flow rate of the sprayer was measured
just before each experiment. The substratum was sprayed evenly, from a
distance of about 0.3 m above the substratum, for the length of time nec-
essary to release 250 ml of oil. Areas surrounding the pollution quadrats
were protected from oil spray by a continuous wall of moist paper towels
about 30 cm wide. The paper towels were placed around the outside of
quadrats treated with oil, not in any quadrats, for the brief period of the
actual spraying operation.

Experiments were set up in the Tetraclita Zone, Paitilla Beach, as follows.
A total of six experimental quadrats were selected on a horizontally flat
top ridge of andesite rock standing about 1.8 m above mean sea level which
offered a typically abundant standing crop of Tetraclita stalactifera
Panamensis. The quadrats were marked with Sea Goin' Poxy Putty. Three
quadrats about 1 meter apart were used to study the possible effects of
oil on a community of live Tetraclita. The other three quadrats, standing

77


percentage of barnacles lost over a period of 15 months was as high as 62
percent of the initial experimental set. The same table indicates that
settlement of new Tetraclita in the area occurs throughout the 16 months

and also that there is considerable mortality of young Tetraclita between
collections.

32


co
i
ovo o so 2
< od ¥ ood o
7 cs} a n °
- i= <7 n =
3 2 2 2 2
i J o o oO
8 3 8 é 2
Hyalina avena 5/20 4/20 5/16 1/16 6/16
1-1-1 1-2-5 1-1-4 1-1-3
(2.0) (4.0) (4.5) (0.5) (6.5)
Hyalina 1/20 2/16 1/16
albolineata 1 1-1 1
(0.4) (1.0) (0.5)
Hyalina 2/20 1/20
tenut Labra 1-2 1
(1.2) (0.5)
Conus mus 1/20 5/20
1 1-1-2
(0.4) (3.2)
Crassispira sp. we
(0.5)
Mangelia fusea 1/16
1
(0.5)
Daphne tla 1/16
lymnet formis 1
(0.5)
BIVALVIA
Area imbricata 15/20 9/20 6/16 2/16 7/16
1-1-3 2-2-3 1-3-3 1-3 1-2-4
(12,042.6) (8,842.8) (7,543.1) (2.0) (9.0#3.4)
9.0 3.0 5.0 4.5
1.241 2.164 2.589 3.032
Barbatia spp. 18/20 15/20 14/16 7/16 15/16
(both B, 1-3-6 1-1-4 5-8-11 1-1-3 2-6-19
domingensis (27.2#5.9) (12.843,1) (65.5#12.9) (10.546.0) (88.5+27.7)
and B. tenera, 20.4 4.4 43.5 28.4 44.6
cf. Appendix C) 1.546 1.572 1.471 5.332 2.392
Arcopsis 6/20 6/20 6/16 3/16 4/16
adamst 1-1-1 1-2-3 1-4-7 2-3-10 6-11-14
(3,641.7) (4,441.8) (12.545.6) (7.5) (22.0)
2.7 1.5 8.3
3.332 2.544 3.520
Modiolus 1/20 1/16
americanus 1 1
(0.4) (0.5)

118


o
-
2 e g ° 2
= 2 = a 2
‘s 2 € = €
TAXA 8 3 8 = 8
Enteromorpha sp. 5/20 11/20 5/16 11/16 8/16
green crust 2/20 1/20 9/16 1/16
Halicystis
osterhoutii 10/20 1/20 2/16
Halimeda opuntia 16/20 15/20 15/16 13/16 10/16
Halimeda tuna 9/20 2/16
Pentcillus
capt tatus 4/16 6/16
Struvea
anastomosans 6/20 4/20 1/16 2/16 5/16
Valonta
utricularis 720
Valonta
ventricosa 1420
PHAEOPHYTA
brown crust 5/16
Dictyota sp. 3/20 1/20 1/16
Dietyopteris 2/20 3/20 1/16 2/16
delicatula
Giffordia indiea 1/20 2/20 2/16
Sphacelaria
tribuloides 6/20 5/20 8/16 10/16 7/16
Lobophora 2/20
variegata
RHODOPHYTA
Acanthophora 14/20 4/16 14/16
sptetfera
Amphi roa
brast lensis 5/20 5/20
Amphiroa
fragt lissima 7/20 2/20 2/16 3/16 4/16
Amphiroa rigidia
v. antilliana 8/20 8/20 a/n6
Amphiroa sp. 8/20 9/20
Antithamnion-type 2/20 3/20 1/16

102


¢
°
2 2 a x 6
= 2 2 3 2
Load o » oO »
g 5 a ‘s 3S
8 Ss 8 = =
HOLOTHUROIDEA
holothurian 8/24 14/24 2/20 3/20 3/20
spp. 1-1-2 1-5-14 1-1 1-2-3 1-2-2
(15.0211.9) (34.7411.3) (0.8) (2.4) (2.0)
15.321 3.249
HEMI CHORDATA
hemichordate 2/24 1/24 1/20 4/20 6/20
spp. (pos- 1-4 1 1 2-4-4 1-2-3
sibly 2 spp.) (1.6) (0.3) (0.4) (5.6) (5.6+4.3)
POLYPLACOPHORA
Lepidochitona 16/24 2/24 1/20 1/20
liozonis 1-1-2 2-2 1 1
(9.320.3) (1.3) (0.4) (0.4)
14.4
2.222
Acanthochitona + 6/24 5/20 4/20 2/20
hemphilli 1-3-3 1-2-2 1-1-1 1-5
(4,040.2) (3.2) (1.6) (2.4)
2.7
3.273
Aecanthochitona 4/24 4/24 1/20
spteulosus 1-1-1 ]-1-1 1
(1.3) (1.3) (0.4)
Acanthochttona 19/24 20/24 5/20 3/20
interfissa 2-2-3 5-8-16 2-2-4 ]-2-3
(23,340.8)  (79,3+2.2) (8.0) (2.4)
36.1 53.2
2.306 2.019
Acanthochitona 5/24 18/24 4/20 2/20 3/20
pygmaea 2-2-2 1-2-3 1-1-3 1-1 1-1-2
(3.3) (13.040. 3) (2.4) (0.8) (1.6)
8.7
1.101
Choneplax lata 11/24 19/24 7/20 3/20 4/20
1-2-3 2-3-5 2-6-7 1-1-2 1-2-3
(7.340.2) (21.740.5) (12.820.6) (1.6) (2.8)
11.3 14.5 26.9
1.662 1.431 3.065
Calloplax 5/24
janeirensis ]-1-1
(1.7)

111


£
oO
wo 7 oo =
i oa a oa a
— re} J nw °o
- i= c— un c=
— oO p oS S
oO Ss i= _ i=
i Ss oe oO i
fo} oO oO A 9
oO — N er =<
Creptdula plana 1/16
]
(0.5)
Strombus raninus + +
Cypraea zebra +
Polinices 4/16 4/16
lacteus 1-2-2 1-1-2
(3.0) (2.5)
Cypraecassis testiculus +
Charonia variegata + +
Cymatium nicabaricum +
Cymatium pileare 1/16
1
(0.5)
Bursa cubantana 1/20 1/16
1 1
(0.4) (0.5)
Drupa nodulosa 15/20 5/20 2/16 1/16
1-2-4 1-1-1 1-2 1
(20.8+6.2) (3.6) (1.5) (0.5)
28.7
2.368
Risomurex 4/20 1/20 1/16
murt cotdes 1-2-2 1 1
(2.0) (0.4) (0.5)
Risomurex roseus 1/20
1
(0.4)
Purpura patula +
Thais 1/20 2/20 1/16
haemastoma 1 1-1 1
(0.4) (0.8) (0.5)
Thais 3/20
deltoidea 1-1-3
(2.0)
Coralttophila 3/20 1/16
aberrans 1-1-1 1
(1.2) (0.5)

116


Actaea
setigera

Leptodius
floridanus

Xanthodius
denticulatus

Panopeus
bermudensis

Panopeus sp.

Mieropanope
sp.

Pilumus
dasypodus

Pilumus
laeteus

Pilwmus
holosericus

Pilwmus
reticulatus

2
°
g 2 Ps 2 3
cad J oJ wn c=]
= F 5 2 5
g - F 3 F
8 3 & = E:
5/20 1/20
1-1-1 1
(2,041.3) (0.4)
0.4
0.000
1/20 1/16 8/16 6/16
2 1 1-2-4 1-2-4
(0.8) (0.5) (11.044.1) — (7.042.9)
27.5 8.9
2.494 2.637
4/20 2/20 1/16
1-1-2 1-2 1
(2.4) (1.2) (0.5)
1/20 4/20 5/16 4/16 10/16
1 1-1-1 1-1-1 1-1-2 1-2-4
(0.4) (2.8) (3.0#1.4) (3.0) (13.0#4.0)
6.6 16.5
2.133 1.871
3/20 3/20 2/16 5/16 3/16
1-1-1 1-2-6 1-2 1-1-3 1-1-3
(1.2) (3.6) (1.5) (3.540.2) (2.5)
8.8
2.667
2/16
1-1
(1.0)
10/20 2/20 3/16 2/16
2-2-3 1-3 1-1-1 1-1
(9.6#2.9) (2.0) (1.5) (1.0)
2.0
1.594
1/20
]
(0.4)
7/20 1/20 1/16
1-1-4 1 1
(7,243.2) (0.4) (0.5)
1.5
3.922
3/20 1/16
1-1-3 1
(2.0) (0.5)

140


APPENDIX D

Catalog of mollusks from the high intertidal "splash" zone at the Galeta
marine laboratory. The "splash" zone consists of a pile of rubble along the
base of the wall of the laboratory building next to the Acanthophora zone.
The descriptive statistics are the same as explained for Appendix B.

Nerita fulgurans 19/40
1-5-16
(82,0£25.5)
12.3
4.587

Nerita versicolor 14/40
1-4-7
(31,2£11.5)
4.7
5.834

Nerita tesselata 15/40
1-3-3
(19.626.6)
2.9
4.694

Nerita peloronta 2/40
1-3
(1.6)

Littorina ziczac 16/40
1=2-10
(36.813.5)
5.4
5.905

Littorina lineolata 19/40
7-11-48
(181,2254.2)
27.1
4.407

Littorina tesselata +

Littorina meleagris 4/40
(6.0)

Nodilittorina tuberculata 4/40
a)

Teetarius muricatus +

144


EPA-600/3-76-028
May 1976

SURVEY OF MARINE COMMUNITIES IN PANAMA

AND EXPERIMENTS WITH OIL

by

Charles Birkeland
Amada A. Reimer
Joyce Redemske Young
Smithsonian Tropical Research Institute
Balboa, Canal Zone

Contract No. 14-12-874

Project Officer

Donald K. Phelps
Environmental Research Laboratory
Narragansett, Rhode Island 02882

U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
ENVIRONMENTAL RESEARCH LABORATORY
NARRAGANSETT, RHODE ISLAND 02882


£
g g P 2 3
-_ cs} J wn ce}
= = = a 2
‘s 2 = = €
g 2 g 2 §
oO a N od <
Tanystylum sp. 1120
(0.4)
Nymphopsis 1/20 2/16
duodorsospinosa 1 1-1
(0.4) (1.0)
Pigrogromitus 3/20 1/16
timsanus 1-1-4 2
(2.4) (1.0)
Callipallene sp. 1/16
2
(1.0)
CRUSTACEA: STOMATOPODA
Gonodacty Lus 8/24 15/24 3/20 3/20 6/20
oerstedit 2-3-4 1-3-5 1-1-3 1-1-1 1-2-4
(7.7#0.3)  (14.040.4) (2.0) (1.2) (4.80.3)
100.0 70.0 34.3
2.751 1,672 3.636
Gonodacty lus 5/24 1/20 10/20 9/20
bredint 1-1-2 1 1-2-2 1-1-3
(2.7) (0.4) (8.4#0.4)  (8.0#0.4)
61.8 57.1
2.286 2.526
Gonodacty lus 5/20
austrinus ]-1-1
(2.0)
Gonodactylus sp. 6/24 6/24 1/20 3/20 3/20
(unidentified 2-2-4 1-1-2 1 1-2-2 J-1-1
juvenile) (4,640.2) (3,340.2) (0.4) (2.0) (1.2)
-- 16.7
3.956 3.733

134


TABLE 39 (Continued). DIFFERENT PATTERNS OF SURFACE COVERAGE BY FOULING
ORGANISMS ON CLEAN SCRAPED PLEXIGLASS PLATES (CONTROLS) IN COMPARISON WITH
PLATES COATED WITH BUNKER C (BC) OR MARINE DIESEL (MD) OIL.

Average per cent sur-

Period face coverage of plates
(days) _‘ControTs oil coated t d.f. P

TABOGUILLA (Pacific)
Upper Surface

Algae - 1972 59 52.5 BC - 63.8 0.72 10
MD - 34.5 1.22 10
- 1972 126 53.5 BC - 43.2 0.65 10
MD - 24.0 2.11 10 <1
Animals - 1972 59 35.6 BC - 19.8 1.78 10
MD - 52.2 1.22 10
- 1972 126 45.1 BC - 51.0 0.41 10
MD - 74.0 2.08 10 <1
Under Surface
Algae - 1972 59 18.9 BC - 11.8 0.99 10
MD - 0.2 2.69 10 <.05
- 1972 126 1.8 BC - 2.0 0.14 10
MC - 3.8 0.93 10
Animals - 1972 59 6.15 BC - 47.4 1.81 10
MD - 95.0 6.36 10 <.001
- 1972 126 97.0 BC - 89.0 0.72 10
MD - 95.2 0.90 10
Open space - 1972 59 19.2 BC - 40.8 5.80 10 <,001
MD - 4.5 3.71 10 <.01
- 1972 126 1.2 BC - 9.0 2.53 10 <.05
MC - 1.0 0.31 10

95


TABLE 20. DEGREE OF "SEASONALITY" AND "YEAR-TO-YEAR VARIATION" IN RECRUIT-
MENT OF ANIMALS TO SETTLING PLATES IN CARIBBEAN AND PACIFIC PANAMA. The
definitions of the indices are given in the text.

Index Pacific (Taboguilla) Galeta (Caribbean)
Seasonality 0.42 0.65
Year-to-year variation 0.68 0.66

TABLE 21. CHI-SQUARE TEST OF THE SIGNIFICANCE OF DIFFERENCES BETWEEN
TABOGUILLA AND GALETA SETTLING PLATE COMMUNITIES IN TERMS OF CATEGORIES
INVOLVED IN CALCULATIONS OF "SEASONALITY" AND "YEAR-TO-YEAR VARIATION"
INDICES.

a. Seasonality.

Total number

Location ny + Ne Ng of species
Taboguilla (Pacific) 30 41 7
Galeta (Caribbean) 56 30 86
% of grand total 54.8 45.2 157

x? = 8.23 with 1 d.f.: P<0.07

Reject Hy: conclude that seasonality index differs for Taboguilla
and Galeta settling plate communities.

b. Year-to-year variation.

Total number

Location ny tn, Mt of species
Taboguilla (Pacific) 4) 29 70
Galeta (Caribbean) 59 31 90
% of grand total 62.5 37.5 160

x? = 0.819 with 1 d.f.: not significant
Fail to reject Hj: conclude that year-to-year variation index is

not different for Taboguilla and Galeta settling
plate communities.

55


3. The epiphytic algae from the prop roots, the pieces of coral rub-
ble and the mat of algae that covers the substratum were examined for small
faunal species.

Results and Discussion

The intertidal habitats resulting from the structure of mangrove trees,
Rhizophora mangle, form a topographically heterogeneous region. Attention
was given to characterizing the several habitats for marine organisms pro-
duced by the Rhizophora mangle (Table 14). One habitat is formed by the
prop roots which support a typical association of algae: Bostrychia
binderi, Catenella repens, Caloglossa leprieurii and Murrayella periclados.
These grow as dense masses with each plant attached to others by holdfasts.
Several species of amphipods and some xanthid and oxypodid crabs are usu-
ally found associated with the epiphytic algae of the prop roots. The
roots themselves are almost barren of animal life except for some epizoic
barnacles and a few polychaete worms which build tubes in cracks and
galleries.

Another mangrove habitat is the ground between the prop roots which consists
of fine sand or mud and is usually covered by a dense mat of algae (Table
14). Large numbers of mollusks such as Batillaria minima and hermit crabs
of the genus Clibanarius move around on this algal mat. In the sand or mud
underneath there are few polychaetes, some sipunculans of the genus Gol~
fingia, and some crustaceans.

A third habitat of the mangrove is the submerged roots which were completely
barren of organisms in all our samples. Another probably habitat is the
dense mat of root hairs which weighed an average of 6.6 kg (wet weight) per
m2 (Table 15). Here only Batillaria minima and Clibanarius were found.
Coral fragments washed from the Galeta reef constitute perhaps the richest
habitat for animal species, but these cannot be considered typical of the
mangroves. For example, most of the polychaetes and sipunculans found in
quadrats 6 and 9 (Appendix F) were collected from coral fragments and are
also present in the Galeta reef. The coelenterate Zoanthus sociatus and
the algae Laurencia papillosa, crustose red coralline, creeping Gelidiale
and Halimeda opunctia are also typical reef inhabitants and are only found
in the mangroves on coral fragments washed from the reef.

The most striking characteristic of the mangrove community shown by our
data is the variability in the species composition, in the relative abun-
dance of species and in proportions of habitat surfaces available to plants
and animals. Because of the tremendous habitat diversity or spatial heter-
ogeneity involved for invertebrates in the mangrove forest, the abundance
and association data of Appendix F must be compared for each sample with
the data in Tables 14 and 15. The variation between samples precludes sum-
marization. The large differences in species composition and relative
abundances between samples taken during the same periods of time also pre-
clude definite conclusions about seasonal variations. Table 16 gives an

41


APPENDIX F

A catalog of macroscopic species found in ten 0.125 m? quadrat samples in
the mangrove community adjacent to the Galeta laboratory. A "+" indicates
presence; "++" indicates great abundance. Joyce Redemske Young provided

the data for the algae.
Quadrat Number

TAXA “T 2 3° 4 5 6 7 8 9 10 Ave/m?

CYANOPHYTA
Filamentous blue-
green

Large bulbous
blue-green

CHLOROPHYTA
Caulerpa
fastigiata

Chaetomorpha
brachygona

Chaetomorpha
elavata

Chaetophoraceae-
- appressed
green coalesced
filaments +

Cladophora sp. +

Cladophoropsts 44g + + + oth + tt
membranacea

Halimeda opuntta +

RHODOPHYTA

Bostrychia ++ + ot tht ++
bindert

Caloglossa . + + + + +
leprieurit

Catenella repens ++ + ++ t+ tt tt +

Centroceras
elavulatun

crustose red
coralline

creeping gelidiale + +

Laurencta
papillosa

Murrayella
periclados

Peyssonne lia
amorica

162


so that the larger tree received a thinner coating. It seems quite likely
that spraying leaves with marine diesel oil caused at least temporary de-
terioration in the health of the small Rhizophora mangle.

It was also striking that three of the 13 trees were removed by large drift
logs which were carried across the reef flat during the windy dry seasons.
The logs rip away or roll across the small recruiting trees, then drift up
against the outer edge of the forest and stop, piled up against the solid
outer band of stilt roots. The drift logs were not seen to do any obvious
damage to the forest itself, but could quite possibly greatly hinder the
spread of the forest across the intertidal reef flat by destroying isolated
advancing recruits. Drift logs are recognized as an important distruptive
factor in the rocky intertidal zone of temperate zones (Dayton, 1971); they
could well be important in the tropics as well. The drift logs observed
were the trunks of large trees with the base of the branches and root sys-
tems still attached, which indicates the logs were probably natural and not
due to logging operations.

90


TABLE 4, SHANNON-WIENER INDEX OF DIVERSITY CALCULATIONS FOR EACH OF TEN
CATEGORIES OF MOTILE MACROINVERTEBRATES IN EACH OF THE FIVE INTERTIDAL
ZONES ON THE ‘CARIBBEAN REEF FLAT AT GALETA MARINE LABORATORY. The formula
used to calculate the indices was ~Ep;Logop,-

i

£
°
2 - a = a
- oO 3 wn co]
- < = a =
= o 2S © ax]
o cs < - <
x 3 3 © 6
9 6 oO < i)
3 a N - <=
OPHIUROIDEA 3.02 2.20 0.88 1.75 1.22
ECHINOIDEA 0.90 1.73 0.14 1.86 1.84
AMPHINEURA 2.71 2.15 2.49 2.25 2.70
GASTROPODA 3.72 3.04 3.80 2.72 3.52
BIVALVIA 2.34 1.93 3.89 2.64 2.51
SIPUNCULA 3.50 3.95 3.20 2.74 2.45
POLYCHAETA 3.74 2.37 3.10 3.52 3.04
PYCNOGONIDA 2.51 2.63 2,52 1.39 2.61
NATANTIA 2.91 3.08 1.76 2.30 2.66
REPTANTIA 2.81 2.40 3.10 2.33 2.45
MEAN DIVERSITY
OF ALL TEN 2.82 2.55 2.49 2.35 2.50

CATEGORIES

15


TABLE 1. DESCRIPTION OF ZONATION ON THE CARIBBEAN INTERTIDAL REEF FLAT

AT GALETA IN TERMS OF PERCENT SURFACE COVERAGE.
x?/d.f., each sample consisting of about 250 or 500 points.

Variance is defined as
For easy

reading and comparisons, all data were transformed to percentages after

analysis. Red algae and anthozoans were vastly predominant.

In order to

provide quick class or phylum recognition for those unfamiliar with local

species, the names are followed by the following letters:

C = Chlorophyta, P = Phaeophyta, A = Anthozoa, S = Porifera.

R = Rhodophyta,

£
ov oO oO 2
= i a - a
= o 3 ” 8
Ll i— = wn =
- o > o Fs)
oO S = _ i=
S PJ oO o oO
fo} oO i} = oO
oO —_ TMs ee 4
TOTAL SAMPLE SIZE IN
RANDOM POINTS 2491 1750 3000 1750 2250
crustose coral Tine 53.4320.48 15.2081.88 7.3020.34 0.57 1.2040.18
Halimeda opuntia C 14.8940.28 8,5741.80 5.2341.05 3.0321.51 2.22#0.27
Laurencia 1.0841.08 59.37#1.17 1.40+0.58 0.11 14.2241.06
papillosa R
Acanthophora 1.8340.27 1.0340.33 21.06#0.74
spictfera R
Zoanthus 0.80  65.4320.31 0,05
soctatus A
Zoanthus
elandert. A 9.0340.37
Thalassia 0.16 26.1721.65 5.86+0.49
testudinum
Millepora 4.4240.32 0.80 0.33 0.04
complanata
Porites fureata A 4.1840.20 0.29
Porites
astreotdes A 1,04+0.10
Palythoa 3.0920.10 0.06
earibaeorum A
branching coral-
Tine algae R 1.1240.42  1.7720.37 0.40 0.34 0.97
short filamentous > 4141.96 1.2620.27 2.2320.90 2.0421.43
green algae C
Phyllactis
Htoculifera A 0.08 0.29 2.8020.11
Erythropodium
caribaeorum A 0.9240.16 0.06

il


TABLE 39.

DIFFERENT PATTERNS OF SURFACE COVERAGE BY FOULING ORGANISMS

ON CLEAN SCRAPED PLEXIGLAS PLATES (CONTROLS) IN COMPARISON WITH PLATES
All plates were

COATED WITH BUNKER C (BC) OR MARINE DIESEL (MD) OIL.
set out in April for lengths of periods noted in the first column.

Results of analysis by t-test between controls and oi1-coated plates
Data on coralline algae are not included in the table so

are given.

the per cent coverages do not always total 100.

GALETA (Caribbean)
Upper Surface
Algae - 1973
- 1972

- 1972

Open space ~- 1973

- 1972
- 1972
Under Surface
Algae - 1973
- 1972
- 1972

Animals - 1973
- 1972

~ 1972

Open space - 1973
- 1972

- 1972

Average per cent sur-

Period face coverage of plates
(days) Controls ail coate t d.f. Pp
60 58.4 BC - 79.0 3.98 14 <.01
MD - 20.1 8.13 14 <.001
59 38.1 BC - 68.8 2.25 10 <.05
MD - 35.8 0.13 10
92 62.8 BC - 86,5 1.95 10 <.1
MD - 66.2 0.28 10
60 6.2 BC - 19.5 2.47 14 <.02
MD - 41.9 5.04 14 <.001
59 20.4 BC - 20.2 0,02 10
MD - 23.2 0.41 10
92 17.8 BC - 11.2 0.84 10
MD - 15.2 0.31 10
60 16.6 BC - 40.1 3.93 14 <.01
MD - 17.6 0.21 14
59 8.5 BC - 12.0 0.42 10
MD- 4.0 1.00 10
92 8.6 BC - 18.2 1.26 10
MD 5.8 0.39 10
60 42.1 BC - 31.2 0.89 14
MD - 27.9 0.82 14
59 17.9 BC - 43.2 3.51 10 <.01
MD - 15.0 0.45 10
92 24.4 BC - 39.8 1.71 10
MD - 42.0 1.69 10
60 39.0 BC - 28.7 0.60 14
MD - 39.4 0.04 14
59 66.5 BC - 44.8 3.85 10 <.01
MD - 69.8 0.45 10
92 55.9 BC - 29.2 1.86 10 <1
MD - 45.2 0.81 10

94


Lithophaga aristata

Isognomon recognitus

Ostrea eonchaphita

Ostrea tridescens

Ostrea palmula

Cardita radiata

Lasaea rubra

Chama echinata
Cumingta lamellosa

Sphenia fragilis

AMPHINEURA
amphineuran spp.

BRACHIOPODA
Disetnisea strigata

POLYCHAETA
(Families presented in
alphabetical order)
Arabel lidae

Arabella mutans

Abietinaria

+) Chthamalus

Tetraclita

Littorina

4/8
3.4

151

T2/12
236.4
10.6

12/12
86.4
3.8

2/2
0.05
4/12

on
PO

nr

on~N OnN OFS

a

a
POM WON NADY

1/12
0.6

0.03

12/12

984.6
44.3

Wiz
14.4

1/12


< un oO
3 3 = g
lod = iS] ‘=
3 2 £ 3
a rs] rs} Pp
2 & 2 3
Bhawania riveti 478 2/12
10 4.2
1.2 0.4
Phyllodocidae
Anaitides panamensis 4/2
8.4
0.8
Anaitides sp. 1/8
1
0.1
Eteone sp. indet. 1/8
3
0.4
Eulalia myriacyelun 2/8
2
0.2
Eulalia cf, viridis 2/8
8
0.9
Eumida bifoliata 1/8
1
0.1
Notophyllum sp. indet. 1/8 Wz
2 0.6
0.2 0.05
Phyllodocid sp. indet. 2/8 1/12
13 0.6
1.5 0.05
Polynoidae
Lepitdasthenia gigas 1/8
1
0.1
Lepidonotus ecrosslandi 2/8 6/12
6 6.6
0.7 0.6
Lepidonotus nesophilus 2/8
24
2.8
Lepidonotus (?) pomarae 1/8
1
0.1

154


oO
= 3 = =
— i= Vv [<
rp S os °°
ov — >
oa rx) re had
a 5 2 5
Pigromttus timsanus 1/12
0.6
50.0
Anoplodactylus erectus 1/8
3
0.8
Anoplodactylus evelinae 5/8
59
12.7
Anoplodactylus portus 4/8
18
4.7
Anoplodactylus pygmaeus 3/8
3
0.8
Anoplodacty lus 5/8 1/12
viridintestinalis 65 0.6
16.9 50.0
Anoplodactylus sp. 2/8
4
1.0
Pyenogonum cessaci 3/8
14
3.6
CRUSTACEA: CIRRIPEDIA
Balanus amphitrite +
Balanus inexpectatus +
Balanus tintinnabulum
Chthamalus pananensis +
Tetraclita stalactifera 12/12
panamensis 318.6
44.6
CRUSTACEA: STOMATOPODA
stomatopods (number of 2/8
species unknown) 4
0.2

CRUSTACEA: TANAIDACEA
tanaids (number of 2/8 4/12
species unknown) 4
0.2 2.3

158


the unpredictability of the survival of the predominant species in the zone,
Zoanthus sociatus. In Caribbean intertidal areas occupied mainly by sessile
animals, mostly anthozoans or sponges, the surface coverage patterns tend
not to fluctuate regularly but to undergo unpredictable catastrophes,
usually because of desiccation. The greatest variability with time and
seasonal change is found in zones in which algae are the predominant space-
holders. A study of the patterns of variation in time of the biotic com-
munities on the Galeta reef flat and its influence on adaptive strategies

of the resident species and on community structure was begun during this
EPA study and is being continued as part of the Environmental Sciences
Program of the Smithsonian Institution.

VARIATION IN BIOMASS OF THE PREDOMINANT RED ALGA, Laurencia papillosa

Our survey of the intertidal reef flat at Galeta was begun with the expec-
tation of disproving the stereotypic picture of a tropical marine community
as a system with very small fluctuations in abundances of the predominant
species. To our surprise, we indeed found no gross seasonal changes in
numbers or surface coverages of predominant species. The observed seasonal
variations were not large enough to change the general appearance of the
area and the irregular variation between years was more obvious than the
seasonal changes. /The data and information on these temporal variations

in the reef flat community are available as photo-~offset copies from
the Smithsonian Tropical Research Institute. One should ask for pages

227 to 231 of Environmental Monitoring and Baseline Data compiled_under
the Smithsonian Institution Environmental Sciences Program (1973)/ It
appeared, however, that the biomass may be changing on a larger scale than
the surface coverage data indicated. That is, the Laurencia looked as if
it were becoming flatter and thinner while still occupying most of the
space previously occupied. In order to test and quantify this observation,
we decided to take samples and measure the dry weights. Laurencia papillosa
was selected because of its predominance on the reef flat, especially in
the Laurencia Zone (Table 1) and because its seasonal variation in spatial
occupation was the most pronounced.

Methods

Thirty-six permanent markers were placed along the seaward edge of the
Laurencia Zone, 2 meters apart (railroad spikes, 18 to the left and 18 to
the right of our transect line). These markers served as reference points
from where a distance in the numbers of centimeters acquired from tables
of random numbers were measured along the zone's edge. Another distance
value, measured at_a right angle inward to the first gave a point in the
center of a 0.06 m2 quadrat. Distances were measured very accurately in
centimeters and placement data for all quadrats collected were kept in
order to avoid sampling the same spot twice. If a placement fell on a
tide pool or on a patch with over 50 percent Halimeda coverage, a new
placement for that quadrat was found.

23


Quadrat Number

TAXA 1 2 3 4 5 6 7 8 9 10 Ave/m
Family Capitellidae
Notomastus lineatus 8 3 8.8
Family Glyceridae
Glycera
oxycephala 1 0.8
Family Leodicidae
Eunice afra 8 6.4
Eunice aphroditois
Eunice caribaea 1 1 1 6 7.2
Family Nereidae
Nerets callaona 3 2.4
Perinereis
elenacasot 4 99 82.4
Platynerets
dumeri lit 1 0.8
Pseudonerets
gallapagensis 1 2 2.4
Family Phyl lodocidae
Eulalia } 0.8
myriacyelum .
Family Sabellidae
Hypsicomus
torquatus 1 0.8
Family Syllidae
Autolytus magnus 1 1 1.6
Langerhansia
cornuta ] 0.8
Opisthosyllis
brunnea i 0.8
Family Serpulidae
Serpulid sp. 1 1 0.8
Serpulid sp. 2 2 1.6
Sptrorbis Sp. +H tt +H tt
Family Terebellidae
Eupolynnia ?
nebulosa 2 1.6
Loimia medusa 1 0.8
ARTHROPODA
Class Crustacea
Order Decapoda
Suborder Natantia
Natantia sp. 1 1 ] 1.6
Pasiphaeid sp. 1 2 2 2.4

164


o
-
3
2 2 a a 6
= is] Ss un co}
= S 3 8 S
o L <7 _ i=
LS a oO 3 o
TAXA 8 5 S = Es
Fostella sp. 7/20 16/20 4/16 12/16 13/16
Gelidiella
acerosa 6/20 2/16
Gelidium pusillum 19/20 13/20 8/16 5/16 7/16
Gontotrichiun
aletdii 6
Gractlarta 1/16 1/16
mammi Laris
Grif fithsia
radicans 8/20
Gri ffithsia
globt fera 1/20
Herpostphonta
secunda 1/20 1/20 3/16 3/16 3/16
Herposiphonta
tenella 20/20 15/20 13/16 11/16 10/16
Hypnea sp. 6/20 4/20 1/16 2/16
Hypnea cervicornis 5/20 3/20 1/16
Hypnea spinella 1/20 1/20 3/16
Jania sp. 13/20 18/20 13/16 10/16 10/16
Janta adherens §/20 3/20 2/16 1/16 /16
Laurencta
papillosa 9/20 20/20 8/16 2/16 13/16
Lophosiphonia sp. 1/20 1/20
Peyssonnelia rubra 1/20
Peyssonnelia
<moriea 9/20 11/20 10/16 9/16 8/16
Peyssonnelia
ordstedtit 2/20 8/20 2/16 1/16
Polystphonia sp. 9/20 5/20 6/16 3/16
Polysiphonia
subtilissima 1/20 1720
Taenioma macrourun 6/20
Wrangelia argus 13/20 1/20 1/16 1/16 1/16
PTEROPHYTA
Thalassia testudinum 16/16 7/16

104


oO
5
wo oo o =
= ° $ 3 S
= o 3 s S
g 5 8 s s
8 § nd = <
Eunicidae
Eunice afra 11/24 24/24 15/20 9/20 16/20
1-3-25 1-22-59 5-14-26 1-3-12 1-10-88
(36.3#11.5) (189,.3429.8)(76.8413.9) (13.6£6.2) (108.4235. 3)
1.3 3.2 5.2 2.0 7.3
3.096 1.530 1.527 4.456 2.959
Eunice 13/24 9/24 5/20 4/20 5/20
antennata 1-1-7 1-2-4 1-1-2 ]-2-2 1-2-4
aedificatria (10.64+2.8)  (5.6#1.8) (2.4) (2.8) (4.0)
0.4 0.09
1.828 2.117
Eunice 6/24 6/20 1/20 1/20
aphroditois 1-2-2 1-1-4 1 2
(3,341.3)  (3.3#1.5) (0.4) (0.8)
0.1 0.05
2.133 3.733
Eunice 24/24 24/24 20/20 16/20 20/20
(Nicidion) 4-89-419 107-452-993 2-41-304 1-13-74 4-51-144
caribaea (92941495) (3924.62447, 1)(525.2+151.2) (118.4239 .0) (469.6+82.9)
33.4 65.9 39.4 17.8 31.6
1,585 1.295 2.575 3.010 1.576
Eunice 12/24 13/24 6/20 6/20 7/20
filanentosa 2-5-26 1-5-43 1-3-7 1-4-12 1-4-5
(26.6+9.3) (69.0+22.5)(8.824.1) (13.246.6) — (8.4#3.3)
0.9 0.2 0.7 1.9 0.6
3.546 3.337 5.378
Eunice 3/24 3/20 2/20 2/20
vebsteri 2-2-4 1-1-2 1-1 1-4
(2.6) (1.6) (0.8) (2.0)
Eunice sp. 1/24 1/24
indet. 3 1
(1.0) (0.3)
Marphysa Nn. 6/24 3/24 3/20 3/20
sp. 1-1-16 q-1-1 1-2-4 1-3-5
(7,045.3) (1.0) (2.8) (3.6)
0.3
13.714
Onuphis 2/24 1/20 17/20 1/20
vermillionensts 1-2 1 1-4-32 2
(1.0) (0.4)  (58,4416.4) (0.8)
8.8
2.378

125


Quadrat Number
TS 6 7

TAXA 2 9 TO Ave/m?
Cerithiopsis 1 0.8
emersont
Heltiacus 1 0.8
infundibulus
Anachis
erassilabris 1 0.8
Class Bivalvia
Phacotdes
peetinatus i 4 4 i 32.0
Isognomon bicolor 1 1 1.6
Codakia = 1 2 9 13.6
orbicularis
Codakia
orbiculata 1 0.8
Arcopsts adamst 8 1 15.2
Cyathodonta 1 2 6 2 8.8
semirugosa
Brachidontes 2.4
excustus
Lithophaga nigra 4 3.2
Lithophaga 3 2.4
bisuleata
Pinetada 2 1.6
radiata
Diplodonta 1 0.8
punctata
ECHINODERMATA
Class Ophiuroidea
Ophiolepis 1 0.8
paucispina
Ophiuroid sp. 1 0.8

166


The infauna was separated from the large sand particles by pouring an en-
tire sample into a saturated sugar solution. As the sand sunk to the bottom,
the animals floated on the surface where their activity made them readily
observable. Using a pipette, the animals were then washed in seawater and
transferred into vials containing 10 percent formalin. Since the larger
mollusks do not float, the remaining sand particles were examined for them.

Results and Discussion

The results of our sandy beach studies are summarized in Tables 17 and 18.
In Table 17 we compare the abundances of macroscopic infaunal species found
in our study in December, April, and August with each other and with the
abundances found by Dr. Deborah Dexter in the summer of 1969 (Dexter, 1972).
Most species (16, or 76 percent) were rare (averaged from all samples as
less than 2 per m“). The abundances of Ancinus brasiliensis, Excirolana
salvadorensis and Cyclaspis sp., the three most common animals found during
the summer of 1969, were different in each sampling period. We have no
suggestions to explain these differences except that certain populations
may fluctuate not only with period of the year but perhaps with the time

of day and stage of the tide.

It is clear from these data that the surf-swept intertidal sandy beach
supports a fauna with great temporal variability in species composition
and abundance. A possible cause of this temporal variability was suggested
to us by Dr. Dexter. She observed that the sand on several of the beaches
during our sampling in December was composed of coarser grains than during
her sampling period in the summer of 1969. We had an opportunity to con-
firm this later since our samples of December and April contained at least
five times more sand than those taken in August with the same sieve (500 u
mesh).

Dr. Dexter suggested that the grinding action of large sand particles in
heavy surf probably creates a very hostile environment for soft-bodied
infaunal animals such as nerinid polychaetes. This is quite possible.
However, our data cannot separate this grinding action from other important
factors such as water retentive capacity of the sand, its absorptive capac-
ity, its capillarity and porosity to gases and water, all of which depend
on the sand grade and could affect the organisms living in the beach.

Table 18 shows that the largest diversities and abundances of organisms
are found throughout the year in the middle and lower intertidal zones,
both of which harbor a number of rare species that are not found in the
high intertidal zone. This last zone is characterized throughout the year
by the isopod Excirolana salvadorensis. The abundance of another isopod,
Ancinus brasiliensis, shifts from the middle and low intertidal zones in
April to the high intertidal zone in August. Scolelepis agilis occurs
throughout the beach during the year with the highest abundances in the
lower intertidal zone.

47


APPENDIX A

Frequency of macroscopic plants in the intertidal reef at the Galeta marine
laboratory. Species found only below spring tide low water are not in~
cluded. Frequency is given as the number of samples in which the species
were present divided by the total number of 0.125 m samples sorted for
plants. Joyce Redemske Young provided the identifications and the data

for this table. g
Oo o oO 2
< - vo - a
= oO 3 a °
- i— = a2) =
-_ o 2 o »
oO = i= _ i=
= S o oO 8
TAXA 8 Ss S € <
CHLOROPHYTA
Acetabularia
erenulata 1/16
Acetabularia
pust lla 15/20 9/20 6/16 7/16 7/16
Anadyomene stellata 2/20 8/20 2/16
Bryopsts plumosa 14/20 6/20 1/16 1/16 1/16
Caulerpa
cupressotdes 1/16
Caulerpa
sertulariotdes 1/20 1/16 1/16
Caulerpa
vickerstae V. 4/20 3/20 1/16
furcifolia
Caulerpa
racemosa 1/20
Chaetomorpha
brachygona 1/16
Chaetomorpha Sp. 9/16 5/16
Cladophora sp. 14/16 16/16 12/12 12/12 10/12
Cladophoropsis
membranacea 16/20 2/20 2/16 2/16
Codium
isthmocladium 2/20
Derbesia Sp.
(bushy) 10/20 14/20 2/16 9/16 5/16
Derbesia sp.
(unbranched) 5/20 2/20 3/16 1/16 1/16
Dietyosphaeria
cavernosa 1/16
Dietyosphaeria
vanbosseae 3/20 4/20 9/16 1/16 5/16

101


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TABLE 6. NUMBER (AND PERCENT) OF "COMMON" SPECIES, DEFINED AS OCCURRING
IN AVERAGE ABUNDANCES GREATER THAN 1/m@. Twelve categories of macroinver-
tebrates are considered separately for each of five intertidal Caribbean
reef flat zones at Galeta marine laboratory.

2
) CJ © 2
= ve) 3 o S
= 5 S 3 $s
£ 5 s 3 8
° o i) < iS]
oO a N re <
ZOANTHINIARIA 3(75) 4(80) 2(100) 2(100) 1(100)
ACTINIARIA 6(100) 6(75) 6(75) 5(100) 4(67)
OPHIUROIDEA 12(67) 8(44) 6(55) 7(64) 9(75)
ECHINOIDEA 3(43) 4(57) 3(50) 3(43) 117)
AMPHINEURA 9(90) 9(90) 6(75) 4(50) 6(86)
GASTROPODA 14(33) 13(42) 7(28) 4(27) 6(22)
BIVALVIA 8(47) 12(57) 9(69) 6(46) 10(56)
SIPUNCULA 16(64) 20(69) 16(73) 13(65) 16(46)
POLYCHAETA 52(65) 52(69) 30(71) 31(57) 30(65)
PYCNOGONI DA 6(67) 6(55) 7(70) 2(67) 7(70)
NATANTIA 14(64) 5(28) 3(43) 2(29) 9(64)
REPTANTIA 24(69) 10(45) 8(57) 5(38) 6(43)
167 149 103 84 105

17


TABLE 35. NUMBER OF SPECTES (FIRST NUMBER) AND INDIVIDUALS (SECOND
NUMBE| IN.0.01 m@ SAMPLES OF KILLED, CLEANED TETRACLITA TESTS
ANF BarReYPD! BONeeR C:MARINE DIESEL = 1:1, AND MARINE DIESEL SPRAYED
QUADRATS IN THE TETRACLITA ZONE, PAITILLA BEACH. Number of species
represents the total found in each sample. Since number of specimens
found in dead barnacles is 5,9 times that found in live ones, a stan-
dardization factor was calculated by dividing the number of live bar-
nacles by 5.9 in each sample and adding it to the number of dead bar-
nacles present in the same sample. Essentially, then, the number of
specimens indicated, is per barnacle and not per sample. BC:MD is an
abbreviation for the term Bunker C:Marine Diesel sprayed quadrats.

Pre-pol- 26 days 61 days 98 days 129 days 159 days

lution after after after after after

Coelenterates

Control 2/11 2/5 1/<l 2/1 2/3 1/2

BC:MD 2/14 V/<l 2/4 3/4 --

Marine Diesel 1/2 -- 2/3 -- 1/<
Polychaetes

Control 5/12 14/15 9/6 10/5 7/7 W/7

BC:MD 2/10 3/4 7/14 6/8 9/10

Marine Diesel 8/10 7/4 13/3 7/7 6/7
Mol lusks

Control 6/106 11/30 10/5 15/16 6/18 9/19

BC: MD 11/64 5/5 7/9 7/11 8/12

Marine Diesel 14/20 3/4 13/30 12/22 9/21
Barnacles

Control 2/145 2/83 2/61 2/93 2/32 2/67

BC:MD 2/23 2/57 2/96 2/55 2/99

Marine Diesel 2/208 = 2/126 2/165 2/64 2/50
Arthropods (other

than barnacles)

Control 7/114 3/3 5/1 3/1 W/7 3/4

BC:MD 5/14 1/<1 2 1/2 3/2

Marine Diesel 6/12 3/1 4/15 2/<1 2/2
ALL TAXA

Control 26/369 = 34/137 27/74 = 35/115 20/93 28/99

BC:MD 24/116 13/66 21/126 27/85 22/122

Marine Diesel 33/254 17/135 = 36/246 25/103 20/90

83


28

29

30

31

32

33

34

35

36

37

38

39

Percentage of live tissue on Pocillopora after treatment with
marine diesel or Bunker C oils.

Percentage of: live and "bleached" tissue on Pocillopora
after treatment with marine diesel and Bunker C oils.

Analysis of variance for a 22 factorial on the amount of
tissue bleached within 5 days and the amount of live tissue
after 109 days treatment of Pocillopora with oil.

Effect of a 1-minute exposure to Bunker C or marine diesel
on Psammacora, Pavona, and Porites.

Number of algal species from experimental quadrats sprayed
with Bunker C:marine diesel mixture or straight marine diesel
or control quadrats.

Number of species and average total number of individuals of
all species from experimental oil pollution quadrats and con~
trol quadrats in the Laurencia Zone at Galeta.

Number of species and individuals in experimental oil pollu-
tion quadrats and control quadrats in the Tetraclita Zone
at Paitilla Beach.

Number of species and individuals in experimental oil pollu-
tion and control quadrats in the area of killed and cleaned
Tetraclita tests at Paitilla Beach.

Characteristics of the fuel oil samples used in pollution
experiments in this report.

Condition of small Rhizophora mangle after having been sub-
jected to oil pollution on two occasions, 22 days apart.

Different patterns of surface coverage by fouling organisms
on clean Plexiglas plates in comparison with plates coated
with Bunker C or marine diesel oil.

Comparison of the dry weights of Caribbean fouling organisms

which grew over a 60-day period on control Plexiglas plates
and on Plexiglas plates coated with marine diesel oil.

xii

Page

70

72

74

79

81

82

83

84

89

93

94


rates of corals varied both in space (a distance of 3 m at the same depth)
and time (two different 61-day periods). The effects of location (3 meter
distance at same depth) and time of year (about two months apart) were
each greater than the effect of 2.5 hours exposure to Bunker C oil (Table
26). Therefore, it is very important that the effects of oil be judged
by accurately situated controls.

TABLE 27. A COMPARISON BETWEEN CONTROLS AND EXPERIMENTALS OF THE PROPOR-
TION OF LIVE BRANCH TIPS THAT FAILED TO GROW DURING THE 61 DAYS FOLLOWING
INITIATION OF THE EXPERIMENT. One Porites head of 10 branches subjected
to Bunker C oi] failed to grow at all although it appeared quite healthy
to superficial observation. In case this occurred due to a factor other
than exceptional individual susceptibility to Bunker C oil, a Fisher exact
probability test was performed on all data (given in the table) then per-
formed a second time disregarding this one Porites head (29 rather than

39 oil-subjected branch tips producing no growth).

No. branches No. branches
Porites that_grew with no growth Total
Control 60 4 64
Subjected to Bunker C 118 39 157
Total 178 43 221

For all data in table: Fisher exact probability: P = 0.0006
Disregarding one head with 10 branches, none of which grew:

Fisher exact probability: P = 0.0064
Reject Hy: conclude that the proportion of live branch that failed to

grow during the 61-day period was greater than in those
Porites heads subjected to Bunker C oil.

66


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72


xI Field Experiments with the Effects of Oil Pollution on Carib-
bean and Eastern Pacific Intertidal Communities 77

xIL Field Experiments with the Effects of Oil on the Mangrove

Tree, Rhizophora mangle 87
XIII Effects of Oil on the Recruitment of Organisms to Plexiglas

Settling Plates 91
XIV References 97
XV Appendices 100

XVI Index of Organisms 168

viii


SECTION XV

APPENDICES

Frequency of Macroscopic Plants on the Intertidal Reef at the
Galeta Marine Laboratory

Catalog of the Larger Invertebrates from the Intertidal Reef
at the Galeta Marine Laboratory

Occurrence of Two Species of Barbatia in 0.06 m2 Quadrats on
the Intertidal Reef Flat at the Galeta Marine Laboratory

Catalog of Mollusks from the High Intertidal "Splash" Zone at
the Galeta Marine Laboratory

Catalog of Species Found on the Intertidal Andesite Rock Beach
at Paitilla, on the Pacific Coast of Panama

Catalog of Intertidal Macroinvertebrate Species Found in the
Mangrove Community Adjacent to the Galeta Marine Laboratory

Names and Present Addresses of the Authors of Each Section

100

143

144

146

162

167


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70


TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing}

THT FORT NO, ? 5, RECIPIENT'S ACCESSIONNO,
-600/3-76-028
(AND SUUTITLE a ~~ Is. REPORT OATE
SURVEY OF MARINE COMMUNITIES IN PANAMA AND May 1976 (Issuing Date)

EXPERIMENTS WITH OTL 6. PERFORMING ORGANIZATION CODE

Charles Birkeland, Amada A. Reimer, and
Joyce Redemske Young

1 AUTHORISY 8. PERFORMING ORGANIZATION REPORT NO.

jo ht Ri OHMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT NO.
Smithsonian Tropical Research Institute
1BA022
P.O. Box 2072 TT CONT! NO.
Balboa, Canal Zone 14-12-874
12 SPONSORING AGLNCY NAME AND ADDRESS 13. TYPE OF REPORT AND PERIOD COVERED
Environmental Research Laboratory
Office of Research and Development 14, SPONSORING AGENCY CODE
U.S. Environmental Protection Agency
Narragansett, Rhode Island 02882 EPA-ORD

16. SUPPLE MENTARY NOTES

[WS ABSTRACT 7
Baseline surveys were conducted on both the Caribbean and Pacific coasts of

Panama. The structure of macroinvertebrate communities along the Caribbean
transect are presented from data collected for over 500 identified species in 108
samples including a total of over 50,000 specimens. Recruitment to benthic
communities was investigated with settling plates. The Caribbean was found to
be seasonalin species occurrence while the Pacific was seasonal in productivity.
The effects of oil pollution on tropical intertidal marine communities
were tested by precisely controlled experiments utilizing tarry Bunker C
and volatile marine diesel oils. Field experiments were performed on a
Caribbean intertidal reef flat community, a Pacific rocky shore community,
settling plates in both oceans, mangrove trees sprayed with oil on the leaves
and/or stilt roots and on coral growth. Bunker C oil had a greater detrimental
effect than did marine diesel oil on coral growth. Marine diesel oil had a
greater detrimental effect than did Bunker C oil on fouling communities of
settling plates. When comparing experimentals with controls, growth rates
were used as an indicator of the presence of unobserved physiological stress
or damage and a quantitative index of the cost of repair. Susceptibility to
oil pollution varied significantly with location and time of year so that very
precise controls were required in the experiments.

7. KEY WORDS AND DOCUMENT ANALYSIS
a DESCRIPTORS _ : ____ JODENTIFIERS/OPEN ENDED TERMS |e. COSATI Feld/Group _|
Ecology Marine benthos
Benthos Oil pollution
Oils Intertidal organisms oF
Ocean environments Community structure
Aquatic biology Ecological survey

Oil induced stress
Tntertidal communities

TEAS THLNUTION STATEMENT 19. SECURITY CLASS (This Report; 21, NO, OF PAGES
RELEASE TO PUBLIC UNCLASSIFIED 193
20. SECURITY CLASS (This page) 22. PRICE
UNCLASSIFIED

EPA Form 2220-1 (9-73)

177
vir U.S. GOVERNMENT PRINTING OFFICE: 1976-657-695/5416 Region No. 5-1!


plates with Bunker C oil because including much of the thick tarry oil
would have been a large error. The toxic effects of marine diesel oil are
also implied by the surface coverage measurements from Galeta plates (Table
39). During the first 59 or 60 days, there was always more bare space,
i.e., less coverage by algae and animals, on both upper and lower surfaces
of plates coated with marine diesel oil than on control plates.

In summary, marine diesel oil appeared to have toxic effects on fouling
organisms while an increase in algal production appeared to be associated
with Bunker C oil. However, the effect of Bunker C oil on algae may upset
the usual organization of intertidal communities. For instance, the algae
May be better able to compete with sessile animals for space. It is in-
teresting to consider the outcome of the wreck of the oil tanker TAMPICO
MARU. The kelp expanded dramatically and this phenomenon was explained as
a result of the failure of the echinoid populations of herbivorous grazers
to recover for over seven years (North, Neushul and Clendenning, 1965).
This explanation is probably correct. A more direct effect of the oil to
algae may have been an additional factor.

96


TABLE 33. NUMBER OF SPECIES AND AVERAGE TOTAL NUMBER OF INDIVIDUALS
OF ALL SPECIES PER 0.01 m@ FROM EXPERIMENTAL QUADRATS IN THE LAURENCIA
ZONE, GALETA REEF. Quadrats were treated with Bunker C:Marine Diesel
oil mixture (1:1 ratio, noted as BC:MD in the table) or straight mar-
ine diesel oi1; the control quadrats were not sprayed with oil. Each
first number refers to number of species, the secgnd numbers refer to
average total abundance of all species per 0.01 for four quadrats
jn each time-place-treatment combination category.

Before oil 7 days 28 days
treatment after after
Polychaeta .
Control 19/26 22/73 23/82
BC:MD (mixture) 14/56 16/56 14/44
Marine Diesel 17/35 17/58 21/86
Sipunculida
Control 8/8 9/17 7/9
BC:MD (mixture) 6/5 8/8 8/12
Marine Diesel 8/6 5/6 10/8

81


Aphrodita n. sp., 123
Arabella mutans, 123, 151, 163
sp., 152
Area, 19
imbricata, 118
mutabilis, 150
Arcopsts adamst, 118, 166
Arene cruentata, 113
tricarinata, 113
ascidians, 56, 58
Ascorhynchus castelltotdes, 133
latipes, 133
Aspella indentata, 149
Asptdostphon spp., 121
Astertas forbest, 98
Astracystis ramosa, 103
Astraea caelata, 113
phoebta, 113
Astrangia solitaria, 107
Atylus mintkoi, 48
Autolytus magnus, 33, 130, 156, 164
n. sp., 130
Automate vrectifrons, 136

Batlya intricata, 117, 165
Balanus, 28, 30, 31, 34
amphitrite, 28, 158
inexpectatus, 28, 158
spp., 30, 31, 33, 36
tintinnabulum, 28, 158
trigonus, 56
Baleis intermedia, 115
sp. 1, 115
Barbatia, 100, 143
domingensis, 118, 143
spp., 118
tenera, 118, 143
Batillavia minima, 41, 145, 165
Bhawanta goodet, 128, 153
riveti, 154
Bittiwn varium, 115
Boeeardia proboscidea, 33, 36, 156
tricuspa, 33, 156
Bostrychia, 42
binderi, 41, 42, 162
radicans, 147
Bostryocladia tenuissima, 147
Brachidontes citrinus, 119

169

exustus, 166
puntarenensis, 36, 150
recurvus, 119
semilaevis, 33, 36, 150
sp., 40, 45
brachiopod, xi
Bryopsts galapagensts, 146
plumosa, 101
bryozoans, 26, 40, 56, 58, xii
Bursa cubaniana, 116

Caecum spp., 148
Caletnus obscurus, 160
Callipallene sp., 134
Catloplax janeirensis, 111
Caloglossa leprieurit, 41, 42,
147, 162
Cantharus auritulus, 165
tinetus, 117
Cardita radiata, 37, 151
Catenella, 42
repens, 41, 42, 162
Cauleriella sp., 124
Caulerpa, 42
cupressotdes, 101
fastigiata, 42, 162
racemosa, 12, 101
racemosa V. occidentalis, 146
sertularioides, 12, 101
vickersiae Vv. furctfolia, 101
Centrocerae clavulatum, 103, 147,
162
Ceramiun byssoideum, 147
eruciatum, 103
fastigiatun, 103, 147
leutzelburgit, 103
personatum, 147
sp., 103
Ceratonereis mtrabilis, 127
Certanthus sp., 105
Cerithiid sp., 165
Cerithiopsis emersoni, 165
Cerithiwn eburnewn, 114
genmatwn, 148
litteratun, 115
sp., 165
sp. 1, 114
stercusmuscarum, 148


Gracilaria brevis, 147 Isehnoplax, refer to Ischnochiton

mammilaris, 104 Isognomon, xi
Gregariella coralliophaga, 119 bicolor, 119, 166
Griffithsia globifera, 104 radiatus, 119, 145
radieans, 104 recognitus, 33, 36, 151
Gymnogongrus crustiforme, 147 isopods, xi
Halicystis osterhoutit, 102 Jaeropsis rathbunae, 159
Halimeda, 23, 24, 25 Jania adherens, 104, 147
opuntia, 11, 25, 41, 102, 162 sp., 104
tuna, 102
Halosydna leucohyba, 128 Langerhansia cornuta, 131, 164
sp. 1, 128 mexicana, 131
Halyosyllis spongicola, 37, 131, 156 Lasaea rubra, 37, 151
Harmothoé sp., 128 sp., 37
Heltacus bisulcatus, 114 Latirus carinifera, 117
eylindricus, 114 Laurencia, 23, 24, 25
infundibultformis, 114 papillosa, 2, 11, 23, 24, 25,
infundibulus, 165 41, 42, 104, 162
hemichordate spp., 111 sp., 157
Hemitoma octoradiata, 112 Lepidasthenia gigas, 154
sp., 112 Lepidochitona liozonis, 111
Hermodice carunculata, 123 Lepidonotus ecrosslandi, 36, 154
Herpostphonia secunda, 104, 147 humilis, 129
tenella, 104, 147 nesophilus, 154
Hestone picta, 126 pomarae, 154
Heterocrypta macrobrachia, 142 Lepidopa spp., 48
Hildenbrandia prototypus, 147 Leptodius flortdanus, 140
Hippa sp., 48, 49 Leucozonia ocellata, 117
Hippolyte curacacensis, 138 Lima pellucida, 119
Htpponix antiquatus, 115 Linopherus canariensis, 128
grayanus, 148 Lioberus castaneus, 119
panamensis, 31, 33, 36, 148 Lithacrostphon sp. 3, 163
ptlosus, 148 spp., 121
subrufus, 115 Lithophaga aristata, 31, 33, 36, 151
holothurian spp., 111 bisuleata, 119, 166
Hyalina albolineata, 118 nigra, 119, 166
avena, 118, 165 Littorina aspera, 148
tenutlabra, 118 duboisa, 148
hydroids, 26 lineolata, 114, 144
Hypnea cervicornis, 104, 147 meleagris, 144
spinella, 12, 104 tesselata, 144
Hypsicomus torquatus, 129, 155, 164 ziczac, 144
Lobophora vartegata, 102
Inachoides laevis, 160 Loimia medusa, 132, 157, 164
Isaurus duchassaingi, 12, 106 Lophosiphonia sp., 104
Ischnochiton papillosus, 112 Lucina pensylvanica, 120
pectinatus, 112 Lumbrinereis inflata, 126, 153
purpurascens, 112 Lysaretid sp., 126

172


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49


average density of each species, but it should be remembered that there is
great patchiness in animal distribution and a large number of species are
not typical of mangrove habitats but can survive in the area if suitable
substrata such as coral rubble are available.

As is indicated in Table 16, the fauna of Crassostrea sp., Brachidontes
sp., sponges, tunicates and bryozoans reported by Rutzler and Sterrer (1970),
as covered with oil, has not returned to the area after 33 months. On
nearby mangrove root communities (Bocas del Toro to the west and San Blas
to the east), a typically lush fauna of sponges, tunicates and oysters is
still present. Old, dried, patches of oil are still present on the mangrove
roots in our study area. This, along with the observed presence of a lush
encrusting community on nearby mangroves and the presumed presence of a
lush encrusting community at Galeta previous to the oil spill (Rutzler and
Sterrer, 1970), implies that the Witwater spill may have had a long-term
impact (33 months+) on the Galeta mangrove community. Unfortunately, this
conclusion is invalidated by the lack of quantitative data before the spill
and confounded by other possible causal factors. For instance, Army Malaria
Control has been spraying the mangroves of Galeta Point intensively for 15
to 20 years. Information obtained from the Navy Office of Public Works in-
dicates that roughly 1200 gallons of Malathion has been sprayed around the
Navy recreation area bordering to our mangrove study area. Previous to
this, DDT was used rather than Malathion. These chemicals were sprayed by
means of a fogging machine. Roughly 300 to 400 gallons per year of Dalapon
(a herbicide) is applied directly to the ground around the Navy's antenna
site approximately 0.8 km upstream from our mangrove study area.

However, Navy Office of Public Works informed us that an intensive mosquito
and sand~fly control program has been underway for 15 to 20 years. If any-
thing, the efforts have been reduced over the last 5 years. In contrast,
the devastation of the mangrove root epifaunal communities appeared to take
place during the Witwater oil spill (Rutzler and Sterrer, 1970). If this
is correct, then the spill has had a major influence which has continued
for better than 33 months.

* at the time of this rewriting of the report (June 1974), 66 months after
the Witwater oil spill, the state of the epifaunal communities on the
mangrove roots still appears to remain in the same condition.

45


SECTION III
INTRODUCTION

On 13 December 1968, the 35,000-barrel oil tanker SS Witwater broke apart
about three miles from the Smithsonian Tropical Research Institute (STRI)
Marine Laboratory on the Caribbean coast of Panama and released approxi-
mately 20,000 barrels of Bunker C and marine diesel oil which spread over
the shoreline. The STRI staff, with aid from US armed forces personnel
and the conditions of high water, cleared much of the oil from the water
around the laboratory and apparently reduced the potential damage to the
natural marine communities (Rutzler and Sterrer, 1970). The marine com-
munities on the reef flat do appear normal now, and did when the project
started two years after the oil spill. The amount of damage could not be
evaluated quantitatively because the Galeta Point laboratory was set up
only a short time before and no baseline data were available for compari-
son. In considering the problem of evaluating the effects of such occur-
rences on tropical marine systems, it became clear that it was not just a
matter of gaining baseline data for the local reef flat. Adequate in-
formation was not available for any Caribbean intertidal reef flat com-
munities.

Although the effects of increasing spillage of hydrocarbon oils into the
sea have been reported since the early 1920's (US Public Health Service,
1924; Lane, 1924, 1925; Orton, 1925), it was not until a major disaster

as the 1967 Torrey Canyon incident that the concern about oil pollution
received intense and world-wide attention. It then became apparent that
it was very difficult, if not impossible, to evaluate the effects of oil
pollution in marine ecosystems, due to the sparsity or complete lack of
prepollution ecological data. Until the beginning of this study, the
only comprehensive account of pre- and postpollution distribution of in-
tertidal organisms is that of Nelson-Smith (1968) who worked in Milford
Haven, Britain. Most of the current information is from studies in tem-
perate regions (Carthy and Arthur, 1968; Pollution Abstracts, 1970~1973).
On tropical marine shores, the sparsity of ecological knowledge has been
particularly eminent. Very little information was available on the struc-
ture of undisturbed intertidal communities in the Caribbean. The informa-
tion available was either qualitative or concerned with a narrow subject.
Consequently, the Environmental Protection Agency (EPA) contracted the
Smithsonian Institution to undertake a project on (1) the normal vari-
ations in structure of Caribbean intertidal communities, and (2) the
effects of oil on these communities.

The research sponsored by EPA at STRI consisted of a 3-year program. During
the first year, a baseline of information on community structure and re-
cruitment patterns on both the Caribbean and Pacific coasts was established.


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36


SECTION VI
SURVEY OF AN INTERTIDAL MANGROVE COMMUNITY AT GALETA

The study of the effects of oil on mangrove forests is particularly impor-
tant because they occupy nearly 25 percent of the world's coastline in the
tropics (25°N to 25°S) and serve as important "nursery" areas for many
species of invertebrates and fishes (MacNae, 1968). The mangrove forest
adjacent to the Galeta Marine Laboratory was visited by Klaus Rutzler and
Wolfgang Sterrer approximately two months after the Witwater oil spill.
They observed that: the mangrove community suffer the most damage from the
oil spill of any of the marine communities at Galeta (Rutzler and Sterrer,
1970). Crassostrea sp., Brachidontes sp., sponges, tunicates and bryozoans
were covered with oil and nearly eliminated in all exposed areas.

In order to provide background information on the composition and charac-
teristics of the mangrove community, we conducted a survey that included
the intermittently submerged floor, aerial vegetation, and permanently
submerged prop roots.

Methods

Ten 0.125 m2 samples were collected from locations along the edge of the
mangrove shore at the south side of the Galeta Road causeway. The samples
were located by selecting coordinates from a table of random numbers and
pacing the distances. A 0.125 m* frame with an open end was laid on the
selected spot and placed on the substratum by sliding it in among the
aerial roots through the open end. The aerial roots were sawed off at a
distance of one foot above the level of the substratum. Pieces of coral
rubble and the mat of algae laying on the surface of the substratum were
collected by hand. The substratum (composed mainly of sand, root hairs,
and continuations of the aerial roots) was collected to a depth of about
three inches with a shovel and diving knives. These two communities were
kept in separate buckets.

The sample was analyzed as follows:

1. The aerial prop roots were stripped of epiphytic algae and animals
and their surface area calculated by measuring the length and determining
an average diameter for each root.

2. The extraordinarily dense mat of root hairs was carefully examined

for possible dwellers. After having been cleaned of sediment by repeated
washings in seawater, the root hairs were measured for volume and wet weight.

40


All colonies in the second and third experiments were finally placed in
well-aerated 3-liter containers under cool white fluorescent light for
12 hours daily.

The upper and lower surfaces of the colonies (Figure 4) were outlined on
millimeter-lined paper and the surface area occupied by live tissue was
calculated by counting the number of squares within the outline of the
colony. The complicated topography of the branches provided many useful
reference points to check the regression or addition of live tissue. This
procedure. does not take into account the three dimensional character of .
the colonies, but, since the changes in live tissue are expressed as a per-
centage of the original, based on two-dimensional drawings, the method is
useful and accurate enough. Percentages of bleached (loss of color because
of massive loss of symbiotic zooxanthellae) and dead tissue were calculated
periodically.

Experiments with other corals.—Branches and small colonies of Pavona,
Psammocora and Porites were exposed to experimental conditions similar to
those described for Pocillopora in the second experiment.

Results and Discussion

Table 28 summarizes the data obtained for three different experiments. The
first experiment shows that the colony tested was able to survive an ex-
posure to pure marine diesel oil for 30 minutes and that it displayed the
same tissue death rate as the control for about one month.

In the second experiment, all the colonies had similar degrees of tissue
death for the first week, but after 13 days there was a very obvious dif-
ference between the control colonies and those that were exposed to oil.
The colonies in marine diesel oil lost almost all of their living tissue
within 13 days; those in Bunker C oil lost from 70 to 84 percent of their
living tissue in the same period. After 16 days, both marine diesel and
Bunker C colonies lost a large portion or all of their living tissue while
the control colonies sustained over 95 percent of it. The third experi-
ment showed that except for colony 1 in marine diesel oil the rest behaved
in much the same way for almost one month. Some sharp differences between
the colonies appeared after 71 days although there was no evident trends
for colonies treated in a particular way. After 109 days, all of the co-
lonies treated with Bunker C oil and one colony of the controls were dead.
The rest of the control colonies and the colonies treated with marine diesel
oil had comparably low percentages of living tissue left. The instances in
which the percentage of tissue at one date was greater than at a previous
one (e.g., colony 6, control for experiment 3 between 31 March and 6 April;
colony 4, control for experiment 3 between 5 April and 13 April; colony 1,
marine diesel oil between 27 April and 10 June) represents actual growth
of new tissue covering areas that were originally dead. In all cases this
new tissue covered small isolated dead patches towards the tips of the

69


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spongicola 3-7-14 1-1-2 1
(24) (4) (1)
Langerhansia 8/8 2/8 4/8 5/20 3/8
cornuta 1-12-41 2-13 12-15-49 2-9-21 1-2-4
(148.0250.1) (7.5) (91) (42) (7)
10.4
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mexicana 1
(0.3)
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(126) (168.0434. 3) (62) (7) (44)
6.4
1.250
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Typosyllis prolifera +
Typosyllis 7/8 7/8 5/8 3/8
vartegata 1-2-40 4-10-18 1-2-6 3-7-22
(80.0+39.5) (80.0+18.0) (14) (32)
1.5 1.0
2.635 1.268
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1
(1.0)
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stripes
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stripes - white +
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Syllid, brown +
dots
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Syllid, gray
Syllid, leafy + +
projections
Syllid, maroon + +

131


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(236.6441.8) (85.6420.6) (20.0410.5) (1.6) (6.4)
8.5 1.4 1.5
1.718 2.249 6.008
Cirratulidae
Cauleriella 1/24
sp. indet. 1
(0.3)
Chaetozone 3/24 1/24
sp. indet. 1-1-1 1
(1.0) (0.3)
Cirratulus ? 1/24
cirratulus ]
(0.3)
Cirri formia 3/24 1/24
luxurtosa 1-3-4 1
(2.6) (0.3)
Cirri forma 2/24 24/24 5/20 4/20 12/20
punctata 1-7 1-13-58 1-2-16 1-2-3 1-5-16
(2.6) (96. 3429.3) (9.2) (2.8) (27.67.6)
1.6 1.9
3.152 2.208
Dodecaceria 2/24 4/24
eoncharum 1-2 1-3-4
(1.0) (2.6)
Tharyx sp. 2/24 1/24
indet. 1-1 1
(0.6) (0.3)
Cirratulid 1/20
sp. unknown 1
(0.4)
Dorvilleidae
Dorvillea 1/24
rubrovittata 1
(0.3)

124


SECTION I
CONCLUSIONS

1. Growth rates provide an indicator of the presence of unobserved physio~
logical stress or damage and a quantitative index of the cost of repair.
Although appearing to be in good health after one day in the field follow-
ing 2.5 hours of exposure to Bunker C oil, the mean growth increments of
the hermatypic corals Porites furcata were significantly smaller than those
of the controls during the following 61 days.

2. The mean growth of branches making up heads of Porites furcata did not
differ significantly between heads used as controls, while the mean growth
of P. furcata branches in heads subjected to Bunker C oil differed signif-
icantly between heads. An individual variation of heads or colonies in
susceptibility to oil pollution at low levels is implied.

3. Precise controls are required for low-level pollution experiments. The
mean growth increments of both control and experimental coral heads varied
significantly in the field over 3-meter distances at the same depth and
during time periods of the same length but 2 months apart. Location and
time of year each had a great enough effect that tests involving 2.5 hours
exposure of corals to Bunker C oil need controls set very close by to ob-
serve growth during recovery. Growth rates from literature cannot be
accurately used for comparison.

4. In laboratory experiments, Bunker C oil had a more damaging effect than
did marine diesel oil on Porites furcata, Pocillopora damicornis, Pavona
gigantea and Psammocora stellata. After short exposures of 0.5, 1.0, and
30 minutes, the rate and extent of tissue death depended on coral species
and did not appear until about 2 weeks after the exposure to oil.

5. Marine diesel oil had a clearly toxic effect on fouling communities.
Dry weight measurements of production showed that plates coated with marine
diesel oil had a significantly lower biomass of fouling organisms than did
the control plates. Surface coverage measurements showed less space
occupied by algae and animals on settling plates coated with marine diesel
oil than on control plates.

6. The percent surface coverage of algae on settling plates was signifi-
cantly higher on plates coated with Bunker C oil than on plates coated with
marine diesel oil or on control plates. Five aquaria previously containing
Bunker C oil each grew more algae than any of five aquaria previously con-
taining marine diesel oil and each grew three to five times as much algae
as any of the five control aquaria. After spraying intertidal quadrats

in the field with Bunker C oil, the number of algal species in the quadrats


£
ov o oO 2
£ = 7) od Qa
_ cs] J wn °o
pam © 2 a s
3 2 € < €
SS J oO oo i]
8 Ss a < <
Onuphis sp. 1/20
1
(0.4)
Palola 21/24 20/24 8/20 5/20 5/20
stciliensis 1-4-57 1-6-20 1-6-13 1-1-3 }-1-4
(51.0418.7) (50.3413.5) (18,026.4) (3.2) (4.4)
1.8 0.8 1.4
3.973 2.500 3.070
Palola sp. 1/24 2/24 1/20
indet. 3 2-4 1
(1.0) (2.0) (0.4)
Glyceridae
Glycera 3/24 1/24 1/20 5/20
oxycephala 1-1-4 1 1 1-1-2
(2.0) (0.3) (0.4) (2.8)
Glycera 2/20 1/20
tesselata 1-1 1
(0.8) (0.4)
Glycera sp. 1/20
1
(0.4)
Goniadidae
Goniada 1/24
acicula 1
(0.3)
Hesionidae
Hestone picta V/20
(0.4)
Ophiodromus 1/24
obseurus 1
(0.3)
Lumbrinereidae
Lumbrinereis 20/24 10/24 2/20
inflata 1-8-98 1-10-31 2-4
(108.0+37.0) (42.6414.9) (2.4)
3.8 0.7
3.635 3.649
Lysaretidae
Lysaretid sp. 1/24
indet. 1
(0.3)

126


TABLE 16. THE MEAN FREQUENCY OF OCCURRENCE IN TEN 0.125 m¢ INTERTIDAL

QUADRATS TAKEN AT THE SEAWARD EDGE OF A MANGROVE FOREST ADJACENT TO THE
GALETA MARINE LABORATORY. &

No. genera/ Mean frequency for each species
Taxa No. species in 0.125 m* samples (n = 10)
Chlorophyta 6/7 0.24
Rhodophyta wl 0.32
Anthozoa 2/2 0.25
Sipuncula 4/13 0.17
Polychaeta 19/22 0.16
Crustacea 19/26 0.22
Gastropoda 15/16 0.19
Bivalvia 9/11 . 0.25

9 For detailed species list and data, refer to Appendix F.

44


e.g., on the growth rates of corals or on recruitment of sessile marine
invertebrate larvae and algal sporelings. The experiments were not set
up to make trivial demonstrations of mass mortality under a thick coating
of oil, but to perform accurate quantitative measurements of effects de-
tectable only through comparisons with controls in the experiments.

iv


Quadrat Number
TAXA 7 2 3 4 #5 6 7 8 9 10° Ave/m

Potystphonta howet +F
Spyridia +
filamentosa
PORIFERA
Class Demospongia
Geodia sp. +
Porifera sp. 1M
Porifera sp. 2M +
COELENTERATA
Class Anthozoa
Anthopleura
krebst 3 3 4.8

Zoanthus
sociatus 275 21 945 992.8

SIPUNCULA

Golfingia sp. 1 7 5.6
Golfingia ? sp. 2 7 5.6
Golfingia ? sp. 3 1 0.8
Golfingta ? sp. 4 1 0.8
Lithaerosiphon 1 0.8

sp. 3 .
Paraspidostphon 2 1.6

fishert .

Paraspidosiphon
spinoso- 2 2 1 9 12.0
scoutatus

Paraspidosiphon 2 3 4.0
steenstrupt .

Parasptdostphon
sp. 4 2 4 4.8

Phaseolosoma
antillarum 2 1.6

erluccne res 22° moe

Phascolosoma sp. 3 3 2.4

Phascolosoma sp. 4 6 1 5.6
ANNELIDA
Class Polychaeta
Family Amphinomidae

Eurytho€ complanata 4 1 2 5.6

Amphinomid sp. 1 2 1.6
Family Arabellidae

Arabella mutans 2 1 6 14 18.4

163


Arabella sp. indet.

Chloraemidae
Pherusa inflata

Piromts americana

Cirratulidae
Dodecaceria concharun

Cirriformia luxuriosa

Cirriformia tentaculata

Tharyxz Sp.

Cirratulid sp. indet.

Dorvilleidae
Dorvillea cerasina

Eunicidae
Eunice sp. indet.

Lysidice ninetta

Palola sictliensis

oe
co $ 8s oO
2 3 = £
_ i= rey S
3 S £ 8
2 $ Pry »
2 & fa 3
178
1
0.1
4/8
34
4.0
2/8
4
0.5
2/8
2
0.2
4/8 4/2
37 9.0
4.4 0.8
1/8
1
0.1
2/8 3/12
2 3.0
0.2 0.3
1/8 in2
1 0.6
0.1 0.05
2/8
2
0.2
8
1
0.1
6/8 10/12
42 14.4
5.0 1.3
4/8 Wiz
27 0.6
3.2 0.1

152


SECTION IX
FIELD EXPERIMENTS WITH THE EFFECTS OF EXPOSURE TO BUNKER C OIL
ON THE GROWTH RATE OF THE HERMATYPIC CORAL, PORITES FURCATA

A number of studies are cited in the literature in which both field and lab-
oratory studies have been made with the effects of oil on hermatypic corals
(Johannes, Maragos and Coles, 1972). Very few of these indicate signs of
damage and almost none show definite evidence. Since hermatypic corals are
very important in the ecology of reef communities, providing habitat as well
as entering importantly into community metabolism, it is important to assess
as thoroughly as possible the effects of oilspills on the health of corals.
When mortality does not occur, rate of growth is probably the best quanti-
tative, objective measure which integrates a variety of physiological effects.
Further, much of a coral’s success in a community, e.g., its strength in
competition with other species for space or its ability to tolerate grazing
and predation, depends in part upon its rate of growth (Glynn, Stewart and
McCosker, 1972).

Methods

In brief, Porites furcata heads were collected, stained to mark the size at
the initiation of the experiment, experimentally subjected to Bunker C oil
or placed in pure seawater as a control, then replaced in the Porites bed
where originally collected. After 61 days, the amount of growth added
since the staining process was compared between the controls and those
treated with oil. The procedures are described in detail in the following
passages. Those who are interested mainly in the results and discussion
may wish to skip directly to that section.

The experiment was repeated over two 61-day intervals, 25 January 1973 to
27 March 1973 and 4 April 1973 to 5 June 1973. Heads of Porites furcata,
all of about the same size (about 10 or 12 branches), were each collected
from a depth of 4.6 m (15 ft) near the Galeta laboratory. They were placed
in plastic bags with Alizarin red S bone stain, sealed closed, and left for
6 hours (1100 to 1700) in shallow water 0.3 m (1 ft) in depth. After 6
hours of staining, they were placed overnight in an outside fiberglass
tank with running seawater.

The next morning, two coral heads were placed in each of six buckets with
just enough seawater to cover them. One hundred milliliters of Bunker C
oil was poured into each of 4 buckets. When poured, the oil reached the
bottom of the buckets but immediately floated to the surface through the
branches of the corals. The water surface was 23 cm in diameter so the
film was 2.4 wm thick. In the first experiment, four corals in two buckets

61


TABLE 5. MEAN NUMBER OF INDIVIDUALS PER M2 FOR ALL MEMBERS OF EACH OF
12 CATEGORIES OF MACROINVERTEBRATES ALONG THE CARIBBEAN INTERTIDAL REEF
FLAT TRANSECT AT GALETA MARINE LABORATORY.

=

o o i 2

< — a = a

_ 8 J wn re}

- iJ = un —

= o a] o re]

o x <7 _— i=

L =i oO o oO

3S ct 3 = )

3 a N = <
ZOANTHINIARIA 4346 1366 4830 50 33
ACTINIARIA 129 79 110 17 36
OPHIUROIDEA 334 166 294 53 323
ECHINOIDEA 34 42 10 13 3
AMPHINEURA 65 149 48 13 14
GASTROPODA 72 60 34 22 28
BIVALVIA 134 288 150 37 198
SIPUNCULA 175 352 265 209 633
POLYCHAETA 2697 5914 1201 640 1073
PYCNOGONIDA 25 34 37 4 38
NATANTIA 270 31 30 10 64
REPTANTIA 471 153 46 40 79

Averag# total

number of macro-

invertebrates

per m? (excluding 4323 7297 2137 1087 2498
coelenterates and

sponges )

4 From Appendix B.

16


*sueaco yzoq uy ALquedisLUBLS
4ajsip SUOSeaS OM} BY} WOUy e7eP aYz Wous SUOLSSaube4 a4} apn_U0D ‘sased 470g UL Oy qoafay

500°0> d ("3°P o1z‘2) 90%°9 4 ueaqq!4e9) uoLssasbar LeNPLALpUL WOU} SUOLZELAD|

)
G00°0> d (‘$"P 222°2) Lpl"6 = 4 opgLoed) UO{ssasbad UOWIOD OF aNp souelsen

° *aUL[ UOLSS2A694 UOUMOD B 314 SUOSeAS OM} BY? WOAS eTeP BY2
yey sp CH §(suoseas Aup pue 78M) uoseas yoea Woy SauL| UOLssaubed LenPLALpUL UO BdURLJeA 40 siskleuy

ed

“diysuopzejau ueauL, quedtspUBLS eB S} 24942 apnjau0d ‘sased YI0q UL Oy qoatay
g00'O> d (°3°P Z2L2‘L) O8L = 4 URaqdi4eD

g00'0> d ($"P veel) BE

UOLSSAUHeA WOUS SUOLIELAD|
UOLSSadbed 0} BNP SIUBLUeA

4

4 Sb hoe
O =g 3243 SL Ou suopssa4Bau uouod UO BdUeLAeA 40 sishLeuy

*ueaco ay UL Sem aze_d ayz SAep JO vaquinu st x saqetd 22 OSL uo Aqpunuwos Guppnoy yo ayBpam Aup st Ky

€€°0 ig*p* 4000°0 = 4 G6 SL 990 03 OL ady
uosees 234
€g°0 te 1% 1000°0 = K 6LL GL udy 03 91 990 (ueaqq14e9)
uoseas Aug e79[e9
9°0 yo°2TM ¥000°0 = k ell GL 290 03 gL udy
uoseas 32M
29°0 €2°z% £000°0 = k ell SL ady 03 91 980 (943298d)
uoseas Aug PLL EnBoqe)
(24) YoTyeUpUNezEp phep sad 7ybpem Kap $0 uorssaubey $ajzeld aeak 30 out uot}e907
$0 UALIL$J309 30 *ON

*sumyjpueGo, Leanzeu 0} pauoysues? | [e 49m e2ep [euLBL4o ayz ‘ueas0 ayz UL Burdolarap uaaq sey A>; UNWOD
3y? YOLYM 4aAo Skep jo saquinu 943 pue ApLunuoD Gul _noy ayy yo yy6yam Kup uaamzaq sdLysuolzejau a4yz 3S23
ALLOILS|}YS 03 pue uoLsseubas uamod ayz a2eLNDLe9 OL “PLO skep gpl pue LZ uaeMZeq SBLZLUNWUIOD Wo4s
uaye} auam S2Y6L9q “a7e[d sad pUD OGL JO L230} B Uoy SRaue UL DID G/ 24e saze_d 7eLy a42 JO Sapis yy0g
*SalV1d SWTSIX31d NO SWSINVOYO ONITNOS JO SIILINNWWOD 3HL JO LHOISM AUG NI 3SWIYINI JO Salve “ye J1aVL

59


g
°
ov o iJ =
= - 7) - [-s
— Vy s “a °o
- = = n p<
‘s 2 = = =
5 z é E 8
Oo a N e 4
CRUSTACEA: DECAPODA: NATANTIA
Penaeidae
Trachypenaeus 1/20 1/16
stmilis 1 1
(0.4) (0.5)
Stieyonta 1/16
parrt 1
(0.5)
Palaemonidae
Periclimenes 2/16
americanus 1-2
(1.5)
Gnathophy1lidae
Gnathophyllum 2/20
americanum 1-1
(0.8)
Alpheidae
Alpheus 6/20 7/16 7/16 12/16
armillatus 1-2-2 1-3-7 1-1-3 1-3-10
(3.6£1.4) (9,243.6) (11.0£3.9) (27.547.1)
11.5 36.5 45.0 42.3
1,667 2.563 1.778 1.789
Alpheus 1/20 4/16
bahamensis 2 1-5-17
(0.8) (9.0)
Alpheus 16/20 1/20
eristulifrons 1-5-30 2
(48.0#9.4) (0.8)
16.8
1.414

135


which may confound comparative measurements. For example, the diversity or
complexity of temporal organization could have been expected to be greater
in the eastern Pacific if basalt was used or greater in the Caribbean if
limestone was used. Therefore, wedecided to use plexiglass, a more stan-
dardized material with less bias biologically. Also, the surfaces of natural
substrata vary more in microtopography and texture between replicates than
plexiglass plates roughened by scraping in a standard pattern. The stan-
dardized plexiglass plates were made to fit well under the dissecting micro~
scope for examination. For further explanation of our choice of plexiglass,
refer to paragraph 2, page 91.

Each line and box set was suspended from a styrofoam float and anchored
with a cement construction block. The blocks were placed at depths of about
8 m in both the Caribbean (Galeta Marine Laboratory) and Pacific (Isla Tabo-
guilla). It must be remembered that the depth varies through a tidal range
of 6 m in the Pacific and 0.5 m in the Caribbean. The plates were suspended
approximately 1 m above the bottom in either case. The Galeta plates were
situated on a coral reef; the Taboguilla plates on a rocky "reef."

For recruitment periodicity studies, two lines (a total of eight plates)
were collected for each of 1- and 2-month intervals. One-month sets were
collected and replaced each month. At the same time, four sets of 2-month
plates were set out and collected in pairs on alternate thonths. The inter-
vals were as near as logistics and weather permitted to one and two months
in length. For the productivity studies, pairs of lines were left out for
different periods ranging between 31 and 148 days.

When the plates were collected, they were examined under 12-power magnific-
ation. Plates were held under a dissecting scope by placing them on non-
toxic modeling clay supports while emersed in seawater in a Pyrex baking
dish. Surface coverage counts were made by tallying the substrata or organ-
isms under the 13 points along the line in the ocular micrometer of the
microscope eyepiece. The surface of the plate was covered by 8 positions
when shifting the plate under the microscope. This gave a total of 104
data points for surface coverage on each surface of each plate. Both

upper and lower surfaces were examined and the data were recorded separate-
ly. To facilitate both recording and analyzing the data, labeled data forms
were mimeographed.

After noting the species present and quantifying surface coverage patterns,
the plates were placed in an oven at 85°C for at least two days to dry for
weighing. To prevent added weight from crystallization and accumulation
of salts, the plates were rinsed gently in fresh water before drying.

Results and Discussion
The distribution of lengths of recruitment periods for benthic animals in

the Pacific and the Caribbean were estimated from the records of animals
settling on plexiglass plates. The data were classified into four categories

52


PART I

BASELINE SURVEYS OF THE MARINE COMMUNITIES


SECTION V

SURVEY OF THE PACIFIC INTERTIDAL ANDESITE ROCK BEACH AT PAITILLA

DISTRIBUTION AND ABUNDANCE OF INVERTEBRATES

The Pacific coast of Panama is made up predominantly of sand or andesite
rock substrata with a pronounced vertical zonation of the biota and extreme
tidal fluctuations. Because of the differences in substrata, hydrography
and the much wider but more regular fluctuations of parameters such as
temperature, nutrient upwelling and salinity, it was of interest to survey
a Pacific locality and to investigate the effects of oil pollution on that
locality. Because of adaptation to a more widely fluctuating but predict-
able environment, the Pacific coast communities may respond to pollution
in a different way than the communities on the reef flat on the Caribbean
coast.

At first sight, Paitilla beach appeared to be rather barren of organisms
and very simple in the structure of its invertebrate communities. It is
characterized by an upper intertidal zone of littorinids, a very wide ex-
panse where the dominant species was the barnacle Tetraclita stalactifera
panamensis, an area dominated by Chthamalus panamensis, and a lower
Abietinaria Zone of hydroids and bryozoans. The paucity of organisms and
simplicity of structure were, however, only apparent. As an example, the
sorting to major taxonomic categories of a 0.125 m2 sample from the
Abietinaria Zone required 80 hours of labor. The Tetraclita Zone had an
extremely rich fauna of mollusks and polychaetes associated with the barna-
cle tests. Because of the tremendous amount of time required for the sort-
ing of samples, our work on the Pacific shore was very limited and only
represents a preliminary study of the area.

Methods

The study area was located at Paitilla, an eastern suburb of Panama City,
directly southeast of the Club Union de Panama (Via Italia and Tomas G.
Duque Street). A transect line was determined by walking with a compass
southwest from the back steps of the Club Union de Panama along the reef.
Four zones were evident along the intertidal portion of the beach. They
were named the Littorina, Tetraclita, Chthamalus, and Abietinaria Zones,
according to the most conspicuous species present in each zone.

Once a particular zone was reached along the transect line, four 0.125 n2
samples were taken at positions determined from a table of random numbers.
In the Abietinaria Zone the samples were obtained by two methods: scraping
the rocks and chipping off and collecting the rocks. In the Chthamalus

26


APPENDIX E

Catalog of species found along the transect line on the intertidal andesite
rock beach at Paitilla on the Pacific coast of Panama in Panama City. Cal-
culations are based on eight 0.125 m* samples in the Abietinaria Zone, two
0.06 m? samples in the Chthamalus Zone and twelve 0.125 m? samples in the
Tetraclita Zone. Abundances of gastropods were estimated from twelve 0.125 m?
quadrats in the Tetraclita Zone, four 0.125 m? quadrats in the Abietinaria
and Chthamalus Zones, ten 1 m? quadrats in the Abietinaria and Littorina
Zones and one hundred twenty 1 cm? quadrats in the Chthamalus Zone. Species
observed in the zones or samples but not counted are indicated by "+". The
descriptive statistics are as follows, from top to bottom in each unit:

1. Frequency: no. of samples in which the species were present/
total no. samples sorted for this species.

2. Abundance (1 m? calculated).

3. Relative abundance: per cent of class within the zone numerically
represented by the species.

The algae were identified by Joyce Redemske Young.

= yn oO
[ Ej aa os
o Lot _ [=
= & 9 tc
» oO o °
@o <= s Px)
— re) ety e
2 & & 3
CHLOROPHYTA
Bryopsts galapagensis +
Caulerpa racemosa V. +
occidentalis

Chaetomorpha antennina

Chaetomorpha Sp.

Cladophora sp.

Codium santamariae

Enteromorpha flexuosa

Ulva Laetuea +

Cladophoropsis robusta +

PHAEOPHYTA
Dietyota conerescens
Padina sp.

Sphacelaria sp.

146


SECTION VII
SURVEY OF A SAND BEACH COMMUNITY

Studies of the Torrey Canyon disaster showed that white sandy beaches which
appear clean after an oil spill are not necessarily free from pollution
(Nelson-Smith, 1968). Due to the paucity of the beach fauna in the imme-
diate vicinity of the laboratory, a survey of beaches was made east of
Galeta Point along the road to the town of Portobelo. Beaches to the west
of Galeta had been sampled by Dr. Deborah Dexter, San Diego State Univer-
sity, who was our advisor in the sandy beach program. The beach selected
was Shimmey Beach at Fort Sherman (west of Galeta Point) which had the
richest macroscopic fauna of the beaches sampled and had been intensively
surveyed from June through August of 1969 (Dexter, 1972).

Methods

In order to locate the sample quadrats, pairs of numbers were obtained from
a table of random numbers. From the first number of each pair, which rep-
resented the number of paces from the high tide line, the quadrat could be
located in one of the following three intertidal "zones": upper (range

0-5 paces), middle (range 6-10), and lower (range 11-15). The second num-
ber in each pair represented the paces to be taken parallel to the shoreline
and these fell within a range from 0 to 99. Eight samples were taken from
each zone, using either of the following two methods, depending on whether
or not the quadrat area was exposed by the tide:

1. Exposed quadrat area. An 0.1 n? frame was placed on the area to
be sampled and all the sand within the frame to a depth of two inches was
troweled into a 500 yu sieve.

2. Water-covered quadrat area. A coring device, consisting of a
stainless~steel cylinder with a valve on the upper (closed) end, was pushed
into the sand with the valve open. After closing the valve, the coring
device was pulled up and the sample placed in the 500 u sieve.

According to Dr. Dexter, one frame sample (0.1 mn) is equivalent to four
core samples (0.025 m* each) and there is no significant difference between
samples taken with the frame and those taken with the core.

The majority of the sand was washed through the 500 u sieve. The remainder
of the sample, consisting of animals and large sand particles, was troweled
and washed into a labeled (by its pair of location numbers) plastic bag. A
series of 24 samples (8 in each intertidal zone) was collected in December
1970 and April and August 1971.

46


TABLE 1 continued. DESCRIPTION OF ZONATION ON THE CARIBBEAN INTERTIDAL

REEF FLAT AT GALETA IN TERMS OF PERCENT SURFACE COVERAGE. S
2 2 P £ 2
= [s} J un °o
al i= = wn =
a oO es} cs r=)
o x i= = <7
LS a oS o 8
8 Ss ag #« 2

Dichoeoenia

stokesti A 0.24 0.06
filamentous brown
algae R & P 0.16

Trididemum solidum 0.12

Agaricia agaricites A 0.08

Caulerpa racemosa C 0.08 0.11 0.26

Caulerpa

sertulariotdes C 0.06 0.28

Peyssonnelia

nordstedtit R 0.08 0.06
Dietyosphaeria
cavernosa C 0.04 0.16

Wrangelia argus R 0.04 0.03

Hypnea spinella R 0.04 0.35

brown sponge S 0.04

anemone spp. A 0.04 0.04

Isaurus

duchassaingi A 0.06
Gelidiella acerosa R 0.46 0.10
Penictllus

capitatus C 0.68 0.13
Anthosigmella

vartians S 0.22 0.75
Craniella sp. S$ 0.17
gray sponge S 0.04

bare rock, sand
or detritus 3.3340.22 8.8641.32 13.9340.42 67.49+1.09 50.84+0.97

12


Streblosoma
erasstbranchia

Thelepus
setosus

PYCNOGONT DA
Anoplodacty lus
eve linae

Anoplodacty lus
batangense

Anoplodacty lus
spp.

Ache lia
sawayat

Ascorhynchus
lattpes

Ascorhynchus
castellioides

Ammothella
spp.

Ammothe lla
appendiculata

Burycyde
raphiaster

Eurycyde sp.

Rhynchothorax
Sp.

£
u oO oO 2
= ed un -_ a
_ co) > w co}
ba 5 5 3 3
oO — i= -_ ‘7
5 x 8 < 8
(=) = N = 4
5/24 3/24 1/20 2/20
1-1-2 1-1-2 2 1-11
(2.3) (1.3) (0.8) (4.8)
1/24
1
(0.3)
1/20 +
1
(0.4)
1/20 1/16
1 2
(0.4) (1.0)
6/20 8/20 2/16 4/16
1-2-3 1-1-3 2-2 1-1-2
(4.8) (5.6) (2.0) (2.5)
3/20 7/20 2/16 4/16 7/16
1-1-2 1-2-2 q-1 ]-1-1 2-2-2
(1.6) (5.2) (1.0) (2.0) (9.0)
5/20 9/20 9/16 2/16 9/16
1-2-3 1-1-3 2-4-6 1-3 2-2-3
(4.4) (6.4) (17.5) (2.0) (14.5)
3/16 1/16
1-5-6 3
(6. 0) (1.5)
7/20 14/20 2/16 2/16
3-3-4 1-2-3 1-3 1-8
(9.2) (10.8) (2.0) (4.5)
1/16
1
(0.5)
1/20 1/20 3/16 3/16
1 1 1-1-2 1-2-2
(0.4) (0.4) (2.0) (2.5)
6/20 2/20 2/16 1/16 3/16
]-1-1 1-1 1-2 1 1-1-1
(2.4) (0.8) (1.5) (0.5) (1.5)
2/20 2/20 3/16
1-2 1-2 1-2-3
(1.2) (1.2) (3.0)


TABLE 32. NUMBER OF ALGAL SPECIES FROM EXPERIMENTAL QUADRATS SPRAYED
WITH BUNKER C:MARINE DIESEL OIL MIXTURE (1:1 RATIO) OR STRAIGHT MARINE
DIESEL OR CONTROL QUADRATS NOT SPRAYED WITH OIL IN THE LAURENCIA ZONE,
GALETA REEF. @ The first number refers to total number of species,
the second number refers to the average number of species per 4 quad-
rats in each time-place-treatment combination.

Before oil 7 days 28 days
treatment after after
Control 33/18 32/16 26/16
Bunker C:Marine Diesel 20/10 24/14 28/16
Marine Diesel 29/14 19/12 26/14

& Algal identifications were provided by
Joyce Redemske Young.

79


Portunidae
Portunus sp.

Xanthidae
Eriphia squamata

Menippe obtusa

Panopeus bermudensis

Platypodia (?) sp.

Pilumus reticulatus

Xanthodius stimpsoni

xanthid indet.

oS
c 3 s 3
= s = =
3 5 re 8
ov = = Pp
-_ ca r »
2 & 2 a
1/8
]
0.05
1/8 3/8
1 2.4
0.05
1/8
2
0.1
4/8 4/12
6 8.4
0.3
1/8 1/2
3 0.6
0.2
4/8
4
0.2
4/8
19
0.9
3/8 2/12
4 3.6
0.2

161


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UL 032700192 ]| -Ua2Uad DAI oOvA7ea] Aad SuawllLdeds yO saquny

$0 abequaouag

“SISNAWENYd VAPATLOWIVIS WIITOWaLaL (10) dv3q aNy (11)
JAI1 A@ GAGIAONd S3HOIN FOWdS NI S3IDAdS JLVYGSLUIANI LNVONNAY GNV NOWNOD 3HL JO NOILNATYLSTd “OL J18VL

33


TABLE 30. ANALYSIS OF VARIANCE FOR A 2¢ FACTORIAL ON THE AMOUNT OF TISSUE
BLEACHED WITHIN 5 DAYS AND ON THE AMOUNT OF LIVE TISSUE AFTER 109 DAYS
TREATMENT OF Pocrizopora CF. DAMICORNIS WITH OIL (FACTORS ARE OIL AND QUAN-
TITY OF OIL, NS = NOT SIGNIFICANT). For experimental design see text, ex-
periment 3 and Table 29,

Per cent of tissue Per cent of live
bleached within tissue left after
5 days in colonies 109 days on colonies
treated with treated with
Bunker C or Bunker C or
marine diesel marine diesel
Variance ratio for
colonies 0.33 1.43
d.f. colonies 5, 15 2, 11
F at P = 0.05 4.62 5.14
Significance NS NS
Variance ratio for
treatments 1.33 9.97
d.f. treatments 3, 15 3, 11
F at P = 0.05 8.70 4.76
Significance NS NS
Effect:
Upper oi] +61.97 NS +117.66 NS
Upper no oi] +16.13 NS +14.00 NS
Lower oi] -38.63 NS +25.33 NS
Lower no oil ~4.11 NS -4.3 NS
5 per cent point +521.01 +455,77

74


Quadrat Number
4 5 6 7 8 9 10 Ave/m?

TAXA 1 2

v9]

Alpheus sp. 7 0.8
Alpheus viridart 1 0.8

Alpheus
‘Llatus i 1 3 1 4.8

Ambidexter 1 0.8
symmetricus

Suborder Reptantia
Upogebia sp. 2 1.

Clibanarius sp. 10 8 131 6 9 8 #17 4 153.
Panopeus sp. 1 Es) 2 1 1
Panopeus sp. 2 3 1 1
Panopeus sp. 3 1
Pachygnapsus ] 1 2 2
Microphrys 1 1 1

bicornutus
Uca sp. 1 i] 1 1 2.4

MOLLUSCA
Class Gastropoda

Batillaria
minima 820 79 324 147 49 17 25 227 1350.

- OF &
~wrnaowanan

i)
p

>

Neritina 1 2 a7 4
virgines

fon)
foo)

Nassarius vibex 3 1 1

a

Planaxis nucleus

Planaxis 1
lineatus

Tricolia bella 1
Gastropod sp. 1
Cerithiid sp.

Bailya intricata

Cerithium sp.

- nN wnnoag 2 cof
DPNFHRO © 0S 2

Nw PND

Hyalina avena

Rissoina 2
decussata

a

Cantharus
: 1 0
auritulus

oo

165


SECTION VIIL
RECRUITMENT PATTERNS IN CARIBBEAN AND EASTERN PACIFIC BENTHIC COMMUNITIES

In benthic marine habitats, recruitment is probably one of the most impor-
tant processes in understanding the functional organization of the commu~
nity (Thorson, 1957, 1966; Loosanoff, 1964). The scheduling of the repro-
ductive processes is an indication of how natural selection on the species
in question is guided by the predictability or periodic harshness of the
physical environment (Murphy, 1968) or the periodic changes in the condi-
tion of competitors or predators (Thorson, 1960, 1966). Although over 99
percent of the mortality for most marine organisms with pelagic larvae
occurs during the planktonic stage of development and full-grown adults
often have an exceptionally high probability for survival, the "bottle-
necks," or controlling factors, for a benthic species are usually found
during the processes of settling and metamorphosis. (The distinction be-
tween destruction and control should be kept in mind—cf. Nicholson, 1933.)
The larvae of benthic animals are very selective in location and timing of
settlement (Wilson, 1960; Thorson, 1957, 1966; Birkeland, Chia and Strath-
mann, 1971) which attests to the importance of settlement in natural selec-
tion. It is not merely a numbers game to the extent of their planktonic
life. In the communities of adult benthic organisms, the disturbance fac-
tors are often haphazard in timing and the pattern of succession may depend
on which species sets in the cleared space first. Since the basic patterns
of recruitment are of fundamental importance in understanding the functioml
organization of benthic communities, we conducted settling plate experiments
on both the Caribbean and Pacific coasts of Panama. It would also be of
great interest to compare the data with results obtained in other geograph-
ical regions. To enhance the validity and ease of the comparisons, the
methods and materials used should be the same; consequently, we have out~
lined the methods in detail. Those not wishing to conduct similar studies
will probably prefer to skip the methods section and move ahead to Results
and Discussion, page 52.

Methods

Settling plates were made of 0.6 cm thick plexiglas cut into rectangular
pieces 5 cm wide by 15 cm long. The plates were roughened on both upper
and lower surfaces by rubbing with "coarse" grade sandpaper, with at least
10 strokes along the length and 10 strokes along the width. Plexiglas
was chosen for settling plates in this study in preference to natural sub-
strata for several reasons. First, since the coasvs of Panama differ in
the prevalence of different kinds of natural substrata, e.g., basalt is
far more prevalent in the eastern Pacific and limestone is more prevalent
in the Caribbean, a direct comparison of the communities using either of
these substrata was originally considered to be a potential source of bias

51


peap anssi2 28L peap anssi? 41 aBbueyd ou 8941404 (e°s X 18) L auou
ui peop nesit xgor «SMB OH BUND ov erat ELEN aang
(pawaaooeu ansstz 40
we ap onsse) te-3t anssit 2/8-S1 abueyo ou een Mod ee loa “OW
paulequleuw anssiz Mau = anssi} Mau zum gt abueyo ou puoaog ($*¢ X $°S) L auou
peap anssl? ZOOL peap anssi2 40S aBueys ou Duoand (9°2 X O'v) L “O°a
peap anssl} 221 peap anssiz 221 aBueyo ou Duong (2°90 X Z*) L “aw
anssi3 mau Wl Z aBueyo ou aBuey2 ou pLoomuum sg OE ete) 2 auou
aBueyo ou aBueyo ou aBueyo ou pDaLooDuMosg O's “39
abueyos ou abueys ou abueyo ou paoommmsd (6°2X 0°S) L “aw
skep git skep €6 sep 21 salads ("wo ul) [Lo
daze daze daqse abueu azis 40 adky
uo 109 Auo 109 Kuo 109 alayy pue
$0 3229S $0 a7e75 go 37e95 saluoloo jo #

*WLWOUAd SAITYOI ONY ¥ALNWOTD WAOAWd ‘YLYTIGLS
WuOOOHWESd NO ("Q°W) TaS3IC 3NIBWW YO (°9°a) 9 YFINNG OL FUNSOdXS SLNNIW-L W 4O 103443

“Le Fal

15


£
ov o oO 2
< oa a - a
_ [s) Ss nn °o
= < = a =
5 2 2 2 2
LS 3 oO oO oO
& 5 8 = 2
Ophtiothrix 20/24 15/24 9/20 3/20 6/20
angulata 5-10-15 1-3-7 12-10 1-1-2 2-4-7
(84,0#19.3) (43,7420.8) (20.8410.5) (1.6) (14.447.9)
25.2 25.9 7.1 4.5
2.126 6.077 4.477 6.413
ophiothricid sp. 1/24 2/24
2 1-1
(0.7) (0.7)
Ophiacantha 1/24 1/20
ophiactoides 1 1
(0.3) (0.4)
Axtognathus 1/24
squamata 43
(14.3)
ECHINOIDEA
Eucidaris 2/24 2/24 + 1/20 +
tribuloides 1-1 1-1 1
(0.7) (0.7) (0.4)
Tripneustes esculentus +
Lytechinus 1/24 6/24 3/20 1/20 1/20
variegatus 1 1-1-2 1-1-2 ] 1
(0.3) (3.3) (1.6) (0.4) (0.4)
Echinometra 19/24 19/24 19/20 4/20 2/20
lueunter 3-4-6 1-2-6 1-2-2 1-1-1 1-1
(29.744.8) (19.3+5.0) (6,041.7) (1.6) (0.8)
86.4 46.4 62.5
1.348 2.192 1.334
Echtnometra 4/24 5/24 1/20 2/20 1/20
viridis 1-1-1 al 1 1-1 3
(1.3) (1.7) (0.4) (0.8) (1.2)
Diadema 2/24 24 + + +
antillarun 1-1 1
(0.7) (0.3)
Echinoneus 3/24 13/24 3/20 6/20 1/20
cyelostomus 1-1-2 2-5-5 1-1-2 1-2-4 1
(1.3) (16.0+3.8) (1.6) (7,243.8) (0.4)
38.4 56.2
1.851 5.621
Brissus 1/24 24 3/20 +
untcolor 1 1 1-2-3
(0.3) (0.3) (2.4)

110


o
=
ov o oO 2
< oad a - a
_ S} S wn °
= 5 5 g 5
oO x i= - i=
aS 3 oO 3 s
8 Ss S = 2
Diodora 3/20 1/16 2/16
cayenensis 1-1-1 1 1-1
(1.2 (0.5) (1.0)
Fissurella 3/20 5/20
barbadensis 1-1-2 1-1-1
(1.6) (2.0)
Fissurella 4/20 2/20
angusta 1-1-1 1-1
(1.6) (0.8)
Acmaea 10/20 1/16
antitlarum 1-1-3 1
(8.843. 2) (0.5)
12.2
2.682
Acmaea 1/16
pustulata 1
(0.5)
Aemaea Sp. 1/20
1
(0.4)
Cittartum pica + +
Tegula fasetata 1/20 1/16
1 1
(0.4) (0.5)
Arene eruentata +
Arene 1/20
tricarinata 1
(0.4)
Astraea caelata +
Astraea phoebta 1/20
4
(1.6)
Tricolia adamst 4/20 1/20 1/16
1-2-5 2 1
(3.6) (0.8) (0.5)
Tricolia bella 1/24 3/20 2/20
1 1-1-2 1-1
(0.3) (1.6) (0.8)

113


clarity, informativeness and reality are Ophiactis in the Zoanthus Zone
and Perinereis in the Acanthophora Zone.

Although not a realistic statistic for most species of intertidal inverte-
brates, the most usual presentation of abundance counts in the literature
are in terms of mean and standard error of the mean. ~ Therefore, these
numbers are included for easy comparison with other surveys in the litera-
ture. The number is in parenthesis because the calculations are made to
conform to the square meter area standard in the literature while the other
lines are on a one-eigth square meter to conform to our sample size.

The relative abundance of a species to others within its class in a zone

is of more direct and immediate value as information pertinent to func-
tional characteristics of a species than is absolute abundance. The major-
ity of theoretical essays on community structure have been based on this
form of information. Data presented at the class level summarize the de-
gree to which a few species are predominant and whether most are rare.
However, predominance (a large relative abundance) does not necessarily
imply dominance (importance of functional role in the community).

Dispersion pattern is a very important description category for species in
both the pollution and baseline work. The vast majority of invertebrate
species are clumped in distribution. This, of course, is responsible for
the requirement of extensive sampling in following the fate of most species.
Morisita's index of dispersion is of primary interest in raising questions
on the physical and biological environmental factors which affect the dis-
tribution patterns of each species. For instance, if the index of disper-
sion of a species drops below unity as its becomes more abundant, then an
increase in intraspecific competition may be suspected. If a species is
more clumped in one zone than in others, reproductive behavior or certain
predators may be restricted to these zones or the physical environment
relevant to the particular species, though not obvious to us, may be more
patchy.

Discussion

For the convenience of the reader, the specific data in the appendices are
summarized at the level of classes or orders for the communities of each
zone (Tables 2 through 6). The number of identified species and genera
living together in each zone are summarized in Table 2. For most classes,
there is usually an average no higher than 2 species per genus. For the
sipunculans, however, there is an average of 4 to 6 species per genus
except in the Thalassia Zone. Although there are often 2 or 3 times as
many species of polychaetes in an area, the sipunculans appear more tightly
"packed." For instance, terebellid, nereid, sabellid and amphinomid poly-
chaetes are very different in their morphology while most sipunculans
appear relatively similar to each other. Because of this, more species
tend to fall into fewer genera and this may serve as a rough index of
"packing."

20


Batillaria minima 9/40
1-2-3
(14.0+8.5)
2.1
15.832

Cerithium variabile 1/40
1
(0.4)

Planaxis lineatus 8/40
8-18-36
(286.8+235.4)
42.9
27.261

Planaxis nucleus 4/40
20)
Drupa nodulosa 3/40
G3)
Thais haemastoma 4/40
aa)
Isognomon radiatus 140

(1.6)

145


SECTION XVI

INDEX OF ORGANISMS

Acanthina brevidentata, 37, 149
muricata, 149
Acanthochitona hemphilli, 111
interfissa, 111
pygmaea, 111
sptculosus, 111
Acanthonyx petiverti, 141
Acanthophora sptctfera, 11, 102
Acanthopleura granulata, 101
Acetabularta crenulata, 101
pusilla, 101
Achelia sawayat, 133
Aemaea antillarum, 113
pustulata, 113
sp., 113
Actaea setigera, 140
Agavicia agaricites, 12, 107
Attpasia tagetes, 106
Aletrona insularis, 159
alpheids, xi
Alpheus armillatus, 135, 165
bahamensis, 135
ertstultfrons, 135
fromosus, 136
normanni, 136
nuttingi, 136
paracrinitus, 136
peaset, 136
ridleyi, 136
sehmitti, 136
simus, 136
sp., 136, 165
viridart, 165
Ambidexter symmetricus, 138, 165
Ammothea sp. 1 & 2, 159
Amnothetla appendiculata, 133
spp., 133
amphineuran spp., 151
amphinomid, 20
Amphinomid sp. 1, 123, 163
sp. 2, 123
Amphiodia repens, 109

168

Amphiodia sp. L, 109
Amphipholis sp., 109
sp. A, 109
amphipod, 49, 80
Amphiroa brasilensis, 102
fragilissima, 102
polymorpha, 147
rigtdia V.antilliana, 102
sp., 102
amphiurid ophiuroids, xi
Anachts botvini, 150
eatenata, 117
erassilabris, 166
diminuta, 150
fluctuata, 150
fulva, 150
lyrata, 150
rugosa, 37, 150
sp. 1, 117
sp. 2, 117
varia, 150
Anadyomene stellata, 101
Anattides erythrophylla, 128
sp., 154
Aneinus brasiliensis, 47, 48, 49
anemones, 2, 28, 107
Anoplodactylus batangense, 133
erectus, 158
evelinae, 158
portus, 158
pygmaeus, 158
sp., 158
spp.» 133
virtdintestinalis, 158
Anthopleura dowii, 33, 36
krebsi, 116, 163
sp., 116
Anthosigmella varians, 12
anthozoans, 23
Antithamion occidentale, 147
Antithamnion-type, 102
Aorotrema sp., 148


10

11

12

13

TABLES

Description of zonation on the Caribbean intertidal reef flat
at Galeta.

Number of genera/number of species in each of 15 categories of
organisms in each of 5 intertidal reef flat zones.

Number of species necessary to make up 50% of the individuals
in each zone for each of 11 categories of macroinvertebrates
on the intertidal Caribbean reef flat.

Shannon-Wiener index of diversity calculations for each of 10
categories of motile macroinvertebrates in each of the 5 inter-
tidal zones.

Mean number of individuals per square meter for all members of
each of 12 categories of macroinvertebrates along the Caribbean
intertidal reef flat transect.

Number (and percent) of "common" species, species with average
abundances greater than 1/m*, in each of 5 intertidal zones.

Biomass of predominant algae in Laurencia Zone on four differ-
ent collection dates.

Numbers of live and dead barnacles and areas they occupy in
the Tetraclita Zone, Paitilla Beach.

Relative importance of different surfaces of live and dead
Tetraclita stalactifera panamensis to invertebrate populations.

Distribution of the common invertebrate species in space
niches provided by tests of live and dead Tetraclita.

Relative importance of different space niches for common
species associated with Tetraclita.

Collections of species through succession in tests of
fetraclita over a period of 15 months.

A record of the collection of tests, natural loss of tests and
recruitment of young Tetraclita following an experimental kill
of barnacles.

Page
11

13

14

15

16

17

25

29

30

33

34

36

39


Pseudonereis

gallapa gensis

Oweniidae
Quenta collaris

Palmyridae
Bhawanta
goodet

Phyl lodocidae
Anaitides
erythrophylla

Eulalia
myrtacyelum

Linopherus
canartensis

Sige orientalis

Polynoidae
Halosydna
leueohyba

Halosydna sp. 1

Harmotho& sp.
indet.

128

£
co}
2 2 4 2 5
-_ 8 Ss n co}
= S $ 8 $
g 5 S s S
8 5 a = <
8/24 6/24 2/20 2/20 2/20
2-4-8 1-2-10 1-2 1-1 1-2
(11.043.8)  (7.3+3.6) (1.2) (0.8) (1.2)
0.4 0.1
3.227 5.818
1/20
1
(0.4)
7/24 4/24 1/20 1/20
1-1-2 1-1-3 1 1
(3.0) (2.3) (0.4) (0.4)
1/24
1
(0.3)
2/24 7/24 1/20 1/20 4/20
1-1 1-2-3 1 i 1-1-2
(0.6) (4.0£1.4) (0.4) (0.4) (2.0)
1/20
1
(0.4)
3/24 2/20 1/20
1-1-3 1-1 1
(1.6) (0.8) (0.4)
10/24 21/24 1/20
1-1-3 1-4-9 1
(4.6#1.4) (28, 343.8) (0.4)
0.2 0.5
1.318 1.163
8/24
1-1-2
(2.6#1.0)
0.09
1.714
1/24
1
(0.3)


2
g £ . 2 2
— [3) s w c-}
= S 3 3 3
=) a N re <=
Alpheus 5/20 3/16
formosus 1-1-2 ]-1-2
(2.4) (2.0)
Alpheus 2/20 5/20 1/16 2/16 2/16
normannt 1-2 1-1-2 1 2-2 1-1
(1.2) (2.8) (0.5) (2.0) (1.0)
Alpheus 5/20 10/20
nuttingt 1-1-5 1-3-6
(4.3) (13,2#3.8)
42.2
1.856
Alpheus 11/20 3/20 WW/16 V16 8/16
paracrinitus 1-4-5 1-2-3 1-2-8 2 1-2-3
(14.4#4.0) (3.6) (14.545.0) (1.0) (7.0#1.0)
1.5 32.2 10.8
1.809 2.167 1.670
Alpheus 4/20
peaset 1-1-2
(2.8)
Alpheus 3/20
sehmitti 1-3-3
(2.8)
Alpheus simus vie
(0.5)
Alpheus sp. 720 2feo 116
(0.4) (0.8) (0.5)
Alpheus 1/20 1/20
ridleyi 1 1
(0.4) (0.4)
Automate 1/20
rectifrons 1
(0.4)

136


£
wv oO oO 2
r= as o — =
= is) 3 a °
= 5 $ 3 5
oO = i _ i=
= S LJ oO oO
8 3 g z 2

Mithrax (Mithrax) 1/16
acuttcornis 1

(0.5)

Mithrax (Mithrax) 4/20 2/20 1/16

sp. ]-1-1 1-2 1
(1.6) (1.2) (0.5)

Mithrax 19/20 17/20 5/16 1/16 3/16
(Mithraculus) 4-10-21 1-4-9 3-4-6 1 1-1-2
coryphe (119.2428.5) (40.4#10.9) (12.546.2) (0.5) (2.0)

25.3 26.4 27.5
2.025 2.198 4.213

Macrocoeloma 2/20 2/20 1/16

subparallelun 1-1 1-2 1
(0-8) (1.2) (0.5)

Microphrys 5/20 17/20 5/16 11/16 14/16

bteornutus 1-1-2 1-4-9 1-1-2 1-2-5 2-3-10
(2,841.2) (37.648.3)  (6.5£4.0) (17.544.5) (36.029.1)

0.6 24.6 14.3 43.8 45.6
1.905 1.739 5.949 1.587 1.753

Majid sp. F 1/20 1/20

2 1
(0.8) (0.4)
Parthenopidae

Heteroerypta +

maerobrachia

142


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FIGURES

Map of Panama, with inset of Isthmus of Panama, indicating
the major study sites discussed in this report.

A comparison of the total abundance, number of species and
diversity of macroscopic invertebrates with the pattern of
spatial heterogeneity in the communities of encrusting or-
ganisms on intertidal zones at Galeta.

Changes in density of the components of the community as-
sociated with Tetraclita tests in the Pacific intertidal
region at Paitilla over a period of 15 months.

Number of species associated with Tetraclita tests through
succession over a period of 15 months.

Experimental laboratory setup used to examine the effect of
oil on Pocillopora.

Change in average abundance of Eunice caribaea in quadrats
sprayed with Bunker C or marine diesel oil or left as
controls.

Map of the relative positions of Rhizophora mangle trees
involved in oil pollution experiments.

35

68

86

88


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29


£
vo oO oO 2
= o $ 3G ey
= 5 ee} s S
oO L i - [<7
L > oO o oO
8 5 a = =
Ophtactis 17/24 15/24 10/20 8/20 18/20
savignyt 3-9-16 2-4-14 1-9-70 2-2-3 3-12-26
(74,3422.5) (64.7435.3) (253.24151.1) (9,644.1) (252.4+92.4)
22.3 38.4 86.1 18.5 78.2
3.009 7.761 7.748 3.913 3.522
Amphtiura 10/24 3/24 1/20
(Nullamphiura) 3-5-10 1-1-2 1
sp. (33,0214.5) (1.3) (0.4)
9.9
5.259
Amphiura 10/24 2/24 1/20
(Monamphiura) 2-2-3 1-2 1
sp. (9.0+3.1) (1.0) (0.4)
2.7
2.872
Amphipholis sp. 15/24 17/24 5/20 13/20 10/20
2-5-22 2-4-6 1-2-10 2-3-9 2-4-14
(52.7418.0)  (29.328.9) (9,225.4) — (32.449.1) (29.6412.2)
15.8 17.4 3.1 62.3 9.2
3.572 2.890 6.956 2.593 4.017
Amphipholis 3/24 2/24 4/20 6/20
sp. A 1-1-4 1-1 1-1-3 1-1-3
(2.0) (0.7) (2.4) (4,422.0)
1.4
3.273
Amphiodia 1/24 1/20 1/20
repens 1 3 2
(0.3) (1.2) (0.8)
Amphtodia 3/20 3/20
sp. L ]-1-1 1-2
(1.2) (1.2)
Ophiuroid sp. B 11/24 12/24 2/20 3/20
1-2-5 1-2-4 1-2 5-5-9
(22,7£12.1) (12.744.5) (1.2) (7.6)
6.8 7.5
7.312 3.380
Ophtozonoida 6/24 2/20 1/20
(2) sp. 1-2-7 1-1 1
(6,344.0) (0.8) (0.4)
1.9
9.544

109


Studies of the rocky intertidal, reef flat intertidal, sandy beach, and
mangrove habitats were included. During the second and third years, normal
temporal variability in both community structure and recruitment were eval-
uated by comparing data taken over the three-year period. During the sec-
ond year, controlled experiments were begun on the effects of oil pollution
at both the levels of tropical marine communities and physiology of indi-
vidual organisms.

The oil pollution experiments were not set up to make trivial demonstrations
of mass killoffs under a heavy coat of oil, but to perform a quantitative
analysis of oil effects detectable only by comparisons with controls in the
experiments. The report is presented in two separate parts, the baseline
surveys (Sections IV through VIII) followed by the oil pollution experiments
(Sections IX through XIII).

A reference collection for the species listed in this report is kept at the
STRI Marine Laboratory at Galeta to confirm identifications in future pro-
jects at the same locality and to assist in verifications of the records in
this report. A few species which are represented by only a few specimens
have been submitted to the organizations of the taxonomic authorities that
provided the identifications. These locations can be found in the acknow-
ledgments section.


increased significantly while the number of species in quadrats sprayed
with marine diesel oil and control quadrats did not increase significantly.

7. The spraying of leaves of mangrove trees (Rhizophora mangle) with the
volatile marine diesel fuel oil was correlated with reduced leaf coverage
or no growth of the trees during the following year. Coating the stilt
roots with tarry Bunker C oil was of less definitive effect. This may ex-
plain why the most obvious defoliation of mangrove trees following the
wreck of the SS Witwater was in a band along the windward edge of the
forest facing the sea from the other side of a causeway. As Ritzler and
Sterrer (1970) noted, "high winds caused a spray of mixed seawater and oil
to cover mangrove trees . . . to a height of 2 m above mean tide level" and
that the oil had ". . . already killed many of these plants." However,
the trees were probably not killed but were greatly defoliated.

8. Each class or category of motile animal species on the Caribbean reef
flat at Galeta has its ow pattern of community structure. There is a
general trend for the number of species of epifaunae to correlate posi-
tively with spatial heterogeneity.

9. No matter how many species of a class of motile animals are found in
a zone and no matter how abundant the total class is in the area, there
are usually about two "relatively abundant" species making up 50 percent
of the total individuals in each zone. Only sipunculans and gastropods
require four species to make up 50 percent of the total number of individ-
uals in certain zones.

10. Sipunculans are a particularly "packed" group of species on the inter-
tidal limestone reef flat, having a high diversity, by far the highest
species per genus ratio, a high number of common species on both a relative
basis and an absolute areal basis, but not a particularly large number of
species per zone.

11. A predominant intertidal red algae, Laurencia papillosa, undergoes
significant changes in dry weight biomass, but the population does not
vary seasonally on the Galeta transect to the extent that it does in
Florida.

12. On the andesite rock shore at Paitilla on the Pacific coast, the bar-
nacle Tetraclita stalactifera panamensis provides a series of space niches
for 32 species of mollusks, 37 species of polychaetes and several species
of crustaceans, anemones, turbellarians, nemerteans and other invertebrates.
When a Tetraclita dies, invertebrates colonize the empty test within a
month. The abundance and diversity of these associates increases steadily
for six months, then continues about a mean with slight fluctuations.

13. Drift logs hinder the spread of the mangrove forest across the inter~
tidal reef flat by destroying isolated advancing recruits. The logs then


ABSTRACT

Baseline surveys were conducted on both the Caribbean and Pacific coasts
of Panama. The structure of macroinvertebrate communities along the
Caribbean transect are presented from data collected for over 500 iden-
tified species in 108 samples including a total of over 50,000 specimens.
Recruitment to benthic communities was investigated with settling plates.
The Caribbean was found to be seasonal in species occurrence while the
Pacific was seasonal in productivity.

The effects of oil pollution on tropical intertidal marine communities
were tested by precisely controlled experiments utilizing tarry Bunker C
and volatile marine diesel oils. Field experiments were performed on a
Caribbean intertidal reef flat community, a Pacific rocky shore community,
settling plates in both oceans, mangrove trees sprayed with oil on the
leaves and/or stilt roots and on coral growth. Bunker C oil had a greater
detrimental effect than did marine diesel oil on coral growth. Marine
diesel oil had a greater detrimental effect than did Bunker C oil on foul-
ing communities of settling plates. When comparing experimentals with
controls, growth rates were used as an indicator of the presence of un-
observed physiological stress or damage and a quantitative index of the
cost of repair. Susceptibility to oil pollution varied significantly
between individuals. The growth rates of corals differed significantly
with location and time of year so that very precise controls were required
in the experiments.

This report was submitted in fulfillment of Program Element Number 1BA022,
Contract Number 14-12-874 to the Smithsonian Tropical Research Institute,
P. 0. Box 2072, Balboa, Canal Zone, under the (partial) sponsorship of
the Water Quality Office, Environmental Protection Agency.


g
co}
g £ ¥ £ 5
_ is] Ss wn ce}
= 5 S 3 s
£ 5 3 s S
8 Ss a = &
Sphenia 2/20 4/20 2/16 1/16
antillensis 1-1 1-1-2 1-1 1
(0.8) i. 6) (1.0) (0.5)
Corbula 1/16 2/16
contracta 1 1-1
(0.5) (1.0)
Gastrochaena 4/20 2/20
hians 1-2-3 1-1
(2.8) (0.8)
Cumingia 2/20 13/20 13/16 5/16 10/16
antillarun 1-3 4-7-13 4-6-12 1-2-16 2-4-6
(1.6)  (41.6411.4) (45.0+10.8) (8.4) (30.0£12.5)
1.2 14.5 29.9 28.4 15.1
10.0 2.254 1.706 9.218 3.371
SIPUNCULA
Aspidosiphon 16/24 16/24 9/20 11/20 11/20
broki 1-4-15 1-6-31 1-10-29 1-4-15 1-3-14
(27.047.1) (37.3411.4) (38.8415.9) (22,047.59) (18. O26. 5)
15.5 0.1 14.5 11.0 2.7
2.066 2.930 1.611 1.190 3.111
Aspidosiphon 3/24 2/24 3/20
spp. (probably 1-3-10 3-6 1-1-6
7 spp. 5 (4.7) (3.0) (3.2)
Dendrostomum 2 1/20
Sp. 2
(0.8)
Golfingta sp. 5/24 4/20 2/20
1-2-3 1-1-1 1-2
(3.0) (1.6) (1.2)
Lithacrostphon 17/24 16/24 13/20 4/20 11/20
spp. (probably 1-3-11 1-8-28 192-14 1-2-3 1-2-5
5 spp. 5 (21.323.3) (61.0+11.5) (27.2+8.5) (2.8) (12.0#11.3)
12, 16.5 10.2 1.8
2.095 1.695 1.039 17.724
Paraspidosiphon 18/24 17/24 17/20 16/20 18/20
fishert 1-3-9 1-7-35 2-10-32 1-12-53 3-13-25
(21.0#3.5) (62.0415.4) (83.2417.8) (83.2#24.8)(90.0+13.7)
1.9 16.7 31.2 41.6 1.8
1.290 2.296 1.781 1.041 1.353
Paraspidosiphon 2/20
speciosus ? 1-1
(0.8)

121


Thompson, T. W. 1969. Deuteromycete populations in the attached Sargassum
communities off Key Largo, Florida. Doctoral Dissertation to the University
of Miami, Coral Gables, Florida.

Thorson, G. 1957. Bottom communities. In: J. W. Hedgpeth (ed.),
Treatise on Marine Ecology and Paleoecology. Vol. I, Ecology. Geol. Soc.
Amer. Mem. 67:461-534.

Thorson, G. 1960. Parallel level—bottom communities, their temperature
adaptation and their "balance" between predators and food animals. In:
A. A. Buzzatti-Traverso (ed.), Perspectives in Marine Biology, University
of California Press, Berkeley, pp. 67-86.

Thorson, G. 1966. Some factors influencing the recruitment and establish-
ment of marine benthic communities. Netherlands J. Sea Res. 3:267-293.

U. S. Public Health Service. 1924. Oil pollution at bathing beaches.
Publ. Health Rept. 19, December.

Wilson, D. P. 1960. Some problems in larval ecology related to the lo-
calized distribution of bottom animals. In: A. A. Buzzatti-Traverso
(ed.), Perspectives in Marine Biology, University of California Press,
Berkeley, pp. 87-104.

99


TABLE 23. COMPARISONS OF PREDOMINANCE OF CERTAIN BRYOZOANS AND TUNICATES
IN PACIFIC AND CARIBBEAN FOULING COMMUNITIES.

a. Bryozoa, ascidians and other animals; tally of number of species.

Location Bryozoa | Tunicata | Other animals Total
Taboguilla 22 13 48 83
Galeta 15 28 74 117
% of grand total 18.5 20.5 61.0 200

x? = 6.78 with 2 d.f.:  P<0.05

Reject Ho: conclude that bryozoa and/or ascidians and/or other animals
together differ in importance in Pacific and Caribbean
communities.

b. Bryozoa and ascidians, tally of number of species.

Location Bryozoa Tunicata Total

Taboguilla 22 13 35

Galeta 15 28 43
% of grand total 47.4 52.6 78

x? = 6,06 with 1 d.f.: P<0.02
Reject Hy: conclude bryozoa are relatively predominant and/or ascidians

relatively unimportant in terms of number of species on
Taboguilla settling plates.

58


TABLE 2. NUMBER OF GENERA/NUMBER OF SPECIES IN EACH OF 15 CATEGORIES OF
ORGANISMS IN EACH OF 5 INTERTIDAL REEF FLAT ZONES AT THE GALETA MARINE
LABORATORY ON THE CARIBBEAN COAST OF PANAMA.

P
g

o o oC 2

i - a - a

— 8 J n °o

= 5 8 Z 3

o L [= _ i=

LS S o oC oO

oO ° = oO

oO a NL e —<
CHLOROPHYTA 14/17 13/17 W/l2 1/15 13/18
PHAEOPHYTA 5/5 4/4 2/2 4/4 2/2
RHODOPHYTA 21/41 19/35 13/20 18/27 18/29
ZOANTHINIARIA 3/4 3/5 2/2 2/2 val
ACTINIARIA 5/6 6/8 6/8 5/5 5/6
OPHIUROI DEA 11/18 9/18 9/11 9/11 8/12
ECHINOIDEA 6/7 6/7 5/6 6/7 6/7
AMPHINEURA 6/10 5/10 4/8 4/8 3/7
GASTROPODA 28/43 23/31 20/25 18/15 22/27
BIVALVIA 14/17 17/21 10/13 10/13 15/18
SIPUNCULA 5/25 6/29 5/22 7/20 6/35
POLYCHAETA 51/80 48/75 33/42 39/54 32/46
PYCNOGONIDA 7/9 8/11 8/10 3/3 7/10
NATANTIA 9/22 5/18 4/7 4/7 9/14
REPTANTIA 18/35 17/22 12/14 10/13 11/14
TOTAL ALGAE 40/63 36/56 26/34 33/46 33/49
TOTAL ANIMALS 146/276 153/255 118/158 114/158 125/197

8 The data for numbers of genera and species include all those recorded in
samples along with others seen in the immediate area in which samples were
taken, but not actually in the samples.

13


Syllid, with
stripes

Syllid, sp.
Syllid, sp.
Syllid, sp.

Syllid, sp.
Syllid, sp.

Syllid, sp.

Syllid, sp.
Syllid, sp.
Syllid, sp.

Terebellidae

10
13

26

37

38
39
41

Eupolymmia ?

nebulosa

Loimia medusa

Pista
fasciata

Polycirrus
sp.

£
g 2 a 2 2
= 2 z a 2
s 2 € = =
LS a oe o o
°o oo oO = is}
oO a N Re x
1/20
2
(0.8)
+
+
2/8
2-2
(4)
+
1/8
7
(7)
1/8
3
(3)
+
+
1/8
2
(2)

11/24 17/24 8/20 8/20 9/20
1-4-8 1-8-3] 1-1-4 1-3-44 1-4-12
(15.344.1) (62.0413.9) (5.6#2.0) (30.0#18.2) (17.246.3)
0.5 1.0 0.4 4.5 1.2
2.226 2.041 2.197 7.863 3.122

5/24 2/24 4/20 7/20
1-1-5 1-4 1-1-8 2-4-15
(3.0) (2.0) (4.4) (18.9#10.8)

1.707

2/24 4/24 1/20

]-1 1-1-2 1

(0.6) (2.0) (0.4)
1/24 1/24
1 2
(0.3) (0.6)

132


ACKNOWLEDGMENTS

During this entire project, the Smithsonian Tropical Research Institute
made available all facilities of the Caribbean coast marine laboratory at
Galeta Point. STRI also provided so many other facilities, we could not
possibly name them all. We are especially grateful to Peter W. Glynn,
Ira Rubinoff and Edward Kohn, who aided us with advice, encouragement and
administrative assistance. Peter Glynn suggested the field experiment on
the effect of oil pollution on coral growth and Ira Rubinoff suggested the
field experiment on the effects of pollution on mangrove trees. Deborah
M. Dexter provided particularly valuable instructions and suggestions on
the survey of the sand beach habitat. We also appreciate the advice and
suggestions of David L. Meyer, coordinator of the Environmental Sciences
Program at Galeta. Joyce Redemske Young provided identifications of the
algae presented in Appendices A, E and F. Peter W. Glynn, Neal G. Smith,
Henk Wolda and Egbert G. Leigh read an earlier draft of the manuscript
and gave suggestions for improvements.

Almost every animal species in this report was identified by taxonomic
authorities, each of whom devoted many hours to our assistance even though
all had many other research and/or teaching commitments. The polychaetes
and crabs were sent to the Allan Hancock Foundation, where Kristian
Fauchald identified all the polychaetes in this report and is preparing
some publications on the material. John S. Garth and Janet Haig, at the
same foundation, identified the species of six families of crabs with in-
credible promptness. The other great source of aid was the National
Museum of Natural History. C. Allan Child always quickly sent identifi-
cations of pycnogonids and returned some specimens for our reference
collection. The stomatopods were identified by Raymond B. Manning, who
also send us a reference collection. Mary E. Rice tutored us in sipunculan
identification and left a good reference collection at the Galeta labora-
tory. Joseph Rosewater identified our gastropods and bivalves and con-
firmed or corrected the identifications we attempted. Helen Hayes helped
with the species of Isognomon. G. Arthur Cooper identified our brachiopod.

The associates of STRI also provided considerable taxonomic assistance.
Lawrence G. Abele provided all our shrimp identifications, the alpheids
being a particular challenge. He is also publishing the description of
anew species of crab. Peter W. Glynn has identified our isopods and in
the process of identification found several species new to science. David
L. Meyer made up a labeled collection of ophiuroids for us to use as a
reference in sorting our samples. Because the amphiurid ophiuroids were
tiny, numerous, diverse and practically indistinguishable from each other,
Michael Kyte of Marine State Sea and Shore Fisheries sorted and identified
each of our collections for us.

xiii


£
ao o iJ 2
—4 - ua - a
— .S] Ss n °o
- iJ = w =
3 2 € = €
xs J os oO oO
oa id ° = 9
oO a N e <=
Pseudopotami lla 1/24
reniformis 1
(0.3)
Sabella 5/24 8/24 1/20 1/20
me Lanostigma 1-1-1] 1-2-3 1 1
(5.6) (4,341.4) (0.4) (0.4)
0.07
1.846
Sabella sp. 17 1/24 1/24 2/20
1 7 1-1
(0.3) (5.6) (0.8)
Sabella sp. 18 3/24 2/20 1/20
1-1-5 1-4 2
(2.3) (2.0) (0.8)
Sigalionidae
Psammolyce 3/24 8/24 8/20 7/20 1/20
spinosa 1-1-3 1-3-5 1-2-5 1-3-5 2
(1.6) (6,342.3) (6.442.7) (8,442.9) (0.8)
0.1 0.5 1.3
2.807 3.416 2.571
Psammolyce~ 1/20
like 1
(0.4)
Spionidae
Prionosptio 1/20
heterobranchia 1
texana. (0.4)
Syllidae

The statistics of the syllidae are based on 8 samples (samples no. 5 through

12).
samples.

Autolytus cf.
magnus

Autolytus
n. sp.

8/8

7-21-50
(182239)

4.1

1,284

5/8
1-22-45
(92)

7/8
1-6-12

0.4
1.497

130

The relative abundance of syllids, however, are based on

2/8 4/8
1-4 2-4-8
(5) (18)
7/8
1-6-14

(40.0212.5) (42,0412.2)

1.430

all 20 or 24

4/8
1-11-37
(61)

2/8
2-4
(6.0)


Lysidice ninetta, 33, 37, 152
Lysmata intermedia, 138

Macoma tenta, 120
Macrocoelona subparallelum, 142
magelonid polychaete,
Majid sp. F, 142
Mangelia fusca, 118
Marphysa Nn. sp., 125
Mediaster aequalis, 97
Megalobrachium poeyi, 139
roseum, 139
sortatum, 139
Megaloma vesiculosum, 129
Melinna n. sp., 123
Membranipora hastingsae, 28
tuberculata, 28
Menippe obtusa, 161
Mesanthura, 159
Metalpheus rostratipes, 137
Micropanope sp., 140
Microphrys bicornutus, 142, 165
Microprotopus sp., 48
Millepora complanata, 11, 105
Mithraculus, refer to Mithrax
Mithrax acuticornis, 142
eoryphe, 142
sp., 142
spinossissimus, 141
Mitra lens, 150
sp., 117
Modiolus americanus, 118
Modulus disculus, 148
modulus, 114
mollusks, 2, 18, 26, 27, 31, 41,
82, 100, xii
Monamphiura, refer to Amphiura
Morula lugubris, 149
Muricanthus radix, 149
Muricopsis zeteki, 149
Murrayella periclados, 41, 42, 162

Nassarius extlus, 150
vibex, 165

Natantia sp. 1, 164

Neanthes n. sp. 1, 127
speudonoodti, 153
sp., 127

173

nemertean spp., 107
nemerteans, 2, 28, 33, 36, 48
Neopisosoma mexicanun, 160
nereid, 20, 153
Nereis callaona, 33, 36, 127,
153, 164

n. sp. A, 127

risett, 127
nerinid, 47
Nerita fulgurans, 144

funieulata, 37, 148

peloronta, 144

seabricosta, 148

tesselata, 144

versicolor, 144
Neritina virgines, 165
Nicidion, refer to Eunice
Nitidella nitida, 117

sp. 2, 117
Nodilittorina tubereculata, 144
Notoacmea filosa, 148
Notomastus lineatus, 119, 164
Notophylium sp., 154
Nullamphiura, refer to Amphiura
Nymphopsis duodorsospinosa, 134, 157

Odontosyllis sp., 131, 156
Oenone fulgida, 123
Onchidella binneyi, 36, 150
hildae, 33, 36, 150
Onuphis sp., 126
vermtlltonensts, 125
Opalia erenata, 115
pumilio, 115
Opeatostoma pseudodon, 150
Ophiactis, 20
savignyt, 109
Ophidiaster guildingii, 108
Ophiocoma echinata, 108
pumila, 108
wendti, 108
Ophioderma appressun, 108
brevicaudum, 108
brevispinun, 108
etnereun, 108
Ophiodermatid sp., 108
Ophiodromus obscurus, 126
pugettensis, 153


Methods

The transect line extended from the northeast corner of the Galeta Marine
Laboratory (Acanthophora Zone) to the furthest and lowest point in the
intertidal (Coralline Zone) and was divided into 5 segments according to
the pattern described in Table 1. The boundaries were marked by iron con-
crete-reinforcing rods which were hammered into the reef top and, surpris-
ingly, are still in good condition after three years. The specific loca-
tion of each quadrat sample in each zone was determined by selecting two
coordinates from a table of random numbers: the first representing those
paces taken directly along the transect line perpendicular to shore; the
second representing paces taken perpendicular to the transect line at that
point.

A sledge hammer and chisel were used tg dig up all the material to a depth
of 6 to 8 cm that lay within a 0.125 m* frame tossed on the sample site.
The dead coral fragments, large pieces of dead coral and plants were then
rinsed in seawater while the sand and silt were sieved. The silt, sand,
and rinse water were then each carefully examined for small faunal species.
The macroscopic fleshy algae, Thalassia, crustaceans, mollusks, echinoderms
and some worms were removed from the dead coral fragments and separated.
Further examination of dead coral fragments and rocks for sponges, tuni-
cates and other faunal species followed. The coral fragments and macro-
scopic fleshy algae were examined under a dissecting scope for smaller cor-
alphytic and epiphytic algal species. Finally the large pieces of dead
coral were broken down into smaller ones in order to facilitate the search
for burrowing sipunculans, bivalves, and crevice-inhabiting polychaetes.

The small pieces of coral were then placed in the refrigerator in a tray
of fresh seawater. Many polychaetes emerged after this treatment and all
polychaetes and sipunculans were relaxed more effectively by cooling over-
night rather than by utilizing MgSO,.

Results

Findings from the survey are summarized and presented in the tables of
Appendices A through D and Tables 2 through 6. In many descriptions of
the spatial and temporal structures of communities, only abundances of
each species in terms of mean plus standard deviation are presented. In
contrast, we believe that statistics concerning frequency, predominance,
and dispersion should be presented in addition to abundance and that for
the vast majority of intertidal invertebrate species, tropical or temper-—
ate, mean plus standard deviation are not the best statistics. Further,
we placed each of these statistics for each species in the same location
in the table in order to give the reader the ability to make quick com-
parisons of these different measurements for a single species in the same
location. To extend this comparison within the species to different zones,
the reader shifts laterally in the table; to compare these measurements of
different species within the zone, the reader moves vertically. The main

18


polynoid indet.

Sabellariidae
Phragmatopoma sp. indet.

Sabellaria aleocki

Sabellaria floridensis

Sabellaria mooret

Sabellaria spinulosa

Sabel lidae
Hypstcomus torquatus

Pseudopotamilla ?
brevibranchiata

Sabella melanostigma

Sabella sp.

Serpulidae
Serpulid sp. 1

Serpulid sp. 2

Serpulid sp. 3

Abietinaria

Chthama ius

Tetraclita

Littorina

o -j
. ~~!
wo

2/8
2
0.2
2/8
3.5
1/8
5
0.6

1/8
28
3.4

4/8
11
1.3

3/8
3
0.4
1/8
0.1
1/8
2
0.2
5/8
6.7

1/8
1
1/8
1
0.1

155

1/12
0.05

11/12
258.0
23.2


Pocillopora, 67, 69, 71 Sabella melanostigma, 130, 155
damicornis, 1, 67, 68, 70, 72, 74 sp. 17, 130, 155
Polinices lacteus, 116 sp. 18, 130
polychaetes, 2, 18, 19, 20, 21, 26, Sabellaria aleocki, 129, 155
31, 41, 47, 48, 49, 82, 83, 85, xi floridensis, 129, 155
mooret, 155

Polycirrus sp., 132 spinulosa, 155
polynoid, 155 sabellariid, 129
Polynoid sp., 129 sabellid, 20
Polystphonia homta, 147 Salmoneus ortmanni, 137
howet, 163 Sargassun, 98
sp., 104 Scolelepis agilis, 47, 48, 49
subtilissima, 104 Serpulid sp. 1, 33, 36, 155, 164
Porifera sp. 1M, 163 sp. 2, 155, 164
sp. 2M, 163 sp. 3, 155
Porites, 61, 62, 63, 64, 65, 66, 67, sp. 4, 156
69, 71, 75 sp. 5, 156
astreoides, 11, 111 sp. 6, 156
furcata, 1, 11, 61, 62, 63, 64, 65, sp. 7, 156
67, 71, 75, 107 sp. 8, 156
Portunus sp., 161 sp. 9, 36, 156
Potamilla fonticula, 129 sp. 11, 156
Prionospto heterobranchia texana, 130 sp. 12, 37
Processa bermudensis, 138 Sicyonia parri, 135
fimbriata, 138 Stderastrea radians, 107
Psammocora, 69, 75 siderea, 107
stellata, 1, 67, 71, 75 Sige orientalis, 128
Psammolyce, 130 Siphonaria, 27
spinosa, 130 maura, 31, 33, 36, 150
Psarostola monilifera, 117 sipunculans, 2, 18, 20, 21, 28,
Pseudonereis gallapagensis, 31, 41, 48, 49, xi
33, 36, 128, 153, 164 Smaragdia viridis, 114
Pseudopotamilla brevibranchiata, 155 sphacelaria sp., 146
reniformis, 130 tribulotdes, 102
Pterocladia musctformis, 147 spaeromatid, 159
sp., 147 Spaeromitid sp. 1, 159
Purpura patula, 116 Sphenia, 31
pycnogonids, 21, xi antillensis, 121
Pyenogonun cessact, 158 fragilis, 31, 33, 36, 151
Pseudochama arcinella, 120 Spirorbis sp., 164

sponges, 23, 40, 41
Rhtzophora mangle, 2, 41, 87, 88, 89  spyridia filamentosa, 163

Rhodymenia paimetta, 147 Stenoplax, refer to Ischnochiton
Rhynchothorax sp., 133 stomopods, 158, xi
Risomuwenx muricoides, 116 Streblosoma crassibranchia, 133
roseus, 116 Strigilla sp., 120
Rissoina bryerea, 114 Strombus raninus, 116
decussata, 114, 165 Struvea anastomosans, 102

175


SECTION XII
FIELD EXPERIMENTS WITH THE EFFECTS OF OIL ON THE
MANGROVE TREE, RHIZOPHORA MANGLE

Rutzler and Sterrer (1970), in observations made two months after the wreck
of the 35,000~barrel oil tanker SS Witwater, noted that “high winds caused
a spray of mixed seawater and oil to cover mangrove trees and shrubs in the
supra-littoral zone to a height of 2 m above mean tide level" and that the
oil had "already killed many of these plants." Although oil flowed in
through tide channels and covered the stilt roots of mangroves a good dis-
tance in from the open sea, Ira Rubinoff pointed out two years later that
the most obvious defoliation was in a band of mangrove trees at the edge

of the sea and possibly could be a result of the spray of oil onto the
leaves rather than the coating of the stilt roots. We set up the experi-
ment to test this hypothesis.

Methods

Thirteen small Rhizophora mangle trees were sprayed with oil. All were

0.6 to 2 meters tall, except for one which was 3 meters tall. They were
growing at the edge of the forest but isolated so their sizes could clearly
be determined by planimetry from photographs taken with a scale included.
Four trees were sprayed on the leaves from the direction of the wind with
300 ml of marine diesel oil (trees 5-8, Figure 6). Three trees were evenly
sprayed on the stilt roots with 300 ml of marine diesel and Bunker C oils
in a l:l ratio (trees 9-11, Figure 6). (Pure Bunker C oil is too viscous
for the sprayer to handle, so it had to be diluted with marine diesel oil.)
Trees 12 and 13 were sprayed both on the roots with 300 ml of mixture and
on the leaves with 300 ml of marine diesel oil. Four trees were not sprayed
and left as controls (trees 1-4, Figure 6). All trees were sprayed and
photographed on 17 January 1972. The same spraying procedure was repeated
22 days later. After 372 days, the trees were again photographed from the
same angle with the same scale. Measurements of leaf coverage were made
with a Gelman planimeter.

Results and Discussion

All trees that had leaves sprayed with oil had fewer leaves and more bare
branches than the year before and showed no growth of the trunk or branches
(Table 37). Two of the control trees grew and seemed quite healthy, but a
third did not show a change in size. Of those sprayed on the roots with
Bunker C oil, a small individual (0.6 m tall) deteriorated to about half
its original size in terms of leaf coverage, while the largest (3 m tall)
apparently remained in fine health. Both were sprayed with 300 ml of oil,

87


Lepidonotus
humilis

Polynoid sp.
unknown

Sabel lariidae
Phragmatopoma
sp. indet.

Sabellaria
aleocki

Sabellaria
floridensis

sabellariid
indet.

Sabellidae
Chone sp.

Demonax Sp.

Hypsicomus
torquatus

Megaloma
vestculosum

Potamilla
fonticula

£
co}
2 = a < 6a
= 2 2 a 2
s 2 e & €
8 3 y = 8
=) eal N e 4
12/24 3/20 2/20 3/20
1-2-3 ]-1-2 1-4 2-2-2
(7,341.6) (1.6) (2.0) (2.4)
0.3
1.142
1/24
1
(0.3)
1/24
1
(0.3)
1/24
1
(0.3)
3/24 2/24 1/20
1-2-3 1-1 1
(2.0) (0.6) (0.4)
2/24
1-1
(0.6)
1/24
1
(0.3)
3/24
2-3-3
(2.6)
16/24 15/24 3/20 2/20 1/20
1-5-17 1-2-20 1-1-2 2-2 1
(31.0£7.2)  (17.626.8) (1.2) (1,6) (0.4)
11 0.3
2.002 4.049
2/20
1-1
(0.8)
3/24 4/24
1-3-4 3-15-52
(2.6) (28.0)

129


It is interesting to note that algae recovers (in fact, expands dramati-
cally) after heavy oil spills such as that following the breakup of the
TAMPICO MARU (North, Neushul and Clendenning, 1965). The expansion of kelp
was assumed to be caused by the failure of the populations of herbivorous
echinoids to recover for more than seven years following the spill. This
is probably correct, but confounded by the apparent influence of certain
oils, such as Bunker C, on algal recruitment.

The animal communities, on the other hand, showed no evidence of a long-
term effect of oil pollution (Tables 33, 34, and 35). Thousands of amphi-
pods were seen to be killed immediately by the oil spray at Galeta and
many crabs ran out of the area when the experimenters approached. Both
groups of crustaceans had reinvaded the polluted areas within one week.

Table 34 shows the number of species and specimens found in controls and
treated quadrats of the Tetraclita Zone during a series of collections
following the oil treatment. The number of species and their abundances
show no clear trends following the experimental pollution. Variations in
the controls were just as great as those in the treated quadrats and are
probably a reflection of the great patchiness of the community rather than
of the effects of oil. The same is evident in the area where barnacles
had been killed and cleaned in order to study effects of the oil on the
recruitment and succession of invertebrates to the barnacles' tests. Table
35, where these results are presented, shows no trend of increase or de~
crease in the number of species or in their abundances. Furthermore,
there are no changes in the kinds of species present in either the regular
Tetraclita Zone or the recruitment and succession experiment.

The same situation is apparent in animals from our experiments in the
Laurencia Zone on the Galeta reef. Table 33 shows no significant changes
in number of species or in abundances between control and experimental
quadrats.

A factor that may account for the survival of organisms in the experimental
quadrats is the size of areas involved. One square meter quadrats sub-
jected to each treatment were separated and placed between quadrats sub-
jected to other treatments. An isolated square meter could be supplied
with unaffected plankton and nutrients as surrounding water washes across.
It may be necessary to test this factor by experimental pollution on the
scale of hectares rather than square meters, but this is not a reasonable
field experiment for a marine laboratory to undertake.

Another important factor is the toxicity of the particular oils involved.
The fuel oils, Bunker C and marine diesel, were chosen because they were
the types most commonly involved in local oil spills and because they rep-
resent two opposite categories of volatility. Mr. Eugene Lau, Chief
Chemist of the local Refineria de Panama, S.A., gave us technical inform-
ation on the contents of these oils when the oils were supplied. This in-
formation is given in Table 36 so the reader can judge potential toxicity

80


Cirripeds were identified by Dora P. Henry, Department of Oceanography,
University of Washington, and Peter R. Bacon, of the University of the West
Indies, Trinidad. Bryozoans are being worked on by William C. Banta, The
American University, Washington, D.C., and tunicates by R. H. Miller,
Dunstaffnage Marine Research Laboratory, Oban, Scotland. Robert C. Bullock,
of Florida Technological University, identified our chitons.

We wish to express our gratitude to Mr. Juan L. Obarrio, Director General,
Marine Resources, Ministry of Commerce and Industry of the Republic of
Panama, and to Mr. Charles I. McGinnis, Director of Engineering and Con-
struction for the Canal Zone Government, for their rapid response to our
request for permission from authorities of the Republic of Panama and of
the Canal Zone to perform field experiments on the effects of oil pollution
on natural marine communities. We also wish to give sincere thanks to Mr.
Mauricio Salazar and Mr. Eugene Lau, Vice President and Chief Chemist,
respectively, of Refineria de Panama, S.A., who kindly supplied the oil
used in these experiments and technical information concerning the oil.

We also thank Mr. R. A. Williams, Chief, Southern Sanitation Area, Canal
Zone, for loaning us two new, unused X~Pert 2-gallon Professional Sprayers
which we used in applying oil to our experimental areas.

Finally, we wish to express our sincere appreciation for the dedicated
assistance we received in tedious work. Ina Tumlin, Kay Kerwin, and Betty
Womble spent many long hours meticulously sorting the samples, as well as
assisting with many other projects, which included drafting many of the
figures of this report. Diana Werder assisted with the preliminary sort-
ing of the samples, principally making the mollusk identifications as the
samples were first collected and sorted. Caryl Buford spent many long
hours at the microscope taking most of the settling plate counts. James
P. Stames managed the laboratory facilities and provided a major portion
of help in collecting and sorting of samples. Bruce Hitchko and Richard
Eddy helped with collecting and sorting the samples. Esther J. Birkeland
typed and edited the monthly reports and the final draft with good cheer
in spite of our inordinate demand for lengthy tables and incessant type-
print changes, which demanded more time in the typing of the reports than
would normally be necessary.

The support of the project by the Water Quality Office, Environmental
Protection Agency, is acknowledged with sincere thanks.

xiv


Figure 5.

Number of Eunice caribaea per 0.01 m?

60-4

Change in average abundance of Eunice caribaea in quadrats for
experimental control and for quadrats sprayed with Bunker C or
marine diesel. Two samples were taken on each date for two
spatially separated quadrats for each treatment so n = 4 for
each point. The populations in quadrats subjected to marine
diesel or left untreated did not differ significantly and both
underwent a significant increase. The populations in quadrats
treated with Bunker C, separated from each other, but located
between quadrats treated in the other ways, decreased signi-
ficantly.

CONTTO] aacanecnenemenewne:

marine diese] +=" ——"=

Bunker C ——— eam

day 0
before

T 1
7 days 28 days

Time since quadrats were sprayed with oi]

86


Syllid, black stripes, 131 melones, 149

black stripes-white bands, 131 trangularis, 149
brown dots, 131 Thalassia, 18
checkered, 131 testudinum, 11, 104
syllid epitoke, 157 Tharyx sp., 124, 152
Syllid, gray, 131 Thelepus setosus, 133
leafy projections, 131 Themiste spp., 122
maroon, 131 Thoe puella, 141
sp. 4, 132 Thor manningi, 138
sp. 9, 157 sp., 160
sp. 10, 132 Thunor rathbunae, 137
sp. 13, 132 Trachypenaeus similis, 135
sp. 26, 132 Trichophoxus floridenus, 48
sp. 36, 132 Tricolta adamsi, 113
sp. 37, 132 bella, 113, 165
sp. 38, 132 phastanella, 148
sp. 39, 132 Trididennun solidum, 12
sp. 41, 132 Tripsycha tulipas 148
with stripes, 132 tunicates, 18, 40, 45, 56, 58, xii
Syllis gracilis, 33, 36, 157 turbellarian spp., 107
Synalpheus anasimus, 137 turbellarians, 2, 28, 33, 36
fritzmuellert, 137 Typosyllis aciculata, 36, 131, 157
herricki, 137 prolifera, 131
minus, 137 sp. A, 13]
pandionis, 137 variegata, 131, 157
sp., 137, 160
tenutspina, 137 Uca sp. 1, 165
tounsendt, 137 Uhlias limbatus, 139
Ulva lactuea, 146
Taenioma macrourun, 104 Upogebia sp., 165
tanaids, 158
Tanystylun sp., 134 Valonia utricularis, 102
sp. 1, 157 ventricosa, 102
sp. 2, 157 Vaswn muricatum, 117
Tectartus muricatus, 144
Tegula fasciata, 113 Witwater, 2, 6, 87
panamensis, 148 Wrangelia argus, 12, 104
Tellina fausta, 120
Telmatactis americana, 107 xanthid, 161
rosent, 107 Xanthid sp. F, 141
terebellid, 20, 157 Xanthodius denticulatus, 140
Tetraclita, 2, 28, 29, 30, 31, 32, stimpsont, 161
33, 35, 39, 77, 83
stalactifera panamensts , 2, 26, Zoanthus sociatus, 11, 23, 41, 106,
27, 30, 31, 33, 34, 35, 36, 38, 163
77, 158 solandert, 11, 106

Thats béserialis, 149
deltotdea, 116
haemastoma, 116, 145

176


SECTION XIII
EFFECTS OF OIL ON THE RECRUITMENT OF ORGANISMS TO
PLEXIGLAS SETTLING PLATES

There is a variety of natural factors that cause mass mortality in marine
intertidal communities, e.g., unusual water temperature changes, current
changes, severe storms, dinoflagellate blooms (Brongersma-Sanders, 1957),
drift log battering (Dayton, 1957), or desiccation (Glynn, 1968). Oil
spills, of course, are a cause of mass mortality to which organisms have
not evolved adaptive response. But the mortality caused by the oil spill
is not as great an interest as is the influence of oil on the pattern of
recruitment and succession following the catastrophe. That is, we are
especially interested in the effect of oil on the ability of the community
to recover. To approach this problem, we investigated the effects of rel-
atively volatile (marine diesel) and relatively viscous (Bunker C) oils on
the recruitment of organisms to settling plates.

Plexiglas settling plates were selected for this study because the basic
substratum material of the experimental and control samples are precisely
standardized with uniform surface, area, shape, location and exposure
time. Also, the samples could be collected and analyzed intact under a
dissecting microscope. Because of the standardization benefits of this
sampling process, growth rates, productivity and species composition of
communities of fouling organisms are used as indicators of the amount of
pollution in local waters (Anonymous, 1970).

Methods

The settling plates were prepared and set out in the same manner and at the
same stations as the plates for the regular recruitment study discussed in
Section VIII. See that section for details of the methods and materials
involved. The controls for this experiment also provide data for the pro-
gram described in Section VIII.

To coat plates with oil for the experiment, 24 plates were set for 24 hours
in a large jar of Bunker C oil and another 24 plates were set in marine
diesel oil for 24 hours. The plates were then set out in air, propped up
on the work bench until dry, then tied in sets of 4 on settling plate lines.
After 126 days in the ocean, the Bunker C-treated plates were still coated
with oil. Films of oil formed on the surfaces of the trays of water con-
taining marine diesel-treated plates which had been in the ocean for 126
days and then preserved in 10 percent formalin for nearly a year. We can
assume there was enough oil present to measure its effects on recruitment.

91


g
fo}
ov oO oO =
< oad a - a
= [s} 3 un °o
= 5 & 2 5
Lo] = i= _ =
= a oS oO oO
8 c| g = g
Telmatactis 2/24 1/20 1/20
americana 1-2 5 1
(1.0) (2.0) (0.4)
Telmatactis 13/24 17/24 5/20 2/20 2/20
rosent 1-3-7 1-4-14 1-2-5 1-2 2-2
(13.0#3.2)  (29.6+6.6) (4.8) (1.2) (1.6)
9.8 35.7
1.846 1.989
anemone sp. 2/20
(unknown) 1-2
(1.2)
Order Scleractinia
Agari cia 2/20
agaricites
Astrangia
solitaria 1/24
Dichocoenta
stokesii Wea
Favia fragum 3/24
Porites
astreoides 3/24
Porites fureata 7/24 1/24 3/20
Siderastrea
radians 1/20
Siderastrea
stderea 1720
TURBELLARIA
turbellarian 6/24 13/24 5/20 4/20 4/20
spp. (number of 1-1-2 1-2-19 1-2-10 1-1-2 1-2-3
species unknown) 2.6 (18.626.8) 7.2 2.4 3.2
NEMERTINA
nemertean spp. 11/24 10/24 12/20 8/20 7/20
(number of 1-3-11 1-3-6 1-2-5 1-3-4 1-2-4
species (12.3£7.1)  (10.843.0) (10.4#5.2) (7,640.4)  (6.845.1)
unknown)
BRACHIOPODA
Diseinisea 6/24 4/24 1/20
strigata 1-1-1 1-1-1 1
(2.3+0.9) (1.3) (0.4)
1.143


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54


PART IL

EXPERIMENTAL STUDIES ON THE EFFECTS

: OF OIL POLLUTION

60


SECTION IL
RECOMMENDATIONS

It is obvious that an extensive treatment with oil will kill animals, but
it is not safe to conclude a lack of harmful effects if the creatures ap-
pear to be in good health following an oil spill. The presence and cost
of repair of unseen physiological damage must be determined and measured
with an objective, quantitative indicator. Decrease in growth rate is an
indicator of the general cost of repair and should be utilized as a stand-
ard measure. The balance in many populations, especially in corals, be-
tween rates of growth and grazing or other factors of deterioration are
of basic importance.

Mass mortality is not an unusual occurrence in marine communities, but

most natural communities are stable in that they respond with a predictable
pattern of recovery to natural catastrophes. Mortality itself should not
be the main subject of interest in pollution studies. Of greater importance
is the effect of pollution on recruitment. The eventual final stage in
succession may be modified by an alteration of relative success of different
organisms in the earlier stages.

We learned that experiments concerned with the effects of oil on whole com-
unities cannot be conducted on one meter square experimental and control
quadrats because of the constant washing with fresh seawater. Each exper-
imental and control quadrat should be much larger, a program that is not a
recommended way to treat the shoreline because of potential damage to sur-
rounding areas, the possibility of interfering with other studies, consid-
eration of local people and difficulty in obtaining permission from author—
ities. Instead, we recommend concentrating on specific questions for which
experimental tests with precise controls can be designed, e.g., growth rate
or recruitment experiments. Examining the effects of pollution on entire
communities required too large an experimental area,and precise controls
are difficult to obtain.

For all experimental studies on the effects of oil pollution, experimental
controls should be emphasized because of natural variation between local
areas for physiological events in tropical species. A horizontal distance
of 3 m or periods of time 2 months apart had greater effect on the growth
of corals than 2.5 hours exposure to Bunker C oil, although the effect of
oil was statistically significant. The latter was determined by comparison
with very precise controls.

In order to evaluate the effects of unpredicted events on community struc-
ture and to provide a foundation for understanding the communities with
which we are working, baseline studies should be performed in regions of


Fossarus atratus

Fossarus megasoma

Creptdula aculeata

Crepidula ineurva
Crepidula lessonii

Crepidula marginalis
Crepidula onyx
Crepidula striolata

Cypraea arabicula
Cypraea cervinetta
Cymatium gibbosum
Murtecanthus radix
Murtcopsis zeteki
Aspella indentata
Eupleura nitida
Coralltophila squamosa
Thais triangularis
Thais biserialis

Thats melones

Acanthina brevidentata

Aeanthina muricata
Morula lugubris

Abietinaria

Tetraclita

Littorina

+

ee ee

149

+] Chthamalus

+

ww
=

ocOo~ CON HBS)
NAM YAN wn

=
~
i

0.6

3/12
20.4
6.5

9/12
22.8
7.3


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To) x O*

x

2)
isauod ‘O)

JAOYINVWW

*LOAquod e se paydeub
-070Yd AO Juauwiiiadxs 943 UL pasn you a76rmm -y | [PWS B 02 S4asa4 4X, “Py PLGE) UL
uaAlB SL 9a43 pavaqunu yoea Jo JUaWZea4} a4, “AuUaulluadxe a4] UL pasn Saaz ay2 07
4ajad Suaquinu ay, ‘valid ayz ueau pazes0, si AuoQeVOGe] auLUeW e2a1e9 *SqUauLUadxa
UOLINLLOd [LO UL PAALOAUL Saa4z a7buDW DLOYdozLyy 40 SUOLZLSOd BALeLaA ayy JO dey

PIER

*g aunbly

88


SECTION IV
SURVEY OF THE CARIBBEAN INTERTIDAL REEF FLAT AT GALETA

The baseline survey program of the Galeta laboratory was organized around
a consideration of the intertidal as consisting of five distinct zones.
Although the extreme range in tidal fluctuations covers only 0.7 m, the
five communities of organisms from the laboratory (Acanthophora Zone) to
the surf (Coralline Zone) was obvious on the first view of the reef flat
(Table 1). The composition of occupation of primary substrata in the five
zones was measured through the contact made by the fall of 25 point-set
quadrats in positions located by coordinates obtained from tables of ran-
dom numbers. The actual data consist of independent counts, not measures
or percentages, although data are transformed into percentages for presen-
tation and discussion for easier comparisons.

DISTRIBUTION AND ABUNDANCES OF INVERTEBRATES

The main purpose of the baseline study was to acquire a quantitative esti-
mate of the community structure of a tropical intertidal reef flat. In
this section we will discuss the communities of motile epifaunal and in-
faunal macroinvertebrates collected along an intertidal transect at the
Galeta Marine Laboratory. Macroscopic invertebrates are operationally
defined as those we could sort out with forceps in trays without requiring
a dissecting microscope. This means the animal is at least 2 millimeters
in length or width.

During the sampling program, approximately 50,000 specimens were sorted
for 520 different species which were identified to genus or species. The
descriptive data in a catalog of species for the Caribbean intertidal reef
flat transect at Galeta would disrupt the text, so the data are organized
in Appendices A through D. Although the data are summarized at the level
of order and class in Tables 2 through 6, the information for each species
is presented in the appendices in order to provide the reader with the op-
portunity to derive answers to original questions he might have. This also
allows for more accurate and extensive comparisons with communities or
specific groups of intertidal organisms in other localities or long-term
changes in populations of selected species on the Galeta transect.

For conveniently and accurately making comparisons, we have attempted to

design the appendices in an efficient format that perhaps could serve as

a standardized form of data presentation. In the Results section below,

the explanations and justifications for the statistics and format used in
the appendices are presented. If the reader does not wish to spend time
with explanations of procedures, but mainly wishes a summary of the find-
ings, then the reader may skip the Methods and Results sections below and
move straight to the Discussion section on page 20.

10


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39


TABLE 36. CHARACTERISTICS OF THE FUEL OIL SAMPLES USED IN POLLUTION

EXPERIMENTS IN THIS REPORT.

Specific gravity

Density (API at 15.5°C)
Viscosity (SFS at 50°C)
Flash point, °F (PM)

Pour point, OF

Sulphur total, % weight
Water and sediment, % volume
Ashes, % weight

Calorific value, BTU/1b (gross)

Explosivity, %

84

Bunker C. Marine Diesel
0.9646 0.8767
15.2 29.9
161.0 49.0
162 194
+25 +30
2.33 0.93
0.05 trace
0.05 0.005
18,800 --
40 --


Codes and ordinate scale units are as follows:

Spatial heterogeneity. Shannon-Wiener measure of counts of sessile
species and substratum categories contacted by the fall of random
points obtained from a random number table. Each unit on the or-
dinate axis = 0.5 bits per individual.

Shannon-Wiener diversity measurements in each zone averaged over
nem the 10 major categeries of macroscopic motile invertebrates.
Each unit on ordinate = 0.5 bits per individual.

No. individuals/m? for 10 categories of macroscopic motile inver-
tebrates combined. Each unit on ordinate = 2000 individuals/m*.

Total number of species in all categories of macroscopic inverte-
brates. Each unit on ordinate = 50 species.

--———- Total number of algal species. Each unit on ordinate = 25 species

ol T T T

q v
Coralline Laurencia Zoanthus Thalassia Acanthophora

Figure 1. A comparison of the total abundance, number of species and diversity
of macroscopic invertebrates with the pattern of spatial heterogeneity
in the communities of encrusting organisms on intertidal zones at
Galeta.

22


Opisthosyllis sp. indet.

Syllis gracilis

Typosyllis acteulata

Typosyllis variegata

syllid epitoke indet.

Syllid sp. 9

Terebellidae
Eupolymmia (?) nebulosa

Lotmia medusa
Pista brevibranchiata
terebellid indet.

PYCNOGONIDA
Ammothea sp. 1&2

Nymphopsis
duodorsospinosa
Tanysttlum intermedium

Tanystilum sp. |

Tanystilum sp. 2

Abietinaria

Chthamalus

Littorina

18
2.1

1/8
1
0.1
1/8
8
0.9
1/8
8
0.9
1/8
1
0.1

2/8
1/8
1/8
2/8

5/8
36
9.4

5/8
29
7.5

5/8
35
9.1

5/8
12
0.3

5/8
109
28.3

157

nN

OPA Tetraclita

wo oo
al uBe
On OAM NFAY

°o
~

1/12
1

0.1

Wi2

0.1

2/2
4.8
0.4

ie
0.05


£
o oO os 2
= o 3 G o
= S 3 3 S
S ra © ~ =
SS Ss oS os cS
8 Ss a = <
Paraspidosiphon 5/24 10/24 9/20 12/20 16/20
spinoso- 1-1-4 1-1-5 1-2-7 1-3-13 1-5-16
scoutatus (2.6) (5.72.1) (10.823.9) (22.827.0) (35.6+7.8)
1.5 4.1 11.4 5.3
2.470 2.905 1.002 1.700
Paraspidostphon 11/24 16/24 11/20 6/20 11/20
steenstrupt 1-2-4 1-3-1] 1-3-5 1-2-6 1-3-13
(8,342.3) (22,045.2) (11,242.7) (6.0£2.8) (16.8+5.5)
4.8 5.9 4.2 3.0 2.5
1,840 1.963 1.481 1.676 2.694
Paraspidosiphon 6/24 11/24 4/20 7/20 9/20
spp. (probably 2-4-6 1-2-8 1-5-10 1-3-8 1-2-7
7 spp.) (8.73.6) (10.3#3.2) (8.0) (12.425.3) (10.0+3.5)
2.5 2.8 6.2 1.5
4.209 2.529 1.591 2.667
Phascolosoma 18/24 23/24 15/20 10/20 19/20
antillarun 1-2-10 1-5-12 1-5-10 1-3-45 2-32-134
(21.344.9) (46.047.7) (29.624.2) (42.8418.6)(291.2+67.3)
12.2 12.4 Wd 21.4 43.7
1.845 1.477 8.689 1.854 1.989
Phascolosoma 17/24 17/24 14/20 9/20 16/20
perlucens 1-6-25 1-3-13 1-3-17 }-1-3 1-3-8
(38,0+12.9) (26.6£7.8) (27.628.1) (6,442.6) (133.2+94.6)
21.6 7.2 10.4 3.2 20.0
2.589 2.692 2.361 1.200 10.547
Phascolosoma 11/24 20/24 10/20 1/20 10/20
varians 1-3-7 2-5-14 1-3-9 2 1-2-3
(12,643.5) (37,0215.4) (16.4+5.3) (0.8) (7.241.8)
7.2 10.0 6.2 1.1
2.184 1.487 2.585 1.176
Phascolosoma 8/24 7/24 6/20 7/20 11/20
spp. (probably 1-2-4 1-2-8 1-4-6 1-1-7 1-1-4
7 spp.) (5.01.8) (6,341.7) (8.443.5) (5,241.8) (8.0+#2.2)
2.9 1.71 3.2 2.6 1.2
2.514 1.403 3.523 2.153 1.576
Themiste spp. 8/24 12/24 1/20 1/20 1/20
(probably 1-1-6 1-4-9 1 1 2
3 spp.) (4682.0) (18.384.6) (0.4) (0.4) (0.8)
2.7 4.9
4.219 2.225
fragments in- 5/24 11/24 1/20 3/20 6/20
determinable 1-2-2 1-3-8 9 1-1-1 1-2-5
(3.0) (13.6#4.5) (3.6) (1.2) (5,240.9)
3.7 0.8
2.546 3.589

122


high probability of future subjection to pollution. In these surveys, the
pattern and relative magnitudes of the variances are of far greater in-
terest than the values of the means or averages. For instance, recruitment
to settling plates varied seasonally in biomass in the eastern Pacific but
not in the Caribbean. However, recruitment varied seasonally in species
composition more in the Caribbean than in the Pacific. These sorts of
distinctions in patterns of variation provide more power and insight for
analyzing results of experiments and observations than do descriptions of
community structure.


The great temporal variability in species composition and abundance indi-
cate that a study of effect of oil on the organisms inhabiting the beach
would require a very intensive sampling program and that an after~the-fact
assessment of the effects of pollution in this environment would be extreme-—
ly difficult. Identification of changes brought about by pollution would
be confounded by natural changes. For this reason we eliminated the sandy
beach habitat from our study on the effects of oil pollution and confined
this to the reef and andesite rock communities which have a more predict-
able species composition.

50


£
» % © 2
< - a = a
_ [s} J n °o
= 5 6 3 s
£ 5 s ‘s 5
8 5 a = 2
Brachidontes 1/20
eitrinus 1
(0.4)
Brachidontes 1/20
recurvus 1
(0.4)
Lioberus 1/20 1/16
castaneus 1 1
(0.8) (0.5)
Lithophaga nigra af 20 1/16
- 1
(0.8) (0.5)
Lithophaga 3/20 5/16
bisuleata ]-1-2 1-1-1
(1.6) (3.5)
Gregariella 1/16 4/16
coralltophaga 1 1-1-1
(0.5) (2.5)
Isognomon bicolor 11/20 18/20 4/16 6/16
2-3-11 3-12-30 1-2-8 2-6-11
(26,.848.9) (188.8+79.8) (6.0) (29.5£17.8)
20.0 65.6 14.9
2.812 4.360 16.266
Isognomon 18/20 10/20 5/16 4/16
radiatus 3-7-12 1-1-2 1-2-2 1-1-9
(55.647.9) (6,842.2) (4.5) (6.0)
41.6 2.4
1.248 1.910
Pinetada radiata wie
(0.5)
Lima pellucida 1/20 2/20
1 1-1
(0.4) (0.8)
Coralli ophaga 10/20 2/16 2/16
eoralttiovhaga 1-2-4 1-2 1-1
(11.2#3.5) (1.5) (1.0)

119


6
=
ov oO oO 2
= 5 n - o
= oO 3 w rs)
a = c— n ‘=
Lot ov » o p
o S = - c
s 3 o cj o
TAXA 8 5 8 = $
Astracystis
ramosa 2/16 2/16
Centroceras
elavulatum 3/20 1/16 4/16 76
Ceramiun
eructatum 3/20 8/20 2/16
Ceramium
fastigiatwn 1/16
Ceramium
leutzelburgit 6/20 2/20 4/16 1/16
Ceramium sp. 10/20 10/20 7/16 5/16 7/16
Champia parvula 1/20 1/20
Chondria
floridana 2/20
Chondria
tenuissima 1/20
crustose
coralline spp. 20/20 20/20 15/16 14/16 10/16
Crustose
coralline sp. B '4/14 5/12 2ne2 12
Crustose
coralline sp. C 14/14 6/12 var 2/12
Crustose
coralline sp. 0 [4/14 7/12 1/12
Crustose
coralline sp. E 5/14
Crustose
coralline sp. F 2/14 12/12 6/12 3/12 ane
Crustose
coralline sp. G 12/14 1/12
Crustose
coralline sp. H 3/14 2/12 1/12 12 5/12
Euchewna 1/20
echinocarpum
fleshy red crust 11/14 9/12 8/12 12/12 8/12

103


APPENDIX B

Catalog of the larger invertebrates from the intertidal reef at the Galeta
marine laboratory (tidal depth range 0.7 m). Species found only below
spring tide low water or in the Littorina-Nerita "splash" zone are not in-
cluded. Important species definitely observed in a zone but not actually
encountered in a quadrat sample are indicated by "+". Five descriptive
statistics are as follows, from top to bottom in each unit:

1. Frequency (0.125 m* samples): no. of samples in which the species
were present/total no. of samples sorted for this species.

2. Abundance (0.125 m? samples): median plus quartiles of abundance
counts.

3. Abundance (1 m? calculated): mean plus standard error of the
mean in samples including those in which the species was not present.

4, Relative abundance: per cent of class within the zone numerically
represented by this species. (The Coelenterata are analyzed as per cent
of order and decapod crustaceans as per cent of suborder.)

5. Dispersion: Morisita's index of dispersion, unity indicates
random dispersion, larger values indicate greater aggregation and smaller
values indicate more even distributions.

If the species is encountered in less than 6 samples, only the upper 3
statistics are given.

©
xs
vo oO o 2
i= = n — a
ued oO Ss wn °
- i= ‘= un —
S 2 < = €
S a o oO oo
fo} oO oO P= oO
oOo —_ N Ee 4
COELENTERATA
Order Hydroida
Millepora
comp Lanata 8/24 1/20
Order Ceriantharia
Cerianthus sp. 3/20
1-1-2
(1.6)
Order Gorgonacea
Erythropodium
eartbaeorum 7/24
Order Zoanthiniaria
Palythoa 7/24 2/24 2/20 1/20
vartabtlis 12-64-520 14-16 17-29 13
(3504194) (10.0) (18.4) (5.2)
7.4
192.445

105


CONTENTS

Preface

Abstract

List of Figures

List of Tables

Acknowledgments

Sections

I

II

III

Iv

VI
VII

VIIL

Conclusions
Recommendations
Introduction
PART I. BASELINE SURVEYS OF THE MARINE COMMUNITIES
Survey of the Caribbean Intertidal Reef Flat at Galeta

Survey of the Pacific Intertidal Andesite Rock Beach
at Paitilla

Survey of an Intertidal Mangrove Community at Galeta
Survey of a Sand Beach Community

Recruitment Patterns in Caribbean and Eastern Pacific
Benthic Communities

ix

xiii

10

26
40

46

51

PART II. EXPERIMENTAL STUDIES ON THE EFFECTS OF OIL POLLUTION

Field Experiments with the Effects of Exposure to Bunker C Oil
on the Growth Rate of the Hermatypic Coral, Porites furcata

Laboratory Experiments with the Effects of Oil on Hermatypic

Corals from the Eastern Pacific and from the Caribbean

vii

61


TABLE 34, NUMBER OF SPECIES (FIRST NUMBER) AND INDIVIDUALS (SECOND NUMBER)
FOUND IN 0.01 m@ SAMPLES FROM: UNTREATED. BUNKER C:MARINE DIESEL (1:1 RATIO),
AND MARINE DIESEL SPRAYED QUADRATS IN THE TETRACLITA ZONE, PAITILLA BEACH.
Number of species represents the total found in each sample. Since number

of specimens found in dead barnacles is 5.9 times that found in live ones, a
standardization factor was calculated by dividing the number of live bar-
nacles by 5.9 in each sample and adding it to the number of dead barnacles
present in the same sample. Essentially, then, the number of specimens
indicated is per barnacle and not per sample.

Pre-pol- 26 days 61 days 98 days 129 days 159 days

lution after after after after after

Coelenterates

Control + 2/11 1/13 2/15 2/42 5 1/30

BC:MD 2/29 2/15 1/13 1/21 W/

Marine Diesel 2/4 1/8 -- 3/27 1/53
Polychaetes

Control 7/16 2/2 8/12 10/13 8/34 8/38

BC:MD 7/18 8/13 9/16 8/14 7/24

Marine Diesel 14/42 8/12 42 9/21 7/17
MoTlusks

Control 8/39 V/<1 10/7 6/58 8/17 9/12

BC:MD 6/43 6/25 8/30 4/36 7/74

Marine Diesel 9/9 7/17 4/16 8/35 6/52
Barnacles

Control 2/97 2/428 2/60 2/9 2/23 2/23

BC:MD 2/89 2/59 2/89 2/50 2/80

Marine Diesel 2/52 2/94 2/57 2/15 2/88

Arthropods (other
than barnacles)

Control 6/48 5/6 4/21 5/8 asl 4/41

BC:MD 4/17 5/7 6/9 3/8 WV

Marine Diesel 13/10 2/11 -- 5/7 1/2
ALL TAXA

Control 39/224 8/458 23/189 26/132 22/92 24/308

BC: MD 22/168 25/94 = 23/159 29/105 18/180

Marine Diesel 38/117 23/147 11/87 21/134 18/303

82


Zone, samples were scraped from the rocks. In the Tetraclita Zone, barna-
cles were removed from the rock and areas covered with a mat of algae were
scraped. In the Littorina Zone, animals within a 1 m? frame were counted
in the field.

Two sets of 4 samples each were collected in the Abietinaria Zone, one on
29 October 1970 and one on 26 April 1971. One set of 2 samples was col-
lected in the Chthamalus Zone on 29 January 1971. Three sets of 4 samples
each were collected in the Tetraclita Zone: one on 31 December 1970; one
each on 26 and 27 April 1971, and one on 31 January.

To study the succession of organisms that settle on or in the tests of dead
barnacles, Tetraclita stalactifera panamensis, an area 4.7 meters by 0.7
meters was marked in the Tetraclita Zone with Sea Goin' Poxy Putty. Within
the area, 532 Tetraclita were killed and the tests were left in place. The
test of Tetraclita which were dead before the experiment began were removed.
A map of the area showing position and size of each Tetraclita was made
from photographs taken with a 4 x 5 view camera. The fate of individual
barnacles, the settling of new Tetraclita and the colonization of the tests
by invertebrates were followed periodically for 16 months.

Collections of the experimentally killed barnacles were preserved with for-
malin in the field. They were sorted by scraping and counting all the or-
ganisms attached to the external and internal surfaces of each barnacle,
then the test was examined for animals that had settled in the parietal
canals. Separation to species was done under a dissecting microscope.

Results and Discussion

The findings of the survey are summarized for the four intertidal zones at
Paitilla in Appendix E. Observations from other areas in the eastern trop-
ical Pacific indicate that the Paitilla beach fauna is depauperate by com-
parison. Several usually predominant species are missing. This probably
is due to human activity in the area, such as the collection of oysters,
large Siphonaria and other mollusks for food.

The oil pollution experiments discussed later in this report were performed
in the Tetraclita Zone so this zone will be examined in detail. The infor-
mation on organisms in the Tetraclita Zone will be presented in two sections.
First a description of the structure of the Tetraclita community will be
given. This is followed by an examination of an important aspect of the
dynamics of the Tetraclita community, the succession of boring organisms

and the eventual clearing of space by the weakening of the structure of
Tetraclita tests.

COMMUNITY COMPOSITION OF THE TETRACLITA ZONE

The Tetraclita Zone occupies a wide expanse of the beach on the upper shore
near and above mean sea level. The dominant organism ig the barnicle Tetra-
clita stalactifera panamensis. Twelve samples, 0.125 m* each, gave an

27


RHODOPHYTA
Amphiroa polymorpha

Antithamion occidentale
Bostrychia radicans
Bostryocladia tenuissima
Caloglossa leprieurit
Centroceras clavulatun
Ceramium byssoideun
Ceramium fastigiatun
Ceramium personatum

Crustose coralline,
multipored

Crustose coralline,
one pore level

Crustose coralline,
one pore raised

Fostella sp.

Gelidiella sp.
Gracilaria brevis
Gymogongrus crusti forme
Herpostphonia secunda
Herposiphonia tenella
Hildenbrandia prototypus
Hypnea cervicornis
Jania adherens
Laurencta sp.
Peyssonnelia rubra
Polystphonia homota
Pterocladia musctformis
Pterocladia sp.
Fhodymenia palmetta

2 so
= $ » o
oS = os <
i o -
-_ i= oO a
bad oO o fo}
ov — — »
= S$ 3 2
2 s & a
+
+
+ + +
+ +
+
+ +
+
+
+ +
+ +
+ +
+
+
+
+
+ + +
+
+
+
+ +
+
+ + +
+ + +

147


£
3
wv oO oO =
< oa na on a
_ cS) Ss nu ro}
= 5 é Z s
o £ = - c
LS a oO oO oO
8 8 3 é g
Smaragdia 3/20 1/20
viridis ]-1-1 1
(1.2) (0.4)
Littorina 1/24
lineolata 3
(1.0)
Rissoina bryerea 5/24 1/20
1-2-3 2
(3.7) (0.8)
Rissotna
decussata 1/20 1/20
1 1
(0.4) (0.4)
Cyclostremiseus 1/24
beaut 1
(0.3)
Heliacus 1/24 3/24 6/20
infundi- 1 1-2-2 1-2-2
bult formis (0.3) (1.7) (4,441.7)
13.1
2.182
Heliacus 2/24 6/24 10/20 1/20 1/20
cylindricus 1-1 1-1-2 1-2-4 2 1
(0.7) (3,341.4) (10.4#3.1) (0.8) (0.4)
5.6 31.0
2.667 1.969
Heltiacus 1/24
bisuleatus 1
(0.3)
Modulus modulus 3/16 2/16
1-1-2 1-2
(2.0) (1.5)
Cerithium 2/16 4/16
eburneun 2-3 1-2-3
(2. 5) (3.5)
Cerithium 1/16
variabi le 1
(0.5)
Cerithium sp. 1 2/16
1-5
(3.0)


TABLE 37.

CONDITION OF SMALL R#IZOPHORA MANGLE AFTER HAVING BEEN SUBJECTED
TO OIL POLLUTION ON TWO OCCASIONS, 22 DAYS APART.

All trees were isolated

and between 0.6 and 2 m tall except for tree number 11 which was 3 m tall.

Mangrove
Experimental No.
Procedure (Fig. 6) Change in Condition after 372 Days
Control 1 Increased by 3 per cent in side view area,
apparently in fine health.
2 Increased by 5 per cent in side view area,
apparently in fine health.
3 Removed by a drift log.
4 Same size in side view area.
300 m1 of marine 5 Reduced in leaf coverage by 67 per cent,
bare branches.
diesel sprayed
6 Reduced in leaf coverage by 30 per cent.
on leaves
7 Reduced in leaf coverage by 11 per cent.
8 Reduced in leaf coverage by 26 per cent.
300 ml of half 9 Reduced in leaf coverage by 55 per cent,
marine diesel many bare branches.
and half Bunker
C sprayed on 10 Gone--removed by a drift log.
roots
i Apparently in fine health.
300 ml of marine 12 Completely dead, bare branches, but still
diesel sprayed on standing.
leaves and 300 ml
mixture sprayed 13 Carried away by a drift log.

on roots

89


TABLE 9. RELATIVE IMPORTANCE OF DIFFERENT SURFACES OF LIVE (LT) AND DEAD (DT)
TETRACLITA STALACTIFERA PANAMENSIS TO INVERTEBRATE POPULATIONS IN THE INTER-

TIDAL. The data are based on eight 0.125 m* samples, including a total of 238
live Tetraclita and 29 dead Tetraclita.
follows, from top to bottom in each unit:

1. Number in a taxon found per dead or live fetraclita test.

Per cent of each taxon found on the particular surface type.

Four descriptive statistics are as

2
3. Per cent of total fauna on the surface type represented by the taxon.
4. Number of species found on the surface type.

Base of Fallen
External parapet Internal Parietal from
TAXA surface (exterior) surface canals barnacles
LT OT LT OT LT DT LT oT LT OT
Balanus a 33.40 31.70 26.00
(3 spp.) 34 37 29
18.2 17.3 14.0
3 3 3
Mollusca 2.05 2.80 2.94 1.52 10.02 12.24 [0.21 4.68 |10.29 14.08
(32 spp.) 4 5 6 3 -- 24 -- 9 20 28
1.1 1.5 1.6 0.8 | -- 6.7 0.1 2.5 5.6 7.6
12 6 3 2 2 13 3 12 26 26
Polychaeta [0.26 0.58 0.17. «1.29 8.61 |0.16 12.03 {0.45 7.50
(37 spp.) 1 2 1 4 28 1 39 1 24
0.1 0.3 0.1 0.7 4.7 0.1 6.5 0.2 4.0
14 6 2 3 10 7 16 16 8
Actiniaria {0.28 0.20 1.29 1.52 0.41 0.31 {0.44 2.50
(3 spp.) 3 4 19 22 6 5 6 35
0.2 0.1 0.7 0.8 0.2 0.2 0.2 1.4
2 1 2 2 2 2 2 1
Isopoda 0.03 0.39 2.83
(4 spp.) J 12 87
-- 0.2 1.5
1 2 4
Nemertinea 0.03 0.03 {0.01
43 43 14
Turbel laria 0.08 0.13 {0.04
32 52 16
Total Fauna |35.99 35.28 | 4.4 4.3 ]0.02 47.4 |0.37 17.21 {11.62 26.91
42 48 26 29 -- 162 1 149 69 174
19.6 19.2 2.4 2.3 -- 25.6 [0.2 9.3 6.2 14.5
31 16 7 7 2 28 10 33 46 39

4 Numbers for Balanus spp. are calculated from only two 0.125 m? samples which
include 95 live and 10 dead etraclita.

30

Of the Balanus counted, 36% were dead.