Sublethal Metabolic Responses of the Hermatypic Coral
Madracis decactite Exposed to Drilling Mud Enriched With
Ferrochrome Lignosulfonate
Final Report
Grant No. EPA R805441010
"Effects of Drilling Fluids and Oils on Corals Occupying
Hard-Bank Communities"
February 20, 1980
TEXAS* A.&Mr
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Sublethal Metabolic Responses of the Hermatypic Coral
Madracis decacti^ Exposed to Drilling Mud Enriched With
Ferrochrome Lignosulfonate
Final Report
to
Dr. Norman Richards
Environmental Protection Agency
Gulf Breeze Environmental Research Laboratories
Sabine Island, Gulf Breeze, Florida 32561
Grant No. EPA R805441010
"Effects of Drilling Fluids and Oils on Corals Occupying
Hard-Bank Communities"
by
Michael A. Krone
Graduate Research Assistant
Department of Oceanography
Texas ASM University
under the supervision of
Douglas C. Biggs, PhD Thomas J. Bright, PhD
Project Co-Director Project Co-Director
February 20, 1980
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ABSTRACT
Sublethal Metabolic Responses of the Hermatypic
Coral Madracis^ decactis Exposed to Drilling Mud
Enriched with Ferrochrome Lignosulfonate. (December 1979)
Michael August Krone, A.A., Skyline College;
B.A., University of California at Santa Barbara
Chairman of Advisory Committee: Dr. Douglas C. Biggs
Madr cis decactis corals were exposed for 17 days in laboratory
aquaria to suspensions of 100 ppm drilling mud spiked with 0, 3, and 10
ppm ferrochrome lignosulfonate (FCLS). During the first week of expo-
sure, these corals increased their oxygen consumption and ammonium ex-
cretion, relative to uncontaminated controls. Those corals exposed to
the highest enrichments of FCLS demonstrated the greatest increases in
respiration and excretion and also the largest variations in respiration
and excretion between individual experimental animals. Corals reached
their highest average rates of respiration and excretion by the end of
the first week of continuous exposure. Rates then decreased during the
next week and, after a secondary increase in excretion and respiration
between days 10-13 which was most pronounced in those corals exposed to
FCLS enrichment, leveled off at near-initial rates by the end of the
second week-
Two corals, one exposed to 100 ppm drill mud + 3 ppm FCLS and the
other to 100 ppm drill mud + 10 ppm FCLS, became noticeably moribund as
the experiment entered its second week. These were the two corals which
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showed the most rapid and most consistent increases in excretion and
respiration during the first week of exposure to FCLS. By week two,
polyp expansion in both of these corals was dramatically reduced, and
each was removed from the experiment when areas of bare coral!urn sug-
gested the onset of polyp death.
All corals exposed to FCLS reacted by reducing their polyp expan-
sion behavior, although only the two cited above showed mass polyp mor-
tality. When exposure to drill mud + FCLS was discontinued, respiration
and excretion of surviving corals remained low and stable while their
polyp activity returned to normal levels within 48 hours.
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TABLE OF CONTENTS
Page
Introduction: 1
Drilling muds and drilling fluids 1
FCLS toxic-'ty to corals 5
Materials and methods: 7
Coral collection and placement 7
Experimental design 9
Res ul ts: 14
Flush of particulates "4
Adequacy of control s 14
Coral metabolism 15
Experimental and individual variability 18
Analysis of variance 20
Discussion: 23
Sensitivity of Madracis to FCLS 23
Acclimation of Madracis to FCLS 25
Sensitivity of related species to FCLS 27
Corals and zooxanthellae 28
0/NH4-N ratios 29
Ecological implications 32
Alternative measures of physiological stress 34
Cone! usi ons: 34
References: 36
Appendices: Photographs, Literature review, and Raw data 42
Vi ta 68
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VT
LIST OF FIGURES
page
Figure 1: Drilling fluid circulation path 2
Figure 2: Locations of known coral reefs and zones of limited coral
growth within the Gulf of Mexico 8
Figure 3: Diagram of the system used in this study 10
Figure 4-: Ammonium Excretion - Arithmetic averages of the mean
excretion rates of four corals exposed to each treat-
ment (ug-at NH^ g"1 coril protein h"1) 16
Figure 5: Oxygen Consumption - Arithmetic averages of the mean
respiration rates of four corals exposed to each
treatment. Expressed as ml Q£ g~^ coral protein h~^ 17
Figure A-l:
Figure A-2:
Figure A-3: O/NFty-N ratio for each drill mud + FCLS regime 67
Oxygen Consumption - of 4- corals expressed as ml 0^
g-1 coral protein h"1 63
Ammonium Excretion of 4- experimental corals, (ug-at
NHj g~l coral protein h"-"-) 65
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INTRODUCTION
Drilling Muds and Drilling Fluids. According to the U.S. Bureau of
Land Management (1976), over 2700 oil and gas wells have been drilled
since 1968 on the continental shelf of the Northwestern Gulf of Mexico.
In ten years this level of drilling has produced literally millions of
cubic feet of discharge drill mud and other drilling byproducts released
into the environment. The Offshore Operators Committee (1978) estimated
that 17,000 to 39,000 cubic feet of drilling mud and 11,000 to 22,000
cubic feet of cuttings are discharged during the drilling of a single
offshore well.
Drilling mud is a slurry of barite and bentonite clays, water and
chemical additives (American Petroleum Institute, 1978). Since muds are
commonly prepared on the site at the drilling platform, the composition
and proportions of each may be highly variable. According to Knox
(1978), mud is pumped down the center of the drill bit, providing a
stream of thick fluid to suspend the drilled chips at the bottom of the
hole and to carry them to the surface (see Figure 1). The pumping pres-
sure brings the mud and cuttings back up to the platform, where the cut-
tings are separated and mud returned to reservoirs for recirculation.
Besides the primary function of suspending and removing cuttings, the
circulation of drilling mud also cools and lubricates the bit, inhibits
the loss of oil and gas, and helps to prevent the intrusion of water in-
to the bore hole (Adler and Siegele, 1966).
The journal used as a pattern for format and style was Limnology
and Oceanography.
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Figure 1. Drilling fluid circulation path (from Ecomar 1978)
TAW*.
-ANMUUUS
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The very properties which make drill mud effectivedensity, gel
strength, and viscosityprevent dispersal by ocean currents (Knox,
1978). Relatively few studies have attempted to measure dilution rates
and dispersion patterns of drilling fluids discharged from offshore
drilling platforms. The present consensus is that rapid dilution occurs
near the discharge point, with the rate of dilution decreasing as the
discharge plume is advected farther from its source.
Flocculated clay spheroids appear to settle out most rapidly, while
the finer cuttings form a suspended plume that is diluted by convection
and turbulent diffusion as it moves away from the discharge pipe (Ray
and Shinn, 1975; Zingula, 1975; Ecomar, 1978). The data presented in
reports from Tanner Bank (Ecomar, 1978) and the Lower Cook Inlet (Miller/
K.D., 1976) indicate that within 200 meters of the discharge point
particulate concentrations of 100 ppm or greater may be expected. Their
data indicate that beyond 200-500 meters from the discharge point, mea-
sured concentrations of suspended solids and the various drill mud addi-
tives (Ba, Cr, Pb) were indistinguishable from background levels.
Laboratory studies have demonstrated that the major components of
drilling fluids (barite and bentonite) are relatively non-toxic to ma-
rine invertebrates (results summarized in McAufliffe and Palmer, 1976;
Nonaghan jet aj., 1976). However, ferrochrome lignosulfonate (FCLS),
which is one of the principal additives used to thin the clay suspension,
may be highly toxic to selected marine invertebrates. FCLS increases
the pumpability by decreasing the gel strength and yield point, while it
increases the chip carrying capacity by increasing the plastic viscosity
(Kelly, 1964). The enrichment of drill mud with FCLS generally increases
with depth of drilling.
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Two theories have been proposed (see Knox, 1978) to explain the
thinning ability of FCLS in clay suspensions. The first explains the
clumping of clay particles by edge-to-edge attraction; at neutral and
alkaline pH, the alumina-silica matrix has a net negative charge on its
edges. The lignosulfonate complex, a polyanion, disrupts the attraction
by absorbing to the edges of the particles and neutralizing the positive
charge. The second theory is that the important attraction holding clay
particles together is hydrogen bonding of water betv/een the faces, and
that lignosulfonate displaces this water and prevents the attraction.
Neither theory accounts for the importance of chromium and iron to the
thinning properties of FCLS~
In drilling mud the FCLS is not free, but adsorbed onto the clay
particles (Knox, 1978). Consequently, instead of rapid dilution from
effluents pumped into the water column, FCLS precipitates with the clay
particles (Ecomar, 1978). Adsorbance onto the clay is reversible (Skel-
ly and Dieball, 1970) so that FCLS is slowly released into the immediate
vicinity of benthic inhabitants^
It is the chromium content of FCLS that is largely responsible for
its toxicity. Chromium may occur in several oxidation states, the most
common being hexavalent and trivalent. The hexavalent form is more sol-
uble in seawater and more toxic to a wide variety of marine organisms
than trivalent chromium (Mearns and Young, 1977). Marine organisms may
accumulate chromium and other heavy metals by several processes. These.
include direct accumulation, either actively of passively by absorption
and adsorption or indirect accumulation by ingestion of suspended mate-
rial, sediments, and contaminated prey (Alexander et al. 1977).
Laboratory toxicity studies involving drilling muds have
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concentrated primarily on acute responses of adult test organisms to in-
dividual drill mud components (see Table A-l in Appendix). It is now
generally accepted, however, that testing of isolated components of any
complex mixture may be unrealistic. Moreover, few efforts have been
made to relate test conditions such as concentration and exposure time
to field conditions in the discharge area. In addition, laboratory es-
timates of long-term effects of sub-lethal concentrations of drilling
muds on physiological processes and behavioral mechanisms are lacking.
FCLS Toxicity to Corals. Westerhaus (1978) demonstrated that dis-
solved FCLS was toxic to the coral Madracis mirabilis at concentrations
of 50 ppm and 75 ppm within 96 hours of continuous exposure in flow-
through laboratory aquaria. While experimental and individual variabil-
ity were both quite high at these FCLS concentrations, her experiments
suggested that coral respiration and ammonium excretion increased as a
function of FCLS stress. Westerhaus postulated that these parameters of
whole-animal metabolism might provide a readily measurable index of the
relative "health" of corals stressed with drilling fluids.
The purpose of the present study was to expand upon Westerhaus1
work by monitoring the oxygen consumption and ammonium excretion of cor-
als exposed in the laboratory to lower, and presumably sublethal, con-
centrations of FCLS. Rather than testing FCLS independently, a 100 ppm
suspension of drill mud was spiked with serial dilutions of 10 ppm, 3
ppm, and 0 ppm FCLS. These drill mud plus FCLS levels were selected to
simulate loads which corals within 200 meters of the discharge might ex-
perience during an actual drilling operation. Corals were subjected to
17 days of continuous exposure to drill mud plus FCLS regimes to
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contrast differences between short-term (1-7 days) and longer-term
(greater than 2 weeks) responses.
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VII
LIST OF TABLES
Table 1:
Table 2:
Table A-l:
Table A-2:
Table A-3:
Table A-4:
Table A-5:
Table A-6:
Table A-7
Table A-8:
page
Results of the chemical oxygen demand test 15
One and two-way analysis of variance results (days 1-17,
excluding aberrant corals) 22
Results of toxicity studies of drilling mud and individual
components on selected marine organisms 52
Corals used in oxygen consumption/ammonium excretion ex-
periments 54
Average change (x + s.d., n=4) in oxyge" and ammonium con-
centrations in control aquaria (without corals) after a
one-hour measurement period. Prior to each measurement
period, aquaria were flushed with 0.45-um filtered seawater
to remove the drill mud-ferrochrome ngnosulfonate suspen-
sion so that it and natural particulates present in the
aquaria during the normal flow-through mode did not mask
coral metabolism. Positive values denote net production
of oxygen and ammonium, negative values net consumption..55
Raw Data: Weight-specific oxygen consumption of Madracis
decactis (ml 02 9 coral protein hour~l). Values represent
mean + meausred range of twice daily determinations except
on days i, ii, 5, 13, 17, R-l, and R-2 when only single
determinations were made 56
Raw Data: Weight-specific ammonium excretion of Madracis
decactis (ug-at NH| g~l coral protein hour"!). Values
represent mean ± measured range of twice-daily determi-
nations, except on days i, ii, 5, 13, 17, R-l, and R-2
when only single determinations were made 58
Summary of weight-specific oxygen consumption (ml Q^
g~l coral protein hour~l). Values represent the arith-
metic averages of the mean respiration rates of four
corals exposed to each experimental treatment (± stan-
dard deviation, n=4) 60
Summary of weight-specific ammonium excretion (ug-at \\\\\
g'1 coral protein hour"*). Values represent arithmetic
averages of the mean excretion rates of four corals
exposed to each experimental treatment (+ standard
deviation, n=4) 61
0/NH4-N ratio for each drill mud + FCLS regime (X + s.d.).
Values represent the ratio of oxygen atoms consumed to NH4-N
atoms excreted. Three corals which consistently showed
higher than average oxygen consumption and ammonium excre-
tion were deleted from analysis 62
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MATERIALS AND METHODS
Coral Collection and Placement. All experiments were conducted at
Stage-!, a three tiered 100' by TOO1 research platform located 12 miles
offshore from Panama City, -Florida. This offshore laboratory is managed
by the Naval Coastal Systems Center. The laboratory seawater system in-
take at a depth of 29 meters provides oceanic water of 35°/oo.
The scleractinian coral species Madracis decactis was selected as
a test organism since it is one of the most abundant coral species on
Gulf of Mexico hard-bank reefs (Bright and Pequegnat, 1974). Colonies
were collected at 29 meters using SCUBA from the Flower Gardens area of
the Gulf of Mexico, which is the northenmost thriving tropical coral
reef system in this region. This topographic high is situated approxi-
mately 107 nautical miles south of Galveston, Texas on the outer edge of
the continental shelf at 93° 48.5' west longitude and 27° 52.3' north
latitude (see Figure 2).
At the collection site the corals were placed in aerated IGLOO
aquaria for transport to Freeport, Texas. Upon arrival the corals were
transported by car to Panama City, Florida within 24 hours.
On stage the corals were placed on sea tables in the wet lab, where
they were allowed to acclimate for 10 days to salinity, temperature, and'
natural particulate regimes of the Stage-! seawater system. Coral heads
were cleaved to appropriate size and then "groomed" by hand to remove
epiphytic algae, small crabs, and other associated fauna so that these
commensuals would not contribute to subsequent metabolic measurements.
Corals were then placed in flow-through one-liter experimental aquaria
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jo- -
Figure 2. Loutloniot known coral tie'i and lonsiof limljxIcoMl grjwthwilh.n the Gulf o( Moxjco. Al^r $,-ni
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mixed by a magnetic stirrer. I allowed the corals 48 hours to accli-
mate to the circulation regime of the smaller chambers and to recover
from incident handling (Days 1 and 2). All corals appeared healthy
(polyps expanded and actively feeding) within 45 minutes after placement
in the experimental aquaria.
Experimental Design. Sixteen corals were arrayed randomly (using a
random number table) among four series (Table A-2, Appendix). Each se-
ries consisted of five test chambers: four with corals and the one cor-
al-free system control. Corals in series 1 were exposed to raw seawater
uncontaminated with either drilling mud or FCLS. Corals in series 2
were exposed to a 100 ppm suspension of drilling mud collected 3 April
79 from a working drill rig in Mobile Bay, Alabama. Complete chemical
analysis of this drill mud is not yet available, but it was selected for
this series of experiments since it v/as supposed to have a low FCLS con-
centration. Corals in series 3 and 4 were exposed to this 100 ppm drill
mud spiked with 3 ppm and 10 ppm FCLS, respectively. FCLS was obtained
from the Baroid Petroleum Services/NL Industries, Inc., trade nameQ-
Broxin.
The introduction of drill, mud and FCLS was carried out using a Sig-
ma peristaltic pump and a two-channel Milton Roy peristaltic pump res-
pectively (Figure 3). The FCLS was delivered to the drill mud suspen- .
sion at 70° centigrade to approximate down-well conditions. This mix-
ture had cooled to ambient temperature, however, before being introduced
into test aquaria. All peristaltic pumps were calibrated twice daily
during the course of the experiment. FCLS-drill mud stocks were changed
daily to minimize bacterial growth and chemical aging.
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Figure 3. Diagram of the system used in this study.
10
CONSTANT FLOW 1IEAD BOX
n
PUMPED SEAWATER
PERISTALTIC^
i
^
\
70 C
FCLS
100
DRILL XUD
[ MAG - STIfT}
SKRIAL
DILUTIONS OF
DRILLING FLUID
COMPONENTS'
CALIBRATED
S1PHOI1S
>rrxiNG
TUBES
PARTICULAT--7PEE
SEAV/ATZR
SEAWATUa PU1IPED HIOM
29 r.crers
PARTICULATt-FREE
SEAWATER
CALIBRATED SIPTIONS
WITH
CORAL
WITH
CORAL
'..TTHOL-T
CORAL
WITH
CORAL
WITH
CORAL
TEST
AQUARIA
STIF.RLU
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11
Twice daily (noon and 4:00 PM) the flow-through aquaria were shut
down for two-hour monitoring periods. During this time, circulation
within the aquaria was maintained by the magnetic stirrers. Ammonium
excretion was measured by difference between initial and final concen-
trations using a modified Solorzano method (Biggs, 1977) run on site
using a Bausch and Lomb digital spectrophotometer (model 710). For am-
monium analyses, 75 ml of seawater were withdrawn from each aquarium
and filtered through 0.45 urn GFC filters. To minimize contamination
each filter was prerinsed with 25 ml of sample and a new filter was used
to sample each aquarium. The phenol-alcohol reagent was added immediate-
ly to the filtrate and the remaining reagents within two hours of sam-
pling. Color development was carried out in the dark, to avoid photo-
chemical oxidation (Deggobis, 1973). After 5-12 hours, absorbance was
measured in 5 cm cuvettes at 640 nm. New standard curves were con-
structed daily by spiking filtered seawater with 0, 2, 4, and 6 ug-at
NH4C1/liter.
Oxygen consumption was also calculated by difference between ini-
tial and final concentrations determined polarographically using an Or-
bisphere model 2604 multichannel oxygen instrument. The probes were in-
dividually calibrated against water-saturated air between each measure-
ment period to compensate for any drift. At intervals throughout the
experiment, time-course respiration of individual corals was monitored
by connecting probes to a multichannel recorder. As expected, respira-
tion rates were linear throughout the measurement interval and agreed
with oxygen uptake rates calculated by difference.
Prior to each measurement period, suspended particulates were dis-
placed from each test chamber with a 4-5 minute flush of 8-10 liters of
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12
0.45 urn filtered seawater. This minimized extraneous chemical or bio-
logical changes in oxygen and ammonium in the test aquaria and allowed
coral metabolic responses to be isolated for study. Coral metabolic
responses were further isolated by subtracting the appropriate treatment
control aquarium from the individual coral metabolic responses. To con-
firm that this flush displaced the bulk of the 100 ppm drill mud suspen-
sion, particulates remaining in aquaria after the flush were collected
on a 0.45 urn Millipore filter and the flush effectiveness determined by
difference. All surfaces of the experimental aquaria were scrubbed ap-
proximately every four days to control fouling.
Three banks of fluorescent lights were positioned approximately two
feet above the series of test aquaria. Light levels were measured with.
a Nikon light meter and reduced using opaque diffusers to levels char-
acteristic of the Flower Gardens at 30 meters. These fluorescent banks
were automatically timed to turn on and off at 8:00 AM and 8:00 PM, re-
spectively. A black Visqueen hood isolated this study from other experi-
ments being run on the Stage-! sea tables.
After 17 days of exposure to drill mud + FCLS regimes, drill mud -»
FCLS additions were discontinued and the surviving corals allowed 48
hours to recover in uncontaminated seawater (days Rl and R2). Corals
were then weighed, placed in 100 ml of IN NaOH and transported frozen to
College Station, Texas for subsequent protein analysis (Lowry §t al,1951).
All oxygen and ammonium data have been reported on a protein basis to
standardize differences in coral size, morphology, and calcification.
Salinity, temperature, laboratory seawater pH, pH of the drill mud
+ FCLS suspensions, and general weather conditions were monitored daily.
Every night corals were examined, using a dim red-filtered light, for
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13
approximate percentage of polyp expansion, feeding activity, polyp color-
ation, and aberrant behavior (i.e. mesenterial filament extrusion).
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14
RESULTS
Flush of Participates. Trials in which two aquaria containing
flow-through 100 ppm drill mud suspensions were flushed with 0.45 um
filtered seawater prior to closing the systems showed that 8.2+0.3 mg
of particulates remained after a one-minute flush (flush rate 120 liters
hour ). Since the pre-flush concentration of suspended drill mud was
100 mg liter"" , I calculate that such a flush removed 92% of the parti-
culates. In practice, test aquaria were individually flushed for up to
4-5 minutes prior to each measurement interval. Hence, flushing reduced
the concentration of suspended particulates by at least twelve-fold pri-
or to determination of oxygen consumption and ammonium excretion.
Adequacy of Controls. During each two-hour measurement period,
changes in ammonium and oxygen levels in pre-flushed control aquaria
(those without corals) averaged only -0.06 ml 0^ liter' (s.d. = +0.04,
n=80) and 0.01 ug-at NH^1" liter'1 (s.d. = +0.25, n=80). Table A-3 in
the Appendix indicates the mean daily changes in oxygen and ammonium
utilization by these control aquaria. These changes were consistently
low and were uncorrelated with the previous drill mud-FCLS regimes in
all series. A standard test for chemical oxygen demand, using 250 ml
ground glass stoppered bottles, confirmed that there was no significant
COD for any experimental combination of drill mud + FCLS within a three
hour period. Data (following) are expressed as ml 0~ liter (+ mea-
sured range, n=2)r
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15
Table 1. Results of tha chemical oxygen demand test.
Treatment Initial 02 1 Hour Later 3 Hours Later
Filtered SW
100 ppm DM
DM + 3 ppm FCLS
DM + 10 ppm FCLS
Coral Metabolism.
5.6+0.1 5.6+0.1
5.6+0.1 5.6+0.1
5.6+0.1 5.6+0.1
5.6+0.1 5.6+0.1
Arithmetic averages of the mean
5.6+0.1
5.5+0.1
5.4+0.1
5.5+0.1
hourly rates
ammonium excretion and oxygen consumption of the four corals exposed to
j
each experimental regime are illustrated in Figures 4 and 5. In general,
during the first week of the experiment, corals responded to increased
drill mud + FCLS stress by increasing their ammonium excretion and oxygen
consumption. Corals reached their highest average rates of excretion and
respiration by the end of the first week of continuous exposure. Rates
then decreased during the next week, and, after a secondary increase in
excretion and respiration between days 10-13 most pronounced in those
corals exposed to FCLS spikes, leveled off to near-initial rates by the
end of the second week.
Two corals, one exposed to 100 ppm drill mud + 3 ppm FCLS and the
other to 100 ppm drill mud + 10 ppm FCLS, became noticeably moribund as
the experiment entered its second week. These had exhibited the most
rapid and most consistent increases in excretion and respiration during
the first week of exposure to FCLS. By week two, their polyp expansion
was dramatically reduced, and each was removed from the experiment when
areas of bare corallum suggested the onset of polyp death. While all
corals exposed to FCLS reacted by reducing their polyp expansion behav-
ior, only the two cited above showed mass mortality of polyps.
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16
Figure 4. Ammonium Excretion - Arithemetic averages of the mean excre-
tion rates of four corals exposed to each treatment (ug-at
g~l coral protein h~l).
Legend
0 ppm DM
100 ppm DM
100 ppm DM +
3 ppm FCLS
100 ppm DM +
10 ppm FCLS
80
1 2
Day
10 M 12 13 U 15 16 17 Rl R2
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17
Figure 5. Oxygen Consumption - Arithmetic averages of the mean respir-
ation rates of four corals exposed to each treatment.
Expressed as ml Q£ g~* coral protein h~*.
Legend
0 ppm DM
100 ppm DM
100 ppm DM
;u ppm un T
3 ppm FCLS
100 ppm DM +
- 10 ppm FCLS
6.0 _
11 1
Day
7 8 9 10 11- 12 13 14 15 16 17 Rl R2
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18
Experimental and Individual Variability. Oxygen consumption and
ammonium excretion of individual corals v/ere less variable between mea-
surements made twice daily compared with those made on successive days
or between individuals (see Appendix, Figures A-l and A-2, Tables A-4
and A-5). No consistent die! differences were noted between morning and
afternoon measurements although between-individual variability was great-
est at the highest FCLS exposure and least among corals exposed to drill
mud only or to uncontaminated seawater. For instance, ammonium excre-
tion of individual corals exposed to drill mud + 10 ppm FCLS varied by
up to 230 ug-at NH» mg protein hour" , or an order of magnitude great-
er than that of corals in uncontaminated seawater (Table A-5, day 8),
As emphasized in the preceding section, corals exhibited a net in-
crease in oxygen consumption and ammonium excretion during the first week
of the experiment, followed by a net decrease in these parameters during
the next week. Although these trends were most pronounced in the respi-
ration and excretion of corals exposed to the highest drill mud + FCLS
levels, they were also present among corals in uncontaminated seawater.
Moreover, the individual daily increases or decreases in respiration and
excretion rates contributing to these trends were in phase among most of
the experimental animals. For example, 14 out of the 16 corals showed a
sharp decrease in oxygen consumption between days 3-5, which was con-
trary to the overall trend of net increase in respiration during the
first week (Figure A-l). Furthermore, 13 of the 16 showed a temporary
sharp increase in respiration and excretion between days 10-11 before
these parameters declined to near-initial levels by day 14. These
changes in respiration and excretion were not correlated with changes
in temperature, salinity, or pH in the aquaria during the period of our
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19
experiment, which remained effectively constant at 25°+l°C, 35.0+0.5 /oo
and pH of 8.25+0.05, respectively.
It is suggested that this phased variability in respiration and ex-
cretion possibly reflected stochastic changes in ration and/or digestive
efficiency which were superimposed on the corals' metabolic responses to
drill mud + FCLS. For example, food availability in experimental aquaria
depended on its continued presence in the raw seawater pumped from a
depth of 29 meters to a common head tank by the laboratory seawater sys-
tem. It is conceivable that zooplankton and other potential food par-
ticles may have been present near the seawater intake at lower than aver-
age or higher than average densities between days 3-5 and days 10-11, re-
spectively, and so correspond to the unexpected metabolic signatures.
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20
Analysis of variance: Table 1 presents results of a one and two-
way analysis of variance of oxygen consumption and ammonium excretion of
corals through day 17 of this experiment. Corals whose rates of respir-
ation and excretion were aberrant from the others in each series were
excluded from analysis. These included the two corals in FCLS enriched
treatments which subsequently became moribund and were removed prior to
the termination of the experiment and one 'coral uncontaminated by either
drill mud or FCLS. The biomass of this latter coral was 2-3 times great-
er than any of the others (Table A-2), and consistently exhibited aber-
rantly high 0-NH4-N ratios (see discussion).
F values for remaining corals which were calculated for a one-way
analysis of variance indicated that significant variability (p<.0002)
occured among the individual corals in their rates of oxygen consumption
and ammonium excretion within each series, when considered over the 17
day experimental period (Table 1, one-way analysis of variance). Analy-
sis indicated that this between-coral variability was equally significant
over shorter experimental periods (specifically days 1-7, days 8-13, and
days 14-17). Figures A-l and A-2 in the appendix document these indivi-
dual differences in metabolism.
Variability in oxygen consumption and ammonium excretion between
successive days (see DAY, Table 1) was highly significant (p<.0001).
Variability between days accounted for 50% of the total variability with-
in the sums of squares for oxygen consumption and 27% of the total varia-
bility for ammonium excretion. Note from figures A-l and A-2 that in
addition to daily changes in amplitude of metabolism, these changes were
frequently in phase among corals in all series.
A treatment-day interaction was included to assess the interaction
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21
betweem FCLS enrichment and the daily variability in oxygen consumption
and ammonium excretion (see TRT*DAY, Table 1). The interaction of days
and treatments was highly significant for excretion (p<0.001) although
not significant for oxygen consumption (p=0.23). I interpret this to
indicate that any differences in respiration resulting from FCLS enrich-
ment were masked by the observed daily oscilations in oxygen consumption
between treatments. Conversely, the daily oscilations in ammonium excre-
tion between treatments were either of insufficient amplitude to mask
changes resulting from FCLS enrichment or were out-of-phase with the
latter. This hypothesis can be expressed by the following hypothetical
graphs:
c
0
Q.
c. E
> =
X O
O
-------
22
Table 2: One and two-way analysis of variance results (days 1-17,
excluding aberrant corals).
Qne-wav analysis of varianr.p t.n test variability of animals within
treatments.
Series 1:
Series 2:
Series 3:
Series 4:
uncontaminated control (n=3)
oxygen consumption - F = 15.86, pF
TRT
AN(TRT)
DAY
TRT*DAY
ERROR
Dependent
SOURCE
TRT
AN (TRT)
DAY
TRT* DAY
ERROR
3
9
15
45
135
Vari
DF
3
9
15
45
135
13.4582
24.1250
62.0880
13.6876
34.6000
able: Ammonium Excreti
4.48606
2.68056
4.13920
0.30417
0.25629
on
SUMS OF SQUARES MEAN SQUARES
2381.597355
2638.296875
6163.365384
5286.806490
5551.453125
793.85677
293.14409
410.89102
117.48459
41.12188
1.67
10.46
15.99
1.19
F
2.70
7.13
10.86
2.86
0.2420
0.0001*
0.0001*
0.2260
Pr>F
0.1084*
0.0001*
0.0001*
0.0001*
LEGEND: TRT=TREATMENT, AN(TRT)=ANIMALS WITHIN TREATMENTS, DAY=DAYS
1-17, and TRT*DAY=INTERACTION OF TREATMENT AND DAYS.
-------
23
DISCUSSION
Sensitivity of Madracis to FCLS. Thompson and Bright (1977) re-
ported that Madracis mirabilis corals exposed in the laboratory to com-
binations of drill mud and FCLS demonstrated alterations in normal polyp
expansion behavior. Using time-lapse cameras to monitor the percentage
of polyps expanded and searching food, they found that corals exposed to
drill mud suspensions of 1 ppt or greater showed markedly reduced per-
centages of polyps expanded, relative to controls uncontaminated by drill
mud. Corals were more sensitive to FCLS than to drill mud. Those ex-
posed to dissolved FCLS levels of 100 ppm died within five days, which
suggested that these animals were more sensitive to FCLS than the other
marine organisms examined to date (see Table A-l, Appendix)^
Thompson (1977) also reported that M_. mirabilis survived 29 days of
continuous exposure to 100 ppm drill mud and to 10 ppm dissolved FCLS,
but while drill mud at these concentrations had no visible behavioral
effects, all corals exposed to 10 ppm FCLS showed curtailed polyp expan-
sion.
To determine whether coral behavioral changes might have measurable
metabolic analogs, Westerhaus (1978) monitored oxygen consumption and
ammonium excretion of M_. mirabilis corals subjected to four series of
dissolved FCLS (75, 50, 10, and 0 ppm) added to raw seawater in flow-
through aquaria at Stage-! (field season 1977). She reported that oxy-
gen consumption for FCLS-stressed corals, relative to corals in uncon-
taminated seawater, increased daily throughout the first three days of
exposure but decreased on the fourth day. All corals exposed to 50 and
-------
24
75 ppm FCLS died by the fourth day of exposure, and one of the two ex-
posed to 10 ppm FCLS died after the seventh day.
Westerhaus1 data were characterized by extremely high variance,
relative to calculated mean levels of oxygen consumption and ammonium
excretion. Accordingly, when tested by analysis of variance (Steele
and Torrio, 1960), no differences significant at the 0.05 level could be
demonstrated among the four series, days of run, or the cross product of
series and days. Since Westerhaus did not flush her aquaria prior to
shutting them down for determination of oxygen consumption and ammonium
excretion, it is likely that natural particulates in suspension (such as
bacteria, phytoplankton, detritus, and microzooplankton) and their build-
up on aquarium walls masked coral respiration and excretion. In fact,
changes in oxygen and ammonium in "control" aquaria (without corals)
were frequently of the same magnitude or higher than those in experimen-
tal aquaria. When these "control" activities were subtracted, net uptake
of ammonium was indicated in some of Westerhaus1 experimental series.
To reduce changes in oxygen and ammonium in control aquaria, aquaria
were redesigned for the present study to allow particulates to be flushed
efficiently and to permit aquarium surfaces to be scrubbed to remove
drill mud buildup and/or algal growth. The number of experimental repli-
cates in each series was also increased from two corals to four to allow
a more effective comparison between the variation in individual coral
response with differences in response between series.
Not unexpectedly, M_. decactis showed sensitivity to drill mud +
FCLS similar to that reported by Westerhaus for M_. mirabilis, since the
two are congeneric species. Day-to-day increases in oxygen consumption
which Westerhaus reported for M_. mirabilis exposed to the highest FCLS
-------
25
concentrations, followed by a sharp decrease to near-initial values,
were demonstrated by M_. decactis. Since the former species was exposed
to higher levels of FCLS than those corals employed in the present study,
the increase-decrease trend was compressed into four days for M_. mira-
bilis compared to 14 days for M_. decactis.
The higher polyp mortality recorded by Westerhaus, relative to that
found in this study, may indicate: 1) the greater toxicity of dissolved
FCLS, relative to FCLS added in conjunction with drill mud, 2) stress of
accumulation of drill mud on corals when not flushed twice daily, or 3)
interspecific differences in tolerance between M_. mirabilis and M_. decac-
tis.
The present study failed to confirm the apparent ammonium uptake
reported by Westerhaus. As suggested earlier in this report, failure to
flush the natural particulates from Westerhaus1 aquaria undoubtedly con-
tributed to her apparent ammonium fluxes. Alternatively, ammonium re-
lease by the corals may have potentiated growth of an algal fouling
community which then scavenged ammonium produced by the corals. Since
nitrogen is frequently the nutrient in shortest supply in the marine en-
vironment (Ryther and Dunston, 1971), this nutrient is generally the lim-
iting factor to marine algal growth. McCarthy^ al. (1977) have demon-
strated that many marine algae take up ammonium as a preferred nitrogen
source, even at relatively low concentrations of NH.+. In the present
study, I noted that fouling proceeded most rapidly in aquaria subjected
to the highest FCLS concentrations, where aquarium surfaces had to be
scrubbed approximately every three days.
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26
Acclimation of Madracis to FCLS. Corals in the present study
responded to increased FCLS stress by increasing their oxygen consump-
tion and ammonium excretion, compared to corals in uncontaminated sea-
water. After two weeks, respiration and excretion rates declined to
near-initial levels. Although respiration and excretion rates in corals
exposed to FCLS apparently returned to near-initial levels after day 14,
in these corals polyp expansion was markedly aberrant. Photographic
documentation (see pictures in Appendix) of FCLS stressed corals re-
vealed that increasing FCLS enrichment caused: 1) reduction in number of
polyps expanded (i.e., little or no active feeding during either day or
night), 2) extrusion of zooxanthellae (resulting in a banded coloration
of the coral colony), 3) bacterial infections with subsequent algal over-
growths, and 4) large-scale polyp mortality in two of the colonies. In
contrast, corals in uncontaminated seawater or those exposed to drill
mud not enriched with FCLS actively fed and appeared "healthy" through-
out the course of the experiment. Healthy Madracis polyps expanded up
to 1 cm and exhibited tentacular "concerts" individually during the day
and colonially at night.
During the recovery period (days Rl and R2), coral behavior improved
dramatically within one day after drill mud + FCLS stress was discontin-
ued. Except where tissue regression had progressed to bare ccrallum,
activity in surviving corals increased so that near-initial percentages
of polyps were expanded and actively feeding on day R2. This suggests
that corals which survived exposure to FCLS were not moribund or meta-
bolically exhausted, but could recover rapidly when stress was discon-
tinued.
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27
Sensitivity of Related Species to FCLS. During the 1978 summer
field season at Stage-!, comparative studies of drill mud + FCLS stress
were conducted using another scleractinian coral, Oculina diffusa.
Thompson had previously recorded a 96-hour LD (acute static bioassay)
of approximately 12,000 ppm for FCLS. In contrast to Madracis, Oculina
showed no reductions in polyp expansion when exposed to 10, 25, and 50
ppm dissolved FCLS (Thompson and Krone, unpublished).
The differences in sensitivity between Madracis and Oculina corre-
late with the temperature tolerance ranges which each species exhibits.
Madracis has a rather restricted temperature range of 11-27 C (Vaughan
and Wells, 1943), whereas Qculina is more eurythermal (Thompson, person-
al communication). Ocu-lina colonizes habitats ranging from shallow,
nearshore jetties to the legs of offshore drilling platforms (including
Stage-!) to deep water. Madracis has a more restricted geographic range
than Oculina and seems restricted by the photosynthetic needs of its zoo-
xanthellae to shallow reefs (Oculina has proportionally fev/er zooxan-
thellae).
In general, tolerance ranges are influenced by the previous envi-
ronmental history, age, sex, and reproductive status of an organism.
When an animal approaches an environmental tolerance limit, homeostatic
mechanisms must expend energy to maintain equilibrium. In general, ex-
posure to near-threshold levels of one environmental parameter may de-
crease an organism's tolerance to another variable. The wider tolerance
range which Oculina exhibits might thus allow it to be less susceptible
than Madracis to xenobiotic stress (specifically, to stress induced by
FCLS).
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28
Corals and Zpoxanthcllae. Zoo/anthellae arc photcsynthctic unicel-
lular algae of the order Dinoflagel 1 Ida which live endosymbictically in
the tissues of about 150 genera of invertebrates comprising eight phyla
(Droop, 1963). Zooxanthellae are found in all hermatypic (reef-building)
corals and many ahermatypic corals. They maintain a symbiotic relati i-
ship intracellularly in the gastrcdermal cells of the host (Smith ej: aj_.,
1969).
As endesymbionts, zcoxanthellae have an immediate access to a source
of carbon dioxide, they gain protection, and they may utilize crganics
and ir.org-nics from their hosts for protein sources. Mclaughlin and
Ziihl (1959) have found that zooxanthellae may'utilize phosphate, phos-
phoric acid, nitrate, urea, uric acid, as well as guanine, adeninc, and
other ami no acids generated by the host.
The hosts benefit as well from this symbiotic relationship. Corals
may utilize photosyntate products produced by the algae and translocated
to the coral host.(Muscatine and Porter, 1977) and inorganic growth
rates may be enhanced as well (Goreau and Goreau, 1959, 1951; Sirnkiss,
1954; Yamazato, 1966).
The symbiosis between Madracis decactis and its zooxnnthellae de-
termined thn magnitude and direction of the net fluxes of oxygen and am-
monium measured in my experiments. Inasmuch as I did not separate these
endosymbiotic algae from their coral hosts, the ability of the zooxan-
thellae to take up NH* excreted by the corals coupled with possible dif-
ferences in this uptake between stressed and ur.strec.sed zooxanthellae
and probably extrusion of zooxanthellae by corals exhibiting banded col-
oration, all apparently contributed to variability in the metabolic
parameters which were- monitored in this study.
-------
29
O/NH.-N Ratios. A summary statistic which relates the number of
oxygen atoms consumed to the number of nitrogen atoms excreted is a use-
ful index of cellular metabolism (Harris, 1959). Because most aquatic
invertebrates excrete ammonium as the principal end product of protein
metabolism (Schmidt-Nielson, 1975), the whole-organism 0/NH^-N ratio is
conveniently measured to approximate the general level of this cellular
metabolism.
Since many marine invertebrates have low carbohydrate and lipid re-
serves, an increase in ammonium excretion should signal the transition
from carbohydrate and lipid metabolism to catabolism of dietary or tis-
sue protein. Accordingly, normal feeding-digestion cycles as well as
stress may induce elevated ammonium excretion (Gates and Mclaughlin,
1976). A biochemical pathway which incorporates ammonium excretion in
invertebrates coupled to ATP production has been suggested by Pandian
(1975).
L-amino acid <*-Ketoglutarate ,/NH0 /?'NADH\ ADP+P.
'
Transaminai-inn Glutamate Cytochrome system
iransamynaTnon dehydrogenase (oxidative phosphorylation)
CT-keto acid L-glutamate'
NADP'
The 0/NH^-N ratio, by atoms, for most marine invertebrates ranges
from about 7 to 24 (Harris, 1959; Conover and Corner, 1968; Ikeda, 1974,
1977; Reeve _et_aj., 1977; Biggs, 1977). For example, protein averages
16% nitrogen and requires 1.04 liters of oxygen for the complete combus-
tion of 1 gram. If all the nitrogen is deaminated to ammonia, protein
catabolism would be reflected by an 0/NH4-N ratio of about 6.8 (Ikeda,
-------
30
1977). Oxidation of compounds low in nitrogen, like lipid or carbohy-
drate, would be reflected in a very high ratio (i.e. greater than 100).
Oxidation of equivalent weights of protein and lipid requires 2.02 liters
of oxygen for the complete combustion of 1 gram and yields an O/NH.-N
ratio of about 24 (Ikeda, 1974). Since few biochemical substrates have
more than 16% nitrogen, O/NH^-N ratios lower than 6.8 are generally in-
terpreted as a breakdown of normal catabolism or excessive leakage of
nitrogenous compounds (Biggs, 1977).
The coral with the consistently highest 0/NH4~N ratio also had the
highest biomass (Table A-2 in the Appendix). This coral had approximate-
ly three times as much protein as other test corals in this experiment.
Since experimental bias may have arisen due to the large size of this
coral with respect to the one-liter experimental chamber, it was ex-
cluded from 0/NH»-N calculations and from analysis of variance of the
oxygen consumption and ammonium excretion data (see page 20). Corals
which subsequently became moribund were also excluded from O/NH.-N com-
putations and analysis of variance.
O/NH.-N ratios for Madracis decactis in this study are generally in
accord with those reported for marine invertebrates (Table A-8 and Fig-
ure A-3 in the Appendix) and suggest the predominance of protein cata-
bolism. Ratios less than the theoretical minimum of 6.8 were posted by
corals at intervals throughout the experiment (most notably during days
10-14) but were not restricted to FCLS enrichment. As a consequence of
the phased changes in oxygen consumption and ammonium excretion (see
page 18) 0/NH4-N ratios also fluctuated in phase.
Corals not exposed to drill mud or FCLS showed 0/NH4-N ratios (x +
s.d.) of 13.3+4.2 through the first week of the experiment, with those
-------
31
exposed to drill mud or FCLS posting comparable ratios (17.5±6.6).
0/NH4-N ratios for all corals decreased between days 8-12, followed by a
return to initial values after day 15. The low 0/NH4-N ratios between
days 8-12 shown by corals in all series suggest that corals might have
been leaking nitrogen. Such a situation might have resulted from the
presence of lower than average food concentrations at this period in the
Stage-1 flow-through seawater system.
Many coral species exhibit a recycling mechanism between the coral
host and its endosymbiotic algae as a means of conser /ing nitrogenous
nutrients (Lewis, 1973; Pomeroy et_ aj_., 1974; Muscatine and Porter,
1977). Recent work by Muscatine and D'Elia (1978) suggest that corals
with symbiotic algae take up and retain ammonium when presented with
normal die! light regimes. Their work suggests that uptake and reten-
tion of ammonium is enhanced by light and that exposure to several hours
of daylight is sufficient to maintain net ammonium uptake by coral zoo-
xanthellae throughout the night. Since uptake of ammonium by coral zoo-
xanthellae would decrease net NHt excretion and increase coral O/NH^-N
ratios, activity of zooxanthellae might cause the magnitude of tissue
protein catabolism to be underestimated. Figure A-5 indicates that the
O/NH/pN ratios of corals exposed to 10 ppm FCLS were in fact higher and
more variable than those of other corals throughout most of the experi-
ment.
If photosynthesis exceeds photorespiration, there should be a net
increase in the 0/NH4-N ratios. Net photosynthetic activity by zooxan-
thellae will produce available oxygen, increasing the O/Nfy-N ratio:
C02 + 2 HOH-^ CH20 + HOH + 02 (l)
-------
32
while net photorespiration will consume oxygen and release NH* (Keys jet
aJL , 1978), decreasing the O/NH.-N ratio:
2 GLYCINE + HOH SERINE + C02 + NH3 + 2 H+ + 2 e" (2)
Ecological Implications. Corals provide an extensive (15% of the
shallow sea floor within the 0-30 meter depth range) and important ter-
tiary substrate which houses and maintains'complex, highly productive
biocoenoces in areas often surrounded by oligotrophic water (Goreau,
1961; Johannes, 1976; Smith, 1978). Reef systems generate and trap par-
ticulate organic carbon, nitrogen-rich "floes", and ammonium (Coles and
Stratham, 1973; Muscatine and D'Elia, 1978; Smith and Marsh, 1973).
Experiments by Thompson and Bright (1977) demonstrated that corals
were unable to remove loads of drilling mud when these exceeded about 1
ppt. If mud cannot be removed, the polyps eventually suffocate and die
or are overgrown by opportunistic algae. The type of animals that set-
tle and grow in a particular locality appears to be based upon the physi-
cal composition and organic content of the sediment (Thorson, 1957).
Since bare coral rock is a preferred substrate for the settlement of cor-
al planulae, if such areas become sediment covered or overgrown they are
no longer suitable settlement areas for the planulae (Mileikovsky, 1970,
1971; Thorson, 1966). In addition, expansion of existing colonies may
be hampered by surrounding sediment (Dodge, R. E., 1974). Changes in
the composition and relative abundance of settling organisms in the cor-
al reef system could alter interactions among resident animals and in-
terrupt community stability and efficiency, characteristic of the coral
reef system.
-------
33
Corals must produce mucus in order to remove loads of drill mud;
accordingly, elaboration of mucus is a energetic loss to the colony.
Moreover, corals may experience "nematocyst fatigue" if individual nema-
tocysts fire in response to particles in seawater, or during the regur-
gitation of mud ingested by the corals.
Although polyps may be expanded both day and night, our observa-
tions indicate that M_. decactis increased its feeding activity at night
(increased individual and colonial tentacular concerts). Recent field
work suggests that such increases in feeding activity are in phase with
nocturnal migrations of zooplankton which by day dwell in cavities with-
in the reef (Porter and Porter, 1977). Accordingly, although Gulf of
Mexico drilling platforms generally work around-the-clock when produc-
tion is in progress, if drilling discharges were not pumped into the im-
mediate vicinity of coral reefs at night, the corals might recover quick-
ly enough from the stress of daytime sedimentation loads to benefit from
the availability of greater-than-average food concentrations at night.
The two corals which exhibited the most rapid and most consistent
increases in excretion and respiration during the first week of exposure
to FCLS appeared to be infected with a white mucus sheath of bacteria.
A hydrogen sulfide odor was also noted during the regular sampling of
these subsequently moribund corals. The strict anaerobic bacteria of the
genus Desulfovibrio reduces sulfate to hydrogen sulfide which is a po-
tent toxin to most aerobic organisms (J0rgensen, 1977). Since such bac-
teria are common to the marine environment (Zobell and Rittenberg, 1948;
Fenchel and Reidl, 1970; J0rgensen, 1977), the odor of hydrogen sulfide
is speculated as evidence as to the character of the observed infection.
I suggest that the accumulation of drill mud on the bare coral rock
-------
34
or interstitial spaces between colonies may have created a micro-environ-
ment conducive to Desulfovibrio growth. Bacterial growth could have been
potentiated by the presence of mucus elaborated to remove drill mud.
Alternative Measures of Physiological Stress. Levels of internal
amino acid pools and activities of enzymes which regulate -itrogen meta-
bolism may serve as indices of physiological stress which could supple-
ment the "whole animal" responses measured in the present study. Since
most marine invertebrates have minimal carbohydrate and lipid reserves
(Schmidt-Nielson, 1975), internal amino acid pools and/or body proteins
are rapidly catabolized to combat stress. Ammonium excretion serves as
an indirect indicator of this process, since NH, is the most common ex-
cretory product of such catabolism.
Glutamate dehydrogenase (GDH) is believed to be a key regulatory
enzyme involved in intracellular deaminations (Pandian, 1975). Accord-
ingly, increases in GDH activity should correlate with stress responses
in invertebrates. If the composition and concentration of cellular free
amino acid pools changes as a result of GDH activity, this may also serve
as a useful index of stress. Both GDH and total amino acid analysis are
independent of the availability of living animals and may be run on tis-
sue collected in the field and kept frozen in liquid nitrogen until sub-
sequent laboratory analysis.
Conclusions. The efficiency of FCLS as a thinning agent has been
documented in the introduction to this report. However, I suggest that
if economically feasible, it would be ecologically advantageous to sub-
stitute a thinning agent less toxic than FCLS into drilling muds. Alter-
natively, other less toxic metals might be substituted for the chromium
-------
35
in FCLS. In the debate of over-regulation versus laissez-faire regula-
tory policies for offshore oil and gas resource production and develop-
ment, such cost-benefit considerations may have far-reaching impacts.
-------
36
REFERENCES
Adler, S. F., and F. H. Siegele. 1966. Encyclopedia of polymer sci-
ence and technology. John Wiley and Sons, Inc., New York. V. 5,
p. 140.
Alexander, J. E., T. T. White, K. E. Turgeon, and A. W. Blizzrd. 1977.
Rig monitoring. (Assessment of the environmental impact of explor-
atory oil drilling). Volume VI. Baseline monitoring studies,
MAFLA, DCS. Final report to the U.S. Dept. of Interior, Bureau of
Land Management Outer Continental Shelf Office, Washington, D.C.
American Petroleum Institute. 1978. Oil and gas well drilling fluid
chemicals. Bull. 13F: 1-9.
Antonius, A. 1977. Coral mortality in reefs: a problem for science
and management: in Proc., 3rd Int'l Coral Reef Symposium, Miami,
Fla., V. 2, Geology, p. 617-623.
Biggs, D. C. 1977. Respiration and ammonium excretion by open ocean
gelatinous zooplankton. Limnol. Oceanogr. 22: 108-117.
Bright, T. J., and L. H. Pequegnat. 1974. Biota of the West Flower
Garden Bank. Gulf Publishing Company.
Bright, T. J., and R. Rezak. 1978a. Northwestern Gulf of Mexico topo-
graphic features study. Final report to the U.S. Dept. of Interior,
Bureau of Land Management Outer Continental Shelf Office, New Or-
leans, Louisiana.
and . 1978b. South Texas topographic features
study. Final report to the U.S. Dept. of Interior, Bureau of Land
Management Outer Continental Shelf Office, New Orleans, Louisiana.
Bright, T. J., R. Rezak, A. H. Bouma, W. R. Bryant, and W. E. Pequegnat.
1976. A biological and geological reconnaissance of selected topo-
graphical features on the Texas continental shelf. Final report to
the U.S. Dept. of Interior, Bureau of Land Management Outer Contin-
ental Shelf Office, New Orleans, Louisiana.
Bureau of Land Management. 1976. Final environmental statement, pro-
posed 1976 Outer Continental Shelf oil and gas general lease sale,
Gulf of Mexico, DCS sale no. 41. Prepared by the U.S. Dept. of
Interior, Bureau of Land Management.
Gates, N., and J. J. McLaughlin. 1976. Differences of ammonia meta-
bolism in symbiotic and aposymbiotic Condylactus and Cassiopeia
spp. J. Exp. Mar. Biol. Ecol. 21: 1-5.
-------
37
Coles, T., and Strathmann, N. 1973. Observations on coral mucus "floes"
and their potential trophic significance. Limnol. Oceanogr. 18:
673-678.
Conover, R. J., and E. D. Corner. 1968. Respiration and nitrogen excre-
tion by some marine zooplankton in relation to their life cycles.
J. Mar. Biol. Assoc. U.K. 48: 49-75.
Continental Shelf Associates. Inc. 1978. Monitoring program for plat-
form "A", lease OCS-G 3061 block A-85, Mustang Island .vea east
addition, near Baker Bank. A report for Continental Oil Company.
Third quarterly report, V. I, II.
. 1979. Monitoring program for platform "A",
3061 block A-85, Mustang Island area east addition,
Third quarterly report, V. I, II.
lease OCS-G
near Baker Bank.
Dames, J., and Moore, B. 1978. Drilling fluid dispersion and biological
effects study for the Lower Cook Inlet C.O.S.T. well. A report
t for Atlantic Richfield Company.
Degobbis, D. 1973. On the storage of seawater samples for ammonia de-
termination. Limnol. Oceanogr. 18: 146-150.
Dodge, R.E. 1974. Coral growth related to resuspension of bottom sed-
iments. Nature 247: 574-577.
Droop, M. 1963. Algae and invertebrates
Microbiol. 13: 171-199.
in symbiosis. Symp. Soc. Gen.
Ecomar, Inc. 1978. Tanner Bank mud and cuttings study. A report for
Shell Oil Company. Shell Number One Plaza, Houston, Texas.
EG&G, Environmental Consultants. 1976. Compliance with ocean dumping
final regulations and criteria of proposed discharges from explora-
tory drilling rigs on the Mid-Atlantic outer continental shelf. A
report for Shell Oil Company. Houston, Texas.
Fenchel, T. M., and R. J. Riedl. 1970. The sulfide system: a new bio-
tic community underneath the oxidized layer of marine sand bottoms.
Marine Biology 7: 255-268.
Goreau, T. F. 1959. The physiology of skeleton formation in corals. 1,
A method for measuring the rate of calcium deposition by corals un-
der different conditions. Biol. Bull. (Wood's Hole), Vol. 116, pp.
59-75.
Goreau, T. F.
corals.
1961. Problems of growth and calcium deposition in reef
Endeavour 20: 32-39.
Goreau, T. F., N. I. Goreau, and C. M. Yonge. 1971. Reef corals: Auto-
trophs or heterotrophs. Biol. Bull., Vol. 141, pp. 247-260.
-------
38
Harris, E. 1959. The nitrogen cycle in Long Island Sound. Bull. Bing-
ham Oceanogr. Collect. 17: 30-65.
Holland, J. S. 1977. Invertebrate epifauna and macroinfauna. In: En-
vironmental Studies, South Texas Outer Continental Shelf, Biology
and Chemistry, final report to the U.S. Dept. of Interior, Bureau
of Land Management Outer Continental Shelf Office, Washington, D.C.
Ikeda, T. 1972. Chemical composition and nutrition of zooplankton in
the Bering Sea. In A. Y. Tadenouti et al. (ed.;, Biological Ocean-
ography of the Northern North Pacific Ocean. Hokkaido University.
1974. Nutritional ecology of marine zooplankton. Mem. Fac.
Fish. Hokkaido Univ. 22: 1-97.
1977. The effect of laboratory conditions on the extrapo-
lation of experimental measurements to the ecology of marine zoo-
plankton. Mar. Biol. 41: 241-252.
Imhoff, and Truper. 1976. Marine sponges as habitats of anaerobic pho-
totrophic bacteria. Microbial Ecology 3: 1-9.
J0rgensen, B. B. 1977. Bacterial sulfate reduction within reduced mi-
croniches of oxidized marine sediments. Mar. Biol. 41: 7-17.
Kelly, J. 1964. Ferrochrome Lignosulfonate. Oil and Gas Journal. 62:112
Keys, A.J. 1978. Photorespiratory nitrogen cycle. Nature (volume 275).
26 October 1978.
Knox, F. 1978. The behavior of FCLS in natural waters. Masters thesis,
Massachusetts Institute of Technology.
Land, B. 1974. The toxicity of drilling fluid components to aquatic
biological systems, a literature review. Dept. of the Environment,
Fisheries and Marine Service, Research and Development Directorate.
Technical Report no. 487.
Lee, R.F. 1977. Metabolism of hydrocarbons in marine invertebrates:
aryl hydrocarbon hydroylase from tissues of the blue crab, Calli-
nectes saoidus and the polychaete worm, Nereis sp. pp. 111-124 in
C.S. Giam (ed.), Pollutant Effects on Marine Organisms, Lexington,
Mass.: D. C. Heath and Company.
Lewis, D. H. 1973. The relevance of symbiosis to taxonomy and ecology,
with particular reference to mutualistic symbiosis and the exploi-
tation of marginal habitats. In V. H. Heywood (ed.). Taxonomy and
Ecology. Stst. Assoc. Lond. Spec. V. 5. Academic, p. 151-172.
L'owry, O.H., Rosebrough, N.J., Farr, A.L., and Randell, R.J. 1951. Pro-
tein measurement with the Folin Phenol reagent. J. Biol. Chem.
193: 265-275.
-------
39
McAuliffe, C. D., and L. L. Palmer. 1976. Environmental aspects of off-
shore disposal of drilling fluids and cuttings. Society of Petro-
leum Engineers of AIME.
McCarthy, J.J. 1977. Nitrogenous nutrition of the phytoplankton in
the Chesapeake Bay. I. Nutrient availability and phytoplankton
preferences. Limnol. Oceanogr. 22: 996-1011.
Mclaughlin, J. J., and P. A. Zahl. 1959. Axenic zooxanthellae from
various invertebrate hosts. Ann. N.Y.. Acad. Sci. 77: 55-72.
Mearns, A. J., and D. R. Young. 1977. Chromium in the southern Cali-
fornia marine environment. C. S. Giam (ed.), Pollutant Effects on
Marine Organisms, Lexington, Mass.: D. C. Heath and Company, p.
125-14?.
Mileikovsky, S. A. 1970. The influence of pollution on pelagic larvae
of bottom invertebrates in marine nearshore and estuarine waters.
Mar. Biol. 6: 350-356.
1971. Types of larval development in marine bottom inver-
tebrates, their distribution and ecological significance: A re-
evaluation. Mar. Biol. 10: 193-213.
Miller, K. D. 1976. A case study of special biological requirements,
Mustang Island block A-16, lease OCS-G 3011, well no. 1. A report
by Cities Service Company.
Monaghan, P. H., C. D. McAuliffe, and F. T. Weiss. 1976. Environmental
aspects of drilling muds and cuttings from oil and gas extraction
operations in offshore and coastal waters. Sheen Technical Sub-
committee, Offshore Operations Committee.
Muscatine, L., and C. F. D'Elia. 1978. The uptake, retention, and re-
lease of ammonium by reef corals. Limnol. Oceanogr. 23(4): 725-734.
Muscatine, L., and J. W. Porter. 1977. Reef corals: Mutualistic symbi-
osis adapted to nutrient-poor environments. Bioscience 27: 454-460.
Offshore Operators Committee. 1978. Comments on U.S. Environmental
Protection Agency Draft Document, "Permit conditions for NPDES per-
mits at the Flower Garden reefs, Gulf of Mexico, outer continental
shelf - August, 1978." Submitted to U.S. EPA region VI.
Otteman, L. G; 1976. Letter comment to U.S. Dept. of Interior, BLM,
New Orleans, La. regarding OCS sale no. 44, offshore central and
western Gulf of Mexico. From Shell Oil Company.
Pandian, T. J. 1975. Mechanisms of heterotrophy. In: 0. Kinne (ed.),
Marine Ecology, Vol. II, Physiological Mechanisms, John Wiley and
Sons, 449 pages.
-------
40
Payne, J. F. 1977. MFO in marine organisms in relation to petroleum
hydrocarbon metabolism and detection. Mar. Pollut. Bull. 8: 112-
114.
Pequegnat, W. E. 1977. Meiofauna project. In: Environmental studies,
South Texas Outer Continental Shelf, Biology and Chemistry, R. D.
Groover, (ed.), Final report to the U.S. Dept. of Interior, BLM
Outer Continental Shelf Office, Washington, D.C. p. 10-14.
Pomeroy, L. R., M. R. Pilson, and W. J. Wiebe. 1974. Tracer'studies of
exchange of phosphorus between reef water and organisms on the
windward reef of Eniwetok Atoll. Proc. Int. Coral Reef Symp. (2nd),
V. 1, p. 87-96.
Porter, J. W., and K. G. Porter. 1977. Quantitative sampling of demer-
sal plankton migrating from different coral reef substrates. Lim-
nol. Oceanogr. 22: 553-556.
Presley, B. J. and P. N. Boothe. 1977. Trace metals in epifauna. In:
Environmental Studies, South Texas Outer Continental Shelf, Biology
and Chemistry, R. D. Groover, (ed.). Final report to the U.S. Dept.
of Interior, BLM Outer Continental Shelf Office, Washington, D.C.
p. 14-21.
Ray, J. P., and E. A. Shinn. 1975. Environmental effects of drilling
muds and cuttings. In: Proceedings of conferences on environmen-
tal aspects of chemical use in well-drilling operations. EPA,
Houston, Texas.
Reeve, M.R. 1977. Evaluation of potential indicators of sublethal toxic
stress on marine qooplankton (feeding, fecundity, respiration, and
excretion): Controlled ecosystem pollution experiment. Bulletin
of Marine Science 27.
Ryther, J. H., and W. H. Dunstan. 1971. Nitrogen, phosphorus and eu-
trophication in the coastal marine environment. Science 171: 1008-
1013.
Schmidt-Nielson. 1975. Animal Physiology. Cambridge University Press.
Simkiss, K. 1964a. Possible effects of zooxanthellae on coral growth.
Experientia 20: 140.
. I964b. Phosphates as crystal poisons of calcification.
Biol. Rev. 39: 487-505.
Skelly, W. G., and D. E. Dieball. 1970. Soc. Petrol. Eng. J. 140: June
10, 1970.
Smith, D.C., and Marsh, N. 1973. Organic carbon production on the wind-
ward reef flat of Eniwetok Atoll. Limnol. Oceanogr. 18: 953-961.
Smith, D. C., L. Muscatine, and D. H. Lewis. 1969. Carbohydrate move-
-------
41
ment from autotrophs to heterotrophs in parasitic and. mutualistic
symbiosis. Biol. Rev. Cambridge Phil. Soc. 44: 17-90.
Smith, S. V. 1978. Coral-reef area and the contributions of reefs to
processes and resources of the world's oceans. Nature 273: 225-
226.
Solorzano, L. 1969. Determination of ammonia in natural waters by the
phenolhypochlorite method. Limnol. Oceanogr. 14: 779-801.
Steel, R. G. D., and J. H. Tbrrie. 1960. Principals and procedures of
statistics. McGraw-Hill, New York. .
Tagatz, M. E., and M. Tobia. 1978a. Effects of barite in development of
estuarine communities. Est. and Coast. Mar. Sci. 7: 401-407.
1978b. Effects of Dowicide G-ST on development of experi-
mental estuarine macrobenthic communities. In: Pentachlophenol,
K. R. Rao (ed.), Plenum Publ. Corp, p. 157-163-
Thompson, J. H. 1977. Effects of drilling mud on seven species of reef-
building corals as measured in field and laboratory. Work funded
by U.S. Geological Survey Conservation Division.
Thompson, J.H. 1977. Effects of drilling mud on seven sepcies of reef-
building corals as measured in field and laboratory. Report to
the U.S. Dept. of Interior, Bureau of Land Management Outer Cont-
inental Shelf Office, New Orleans, Louisiana.
Thompson, J.H. 1978. Responses of a hermatypic coral to a drilling
mud and Q-Broxin. Report to the EPA Gulf Breeze Environmental
Laboratory. Gulf Breeze, Florida.
Thorson, G. 1950. Reproduction and larval ecology of marine bottom in-
vertebrates. Biol. Rev. 25: 1-45.
Vaughan, T. W., and T. W. Wells. 1943. Revision of the suborders, fam-
ilies and genera of the scleratinia. Geol. Coc. Am. special papers
no. 44.
Westerhaus, M. 1978. Lethal responses of the coral species Madracis
decactis exposed to ferrochrome lignosulfonate. Masters thesis,
Texas A&M University.
Yamazato, K. 1966. Ph.D. dissertation, University of Hawaii, Honolulu.
Zingula, R. P. 1975. Effects of drilling operations on the marine en-
vironment. In: Conference Proceedings on Environmental Aspects of
Chemical Use in Well-Drilling Operations. EPA-560/1-75-004. p. 433-
Zobell, C. E., and S. E. Rittenberg. 1948. Sulfate reducing bacteria
in marine sediments. J. mar. Res. 7: 602-617.
-------
42
APPENDICES
Photographs of experimental aquaria, healthy and stressed corals.
Table A-l: Literature survey of toxicity studies of drilling mud
and individual componts on selected marine organisms.
Tab" = A-2: Corals used in oxygen consumption/ammonium excretion
experiments.
Table A-3: Average change in oxygen and ammonium concentrations
in control aquaria after a one-hour measurement period.
Tables A-4 through A-7: Raw data - tables pertaining to the individual
oxygen consumption and ammonium excretion of Madracis
decactis, this study.
Table A-8: 0/NH4-N ratio for each drill mud + FCLS regime.
Figures A-l through A-3: Raw data - figures pertaining to the in-
dividual oxygen consumption, ammonium excretion, and
0/NH^-N ratios of Madracis decactis, this study.
-------
Experimental aquaria on the Stage-1 seawater tables-
43
-------
44
1: corals in uncontaminated seawater- (note the degree of polyp
expansion and the erect tentacles)
acclimation to smaller chambers-
irst day of experiment-
-------
45
Series 1 continued:
after two weeks-
recovery period-
-------
46
2: corals In ICO ppm drill mud- (note differences in polyp
expansion, coloration, and apparent recovery)
acclimation to smaller chambers-
first day of experiment-
-------
s 2 continued:
after tv/o woeks-
recovery pariod-
-------
48
Series 3: corals exposed to 100 ppm dril"! mud + 3 ppm FCLS- (note the
lack of tentacular activity, bacterial infection, and
tissue regression)
acclimation to smaller chambers-
first day of experiment-
-------
49
3 continued:
after cne week (note the bacterial irifection)-
subsecuent tissue regression where bacterial
infection had occured-
-------
50
Series 4: corals in 100 ppm drill mud + 10 nprn FCLS- (note the increas-
ing degree of tissue regression)
acclimation to smaller chambers-
first day of experiment-
-------
Table A-l. Results of to::lctty studios of drilling cud and individual cotnpiinentn on selected carine organises.
MATERTAL TESTED
ORGANISM
RESULT ac50-96 hour)
Xcr.aSh".ir. (1977)
Daiats/X'jore
(197B)
ECf,G (1976)
FCLS
FCLS
drill mud
FCLS
Dar.cf/Vcorc FCLS
Rainbow trout
Onchrliyclius fco
(pink salmon fry)
Kenlda menlJa
(Atlnntic silverside)
Necravsis integer
2 ppt
3-29 ppt
no effect after 4 days in cages near the discharge
point
100 ppt
49 ppt
74 ppt for a 48 hour LC5Q
ECiiC (1976)
ZOPHL/.KKTGN/
(19V 8)
llor.aphan
(1977)
MJ-:TOFAUN'A
(1977)
Perjuegnnt
(1977)
saltwater gel mud
FCLS
salcuater gel
FCLS
whole mud
7 drill muds
6keletonama costatum
Ac.-rrM.-. tonsa
Pandnlus h y p s i n o t u s
conf ervicolua
nc'i r in sp.
nudus
Foroninifera
100-1000 ppm
10-18 ppt
100-335 ppm
100-300 ppm
32-150 ppt
10-50 p;it for a 48 hour
14-560 ppt
53 ppt
Bhruoil a significant decrease after drilling opera-
tions (t test=0.03). uith the greatest decrease
nt 100 m and rrduccd populntions CO 1000 n
showeJ an Increase in thf nupbors of individuals
'between pre- ar.d posc-drillir.j aatr.plos. this
ir.r.iease v.ip p.-es'jn.abiy r'.ue .to -.-.neural seasonal
variations which c-.auk.cd any j)oter.cial effects
caused -by drilJ.ing
Knox (1970)
Kciisgnnn
(1977)
D.i^jf/M
(1978)
FCLS
drill mud
)-'0'Holi:s n-.od lolua
bnncMc infaur.a
1 ppt
3C ppt with abr.oirnul behavior at 37. -tut not IX
drill r.ui! by volume
no major effect on infauna at distances 100-200 m
firom the drill site
-------
Table A-l. continued.
BEN'THCS/
Holland
(1977)
TsrS"tz/Tobia
(1978)
Alexander
(1977)
heavy metals
Prcs^ly/Bcoth heavy metals
(1977)
KARn B.W COMMUNITIES'
(1978)
Tiionpscr/Brighc used drill mud
(1977)
Westerhaus,
' (1973)
FCLS
Continental Shelf Associates
(1973)
Marine Technical Services
(1977)
ORGANISM
tenthic infauna
benthic Infauna'
benthlc infauna
benthlc Infauna
reef fish
Diplori.n sfrlsosa
Montv;tre.i annular is
M. crwernosa
Madracls rairabllis
tra:idcects - no species
available
transects - no species
available
RESULT (LC50-96 hour)
a decrease in numbers was reported between pre- and
post-drill sites with no discernible chijnse in
populations nt distances greater thar. 100 si
colonization of estuarlne bcnthic community was
significnntly less on sediment covered by barite
of VCLS drill mud
no accuraulations-of heavy metals (Cd, Cr, Cu, Fe,
Pb, Ni) were reported fro;a macrofauna captured
in trawls from the vicinity of drilling operations
found basically the same conclusion? as Alexander
eplbenthlc and demersal fish populations appeared
healthy nt post-
-------
53
TABLE Corals used
A- 2. iments.
Treatment
0 ppm Drill Mud
100 ppm Drill Mud
100 ppm Drill Mud
+ 3 ppm FCLS
100 ppm Drill Mud
+10 ppm FCLS
in oxygen consumption/ammonium excretion expi
Protei-^ (rag) Skeletal Weicht (g)
157
76
457 *
194
170
152
135
225
126
76
187
97
140
170
164
135
40.53
25.66
83.78
31.38
25.03
20.00
34.34
39.37
37.34
28.34
77.07
29.00
44.26
47.57
55.66
37.10
-------
Table Average change (x ± s.d., n=4) in oxygen and ammonium
A-3. concentrations in control aquaria (without corals) after
a one-hour measurement period. Prior to each measurement
period, aquaria were flushed with 0.45-um filtered seawater
to remove the drill mud-f errochrome lignosulfonate suspen-
sion so that it and natural particulates present in the
aquaria during the normal flow- through mode did not mask
coral metabolism. Positive values denote net production
of oxygen and ammonium, negative values net consumption.
Day
Initial day i
Initial day ii
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
Day 8
Day 10
Day 11
Day : 12
Day 13
Day 14
Day 15
Day 16
Day 17
Recovery day 1
Recovery day 2
GRAND MEAN
Oxygen
ml 02 liter"1 h
-0.04
-0.03
-0.06
-0.08
-0.10
-0.04
-0.06
-0.10
-0.13
-0.17
0
-0.03
-0.08
0
0
-0.05
-0.06
-0.03
-0.06
-0.06
-0,06
± .01
± .02
± .01
± .02
± .01
± .02
± .01
± .01
± .03
± .06
± .03
± .01
± .01
± .01
± .03
± .03
± .01
± .01
± .01
± .01
± .04
n=80
Ammonium
ug-at NH4 liter" h
0.1
-0.3
-0.2
-0.1
0.1
0.1
-0.3
0.2
0
-0.2
0.4
0.3
0.5
0.4
-0.1
0
-0.1
-0.3
-0.2
-0.1
-0.01
± .2
± .5
± .5
± .2
± .2
± .1
± .6
± .4
± .2
± .8
± .4
± .4
± .2
± .4
± .1
± .1
± .1
± .1
± .1
± .1
± .25
n=80
-------
55
Table A-4. Raw Data: Weight specific oxygen consumption of Madracis
decactis (ml 0? g-1 coral protein hour~^). Values represent
mean + measured range of twice daily determinations except
on days i, ii, 5, 13, 17, R-l, and R-2 when only single
determinations were made.
Day i li
0 ppn DM 12.2 1.0 1.0
1.3 0.0 0.8
1.5 1.1 1.2
1.4 0.1 0.8
100 ppa DM 2.4 1.3 1.9
1.3 0.5 1.0
1.6 1.1 1.3
2.8 2.6 2.4
100 ppa DM 0.3 1.3 1.0
+ 3 ppm 1.7 2.5 0.2
rCLS 2.1 2.4 2.7
1.3 0.5 1.3
100 ppn DK 1.8 1.9 2.4
+ 10 ppa 0.1 2.3 5.1
rCLS 4.2 4.3 1.8
1.1 1.7 1.6
5 6
1.3 1.6 1 .2 1.7
1.9 2.2 3.5
1.3 1.81.1 2.4
1.1 0.9 i .4 ' 1.3
2.2 3.21.2 2.8
1.4 1.81.3 2.0
2.1 2.11.2 2.0
3.8 2.91.5 3.6
1.2 1.7 1 .2 2.3
2.7 3.1 1 2.3 3.6
4.1 4.6 1 .2 4.6
1.6 2.31.1 1.0
2.S 2.91.4 2.9
8.8 9.7 12.6
o.l 2.7 1 .3 2.6
2.3 3. 11. 2 2. 31
±
*
t
£
±
1
1
1
±
*
t
1
±
1
*
t
7
±
l
l
l
l
l
*
l
1
1
l
l
1
t:
i
.2
.1
.1
.1
.2
.1
.1
.7
.6
.4
.4
.3
.8
.6
.1
.3
.1
.1
.5
.5
.2
.8
.6
.1
.7
1.7
.3
.3
'.7-
4.6
.6
''.7
1.4 ±
2.9 1
1.21
0.7 ±
2.4 1
2.0 t
1.71
2.9 ±
2:3 1
2.5 1
2.9 1
l.( i
2.0 t
4.0 i
2.4 1
1.7 I
8
1.6
3.6
2.11
1.8 1
2.8 1
1.9
1.7
3.8 1
2.8 1
3.4
5.3 1
3.0
3.0 t
6.8 1
2.1 t
2.6 l
.1
.1
. I
.1
.1
1.0
.5
.1
.2
.4
.2
.8
.3
.1
.2
.3
.6
.5
.5
1.1
1.0
1.
0.
1.
1.
1 .
1.
2.
2.
2.
3.
3.
2.
1.
6.
2.
2.
0.
0
1.
0.
0.
0.
0
3
9
6
3
9
9
3
a
i
4
5
1
8
7
3
5
4
4
2
8
6
1.6
0.
4
0.4
.9
.4
1.8
.7
.3
<.
1
1
t
1
*
±
1
i
t
1
1
1
t
1
1
10
t
1
1
1
1
1
1
t
t
t
3.2 1
0
1.6
t
t
9.6 1
0.9
1.0
1
1
1.2
1.2
.5
.1
. I
.2
2.3
1.2
.1
.1
.2
.3
.1
.1
.2
.3
.4
.4
.2
.5
.2
.9
1.0
.1
.2
.4
.2
.3
.9
2.8
.9
.2
1.0
1.0
1.6
1.2
1.7
1.3
0.5
0.5
0.9
2.3
2.5
2.2
2.3
11.4
1.8
2.1
0.4
0.4
1.5
0.3
1.3
1.0
0.6
2.0
0.5
0.8
3.7
0.6
1.4
6.2
1.0
1.3
»
±r
t
t
Z
*.
t
t
t
t
*.
t
t
*
t
t
11
£
i
+
i
i
t
t
i
*
t
£
1
1
t
1
1
.6
.4
.2
.6
1.2
.4
.1
.2
.2
.5
.4
1.2
.4
.6
.4
.6
.2
.6
.2
.3
.2
.3
.2
.6
.1
.3
.3
.5
.1
.8
.3
.2
-------
5i
Table A-4 continued.
12 13 14. 13 16 17 R-l a-2
0.4
1.4 t
1.7
0.6
1.01
0.9 ±
0.6 ±
2.0 ±
0.8 ±
2.3 ±
4.4 t
1.1 ±
2.0 t
6.4 ±
1.7 ±
2.0 ±
.4
.6
.2
.2
.1
.1
.4
.4
.1
1 .2
.3
.1
.1
0.5
0.6
1.7
0.3
1.6
0.9
0.8
1.8
0.6
1.7
nor Ibund
1.0
1.3
2.3
0.9
1.3 ":"
0.4 ±
0.4 ±
0.9 «
0.3 *
2.0 *
0.9 ±
0.8 ±
1.7 *
0 1
1.0 *
0.5 ±
0.6 ±
3.1 ± 1
0.8 ±
0.7 t
.2
.4
.2
.1
.1
.1
.1
.3
.4
.3
.1
.4
.8
.3
.3
1.0
1.7
1.5
0.8
2.8
1.9
1.3
0.5
1.3
1.6
~
2.0
1.8
±
± .
±
±
±
± .
+ .
±
t
±
1
2
3
2
1
2
1
5
1
3
3
9
0.6 *
1.4
1.6
0.6
2.7
1.2
0.9
1.0
0.6
1.4
-
1.0
1.0
i
±
*
.,
±
±
t
±
t
±
+
.1
.1
.1
.1
.2
.1
.2
.2
.1
.1
.1
.1
0.6
1.6
1.7
- 0.5
2.6
0.9
0.7
1.2
0.7
1.4
0.8
1.3
0.9
1.3
1.6
0.7
2.5
0.9
0.9
1.0
0.8
1.3
1.0
1.2
0.9
1.6
1.6
0.7
2.3
1.4
0.7
. 2.7
0.6
1.1
___
1.0
1.0
moribund ____ ___ ___ ___
3.1
0.2
± 1.
1 1.
3
0
1.7
1.3
±
1
.1
. 1
2.0
1.7
1.5
1.3
1.0
1.2
-------
Table A-5. Raw Data: Weight-specific ammonium excretion of ''adracis
decactis (ug-at NHj g~l coral protein hour'l). Values
represent mean + measured range of twice-daily determina-
tions, except on days i, ii, 5, 13, 17, R-l and R-2 when
only single determinations were made.
57
11
0 ppm DM 58 10 11X4
» 47 14 X 2
3 3 311
4 6 8 t 1
100 ppm DM 3 10 9 t 1
9 5 711
10 11 - 12 1 1
17 9 12 1 1
100 ppm UM 6 5 11 ± 2
+ 3 ppm 11 10 18 1 1
FCLS 10 9 10 1 1
21 10 13 1 3
100 ppm DM 6 3 10 1 1
+ 10 ppm 37 24 23 t 1
FCLS 2 5 13 1 2
5 1 8 t 1
6 7
12 ± 1 8 1 4
24+9 13 1 2
3 t 1 3 ± 1
8*1 10 t 5
26 ± 2 14 i 5
612 6 t 1
16 1 9 10 t 1
17 * 2 21 1 2
8 ± 1 8 1 1
14 t I 18 I 3
40 1 3' 53 1 3
17 1 4 12 t 4
15 ± 2 20 t 1
193 ± 39 232 1 36
8X1 10 t 1
10 X 5 < X 2
9 1 1
15 1 5
4 1 1
10 t 1
9 t 1
5 ± 1
12 1 3
14 1 1
612
20 1 1
12 1 2
17 t 11
16 1 3
62 X 13
9 1 1
8 X. 1
8
14 1 3
35 t 3
612
28 1 15
23 ± 6
23 1 15
27 ± 13-
39 1 15
19 X 7
43 1 17
42 ± 25
24 X 4
27 X 9
245 X 17
16 X 8
17 X 3
5
7
2
5
6
19
18
9
6
19
. 18
9
6
103
5
6
5
6
3
4
5
6
9
16
6
16
24
6
11
95
5
7
i
l
l
*
±
i
t
±
l
+
i
l
i
X
x
X
10
t
i
X
1
X
t
I
X
1
X
+
X
X
X
X
X
1
2
1
3
2
4
4
1
5
4
4
1
1
8
3
4
2
2
1
1
1
3
2
2
1
5
3
1
1
2
2
1
8
12
3
5
13
6
9
13
6
28
25
21
12
162
6
8
3
16
3
6
12
a
10
22
55
91
34
13
48
91
41
50
X 4
1 6
1 1
1 1
1 I
t 2
1 3
1 2
t 3
1 17
1 1
t 8
1 2
X 4
X 2
X 1
11
1 2
1 8
X 1
1 1
t 3
X 3
X 1
1 2
X 2
X 2
1 1
X 1
X 1
X 2
X 1
X 1
9
14
3
8
14
9
9
20
9
20
40
9
10
165
4
25
12
12 1
17 t
3 1
3 1
13 X
6 X
11 X
18 X
13 1
20 1
31 X
17 1
8 X
86 X
12 1
10 X
.
5
3
1
2
1
2
2
2
7
1
9
4
5
6
12
9
-------
58
Table A-5 continued.
13 14 ls 16 17 R-l R-2
2
6
2
5
23
3
10
18
8
10
moribund
6 '
4
43
20
S
6 £ 2
1- * 6
2 t I
6 £ 2
23 £ I
9 £ 3
10 £ 2
18 £ 6
8 £ 2
14 £ 2
10 £ 1
10 £ 1
31 £ 2
13 £ 1
9 £ t
6 £ 2
13 £ 6
2 £ 1
5 ±-2
28 £ 2
6 £ 3
5 £ 1
18 £ 7
7 £ 2
13 £ 13
'5 £ 3
5 £ 1
moribund
13 £ 6
7*2.
5 £
8 s
2 S
3 t
30 £
5 i
2 t
IS ±
4 £
8 i
6 £
6 £
16 £
7 £
t
1
1
1
1
1
1
1
1
1
1
1
1
2
5
12
2
3
29
6
4
15
S
9
9
5
12
12
3
6
2
3
21
6
4
17
4
8
6
6
9
10
3
6
2
2
14
3
6
14
3
7
_
5
5
3
10
-------
11
Dav
100 ppm DM 4<0 ± 5 5 0<5 ± Oi6 Ii0 ± 0 2 j 6 ± uo Ii3 ± Oi3 l>2 ± 0>3
100 ppm DM 2-0 ± 0>7 K4 ± 0>9 K7 t 0>6 2 3 t 0>5 2 2 ± 0>A K0 -t 0>s
100 ppm DM + 1-5 ± Oi6 1<7 t 0-9 ,-3 t Ii0 2 3 t 0-5 2<8 ± Oi8 2-0 t 0<7
3 ppm FCLS
100 ppm DM + . 1.8 t 1.7 2.J±1.2 2. 7*1. 6 2.5*1.0 3.'. ±2.3 4.4t*.7
10 ppm FCLS
} 6 7 8 10 11 12
1.6 t 0.4 1.7 t 0.5 2.3 t 1.0 2.3 1 0.9 0.5 t 0.6 0.6 t 0.6 1.0 i 0.6
2.4 t 1.0 2.5 t 0.6 2.6 t 0.8 2.5 t 0.9 0.8 ± 0.7 1.2 t 0.6 1.1 t 0.6
2.4 t 1.3 3.1 ± 1.2 2.9 t 1.6 3.6 t 1.2 1.0 t 1.5 1.4 ± 1.6 2.1 t 1.6
13 14 15 16 17 R-l R-2
0.8 t 0.6 . 0.5 1 0.3 1.3 1 0.4 1.0 1 0,5 1.1 1 0.6 1.1 t 0.4 1.2 t 0.5
1.3 t 0.5 1.3 t 0.6 1.6 t 1.0 1.5 ± 0.8 1.3 t 0.9 1.3 t 0.8 1.8 i 0.9
1.1 t 0.5 0.5 t 0.5 1.6 ± 0.3 1.0 1 0.4 1.0 t 0.4 1.0 i 0.3 0.9 t 0.3
1.4 t 0.6 1.3 t 1.2 1.7 t 1.4 1.3 t 0.4 1.7 t 0.3 1.3 t 0.2 1.0 t 0.1
*0ne of the corals grew increasingly moribund and was removed between days 12 and 13; n=3.
**0ne of the corals grew increasingly moribund and was removed between days 14 and 15; n=3.
OJ
:le A-6. Summary of v
coral prote
averages of
exposed to <
deviation, i
II 0> r+ ZJ fD
^.03" -*
rr fD ma
o 3-
fD 3 C rt
X fD -5 1
TD PJ OO
ro z> i~o
~i tm
-.. -5 -^ o
3 fD ->
CO Ln -+,
rs TD ->
c-f - < 0
fi) -S DJ
i C" O
r-t- c x
<-<-- fD *<
-S O U) LQ
fD 3 fD
59
n consumption (ml 02 g~*
represent the arithmetic
rates of four corals
atment (+ standard
-------
Day " l 2 3 4 s
^ n. . ' mi...
u ppm DM ~
18 * " H 1 20 9 1 5 10 1 5
100 ppm DM
10 * 6 ' * > >° * > 10 1 3 6 t 3 lo t 3
100 ppm DM +
3 ppm FCLS ' * 3 l3 * 3 !* * « u * 6 20 i 10 20 i H
100 ppn, DN+ ,, . u ..,.. . , . nt H
6 7 8 10 II . 12 13 14
,, , a 914 21113 512 815 10 16 412 715
i i i y
1 I :
., , . 13 t 6 28 1 8 9 t 5 13 t 6 12 ± 5 *14 * 9 15 t 7
16x8
20 t u 23 1 21 32 1 12 13 1 9 49 1 33 20 t 8 *8 t 2 *11 1 3
* '
J7 t 9l 68 t 110 76 t 113 29 t 44 58 t 23' 29 t 38 17 t 18 16 t 10
15 16 17 R-l R-2
5±2 412 614 412 3t2
14 til 13 t 12 13 1 12 1218 10 1 5
1 A A A A
8*5 612 812 612 512
*J t 4 *9 * 5 *to 1 4 *8 t 2 *S t 2
* One of the corals grew increasingly moribund and was removed between days 12 and 13
t
Cu
cr
ro
i
r?
rt- ~o Cu IQ t/j
- 0 < ic
o t/i ro » '3
3 ro -s 3
v Q. Cu n Cu
un o -s
^3 n- ro -j <
II O to tn
4a. j o
- ' ro o -h
^3~ c-t- o n>
^r r-t- ->
ro ro ro to
X -J. 3-
ro fD i
-s cu rr isi
-1- 3 O T3
3 c ro
ro ro -s n
3 X 1 -J.
<-+ o i »-t>
Cu -5 i.
-1 ro o
rt- - Cu
-s o < 3
ro 3 cu 3
0> i O
3 Cu fD i.
ro r-i- oo c
n ro 3
rt- 10 -s
ro ro
H- -ti -s n
ro -s
i/> h 1/1 ro
rt- o ro rt-
Qj £ -~j _J»
3 ~S rt- 0
Q- 3
cu n cu
-s o -j *,
Q.-S - C
cu rt-in
CL 3- i
ro to 3 cu
< ro rt
-1- ro n-
& ><- -z.
-------
61
Table A-8: O/NH.-N ratio for each drill mud + FCLS regime (x + s.d.).
Values represent the ratio of oxygen atoms consumed" to NH.-N
atoms excreted. Three corals which consistently showed
higher than average oxygen consumption and ammonium excre-
tion were deleted from analysis.
Day
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
Day 8
Day 10
Day 11
Day 12
Day 13
Day 14
Day 15
Day 16
Day 17
Recovery Day 1
Recovery Day 2
Treatment
Grand Mean
0 ppm DM
7.4+2.0
12.5+5.7
19.3+6.8
13.3+7.2
12.4+0.4
10.0+1.9
18.2+6.2
16.9+16.0
3.9+3.6
3.7+1.3
5.7+2.3
12.2+8.9
4.4+1.6
13-. 6+1. 7
14.7+3.6
12.5+2.2
22.3+4.0
27.3+3.7
11.3+5.0
100 ppm DM
14.7+4.3
23.4+9.5
19.1+10.3
9.9+7.3
11.2+7.8
16.2+7.3
20.2+6.5
8.2+2.2
8.0+5.9
8.6+2.5
8.8+3.7
12.1+9.8
10.1+6.8
15.7+12.0
15.5+10.0
11.0+4.1
12.3+6.2
21.0+14.0
13.3+4.7
3 ppm FCLS
100 ppm DM
6.0+4.3
17.9+14.2
22.7+7.8
10.0+3.1
13.3+2.3
16.0+4.4
17.0+9.2
10.5+3.1
2.7+3.0
1.9+1.9
7.2+2.7
12.3+4.8
3.6+3.3
21.1+13.0
14.6+1.1
11.4+3.1
15.7+1.8
16.5+2.2
11.8+6.4
10 ppm FCLS
100 ppm DM
17.2+4.5
18.0+6.4
36.2+8.9
22.4+4.9
11.1+10.2
25.0+6.8
20.6+6.8
11.7+1.9
13.9+1.9
2.4+2.1
17.6+4.9
18.7+13.0
5.9+0.84
14.3+15.0
13.7+3.7
16.9+5.6
14.8+3.1
13.2+4.0
16.6+7.8
-------
62
Figure A-l. Oxygen Consumption of 4 experimental corals expressed as
ml 02 g coral protein h"-*-.
4.0
3.0
2.0
i.o
i I
0 ppm DM
t i i
12 3 45 67 8 9 10 11 12 13 14 15 16 17 Rl R2
2 3 45 67 8 9 10 11 12 13 14 15 16 17 Rl R2
-------
Figure A-l continued.
63
100 ppm DM
3 ppm FCLS
i ii 1 2 3 45 67 3 9 10 11 12 13 14 15 16 17 Rl R2
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
100 ppn DM +
10 ppn FCLS
1 11 1 2 34 5 678 9 10 11 12 13 14 15 16 17 Rl R2
-------
Figure A-2. Ammonium Excretion of 4 experimental corals, (ug-at NH+
g'1 coral protein h"1) ^
40
30
20
10
0 ppm DM
1 ii 1 2 3 4 567 8 9 10 11 12 13 14 15 16 17 Rl R2
i ii 1 2 3 4 5 67 8 9 10 11 12 13 14 15 16 17 Rl R2
-------
65
Figure A-2 continued,
90 -
100 ppm DM +
3 ppm FCLS
i ii 1 .23 4 5 67
9 10 11... 12 13 14 15 16 17 Rl R2
100
90
80
70
60
50
40
30
20
.10
I
1
t,
-1
x
M
I
\ 100 ppm DM
I \
10 ppm FCLS
1 2 34 56 7 89 10.. 11. 12 13 14 15 16 17 Rl R2
-------
35 >
25
20
15
3
10
Figure A-3: 0.;.XH,-N rp.cio for esch JrlU mud 4 Ir'CLS leglti:.
Legend: C PP^ drill nvjd
100 pp;r. di'ill nuu
. 100 ppic dri.ll ;;.uc + 3 ppa FCtS
100 i>i>a drill cad + 20 pp= FCL3
/
/
\
/v
: v /
i-r&i /
/ \N/
.....AV/
v / / \V
i i I __ !
I_^_i-_U_! I
i 11 1 Z 3
fi 7 8 10 11 12 13 U 1H 16 17 XI
Day of Experinont
R2
------- |