EPA-600/3-77-Q93
August 1977
Ecological Research Series
ELUTRIATOR/MICROCOSM SYSTEM
PILOT MODEL AND TEST
Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Narragansett, Rhode Island 02882
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ECOLOGICAL RESEARCH series. This series
describes research on the effects of pollution on humans, plant and animal spe-
cies, and materials. Problems are assessed for their long- and short-term influ-
ences. Investigations include formation, transport, and pathway studies to deter-
mine 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.
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EPA-600/3-77-093
August 1977
ELUTRIATOR/MICROCOSM SYSTEM
Pilot Model and Test
by
E. C. Evans III and R. Scott Henderson
Naval Ocean Systems Center, Hawaii Lab
Kailua, HI 96734
Interagency Agreement
D6-F941
Project Officer
Kenneth T. Perez
Environmental Research Laboratory
Narragansett, Rhode Island 02882
ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
NARRAGANSETT, RHODE ISLAND 02882
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DISCLAIMER
This report has been reviewed by the Environmental Research Laboratory,
Narragansett, Rhode Island 02882, 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.
ii
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ABSTRACT
An effective technique is described for transferring soft benthic
sediments with their resident infauna intact into special holding systems
(elutriator/microcosms) which permitted the study under controlled condi-
tions of both nutrient exchange from the sediments and the activities of
their infaunal communities. The effects of bioturbic activity on nutrient
exchange rates could not be detected by water column measurements but could
be seen using a specially developed micro-coring technique. Alpheid shrimp
activity was estimated to increase the sediment surface area by 2- or 3-
fold and also tended to mask signs of burrowing by smaller infaunal ani-
mals. An increase in infaunal population after sediment transfer to a
clean-water situation suggested that the sediment itself was acting like an
analogue to an "artificial reef". Continued investigation of this "arti-
ficial-reef effect" is recommended.
The research was funded by the Environmental Protection Agency under inter-
agency agreement EPA-IA6-D6-F941. The construction and maintenance of the
Ulupau Microcosm Facility where this work was done was funded by the
Naval Engineering Facilities Command (NFAC-032B) and by the Office of Naval
Research (ONR-443).
m
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CONTENTS
Abstract iii
Figures vj
Tables vii
Abbreviations and Symbols viii
Acknowledgments ix
1. Introduction 1
2. Conclusions 2
3. Recommendations . . 4
4. Materials and Methods 5
General Statement 5
Pilot Elutriator/Microcosm (E/M) Design 5
Collection and Support Equipment 11
5. Experimental Procedures 14
Collection, Transport, and Holding Operations ... 14
Nutrient Analysis . . 18
6. Results and Discussion 20
Observations of Infaunal Populations 20
Nutrient Analysis 28
References 36
Appendices
A. Nutrient Levels in E/M Flow-through Waters 38
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FIGURES
Number
1 Location of Ulupau Microcosm Facility and Field Collection
Sites 6
2 Elutriator/Microcosm, Model-1 Design - Used to
Hold the Kokokahi Sediment Collection 7
3 Elutriator/Microcosm, Model-2 Design - Used to
Hold the Fuel Pier Sediment Collection 9
4 Inlet Water Concentrations of Ammonia-N versus Time and Tide
for Ulupau Microcosm Facility, 12-13 June 1975 10
5 Ganged Microcosm Arrangement to Create a Long-Residence-
Time "Inlet Box" (LRT-box) 10
6 Micro-coring Apparatus: (A) Micro-corer, (B) Filter
Apparatus for Interstitial Water Extractions 12
7 Trays of Fuel Pier Sediment in Model-2 Elutriator/Microcosm,
showing Alpheid Shrimp Burrows 17
8 Sketch of Alpheid Burrow Locations at Various Times during
the Kokokahi Sediment Experiment - Micro-core Locations
also Shown 21
9 Closeup of Alpheus madkayi Burrow Entrance 22
10 Sketch of Alpheid Burrow Locations at Various Times during
the Fuel Pier Sediment Experiment - Micro-core Locations
also Shown 26
11 10-Day Standard-Error Envelope of Inlet Ammonia-N Concentra-
tion for Ulupau Source Waters 29
12 Typical Kokokahi Field and E/M Micro-cores 32
13 Typical Fuel Pier Field and E/M Micro-cores 32
14 Typical Pearl Harbor Micro-cores 32
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TABLES
Number Page
1 Organisms Found in Kokokahi Sediments after 135 Days in
Ulupau E/M 23
2 Organisms Found at Kokokahi Site 24
3 Organisms Found in Fuel Pier Sediments after 92 Days in
Ulupau E/M 27
4 Seasonal Changes in Nutrient Concentration in Ulupau Sup-
ply Waters 30
5 Ammonia-N Concentrations in E/M and Field Water Samples ... 30
6 Calculated Ammonia-N Content and (Observed Interstitial
Concentration) for Various Micro-core Layers 33
7 Mean Nutrient Concentration in Micro-core Interstitial Waters 34
8 Nutrient Releases on Standard Elutriation Test and Compari-
son with Micro-core Results 35
VI1
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LIST OF ABBREVIATIONS AND SYMBOLS
ABS = acrylonitrile-butadiene-styrene
cm = centimeter
E/M = elutriator/microcosm, see page 5 of text
GF/C = glass fiber/coarse
gpd = gallons per day
HCZDB = Hawaii Coastal Zone Data Bank
HIMB = Hawaii Institute of Marine Biology
hr = hour
1 = liter
1pm = liter per minute
LRT-box = long-residence-time "inlet box", see page 6 of text
m = meter
ml = milliliter
mm = millimeter
MSL = Mean Sea Level
NUC = Naval Undersea Center (now Naval Ocean Systems Center)
ppm = parts per million
PVC = polyvinyl-chloride
rpm = revolutions per minute
std = standard
TN = Technical Note, an informal NUC publication
TP = Technical Publication, a formal NUC publication
pg-at/1 = microgram-atom per liter
viii
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ACKNOWLEDGMENTS
The authors would like to acknowledge the help and encouragement from the
many people that made this report possible. Special thanks are due Dr.
Stephen V. Smith of the Hawaii Insitute of Marine Biology for his helpful
suggestions and Beatrice L. Burch for her careful and painstaking super-
vision of sample sorting and taxonomic identifications. The excellent work
of Miss G. Page Hi Her in polychaete identifications and of Mr. William J.
Cooke in crustacean identifications deserves special mention. Lastly,
thanks are due Dave Barclay and Bob Cutts for their continual efforts in
maintaining and operating the microcosm facilities, also to Karen Klein,
Linda New, and John Toth for their assistance in water chemistry.
This research was performed by personnel of the Marine Environmental Man-
agement Office (Naval Ocean Systems Center, Hawaii Laboratory) and by
members of the University of Hawaii.
ix
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SECTION 1
INTRODUCTION
As a result of several environmental studies (1-3), the City & County
of Honolulu decided to terminate all sewage discharges into Kaneohe Bay,
Oahu. A new outfall with diffusers located from 1250 m to 1543 m offshore
of Mokapu Point at mean depths ranging from 27 m to 32 m below MSL* is pre-
sently under construction. All discharges are expected to be diverted to
this new outfall in August of 1977. As a result, an estimated 19 x 103 m3
per day (5.0 mgd) of secondary-treated sewage will cease to flow into Kane-
ohe Bay. This event provides an excellent opportunity to determine the
response of an Hawaiian estuary to an abrupt change in nutrient supply.
Similar sewage-removal actions by the Navy in Pearl Harbor can be used to
augment the basis of such a study. Since Navy ships can represent a sewage
impact to harbors and estuaries, it is in the Navy's interest to understand
the full nature of sewage impact (both positive and negative) on confined
marine environments. In consequence, the Kaneohe Bay Sewage Relaxation
Study (4) was organized as part of a larger cooperative effort (5) between
the Hawaii Institute of Marine Biology (HIMB) and the Naval Undersea Center
(NUC).
Since Kaneohe Bay has been receiving increasing amounts of sewage over
the past several decades, a considerable nutrient reservoir has accumulated
in its sediments. The size of this reservoir and the exchange rates into
and out of it are an important aspect of the Sewage Relaxation Study. Al-
though field surveys by HIMB are currently in progress to determine reser-
voir size and location, it is also necessary to conduct controlled experi-
ments to obtain accurate information on nutrient exchange rates, and how
such rates are influenced by biological activity, such as turnover by poly-
chaetes (6) or by mechanical disturbances, such as tidal currents or
stirring by ships' propellers (7).
This project was undertaken in response to the second requirement
stated above. Its objectives were to develop and test techniques and
equipment suitable for transferring sediments with their resident infaunal
communities intact from Kaneohe Bay to the NUC microcosm facility at Ulu-
pau. In addition, tanks at the Ulupau facility were converted into pilot
models of elutriator/microcosms (E/M). The transferred communities were
maintained in these E/Ms for periods exceeding 90 days both to test the
models themselves and to assure that the communities exhibited normal ac-
tivity after transfer. Subsequent projects would determine the nutrient
status of the sediments and the effects of bioturbic activity on nutrient
exchange rates under controlled conditions.
* See list of abbreviations and symbols.
1
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SECTION 2
CONCLUSIONS
Two methods of transferring soft-bottom communities from Kaneohe Bay
to the Ulupau microcosm facility were tested. Two different pilot models
of elutriator/microcosms (E/M) were constructed and tested. Both transfer
methods were judged successful as evidenced by representative community
capture and by continuing normal infaunal activity for over 90 days. A
simple bucket-scoop collection procedure was perfected and used for both
types of transfer, namely direct, in which the buckets themselves were
moved into the E/M tanks, or indirect, in which the bucket contents were
transferred to polyethylene trays, which were subsequently placed in the
E/M tanks. The second procedure and E/M design were preferred because the
intermediate transfer gave no evidence of increased stress to infaunal or-
ganisms and because a larger sample of the bottom community could be moved
and uniformly distributed about the E/M tank.
Efficiency of capture was determined by estimating the number of al-
pheid shrimp (Alpheus maakayi.) per unit area of bottom in the field and by
counting the number found in the transferred communities. Observations of
the captured shrimp showed that between 3 and 5% of the burrows, as deter-
mined by counting entrances, were occupied. In both transfer methods
tested, the expected number of shrimp were captured. It was concluded
that bucket-scoop procedure was a reasonably efficient collection method
for the soft sediments of Kaneohe Bay, where shrimp usually do not pene-
trate deeper than about 10 cm.
Judging mainly from alpheid burrowing, the transferred community con-
tinued normal activity despite obvious changes in food availability, re-
cruitment, and water quality. Certainly, the constant "rain" of organic
detritus from the water column found by HIMB (8) to be characteristic of
the Kaneohe Bay collection sites was absent in the E/M tanks. But either
the transferred sediment itself contained sufficient food or an alternate
source from the water column was employed since all 8 of the captured al-
pheids survived more than 90 days. Observation of the captured shrimp
showed that their activity has pronounced effects on bottom micro-topo-
graphy. Not only do they make numerous burrows (about 26 burrow entrances
per shrimp), but they also mask the topographic signatures of smaller in-
faunal residents. Furthermore, either their grazing or their crawling over
the surface removes a brownish diatom matte which tends to form over the
sediment. Similar matte removal has been reported by Reise (9). It can
be concluded that certain infaunal inhabitants cannot be detected by scuba
inspection of the bottom since micro-topographic evidence of their presence
can be masked by the activities of other residents.
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The transferred communities can be maintained in flow-through E/M tanks
for periods well in excess of 90 days. Such maintenance times are cer-
tainly sufficient to conduct controlled experiments on sediment exchange
rates. Design and test of these E/M tanks and of the transfer methods
constitute the principal objectives of this project. Details are pre-
sented in Sections 4 and 5.
Certain additional observations using these transferred communities
have also been included in this report. Increased nutrient concentrations
(ammonia-N, nitrate-N, phosphate-P, and silicate-Si) could not be detected
in E/M flow-through waters even though the captured alpheid shrimp caused
considerable sediment disturbance. Their burrowing activity was estimated
to have increased the sediment-water interface area by 2- or 3-fold, in ad-
dition to the amount of sediment suspended as a result of excavation. No
statistically significant differences in nutrient concentrations were ob-
served between E/M outlet waters and water samples taken 15 cm above the
bottom at either collection site in Kaneohe Bay. These observations sug-
gest that sediment-to-water exchange rates in the E/Ms may approximate
steady state conditions in the field. That loss of nutrients from the sed-
iment was occurring could be shown by micro-coring techniques developed when
water-column measurements failed. Micro-cores established that, for ammon-
ia-N at least, there was a decrease in interstitial water concentrations as
the sediment surface was approached, implying that either surface exchange
or bacterial regeneration was taking place.
The resident infaunal populations were observed to increase approx-
imately 10-fold during the 92 to 135 day periods that the transferred sedi-
ments were maintained in the Ulupau microcosm facility. This increased
population occurred despite the fact that the transferred sediments would
have to be classified as "nutrient polluted" on the basis of the Corps of
Engineers standard elutriation test (10, 11). It should be emphasized
that these sediments did not cause observable increases in the nutrient
concentrations of E/M flow-through waters. Although these preliminary
observations must be substantiated with further controlled experiments,
they do suggest that nutrient-rich sediments can appear to act as an ana-
logue to an "artificial reef". If similar population increases can be
demonstrated for sediments classified as polluted by heavy metals, pre-
sently accepted strictures on the disposition of such dredge materials
would require re-examination.
Finally, an inverse of the infaunal response has been observed in
fouling panels or wood block communities when subjected to the same trans-
fer conditions (12). These populations decrease, apparently through star-
vation, rather than increase. Use of both sediments and fouling panels in
simultaneous transfer experiments can, therefore, complement each other in
the systematic search of bioindicators of water quality.
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SECTION 3
RECOMMENDATIONS
Bucket-scoop collection procedure with intermediate transfer to poly-
ethylene trays should be used in future sediment collections. Further ex-
periments using the second E/M design are recommended to determine the
effect of bioturbic activity on nutrient exchange rates. Since monitoring
the water column for nutrients was shown to be insensitive, these further
investigations should exploit micro-coring techniques described in Section
4. Such techniques might be profitably augmented by nutrient measurements
within the burrow tunnels. Use of quick-setting epoxy resins to determine
burrow dimensions would improve estimates of sediment/seawater interface
areas.
Of greater interest is the observed increase in infaunal populations
when nutrient-rich sediments are transferred to an oceanic environment.
This apparent "artificial reef" effect deserves continued study since it
could relate directly to dredge material disposal problems. Such research
should involve transfers of sediments from various locations both to the
E/Ms already established at the NUC facility and also to similar E/Ms which
could be established at HIMB. Collection locations should include harbors
known to be polluted with heavy metals. Finer screening of both field and
E/M sediments is recommended to obtain better data on population changes
resulting from transfer. Since fouling panel and wood block communities
show population decreases after transfer (an inverse response to that
observed in nutrient-rich sediments), further research is recommended to ex-
ploit these differences.
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SECTION 4
MATERIALS AND METHODS
GENERAL STATEMENT
Stated project objectives required (a) the design and testing of field
collection and transport techniques capable of obtaining representative,
yet relatively undisturbed, samples of sediments with their infaunal com-
munities intact, and (b) the design and operation of a holding system which
could maintain the collected communities in a healthy, active state. There-
fore, this section, rather than those which follow, contains the required
project output.
PILOT ELUTRIATOR/MICROCOSM (E/M) DESIGN
Microcosm Facility
An existing microcosm facility constructed by NUC at Ulupau (Figure 1)
and described in detail elsewhere (5, 12) was used as the basis for the
holding system. Briefly, this facility consists of twelve 600-liter fiber-
glass tanks with gel-coated surfaces continuously supplied with unfiltered,
oceanic or low-nutrient seawater at any desired rate up to 15 1pm*. With
the exception of titanium pump shaft sleeves, all materials used in the
seawater distribution system are of plastic construction. Piping and fit-
tings are PVC* plastic; four 3-inch Y-fittings in the main supply pipes are
ABS* plastic. The entire seawater distribution system is double plumbed,
and is kept free of filter-feeding organisms by alternating between the two
systems at weekly intervals. The unused system is allowed to become an-
oxic, thus freeing it of any organisms that settled during the previous
7-day period of use. Organic debris is back-flushed out of the system just
prior to putting it back into operation.
Elutriator/Mi crocosms
Two methods of holding sediment infaunal communities were tested. The
first, a pilot model built to hold initial test collections, was a fiber-
glass tank, 119.4 x 58.4 x 47 cm deep, with a special diffuser inlet whose
depth in the tank could be adjusted (Figure 2). Tank volume was 328 1 and
inlet box volume was 16 1. The tank was covered with four plys of 2-mm
mesh, gray plastic screen, which reduced light in the tank to 12%% of am-
bient daylight. This was done to approximate the reduced lighting con-
* See list of abbreviations and symbols.
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158°
21°30'
Kaneohe
Bay
miles
0 5
0 8000 Barbers Pt. Nfakapuu Pt
meters
kilometers
PEARL HARBOR
Mokumanu Is.
0 >eet 3000
0 1000
meters
\
\
ULUPAU ^SSm Flyer's
MICROCOSM****^: ^Monument
FACILITY
North '
Pyramid Rock- Beach^
^ Point ^J'&f/J'/Ich.&ttery'xjXvjv
''.?
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WATER FROM RECEIVING TANK
OVERFLOW
STANDPIPE
OVERFLOW
ADJUSTABLE STANDPIPE
INLET PIPE /
INLET AND
SETTLING BOX
47.0 CM
(18.5 IN.)
WATER
LEVEL
VALVE
FLOW RATE
CHECK POINT SAMPLE HOSE TO VALVE MANIFOLD
AND METABOLISM MONITOR LOOP
Figure 2. Elutriator/Microcosm, Model-1 Design
Used to Hold the Kokokahi Sediment Collection
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ditions at the bottom of Kaneohe Bay. Transferred sediment was placed on
the bottom of this tank in nine plastic buckets containing 4.7 1 each and
in a coring device holding a 23-cm core representing 7.4 1. In all, the
tank contained 50 1 of sediment in a seawater volume of 278 1. The planar
area of the sediment was about 0.3 m2 (2889 cm2); the true surface or sedi-
ment/seawater interface is estimated to be 2- or 3-fold greater (see dis-
cussion in Section 6). Flow rates through the tank were varied from 13 1pm
to 0.6 1pm. In general, ambient conditions at the collection site were
closely approximated by this holding system (hereafter called the model-1
elutriator/microcosm or E/M). No attempt, however, was made to simulate
hydrostatic pressure or nutrient status of the water. These departures
from conditions at the collection site do not appear to have serious conse-
quences. After a 135-day test, the greater depth and the adjustable dif-
fuser of the first E/M model did not appear to be required, thus a second
and simpler model E/M was tested.
The second or model-2 E/M used one of the existing microcosm tanks.
These were 117-cm square fiberglass tanks, 41 cm deep and containing 555 1
of seawater (Figure 3). As with the first E/M, the tank was covered with 4
plys of screen, reducing the light to 12*$ of ambient daylight for the
first 27 days; thereafter a completely opaque cover was used. The bottom
of the E/M was "lined" with 7 high-density black polyethylene trays* (di-
mensions: 46.7 x 30.8 x 10.5 cm deep), containing 14 1 of sediment each.
These boxes covered 74$ of the E/M bottom, the remaining area about inlets
and outlets being filled with clean carbonate beach sand. The E/M con-
tained 100 1 of sediment in a seawater volume of 455 1. Planar sediment
area was about 1 m2 (10,068 cm2). Flow rates were varied from 9.6 1pm to
0.6 1pm. Again, no attempt was made to simulate either hydrostatic pres-
sure or nutrient status of the water at the collection site.
Supply Water Problems
The nitrogen content of supply waters at Ulupau varies considerably
with the state of tide and surf (Figure 4). These variations are thought
to result from nitrogen fixation by blue-green algae in a shallow lens of
seawater which remains nearly stationary over the reef flat during low-
tide, low-surf conditions. As the tide rises, this nitrogen-enriched lens
is swept by surf and winds into the Ulupau intake system. In an attempt
to damp this short-period nutrient "noise", a second microcosm tank (555 1)
was plumbed to operate as a long-residence-time "inlet box" or LRT-box (Fi-
gure 5). Both the LRT-box and the model-2 E/M were fitted with opaque cov-
ers. The mean residence time of water in the LRT-box was calculated to be
about 15 hr, or greater than the tidal cycle (12.4 hr). This modification,
made 27 days after the second sediment transfer and continued for the re-
mainder of that experiment, failed to damp variations in nitrogen concen-
tration and apparently increased the ammonia content of the supply waters
(see section 5).
* Distributed under the name "tote box" by United States Plastics Corpora-
tion, Lima, Ohio.
8
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outlet stand pipe
outlet box
microcosm tank
117cm x 117cm
intet port to tank
\
overflow stand pipe
t
r
t
outlet sediment tray inlet I
^\W/////////////////A
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Figure 4. Inlet Water Concentrations of Ammonia-N versus Time and Tide
for Ulupau Microcosm Facility, 12-13 June 1975
overflow-outlet
standpipe
drain
elutriator
tank
Jft
i:
^
c
u
1
tlet . .
inlet
1 1 11 1
1"'
outlet
long residence time
"inlet box"
threaded inlet
standpipe
inlet box
I
Figure 5. Ganged Microcosm Arrangement to Create a Long-
Residence-Time "Inlet Box" (LRT-Box)
10
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COLLECTION AND SUPPORT EQUIPMENT
Collection Equipment
The soft bottom muds at the two collection sites did not require spe-
cialized equipment. Collection was made by two scuba divers using plastic
buckets (mean diameter =19.0 cm, depth =17.8 cm, volume when filled to
within 1 cm of the top = 4.7 1) and a large corer (20.3-cm inner diameter x
24 cm long). The buckets were scooped in a smooth arc through the top 19
centimeters of sediment. The large corer was used to collect minimally
disturbed sediment to a depth of 24 cm. It consisted of a PVC pipe (outer
diameter = 21.5 cm) with one end beveled into a cutting edge. Both ends of
the corer received snap caps which provided a tight seal. This device was
slowly pushed into the sediment by a scuba diver. The device was then
rotated to shear the core and tilted about 10° to create a water passage.
A cap' was then slid down this passage and worked onto the bottom of the
corer. The top was then capped and the corer was carefully withdrawn from
the sediment.
Larger, 14-liter buckets (mean diameter = 28 cm, depth = 28 cm) were
used in the second collection. Again these buckets were scooped in a
smooth arc through the top 28 cm of sediment by scuba divers operating on
the bottom. After thus being filled, the bucket was hauled to the surface.
Its contents were then "slid" with minimal disturbance into a polyethylene
tray, previously described. One bucket just filled a tray to within a cen-
timeter of its rim.
Transport Equipment
Transport equipment was simple. The buckets and the large corer were
moved on flat plastic trays to catch splash or slop. To minimize disturb-
ance during transport, only a 5-mm film of seawater was left covering the
sediment samples which were kept shaded and shielded from the wind at all
times. The polyethylene trays stacked in a manner which sealed them.
These were moved in tiers of 3 or 4 trays at a time. Logistic equipment
included a Boston whaler and a panel truck.
Other Coring Devices
Two other devices were used, namely a small corer and a micro-corer.
The small corer (10.0 cm diameter x 65 cm long) was used to observe strati-
fication and depth of burrowing at the field collection sites. This corer
was also a piece of PVC pipe pushed by a scuba diver into the soft bottom.
The exposed end was then capped and the whole device twisted & tilted to
break suction before removal. At the surface, a plunger was inserted to
extrude the core for inspection. For the sediments sampled in Kaneohe
Bay, good cores of 40 to 60 cm in length could be obtained.
A micro-corer (Figure 6) was used to obtain samples of interstitial
water for nutrient analysis. This corer consisted of a 2.3 cm diameter
11
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60ml centrifuge tube
ro
1.3 mm wall thickness
bevel on inside lip
rubber stoppers back to back
with stainless washer and nut
on either end
SOcc syringe tilt to avo,d
aeration of sample
flexible plastic tubing
10cc polystvrerw tube
tube holder
Figure 6. Micro-coring Apparatus: (A) Micro-corer, (B) Filter Apparatus for Interstitial Water
Extractions
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clear styrene tube, 20 to 60 cm long, depending on the length of core de-
sired. This tube was fitted with a plunger and handle. The mouth of this
micro-corer with the plunger fully inserted was placed gently on the sedi-
ment surface by a scuba diver. The plunger handle was held steady at a
fixed elevation above the sediment while the tube was pushed into the bot-
tom as far as possible. The tube was twisted approximately 360° to shear
the core free, then tilted 10° to 30° off vertical while still in situ to
create water passage to the base of the core. After tilting, the core was
pulled free of the bottom. In transit, both ends of the micro-corer were
plugged with rubber stoppers and the whole was stored on fee in a cooler.
13
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SECTION 5
EXPERIMENTAL' PROCEDURES
COLLECTION, TRANSPORT, AND HOLDING OPERATIONS
Experimental procedures are presented, in part, in the preceeding sec-
tion because the simple material and methods employed are better understood
if accompanied by some description. Some results influencing the field
procedures are better presented here than in the following section. Lab-
oratory and E/M results are to be found in Section 6.
Before any collection was made, the topography of the bottom was care-
fully inspected by a pair of scuba divers. This inspection was used to
estimate the density of alpheid shrimp in residence at the collection site.
Ten-cm cores to the maximum depth possible were made & inspected at the
site to determine both strata and the depth of alpheid burrowing activity.
After inspection, the upper or occupied sections of these cores plus addi-
tional scoop collections were rinsed through a 1-mm mesh screen to obtain a
sample of the resident infaunal population. All organisms found were re-
turned to the laboratory for complete identification.
As mentioned previously, a 5-mm film of seawater was left covering
all sediment samples during transport to the E/Ms at Ulupau. Samples were
kept shaded and shielded from the wind at all times. Temperature shock
did not constitute a problem since water and air temperatures were nearly
the same. The entire operation (collection, transport, and installation
in the E/Ms) took approximately one hour.
Kokokahi Sediments
On 14 January 1976, the first sediment collection was made in 10 m of
water at a site 200 m northeast of Kokokahi Pier (Figure 1). This site was
approximately 500 m east of the Kaneohe sewage treatment plant outfall.
This outfall discharged 13.2 x 103 m3 per day (3.5 mgd) of secondary-treat-
ed sewage. The bottom was soft, reddish-brown silt which appeared largely
terrigenous in origin. Alpheid shrimp burrows (probably Alpheus mackayi),
ranging from 1 to 5 cm in diameter, were dominant; burrow spacing was about
8 cm, or about 200 burrows/m2. Nine 19-cm buckets were filled by the buc-
ket-scoop method and a single 24 cm core was obtained with the large corer.
Total volume of sediment collected was 50 1. The bottom area covered was
about 0.3 m2 (2889 cm2), an area that should have intercepted about 57
shrimp burrows. As reported in Section 6, between 3 and 5% of the burrows
14
-------
are occupied; therefore, about 2 or 3 shrimp would have been expected. Al-
though this first capture was low, subsequent collections yielded the ex-
pected number of shrimp.
A 56-cm core was obtained using the small corer. This core was ex-
truded, sliced lengthwise, and inspected for stratification and burrows.
The top 10 cm exhibited a layered fine structure; at about 30 cm the red-
dish-brown color of the silt darkened, becoming quite black in the last 20
cm of the core. Shrimp burrowing activity was confined to the aerobic top
10 cm. An additional volume of 13.2 1 of sediment was collected by the
bucket-scoop method and washed through a l-mm mesh screen. All organisms
found were returned to the laboratory for identification. A single shrimp,
Alpheus maekayi, found in the top 10 cm of the 56-cm core was added to the
infaunal population installed in the E/M.
The 9 buckets and the large corer filled with Kokokahi sediment were
transported to Ulupau where they were placed in the model-1 E/M (Figure 2).
Tank flow rate was set at 13 1pm the first day, but then reduced to 5 1pm
for the next 50 days. Since no elevated nutrient concentrations could be
detected in the E/M flow-through waters, the flow was further reduced to
0.6 1pm on day-51 day and continued at that rate for the remainder of the
135-day experiment (14 January to 28 May).
Inlet and outlet waters from the E/M were sampled twice daily, roughly
at 0900 and 1500 hours. Samples were analyzed primarily for ammonia-N, but
occasionally for other nutrients (nitrate-N, phosphate-P, and silicate-Si).
Nutrient analyses are described in greater detail later. During the sec-
ond through the fourth day of E/M operation, outlet waters did show a 1.7-
fold increase in ammonia-N concentration (P = 0.01):
inlet ammonia-N (vg-at/1) = 0.50 ±0.05 (5)*
outlet ammonia-N (yg-at/1) = 0.83 ±0.09 (5).
This elevated ammonia-N concentration may have been associated with the in-
stallation of the sediment buckets, since at no other time during the 135-
day run was any statistically significant difference shown between inlet
and outlet nutrient concentrations.
Net oxygen production in the E/M tank was measured reqularly about
1300, using a Yellow Springs Instruments Model 54 oxygen meter. Net oxygen
change (A02) in the waters transitting the tank is considered one of a set
of parameters measuring community metabolism of the E/M residents. Oxygen
content of the supply waters at Ulupau ranges between 6.5 and 7.0 ppm. Un-
der reduced sunlight (12^% of ambient) net oxygen change tended to be
negative (A02 (ppm) = -0.12 ±0.04 (16)) as a result of de-aeration and a
slight amount of respiration.
Of major importance in this pilot study were daily observations to de-
termine whether the captured infaunal populations continued normal activi-
ty. These observations together with a discussion of same are reported in
Section 6. At the termination of the 135-day run, buckets B-l, B-2 and the
corer (total sediment volume = 16.9 1) were washed through a l-mm mesh
* Standard format: mean ± standard error of the mean (number of cases).
15
-------
screen to recover the resident population. The remaining sediment was
washed through a 2-mm screen to obtain the larger organisms only (alpheids
and larger worms). Nothing was found on the 2-mm screen. All organisms
recovered were sent to the laboratory for proper identification.
Fuel Pier Sediments
On 17 to 19 February 1976, microcosm tank #3 at Ulupau was drained,
all material in the tank was removed, and the walls were scraped and washed
with 4 N hydrochloric acid. The tank was converted to a model-2 E/M (Fig-
ure 3) by fitting it with a screen cover reducing illumination to 12^% of
ambient sunlight. Seawater flow was resumed at 9.6 1pm and net change in
oxygen concentration of waters transiting the E/M was determined at 1300
on both 20 and 23 February. That the E/M was nearly free of marine life
was shown by the fact that the A02 values were close to zero, namely -0.35
and -0.20 ppm.
On 26 February 1976, the second sediment collection was made in 10 m
of water at a site 5 m west of the Fuel Pier on the Marine Corps Air Sta-
tion, Kaneohe (Figure 1). The bottom was soft and chalky in color, being
largely calcareous silt. Shrimp burrows U. maakayi) were 1 to 2 cm in
diameter and spaced 8 to 10 cm apart (approximately 160 burrows/m2). Seven
polyethylene trays were filled with sediment using the second collection
method described in Section 4. Total volume of sediment collected was 100
1. The bottom area covered was about 0.8 m2 (8,230 cm2), an area that
should have intercepted about 130 burrows. Using the 3 to 5% burrow-occu-
pancy figure, 4 to 6 shrimp should have been captured. Seven shrimp were
recovered upon terminal inventory, 2 of which were obtained during coring
operations. Thus, 5 shrimp, an expected number, were captured.
The small corer was used to obtain two cores 46 cm in length. These
cores revealed the bottom to be an unstratified mixture of calcareous silt
and rubble. A heavy layer of fragmented bivalve shells at 46 cm prevented
further penetration. These cores (7.2 1 of sediment) were washed through
a 1-mm mesh screen. Two A. maokayi,, which were added to the polyethylene
trays, were found. The remainder of the material retained on the screen
was shell fragments.
The 7 trays were transported to Ulupau and installed in the model-2
E/M (Figures 3 and 7). Due to spread when transferred to the trays, planar
area of sediment exposed in the E/M was about 1 m2 (10,068 cm2). Tank flow
rate remained at 9.6 1pm for the first 8 days. Again in an attempt to de-
tect enhanced nutrient losses, the flow rate was reduced on day-9 to 0.6
1pm where it remained for the duration of the 92-day run (26 February to
28 May).
As with the first E/M run, inlet and outlet waters were sampled twice
daily, roughly at 0900 and 1500 hours, and analyzed as before. Like the
Kokokahi run, net oxygen change in waters transiting the E/M was negative
(A02 (ppm) = -0.16 ±0.11 (8)). Unlike the previous run, no significant
increase in ammonia-N concentration in the outlet waters was observed
shortly after sediment installation even though twice the volume of sedi-
16
-------
Figure 7. Trays of Fuel Pier Sediment in Model-2 Elutriator/Microcosm
Showing Alpheid Shrimp Burrows
17
-------
ment was involved. On 24 March, when the E/M was covered with an opaque
lid and also supplied with water from an LTR-box (Figure 5), inlet ammonia-
N concentration more than doubled (P = 0.01) and was again increased 1.4-
fold (P = 0.05) while transitting the E/M.
At the termination of the 92-day run, tray T-l containing 14 1 of sedi-
ment was washed through a series of screens, 0.5-mm, 1-mm, and 2-mm mesh.
One Eunoe noduiiosa and 1 A. macfayi were found on the 2-mm mesh screen. No
organisms were found on either of the two smaller mesh sizes. Therefore,
the remainder of the Fuel Pier sediment (86 1) was washed through the 2-mm
mesh screen. One A. maokayi was found in trays T-l, T-2, T-4, T-5, and T-
7; 2 in T-6; and none in T-3. According to A. H. Banner (personal commun-
ication), intraspecific conflict between similarly sexed shrimp is common
in A. maekayi. Such conflict could determine the more or less regular
spacing observed. All organisms recovered were sent to the laboratory for
proper identification.
NUTRIENT ANALYSIS
Water Column Samples
Samples of inlet and outlet waters were regularly taken during both
E/M experiments. In addition, simultaneous water samples were taken 15 cm
below the surface and 15 cm above the bottom at both sediment collection
sites, also at Sweep Pier in Karieohe Bay and at Alpha Docks, Hospital
Point, and Merry Point in Pearl Harbor (Figure 1). All samples were fil-
tered through a 2.4-cm-diameter GF/C filter held in a Millipore "Swinnex"
holder into 10-ml polystyrene vials which were capped with polyethylene
lids and frozen immediately. Use of glass filters was found to be required
1n order to obtain valid ammonia determinations. They were therefore used
even in the U.S. Army Corps of Engineers standard elutriation test although
membrane filters are specified.
The samples were later thawed and processed for ammonia-N, nitrate-N,
phosphate-P, and silicate-Si using standard techniques (14) with a Techni-
con II Autoanalyzer. For the ammonia-N analyses, great care was exercised
in sample handling, laboratory cleanliness, and blank preparation. An
internal standard was used and close control was maintained on instrument
gain.
Micro-core Samples
Micro-cores were observed through the clear styrene tube walls for
obvious stratification and resident fauna. Any water which had separated
from the core was carefully decanted and filtered as already described.
The cores were then extruded onto a clean surface and cut into segments
(usually 5 to 10 cm in length). These were separately spooned into 50-ml
round-bottom centrifuge tubes and centrifuged at approximately 3600 rpm for
6 to 12 minutes (maximum extraction volume was usually reached in 6 min-
utes). The supernate was decanted into a 50-ml syringe connected to a GF/C
filter and filtered as described above (Figure 6B). Filter and holder were
changed, and the whole apparatus thoroughly rinsed with filtered Ulupau
18
-------
(oceanic) seawater between each extraction. Approximately 9 ml of each
interstitial water sample was placed into a rinsed 10-ml vial, capped, and
frozen until analysis.
Elutriation Test
On 16 August, 14-liters of sediment were collected using the bucket-
scoop method at both the Kokokahi and the Fuel Pier collection sites. The
collections from a given site were thoroughly mixed and 4 50-ml aliquots
were taken for the elutriation tests. Four 200-ml aliquots of Ulupau inlet
water were also analyzed for nutrients. This water was used as the diluent
in step (a) below. With the exception of the GF/C filters, procedure fol-
lowed was that specified by the U.S. Army Corps of Engineers for the stan-
dard elutriation test (10, 11). The procedure is briefly summarized as
follows:
(a) one part of sediment was combined with 4 parts by volume
of Ulupau source water
(b) sediment and water were shaken mechanically for 30 min-
utes '
(c) the mixture was allowed to settle for 60 minutes
(d) the supernate was decanted and filtered through an GF/C
filter
(e) the filtrate was analyzed as described above for ammonia-
N, nitrate-N, and phosphate-P.
If the concentration of a given moiety in the supernate from this test is
more than 1.5-fold greater than that in the water column where the sediment
is to be deposited (in this case, Ulupau), the sediment, according to the
Corps, is classified as "polluted" in that moiety.
19
-------
SECTION 6
RESULTS AND DISCUSSION
OBSERVATIONS OF INFAUNAL POPULATIONS
After transfer and installation of the sediments in an E/M, the resi-
dent organisms were observed daily for a period of 135 days in the case of
the Kokokahi sediments and for 92 days in the case of the Fuel Pier sedi-
ments. Changes in the surface micro-topography proved to be a convenient
method of recording shrimp activity and of inferring the general health of
the community. These observations are best summarized in a series of
sketches showing major surface features.
Kokokahi Sediments
Burrowing activity of the single Alpheus machzyi added from the small
corer and the other residents collected at Kokokahi (see Section 5), and of
the 14 A. pacificus later added to the E/M may be followed in Figure 8.
This figure shows the surface aspect of the sediment on days 1, 16, 26, 37,
106, and 135. A. mao'ha.yi. makes rdund symmetrical burrow-entrances (Figure
9), while A. paa-lficus makes asymmetrical entrances. The two types of
entrances may be compared in Figure 8C. A. paoificus are usually found in
clean sand on the inner portion of exposed reef flats (15). They tend to
burrow under solid objects because of the coarse-grained nature of their
preferred substrate. Their preference for the sides of the buckets (Figure
8) may be linked to their field behavior. Depressions or "tracks", probab-
ly made by shrimp, are shown as dashed lines. Small mounds, probably made
by annelids, are shown as parentheses. Micro-core sites are shown as tri-
angles.
Note the large number of small mounds appearing on the first day (Fig-
ure 8A) which were quickly obliterated even though there was only one A.
mackayi resident in the E/M. On day-16 (Figure 8B), this single shrimp has
made a total of 18 burrow-entrances (roughly one a day) in only 2 of 10
possible sites, although the absence of the annelid mounds suggests that it
has been active in all 10 containers. Figure 8C shows the surface aspect
four days after two A. pacifians had been added to the E/M. These shrimp
were added to increase bioturbic activity in the hope that elevated nutri-
ent concentrations would be detected in the flow-through waters. No in-
crease in ammonia-N was detected. As they could be caught in the field, a
total of 12 more A. pacif'ious were added to the E/M (1 on day-26, 3 on day-
27, and 8 on day-34). None of these additions caused any detectable in-
20
-------
DAY 1
15176
DAY 36
20H76
D DAY 15
D 30176
r DAY 105
c 291276
MICROCORE LOCATION
DAY 25
9H76
,-nuic
BURROWS
/« ftf* aon«i<
mtcl[iri f,eificM BURROW,
r DAY 134
2 BY 76
Figure 8.
Sketch of Alpheid Burrow Locations at Various Times during the Kokokahi Sediment
Experiment Micro-core Locations also Shown (see text for description)
-------
Figure 9. Closeup of Alpheus maokayi Burrow Entrance
22
-------
crease in outlet ammonia-N concentrations. Figure 8D shows an expansion of
burrowing activity to a number of additional buckets, although the single
A. maakayi present seemed to confine most of his excavation to buckets B-l
and B-2. Sediment was daily thrown out of the buckets onto the floor of
the E/M tank due to these excavations; this was allowed to lie there as a
thin film. By day-36 all vestiges of the brown diatom matte was gone from
all 10 containers. On day-51, the flow rate was reduced from 5 1pm to 0.6
1pm in an attempt to detect elevated nutrient concentrations. No increased
ammom'a-N levels were observed. Although the shape of the burrow entrances
in Figure 8E indicated the continued presence of the single A. maakayi in
bucket B-l, it disappeared from the E/M shortly thereafter. This shrimp,
together with most of the A. paaifious, probably passed out of the E/M on
the flow-through current. Figure 8F (134 days) shows only A. paeificus to
be present. Also shrimp activity was at this time sufficiently reduced so
that smaller sediment surface features (not shown) were beginning to re-
appear.
On 28 May, the Kokokahi E/M run was terminated. The E/M was disman-
tled and the sediment screened as described in Section 5. Two A. paeificus,
as suggested by assymetry and number of burrows in Figure 8F, were found.
All organisms recovered from the Kokokahi sediments are listed in Table 1.
TABLE 1. ORGANISMS FOUND IN KOKOKAHI SEDIMENTS AFTER
135 DAYS IN ULUPAU E/M
(16.9 1 of sediment)
HCZDB* #
1852
374
3763
51
551116
5511206123
5511206124
55112061
552
552101
55210103
5521011001
5521100101
5521100302
55211003
55211101
552113
Organism
Foraminiferida
Actiniaria
Ceriantharia
Nematoda
Nereidae
Lumbrineris heteropoda heteropoda
Marenzeller
Lumbvinevis papi'i'iifeTa Fauvel
Lumbrineris sp.
Sedentaria
Spionidae
tSpioplvmes sp.
Prionospio eirrifera Wiren
Polyoplrthalmas pietus (Dujardin)
Armandia lintermedia
Armandia sp.
Cos sura sp.
Capitellidae
(continued)
B-l
2
-
1
1
-
1
1
-
-
1
1
36
-
-
1
8
17
Number Found
B-2 Corer
2
-
-
-
-
-
-
-
-
1
-
18
-
1
-
11
8
3
2
-
-
1
-
-
1
1
6
3
8
1
1
-
9
7
* Hawaii Coastal Zone Data Bank identification numbers are used by a num-
ber of agencies performing environmental research in the Pacific Basin.
23
-------
TABLE 1 (continued)
HCZDB I
55211701
552122
554
644
6473040103
64730501
6473250208
64732505
6473330201
6483411033
65
7021
7021160101
7022260109
70222601
70225601
831
Organism
Sternasp-is sp.
Terebellidae
Oligochaeta
Copepoda
Amphilochus menehune Barnard
Ampithoe sp.
Elasmopus podllimanus
(Bates) Stebbing
Maera sp.
Jasea lilipuna Barnard
Alpheus paeificue Dana
Insect larvae
Archeogastropoda
Tricolia varidbiHs (Pease)
Rissoina miltisona Tom! in
Eissoina sp.
Triphora sp.
Ascidiacea
TOTAL ORGANISMS
B-l
-
-
2
1
-
1
11
-
-
-
1
1
-
1
1
1
1
91
Number Found
B-2 Corer
58
-
2
1
1
-
-
-
-
-
-
-
-
-
J* -
f*
-
103
_
1
-
2
-
-
1
1
2
2
-
1 f *
1 0*
-
-
-
-
54
* f = fragment; j = juvenile form.
A total of 248 organisms were recovered from 16.9 1 of sediment. From
this total the 2 A. padficus should be subtracted since they were captured
elsewhere and added. The organisms recovered from sediment screened at the
Kokokahi site are presented in Table 2.
TABLE 2. ORGANISMS FOUND AT KOKOKAHI SITE
(13.2 1 of sediment)
HCZDB # Organism
55112061 Iwrfcrineris sp.
552 Polychaete fragment
552101 Spionid sp.
6483411002 Alpheus mackayi Banner & Banner
TOTAL ORGANISMS
Number and Remarks
2
1 with fragment of
sand and mucus tube
1
1, added from small
corer
5
If the shrimp added from the small corer are subtracted, only 4 or-
ganisms were recovered from 13.2 1 of Kokokahi sediment. The remaining
24
-------
organic material on the screen was algal and terrestrial-piant fragments.
To compare resident infaunal populations before and after E/M exposure, the
246 organisms found in the E/M sediments must be reduced to 192 to correct
for the small difference between volumes screened. Thus, after a 135-day
exposure to Ulupau source waters, the resident infauna per unit volume
increased from 4 to 192 or about 50-fold. Some of this increased popula-
tion was possibly only transitting the E/M. Certainly, this was the case
for the A. paoificus (14 were added and only 2 were found in the terminal
inventory). Based on what is known of the biology of the forms reported in
Table 1 (16), the following organisms can probably be assumed to be tran-
sients. Ampkiloous is associated with corals of the genus Pocillopora,
that are abundant on the reef slope off Ulupau. Elasmopus pooillomanus is
also associated with corals and coralline bottoms. The amphipods, Ampi-
thoet Maera, and Jassa, are usually associated with algae such as Saygas-
8-m, Ulva, and Padinat all of which are abundant on the Ulupau reef flats.
A total of 17 more organisms could then be subtracted from the original
count, thus bringing the corrected total to 179 for a 45-fold increase.
While some of the remaining organisms may not be normal residents, cer-
tainly an order of magnitude increase in resident population would seem
reasonable.
Several other features of the Kokokahi sediment run are noteworthy.
Although the movement of reef organisms into the exposed sediment would
tend to mask differences, the minimally disturbed sediment (core sample)
compares favorably with the two scooped samples (B-l and B-2). Secondly,
shrimp activity caused pronounced alterations in the sediment surface in
addition to the appearance of burrow entrances. Small features, such as
the mounds and burrows of annelids, were masked and the brownish diatom
matte that usually forms on undisturbed sediment surfaces was removed.
Thirdly, the shrimp burrows themselves were estimated to increase the sedi-
ment/seawater interface 2- or 3-fold. This increased surface, plus the
amounts of silt suspended as a result of such excavation, caused no de-
tectable increase in the nutrient concentrations of E/M flow-through waters
(see later discussion).
Fuel Pier Sediments
Burrowing activity for this second sediment transfer is presented in
Figure 10. The surface aspect of the sediment is shown on days 1, 3, 10,
and 27. The symbols are the same as those used for Kokokahi (see page 14).
The sequence of observed events is also very similar.
On day-1, 14 burrows, a number of tracks, and many annelid mounds ap-
peared. On day-3, over 70 obvious burrow entrances were counted. Shrimps,
evidently A. maakayi by the shape of burrow entrances, had occupied all but
trays T-3 and T-4 (tray numbers are given in Figure 3). Annelid mounds ap-
peared only where shrimp were not active. Despite all this excavation, no
increased nutrient concentrations in E/M flow-through waters were observed.
On day-5, E/M flow rate was, therefore, reduced from 5 1pm to 0.6 1pm.
Still no increased ammonia-N was detected. By day-10 (Figure IOC), one
week later, the number of burrows had more than doubled. Tray T-3 was
still unworked and still displayed annelid mounds. On day-27 (Figure 10D),
25
-------
en
DAY 1
27 n 76
DAY 3
1 m 76
B
1
0
'^
11
(1 "
/*
r »
% i
i
* ,
t
°0
SMALL
MOUNDS
n
i) n
;, ,, "
*;
O
TRACKS i
*
\{
O
0
DAY 10
8 IE 76
c
, , '
4
* " *
i r f .-
' .*.«
' * *
*
1 ' '
f
1 '
'
* f
«
- *
A 'LOCATIONS
OF MICROCORES
TAKEN ON 12 HI 76 L
DAY 27
25 m. 76
D
A 'LOCATIONS
OF MICROCORES
TAKEN ON 29 H 76
tl
.
f
0
'*»,'
» . ' » » «.
:-. '
w
_, v
. - - . -
*. *
i
.:- - -.
'.
o
*
t
,
.
A
J
* ' * '
.
»
. t »
.
» -
p
o
.A*. .
«
«
1
: ' '
.. - *.
O
': «.'
A f *
*
' * i
* * *
i
*
" /
0 0
. *
*
Figure 10. Sketch of Alpheid Burrow Locations at Various Times during the Fuel P1er Sediment Experiment
Micro-core Locations also Shown (see text for description)
-------
all trays were occupied by shrimp; thus, micro-topographic features were
completely masked. Also on day-27, the E/M was fitted with an opague cov-
er and supplied with water from an LRT-box (see Section 4). The number of
burrow entrances (Figure 10D) per tray were determined as follows:
Tray #1 30 Tray #5 35
Tray #2 19 Tray #6 24
Tray #3 27 Tray #7 25
Tray #4 22 TOTAL ~18T~
Since terminal inventory showed 7 A. maakayi, distributed about one shrimp
per tray, to be resident in the E/M, there are about 26 ±5 burrow en-
trances per shrimp, or, judging from the surface aspect alone, burrow oc-
cupancy can be estimated to be between 3 and 5%. As suggested earlier, in-
traspecific conflict may be the reason for the relatively uniform distribu-
tion of shrimp.
On 28 May, the Fuel Pier E/M run was also terminated. The E/M was
dismantled and the sediment screened as described in Section 5. The organ-
isms found are listed in Table 3.
TABLE 3. ORGANISMS FOUND IN FUEL PIER SEDIMENTS AFTER
92 DAYS IN ULUPAU E/M
(14.0 1 of sediment)
HCZDB #
5511013303
551120
55112061
552108
6483411002
Organism
Eunoe nodutosa Day
Eunicidae
Lwribrineris spp.
Orbiniidae
Alpheus mackayi Banner & Banner
TOTAL ORGANISMS
Number Found
8
2
5
1 & frag.
7
23
Two A. mackayi only were found in the 7.2 1 of sediment screened at
the Fuel Pier collection site. These must be subtracted from the total in
Table 3. If the 21 organisms are adjusted to a 7.2 1 volume, about 11 or-
ganisms were found to be resident in Fuel Pier sediments after 92 days at
Ulupau. This represents a 5-fold or greater increase in population as op-
posed to a conservative 10-fold increase seen in the Kokokahi sediments.
That some smaller animals are apparently missed in the field screening is
shown by the appearance in both E/M runs of annelid mounds within 24 hours
of transfer. Screening effort and mesh size were, however, the same in
both field and terminal inventories. Repeated experiments to confirm the
observed increases in infaunal populations were indeed beyond the stated
objectives of the project and, therefore, were not performed.
In the following discussion of nutrients, the Kokokahi sediments are
shown to be especially rich in phosphorus, an element demonstrated to be
stimulatory to reef communities (13). This fact may have contributed to
the larger increases observed for that experimental run. Although further
corroboration is necessary, there seems enough evidence to suggest that the
27
-------
relatively unoccupied sediments of Kaneohe Bay exhibit about a 10-fold in-
crease in resident infauna, when placed in the clean-water environment re-
presented by Ulupau. This increase may result either from enhanced repro-
duction among organisms already resident or from settlement of new resi-
dents out of the supply waters. It may further be suggested that the con-
dition of waters at the collection sites apparently places constraints on
infaunal residency. In brief, the transferred nutrient-rich sediments seem
to operate like an analogue to an "artificial reef". Furthermore, the be-
havior of the infaunal communities is the opposite of that observed in
transferred fouling panel or wood block communities (12). These latter are
more dependent on water column conditions. It is noteworthy that, although
expressly sought, no statistically significant increases in nutrient con-
centration could be detected in the flow-through waters of either E/M ex-
periment despite the presence of nutrient-rich sediments and despite the
observed bioturbic activities of the infaunal residents (see following
discussion).
These observations are of sufficient interest to substantiate strong
recommendations that further transfer experiments using both sediments and
fouling panels be performed. Sediments should include those classified as
polluted by heavy metals. If similar population increases can be demon-
strated with such sediments, presently accepted strictures on the disposi-
tion of dredge material would appear to require re-examination. Further
study of the inverse response of transferred fouling panels and infaunal
residents should produce greater understanding of marine community reac-
tions to various environmental conditions. Such improved understanding
should result in better selection of practical bioindicators of water
quality.
NUTRIENT ANALYSIS
Water Column Samples
As described in Section 5, samples of inlet and outlet waters were
regularly taken during both E/M experiments. These water samples were
augmented by surface and bottom collections in the field at the sediment
collection sites and at various other locations shown in Figure 1. As
stated in Secion 4, Ulupau source waters exhibit short-period nutrient
"noise" due to combined low-tide, low-surf conditions (Figure 4). Daily
nutrient concentrations reported in yg-at/1 were therefore averaged over
arbitrarily selected 10-day intervals. A plot of the standard error en-
velope for ammonia-N concentrations in E/M inlet waters is presented in
Figure 11. Statistically significant differences are flagged by a delta
and accompanying probability statement, placed between the means in ques-
tion. A significant increase (P = 0.01), which is coincident with the in-
sertion of an LRT-box in the supply line to the model-2 E/M, does appear
in Figure 11. The decrease (P = 0.05), also shown, is not understood. It
is probably an artifact of period selection. Real seasonal (and possibly
other) variations in the nutrient concentrations of Ulupau supply waters do
occur. For instance, a seasonal difference may be seen when mean nutrient
concentrations for this experimental series (#7601) are compared with those
of another series (#7503) performed in the early fall (Table 4).
28
-------
10-DAY STANDARD ERROR ENVELOPE OF INLET AMMONIA-N CONC.
ULUPAU SOURCE WATER
20-
01
3.
1.0-
-KOKOKAHI FUEL PIER
SEDIMENT SEDIMENT
I
15 JAN
24 JAN
I
25 JAN
4 FEB
I
5 FEB
14 FEB
T
15 FEB
24 FEB
25 FEB
5 MAR
1
6 MAR
15 MAR
10 DAY PERIODS (1976)
16 MAR
25 MAR
I
26 MAR
4 APR
I
5 APR
14 APR
Figure 11. 10-Day Standard-Error Envelope of Inlet Ammonia-N
Concentration for Ulupau Source Waters
29
-------
TABLE 4. SEASONAL CHANGES IN NUTRIENT CONCENTRATION
IN ULUPAU SUPPLY WATERS
(mean ± std. error (cases) in yg-at/1)
Nutrient
Ex #7503
Aug-Sep 1975
ammonia-N
nitrate-N
phosphate-P
2.98
0.32
0.11
±0.03
±0.03
±0.01
(18)
(18)
18)
Ex #7601
Change (sign, level)
Jan 1976
1.07
0.98
0.25
±0.
±0.
±0.
14
16
02
18)
18J
18)
0.4x
3.1x
2.3x
decrease
increase
increase
(P-
(P =
P-
0.01)
0.01)
0.01)
Except for silica, the short-period "noise" in supply-water nutrients
remained reasonably constant, as may be seen from an inspection of the
tables of inlet and outlet concentrations given in Appendix A. Except for
the short period after the installation of the Kokokahi sediments discussed
in Section 5, neither the presence of the sediments nor the addition of
shrimp seemed to affect nutrient concentrations in E/M outlet waters. In
fact, there was no statistically significant difference between these out-
let waters and water samples taken 15 cm above the bottom at the collec-
tion sites. Values for ammonia-N are presented in Table 5.
TABLE 5. AMMONIA-N CONCENTRATIONS IN E/M AND FIELD WATER SAMPLES
(mean ± std error (cases) in yg-at/1, Feb-Mar 1976)
Kokokahi
S*
B*
S
B
S
B
CS*
0.65
1.03
Fuel
CS*
2.44
0.91
Pearl
Alpha
3.64
1.55
(1)
(1)
Pier
±0.57
±0.13
(3)
(3)
Sweep
0.57
1.05
Pier
(1)
(1)
CS &
0
1
.61
.04
SP*
±0.04 (2)
±0.01 (2)
E/M
1.15
E/M
0.92
Outlet
±0.14
Outlet
±0.08
(19)
(35)
Harbor
Docks
±1.21
±0.07
Hospital Pt.
(2)
(2)
5.94
2.77
±1.62 (2)
±0.34 (2)
Merry
3
0
.78
.81
Pt.
(1)
(1)
all
4.59
1.89
Pearl Harbor
±0.85
±0.40
(5)
(5)
* B = sample 15 cm above the bottom; CS
cm below surface; SP = Sweep Pier.
collection site; S = sample 15
The similarity in nutrient concentrations between E/M outlet waters
and samples collected 15 cm above the bottom suggests that the sediment-
to-water exchange rates in the E/Ms approximate steady state conditions
at the collection sites.
30
-------
There was, however, a significant difference (P = 0.01) between sur-
face and bottom ammonia-N concentrations at Fuel Pier and at all locations
in Pearl Harbor. Generally, the surface ammonia-N concentrations were
about 2%-fold greater. This trend was apparently reversed at Kokokahi and
Sweep Pier. The other nutrients (m'trate-N and phosphate-P) did not show
surface-to-bottom differences.
Both surface and bottom ammonia-N concentrations in Pearl Harbor were
greater than in Kaneohe Bay (P = 0.05 or 0.01 depending on which means are
compared). With the exception of bottom phosphate, nitrate-N and phosphate-
P concentrations were approximately the same in both harbors. The 3 bottom-
water samples from Kaneohe Bay showed about twice (P = 0.01) the phosphate-
P concentration that was found in the 5 bottom-water samples taken in Pearl
Harbor. In view of the small number of samples and the larger phosphate
concentrations normally reported for Pearl Harbor (17), this observation
may not be generally true for the two harbors. The proximity of the Koko-
kahi collection site to the sewer outfall (see following discussion of
micro-core results) may explain the higher bottom phosphate-P values found
in Kaneohe Bay.
Micro-core Samples
A total of 22 micro-cores were made: 8 in Kaneohe Bay, 6 in Pearl Har-
bor, and 4 in each of the 2 E/M runs (see Figures 1, 8, and 10 for loca-
tions). Since microcoring technique was investigatory in nature, cores
were sectioned in accordance with obvious differences in sediment color,
grain size, or biological activity. Although there were indications of
elevated nutrient losses from surface layers, variations in sectioning
rendered comparisons between field and E/M micro-cores inconclusive. Loss
of nutrients from surface-layer interstitial waters ought to be more pro-
nounced in the E/Ms than in the field, since flow-through waters are lower
in nutrient content and since burrowing activity per unit surface area is
more intense. No statistically significant differences, however, were
observed. For instance, calculated* ammonia-N content (yg-at in 33 ml of
sediment) of the top 8 cm were:
Kokokahi site 2.14 ±0.82 (3) Kokokahi E/M 1.36 ±0.27 (4)
Fuel Pier site 1.26 ±0.54 (2) Fuel Pier E/M 0.58 ±0.14 (4).
The same was true for the other nutrients measured. Some typical micro-
core results are presented in Figures 12 through 14.
A summary of ammonia-N data for all micro-cores is presented in Table
6 on the following page. In Table 6, ammonia-N content has been calculated*
for a section volume of 21 ml; interstitial concentrations were those ob-
served for the full section. Ammonia-N most consistently showed an in-
crease in concentration with depth. The other nutrients showed no consist-
ent trends.
* Ammonia-N content had to be calculated due to variable length of core
sections. The volume of an 8 cm length of micro-core is 33 ml; that of
a 5 cm length is 21 ml.
31
-------
Con #7 Kt*0k*i Fittd Sitt. ?6M»r 1976
ctapth PO. NO, NH, &
0-10 457,2 3.2 154.8 537.3
10-20 2934 \ 1 180.0 558.0
Core 316 Kokohtbi E/M 29 Apr 1976
depth PO. NO, NH, Si
lcml t(ig-»i/ll
wne 0- 4 4.8 S.5 53.5 423
burrow*
4- B 52 63 923 1244
8-14 3.4 43 1240 846
Core*17 Kokokahi E/M. 29 Apr 1978
depth PO, NO, NH,
(cm) l«-»t/l)
4- 8 2.1 3.7 168.9 143.B
8-13 25 3.9 297.7 192.0
JO-30 362 7 0.8 239 4 389 7
Figure 12. Typical Kokokahi Field and E/M Micro-cores
Core »5 fu* Pier Field &te. 26 Mar 1976
dtpth PO. NO, NH, 5<
fine»tt 0- 3 477 1.6 97.4 842-4
9tX9 16
1366
13-23 117.7 10 178-2 2106
23-33 56.7 1.8 128.7 5157
Care=2l Fu»IP«fE,'M, 29 Apr 1976
burrow*
ndvokte
Core =22 Fuel Pier E/M. 29 Apr 1976
PO. NO, NH, Si
0- 4 7.9 4.4
4- 8 11.3 4.6 110.6
Figure 13. Typical Fuel Pier Field and E/M Micro-cores
Core *10 Pwt M»rtxx Alpfia Dock). 28 Apr 1976
PO. NO , NH, S-
0-5 11241 4.4
1525 1025 2.1 333.0 304.6
Core'12 Pwrl Harbor. Ho«>
-------
TABLE 6. CALCULATED AMMONIA-N CONTENT AND (OBSERVED INTERSTITIAL CONCEN-
TRATION) FOR VARIOUS MICRO-CORE LAYERS
(content = yg-at In 21 ml; concentration = yg-at/1)
Core
3
4
5
6
7
8
9
10
11
12
13
14
1
15
16
17
18
2
19
20
21
22
# & Descrp.*
Sweep, Fid
FP, Fid
FP, Fid
Kk, Fid
Kk, Fid
Kk, Fid
Alpha, P.H.
Alpha, P.H.
Hosp. Pt, P.H.
Hosp. Pt, P.H.
Merry Pt, P.H.
Merry Pt, P.H.
Kk, E/M, B-l
Kk, E/M, B-l
Kk, E/M, B-2
Kk, E/M, B-6
Kk, E/M, B-8
FP, E/M, T-2
FP, E/M, T-2
FP, E/M, T-3
FP, E/M, T-4
FP, E/M, T-5
0 to 5
-
0.43
1.14
2.34
1.03
0.75
0.66
cm 15 to 20
[ 39.6
! 47.9
97.4
154.8
cm 25 to
0.45 (108.9) 1.67 I
(
~ ) '
30 cm
' 99.0)
\
/
0.89 (178.2) 0.38 (128.7)
(
- ) -I
:\
/
1.23 (180.0) 1.34 (239.4)
85.9) 1.09 (158.8) 0.72 (158.4)
63.9) 0.92 (157.5) 0.78 (117.0)
2.63 (252.9) 2.49 (333.0) - ( - )
0.55 I
[ 65.7
0.80 (100.8
2.22 (288.9
1.50 |
- '
0.46 i
0.40 i
0.35 i
0.41 i
- 1
0.43 1
0.50 <
0.16 I
0.14 1
0.36 4
1.17 19
2.78 31
4.1) 1.28 (256.5)
3.5) 1.74 (279.9)
1.4) 3.04 (417.6)
[194.4) 2.24 (337.5) 3.24 (354.6)
[ 77.4) - (
[ 60.1) - (
[ 53.5
[ 40.1
[ 49.8
(
(
(
[ 48.0) - (
57.1
[ 54. 7X
; 15.8) - (
[ 15.7) - (
- ) - 1
. ) . i
- )
- )
- <
- )
- )
r \
/
' - )
- )
- )
; \
i ~ i
\
- )
- )
: - )
[ - )
* Cores numbered sequentially according to date of sample; B = bucket; Fid
= field sample; FP = Fuel Pier; Hosp. Pt = Hospital Point; Kk = Kokokahi;
P.H. = Pearl Harbor; Sweep = Sweep Pier; T = tray.
The average interstitial concentrations for the 4 nutrients measured
are presented in Table 7 on following page. Where the standard deviation
was greater than half the mean, the value is followed by a "V". These
large variations were usually caused by low surface-layer values or a sin-
gle high value somewhere in the core sections. Pearl Harbor cores were
higher in ammonia-N and nitrate-N than field samples from Kaneohe Bay, but
lower in phosphate-P. As reported above, lower phosphate-P concentrations
were also found in bottom-water samples from Pearl Harbor. Although sam-
ples varied considerably, the highest average phosphate-P values were ob-
served in the Kokokahi sediments. Perhaps these elevated concentrations
are due to the proximity of the collection site to the sewer outfall.
Apparently, the sediments lost phosphate-P but gained nitrate-N during
their 92- and 135-day exposures in the Ulupau E/Ms. Further work using the
micro-coring technique would be required to substantiate these trends.
33
-------
TABLE 7. MEAN NUTRIENT CONCENTRATION IN MICRO-CORE
INTERSTITIAL WATERS
(yg-at/1; V = std. deviation greater than half the mean)
Core # & Descrp.* phosphate-P nitrate-N ammonia-N
3
4
5
6
7
8
9
10
11
12
13
14
1
15
16
17
18
2
19
20
21
22
Sweep, Fid
FP, Fid
FP, Fid
Kk, Fid
Kk, Fid
Kk, Fid
Alpha, P.M.
Alpha, P.M.
Hosp. Pt, P.M.
Hosp. Pt, P.H.
Merry Pt, P.H.
Merry Pt, P.H.
Kk, E/M, B-l
Kk, E/M, B-l
Kk, E/M, B-2
Kk, E/M, B-6
Kk, E/M, B-8
FP, E/M, T-2
FP, E/M, T-2
FP, E/M, T-3
FP, E/M, T-4
FP, E/M, T-5
146. V
250. V
78.2
432.
371.
45.7 V
27.5 V
144.
32.8
114.
185.
81.8
-
5.20
4.47
2.43
3.48
-
14.4
14.4
15.6
9.60
1.58
1.40
1.50
9.0
7.70 V
1.53 V
4.65 V
2.93
2.68
4.58
2.02
3.17
-
3.70
5.37
4.23
5.45
-
4.55
4.95
6.30 V
4.50
122.
51.1
141.
239.
191.
122.
120.
280.
103. V
174.
312.
302.
77.4
199. V
89.9
169. V
105.
48.0 V
37.6
60.8
16.6
63.2 V
silicate-Si
308.
695.
426.
390.
495.
276.
389.
299.
138.
255.
372.
381.
-
142.
83.8
130.
154.
-
-
-
-
-
V
V
V
V
V
V
V
* see Table 6 for key.
Elutriation Test
Samples of sediment were collected and subjected to the standard elu-
triation test in accordance with U.S. Army Corps of Engineers procedures
(Section 5). The results of these tests and the analysis of the diluent
waters are presented in Table 8 on the following page. As may be seen, the
amounts of phosphate-P, ammonia-N, and silicate-Si released by both Koko-
kahi and Fuel Pier sediments are well in excess of 1.5-fold greater than
that found in Ulupau source waters. Values range from 3-fold to almost 30-
fold. According to the criterion of the Environmental Protection Agency
and the Corps of Engineers, these sediments would be classified as polluted
in phosphate, ammonia, and silicate. However, in the authors' opinions,
the term "nutrient-rich" is to be preferred.
Comparison of elutriation test and micro-core analyses produces inter-
esting results. To enable such comparison, the nutrient release values (R)
from the elutriation test must be corrected (corr.E). This is done by sub-
tracting the ambient concentration of a given nutrient in Ulupau source
water from that released from the sediment and then multiplying by 5 to
correct for the l-to-4 dilution. The resulting value should approximate
34
-------
the mean concentration of that nutrient in the interstitial waters of the
tested sediment. The mean micro-core values were obtained by averaging
data presented in Table 7. With the exception of nitrate-N, corr.E and E/M
micro-core values show good correspondence. Field micro-core values,
however, show striking differences, especially so for phosphate-P. They
suggest that enhanced release of nutrients, similar to that brought about
by the standard elutriation test, is occurring in the E/Ms.
TABLE 8. NUTRIENT RELEASES ON STANDARD ELUTRIATION TEST
AND COMPARISON WITH MICRO-CORE RESULTS
(yg-at/1; mean ± std. error for 4 replicates)
CS/test*
Kk, R
FP, R
UI
ratio: R/UI
Kk, corr.E
Kk, E/M cores
Kk, Fid cores
FP, corr.E
FP, E/M cores
Fp, Fid cores
phosphate-P
1.08 ±0.02
2.53 ±0.07
0.32 ±0.04
3x to 8x
3.8
3.9 ±1.2
283. ±208.
11.0
13.5 ±2.7
164. ±121.
nitrate-N
0.66 ±0.15
0.63 ±0.51
0.48 ±0.14
1.3x to 1.4x
0.90
4.7 ±0.9
6.1 ±4.0
0.75
5.1^0.8
1.4 ±0.1
ammonia-N
27.9 ±1.34
10.0 ±0.39
0.96±0.22
lOx to 20x
135.
128. ±53.
184. ±59.
45.4
45.2 ±19.
96.0 ±63.
silicate-Si
51.8 ±10.9
46.9 ±2.67
12.3 ±13.1
4x
197.
127. ±31.
387. ±110.
172.
560. ±190.
* corr.E = corrected elutriation test (see text); CS = collection site; R =
released nutrient concentration; UI = Ulupau inlet waters; see Table 6 for
rest of key.
For ammonia-N at least, the decrease in interstitial water concentra-
tions as the sediment surface is approached implies either enhanced sur-
face exchange or bacterial regeneration. The latter activity might also
explain the phosphate loses and nitrate gains suggested by the E/M micro-
cores. Evidently, due to currents or diffusion, neither exchange rates nor
the effect of bioturbic activity upon such rates can be measured with the
water-column techniques used. Further use of micro-cores and measurement
of nutrient concentration in the burrow-tunnel waters suggest themselves as
good potential means of making such determinations.
35
-------
REFERENCES
1. Cox, D. C. et al. Estuarine Pollution in the State of Hawaii - Part
II: Kaneohe Bay Study. Water Resources Research Center, Technical Re-
port No. 31, 1969. pp 185-301.
2. Anon. Uses of Kaneohe Bay: An Interim Report of the Kaneohe Bay Task
Force. Governor's Kaneohe Bay Task Force, Sept. report, 1974. 30 pp.
3. Anon. Soil Erosion Control in Kaneohe Bay Region: An Investigation of
Agency Roles. Governor's Kaneohe Bay Task Force, Feb. report, 1975.
10 pp.
4. Smith, S. V. Kaneohe Bay: Responses of a Tropical Estuary to Relax-
ation of Sewage Stress. HIMB research proposal, 1975. 45 pp.
5. Henderson, R. S. and Evans III, E. C. Continuous Flow Marine Organism
Holding Tanks: A Proposed Joint NUC/HIMB Project for Marine Biological
and Environmental Studies. NUC TN-1123, 1973. 58 pp.
6. Nichols, F. H. Sediment Turnover by a Deposit-Feeding Polychaete.
Limnol. & Oceanogr. 19: 945-950, 1974.
7. Evans III, E. C. et al. Pearl Harbor Biological Survey - Final Re-
port. NUC TN-1128, 1974. 718 pp.
8. Smith, S. V. Kaneohe Bay: A Preliminary Report on the Responses of a
Coral Reef/Estuary Ecosystem to Relaxation of Sewage Stress. Proc.
Third International Coral Reef Symposium, 1977, in press.
9. Reise, K. Predator Exclusion Experiments in an Intertidal Mud-flat.
Proc. Sixth International Helgoland Symposium, 1976, in press.
10. Anon. Ocean Dumping Criteria. Federal Register 38(94): 12872-12877,
1973.
11. Anon. Ocean Dumping Final Criteria. Federal Register 38(198): 28610-
28621, 1973.
12. Evans III, E. C. Microcosm responses to Environmental Perturbants -
An Extension of Baseline Field Survey. Proc. Sixth International Hel-
goland Symposium, 1976, in press.
36
-------
13. Henderson, R. S., Evans III, E. C., and Smith, S. V. Flow-Through
Microcosms for Simulation of Marine Ecosystems: Development and In-
tercomparison of Open Coast and Bay Facilities. NUC TP-519, 1976.
69 pp.
14. Strickland, J. D. H. and Parsons, T. R. A Practical Handbook of
Seawater Analysis. Fisheries Research Board of Canada, Bulletin No.
167,1968. 311 pp.
15. Banner, A. H. and Banner, D. M. Contributions to the Knowledge of
the Alpheid Shrimp of the Pacific Ocean - Part XVII. Additional
Notes on the Hawaiian Alpheids: New Species, Subspecies, and Some
Nomenclatorial Changes. Pac. Sci. 28(4): 423-437, 1974.
16. Barnard, J. L. Keys to the Hawaiian Marine Gammaridea, 0-30 Meters.
Smithsonian Contributions to Zoology, No. 58, 1971. 135 pp.
17. Grovhoug, J. G. A Preliminary Evaluation of Environmental Indicator
Systems in Hawaii. NUC TN-1689, 1976. 132 pp.
37
-------
APPENDIX A
NUTRIENT LEVELS IN E/M FLOW-THROUGH WATERS
Ulupau source waters exhibit short-period nutrient "noise" due to
combined low-tide, low-surf conditions. Nutrient levels tabulated below
are therefore presented as means for the following 10-day intervals:
Period A
B
C
D
E
F
G
H
I 5 Apr - 14 Apr
All values are reported in yg-at/liter of the element, using the format:
mean ± standard error (number of measurements). Waters flowing into an
E/M or inlet water are marked by the symbol "I"; waters flowing out or out-
let waters are marked "0". The standard error envelope for inlet ammonia-N
concentrations given in Table A-l are presented in Figure 11 of the text.
15 Jan -
25 Jan -
5 Feb -
15 Feb -
25 Feb -
6 Mar -
16 Mar -
26 Mar -
24 Jan 1976
4 Feb "
14 Feb "
24 Feb "
5 Mar "
15 Mar "
25 Mar "
4 Apr "
TABLE A-l. AMMONIA-N CONCENTRATIONS FOR ULUPAU E/M WATERS
(yg-at/1; mean ± std. error (cases); I = inlet, 0 = outlet)
Period Kokokahi Sediments
A I
0
B I
0
C I
0
D I
0
E I
0
F I
0
1.10 ±0.16 (15)
1.01 ±0.11 (15)
1.05 ±0.10 (12)
1.09 ±0.10 (12)
1.20 ±0.19 (13)
1.10 ±0.11 (13)
0.70 ±0.12 (10)
0.69 ±0.08 (10)
0.97 ±0.16 ( 9)
1.34 ±0.18 ( 9)
1.16 ±0.20 ( 4)
0.84 ±0.22 ( 4)
(continued)
Fuel Pier Sediments
I 1.06 ±0.11 (12)
0 1.11 ±0.15 (12)
I 0.95 ±0.12 (11)
0 1.05 ±0.14 (11)
38
-------
TABLE A-l. (continued)
Period Kokokahi Sediments
G I 0.69 ±0.14 ( 6)
0 1.08 ±0.31 ( 6)
H
I
Fuel Pier Sediments
I 0.77 ±0.15 (12)
0 0.65 ±0.08 (13)
I 1.61 ±0.23 ( 7)
0 2.33 ±0.24 (13)
I 2.14 ±0.26 ( 6)
0 2.49 ±0.28 (14)
TABLE A-2. NITRATE-N CONCENTRATIONS
(yg-at/1; mean ± std. error (cases);
FOR ULUPAU E/M WATERS
I = inlet, 0 = outlet)
Period Kokokahi Sediments
A I 0.92 ±0.16 (15)
0 0.76 ±0.16 (15)
B I 1.29 ±0.56 ( 3)
0 0.88 ±0.32 ( 3)
F I 0.49 ±0.21 ( 3)
0 0.13 ±0.02 ( 3)
G I 0.24 ±0.02 ( 6)
0 0.28 ±0.10 f 6)
Fuel Pier Sediments
I 0.60 ±0.23 ( 7)
0 0.29 ±0.05 ( 7)
I 0.34 ±0.04 (12)
0 0.29 ±0.05 (13)
TABLE A-3. PHOSPHATE-P CONCENTRATIONS FOR ULUPAU E/M WATERS
(yg-at/1; mean ± std. error (cases); I = inlet, 0 = outlet)
Period Kokokahi Sediments
A I 0.25 ±0.02 (15)
0 0.22 ±0.02 (15)
B I 0.25 ±0.02 ( 3)
0 0.25 ±0.03 ( 3)
F I 0.15 ±0.06 ( 3)
0 0.17 ±0.02 ( 3)
G I 0.76 ±0.52 ( 6)
0 0.59 ±0.24 ( 6)
Fuel Pier Sediments
I 0.11 ±0.02 ( 7)
0 0.18 ±0.03 ( 7)
I 0.29 ±0.07 (12)
0 0.54 ±0.27 (13)
39
-------
TABLE A-4. SILICATE-SI CONCENTRATIONS FOR ULUPAU E/M WATERS
(vg-at/1; mean ± std. error (cases); I = inlet, 0= outlet)
Period Kokokahi Sediments Fuel Pier Sediments
(9)
( 9)
B I 12.66 ±4.64
0 3.58 ±0.34
C I 12.72 ±6.70 ( 7)
0 9.22 ±4.54 ( 7)
H I 6.29 ±1.49 ( 6)
0 7.69 ±1.07 (11)
I I 7.57 ±1.19 ( 6)
0 7.57 ±1.18 (14)
40
-------
TECHNICAL REPORT DATA
(I'lcase read laturuc lions nn lite reverse before completing)
t. mi'OHi NO.
2.
_EPA-600/_3-77-093_
1. TITLt AND SUB MILE
ELUTRIATOR/MICROCOSM SYSTEM PILOT MODEL AND TEST
3. RECIPIENT'S ACCESSIOt»NO.
5. REPORT DATE
August 1977 issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHORIS)
E. C. Evans III and R. Scott Henderson
8. PERFORMING ORGANIZATION REPORT NO.
<». PERFORMING ORG \NIZATION NAME AND ADDRESS
Naval Ocean Systems Center, Hawaii Lab
P.O. Box 997, Kailua, HI 96734
10. PROGRAM ELEMENT NO.
1BA608
11. CONTRACT/GRANT NO.
LAG D6-F941
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Research Laboratory- Narragansett, RI
Office of Research and Development
U.S. Environmental Protection Agency
Narragansett, Rhode Island 02882
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/05
16. SUPPLEMENTARY NOTES
16, ABSTRACT
An effective technique is described for transferring soft benthic
sediments with their resident infauna intact into special holding systems
(elutriator/microcosms) which permitted the study under controlled condi-
tions of both nutrient exchange from the sediments and the activities of
their infaunal communities. The effects of bioturbic activity on nutrient
exchange rates could not be detected by water column measurements but could
be seen using a specially developed micro-coring technique. Alpheid
shrimp activity was estimated to increase the sediment surface area by
2- or 3- fold and also tended to mask signs of burrowing by smaller
infaunal animals. An increase in infaunal population after sediment
transfer to a clean-water situation suggested that the sediment itself
was acting like an analogue to an "artificial reef". Continued investigation
of this "artificial-reef effect" is recommended.
17.
a.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Benthos
Aquatic Animals
Underwater environments
b.lDENTIFIERS/OPEN ENDED TERMS
nutrient exchange
Micro-coring techniques
COSATl Field/Group
06F
IT uisrmwurioN STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report I
UNCLASSIFIED
20. SECURITY CLASS (This rage)
UNCLASSIFIED
21. NO. OF PAGES
51
22. PRICE
41
ft U.S. GOVERNMENT PRINTING OFFICE: 1977- 241-037:74
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