XFWC-A 298 1-17 (1968)
U.S. Fish Wildl. Serv.
Circ.

Research Facilities of the

RADIOBIOLOGICAL LABORATORY

BUREAU OF COMMERCIAL FISHERIES

Beaufort, North Carolina

UNITED STATES DEPARTMENT OF THE INTERIOR

FISH AND WILDLIFE SERVICE

BUREAU OF COMMERCIAL FISHERIES Circular 298

UNITED STATES DEPARTMENT OF THE INTERIOR
U.S. Fish and Wildlife Service

BUREAU OF COMMERCIAL FISHERIES

RESEARCH FACILITIES

OF THE

RADIOBIOLOGICAL LABORATORY

BUREAU OF COMMERCIAL FISHERIES

Beaufort, North Carolina

T. R. RICE, Director

T. W. DUKE, Assistant Director

and

Staff

Circular 298

Washington, D.C.
December 1968

The Radiobiological Laboratory is supported jointly by the
Bureau of Commercial Fisheries and the U.S. Atomic Energy
Commission.

11

CONTENTS

Page

Introduction 1

History 1

Facilities 8

Organization 10

Research activities 10

Estuarine ecology 11

Biogeochemistry 11

Pollution studies 16

Radiation effects 16

Future research 17

Research Facilities of of the
Radiobiological Laboratory, Bureau of Commercial Fisheries

Beaufort, North Carolina

ABSTRACT

The history, facilities, and organization are discussed. Research is performed
on estuarine ecology, biogeochemistry, pollution, and effects of radiation.

INTRODUCTION

The Radiobiological Laboratory is concerned
with research that can be summed up in the
term "radioecology." Radioecology is a rela-
tively new term that refers to the study of
radioactivity in our environment and the use
of radioactive elements in ecological studies.
Although the term radioecology was coined
only recently, radioactivity has been present
in man's environment since the earth was
formed, and references to principles that are
ecological in nature appeared in writings of
the early philosophers. The need for this
"new" division of ecology, however, was
brought about by technological advances of
modern man. Radioactivity has been added to
the environment by the explosion of nuclear
weapons in the atmosphere and by the release
of radioactive wastes into streams, estuaries,
and the oceans. Mannnade radioactivity did not
begin to appear in estuaries and the oceans
until 1945.

The Bureau of Commercial Fisheries is
vitally concerned with any situation that nnight
adversely affect our fishery resources. The
introduction of radioactive materials into the
aquatic environment might constitute such a
situation, and those in the Bureau who so
quickly saw the need of a Radiobiological
Program to study these problems deserve
much credit for their insight. Although interest
in radiobiology is now widespread and nnany
organizations in this country and throughout
the world are engaged in radiobiological re-
search, the Bureau's progrann carried on at
the Radiobiological Laboratory was one of the
first and continues to be unique in many re-
spects.

History

The present aims are an expansion of the
objectives outlined in September 1948. The
following statements were included in the

project outline submitted to the Atomic Energy
Commission (AEC) in November 1948.

"Objective:

(a) To ascertain the levels of activity which
will accumulate in various invertebrate
animals of littoral marine waters by the
selective absorption of radioactive ions.

(b) To investigate the avenues of access to
marine organisms of radioactive ma-
terials through direct absorption or in-
gestion of dissolved or suspended fission
products, their transfer throughdifferent
levels in the food chainand their ultinnate
removal through metabolism, decay,
sedimentation, dilution, or transport."

This proposal was subnnitted under the title
"A survey of accumulation of radioactive nna-
terials by marine invertebrate animals." A
supplennental progrann entitled "Uptake of
ra.Uoactive elements by fish, particularly
marine fish" was established in 1954, and
another project entitled "The effects of ioniz-
ing radiation on marine fishery organisms"
was added in 1956.

Most of the earlier work was concerned with
the filter -feeding lamellibranch nnollusks--
oysters, claims, and scallops. Ennphasis was
therefore placed on experimental work with
marine phytoplankton--the food of these mol-
lusks. Also, some studies were carried on dur-
ing the first 2 years on the accumulation and
retention of separated fission products by the
commercially important blue crab. Small tanks
and aquaria were used for these experiments,
and possible food-chain patterns were in-
terpreted fronn data on accumulation in tests
based on single species or limited segmients
of a food chain.

When the program began in 1948, interest
was great in the effects of contamination of
coastal waters, harbors, and estuaries from
atomic bombs, such as were being tested in

Figure 1. — Research activities and laboratory facilities from 1949 to 1964.

Figure 2.--Oysters, which can be seen through the clear sides of a modified "Lund" trough, are held in individual com-
partments and can be fed selected diets of radioactive foods. In such a system, an oyster's preference for certain
species of phytoplankton can be accurately determined, along with its ability to digest and utilize them.

the Pacific. Radiobiologists believed that fis -
sion products would be of chief concern. Be-
cause of this belief, the experimental work
was concerned first with individual fission
products, and later with fission-product mix-
tures. Because scintillation counting tech-
niques had not then been developed, identifica-
tion of beta-emitting radionuclides accumulated
by marine organisms from fission-product
mixtures was laboriously determined by the
use of aluminum -absorption data.

With the discovery of the importance of the
accumulation of zinc 65 in tuna and cobalt 60 in
mollusks collected from the Pacific, emphasis

was shifted somewhat to include accumulation
and retention of neutron-induced radionuclides
by invertebrate species under study. Along
with this research there was a shift in counting
techniques to make use of the more efficient
gamma detectors (scintillation) being de-
veloped. Because of the great interest in con-
tamination of tuna that was being reported, a
supplemental project requested by the AEC
was initiated to emphasize accumulation by
fishes. The large fish-holding tanks at the
laboratory were rebuilt, the laboratory boat
was fitted for collecting and transporting fish,
and a boat crew was employed.

I

Figure 3. — Radioisotopes can be accumulated by marine animals from their food. In this study, zinc 65 and chromium 51
are being followed through four trophic levels of a marine food chain. Newly hatched brine shrimp (second trophic
level) are being removed here from hatching trays and placed in flasks where they feed on radioactive phytoplankton
(first trophic level). After 24 hours, the brine shrimp are fed to postlarval fish (third trophic level), which in turn
are fed to mummlchog (fourth trophic level).

Figure 4. — Research on living organisms has required the development of methods of catching and transporting live
animals to the laboratory. The boat shown here was rigged and trolling for tuna. Fish weighing as much as 15 to 20
pounds were caught, brought to the laboratory In good condltl Jn, and held In laboratory tanks for as long as 5 to 6 weeks
while the accumulation of radioactivity in the fish was being followed.

After we had obtained considerable infor-
mation on both the accumulation and retention
of fission products and several other radio-
nuclides by the adult stage of connmercially
important fish and shellfish, we thought it im-
portant to include studies on these species at
other stages of development and under environ-
ments that might represent certain periods
during their life histories. Since it is important
to know what damage occurs to organisms from
accumulated radionuclides, especially in the
early stages of development of the fishery
organisms that are the most sensitive to radia-
tion, a new project was begun. Funds supplied
by the Saltonstall -Kennedy Act were used to
support research to measure the damaging
effects of radiation on comnnercially important
fish and shellfish and their food organisms.
The laboratory was enlarged to provide salt-
water culture rooms for growing larvae, a

controUed-temperature room, a histological
preparation room, and office space for an in-
creased staff.

In the researchproposalfor fiscal year 1962,
we emphasized that a research facility should
bring together investigators with sufficient di-
versity in education and training to take a
broader approach to the solution of biological
aspects of radioactive pollution in the marine
environment than had been undertaken by any
one organization up to that time. We further
suggested that our organization attempt the
team approach that is obviously necessary to
accomplish the above goal. In addition to
advocating a team appraoch, we also expanded
our laboratory research to include pilot-type
experiments in tanks and ponds and ecological
studies in estuaries.

Investigations along these lines of research
have continued to the present. We have stressed

Figure 5. — The effect of environmental factors, such as temperature and salinity, on the accumula-
tion of radioactivity by invertebrates is studied under controlled conditions in the laboratory. In-
vestigators remove organisms from the experimental environment, analyze the live organisms for
radioactivity content, then return them to the aquaria. The effect of temperature and salinity on
the accumulation of the radioactivity by the organisms is evaluated by statistical analysis of the
data.

Figure 6. — Radioactivity content of organisms used in laboratory experiments is measured with
specially designed electronic equipment containing a scintillation detector. Here the investigator
is placing a plastic container holding one oyster into a chamber where the amount of radioactive
zinc accumulated by the oyster can be measured.

Figure 7. — The rate at which carbon Is converted Into organic matter by marine phytoplankton — primary production — can
be measured by use of carbon 14. Investigator Is preparing to analyze phytoplankton cells for their carbon 14 content
with a gas-flow proportional detector equipped with an automatic sample changer.

the need for collecting data under experimental
conditions that would enable us to make predic-
tions of dangers that might arise from inten-
tional or accidental pollution of an estuary or
ocean area. Emphasis was given to (1) flow
systems which make possible the duplication
of a natural environment in growing phyto-
plankton in the laboratory, (2) the simultaneous
accumulation of radionuclides by sediments
and the biota held in relatively large volumes
of sea water, (3) total-element measurement
so that specific activity in the different com-
ponents of a community can be compared,
(4) total-animal counting so that long-term
community studies are not disrupted by sac-

rificing the animals for radioactivity measure-
ments, (5) observations of factors influencing
the cycling of radionuclides in estuaries, and
(6) the effects of external and internal radia-
tion. Also, it was hoped that a better under-
standing of the cycling of many radionuclides
in the estuary would be obtained by placing in-
creased effort on studies of energy flow. The
rate at which energy flows through the bio-
logical food chain no doubt influences the rate
at which many radionuclides circulate from
environment to organism and back again.

Future research will attempt to understand
the factors that control production of fishery
organisms in estuaries. Natural estuarine

ecosystems, however, are complex, and a study
of the dynamic aspects of a complete eco-
system is difficult. Thus, need will exist to
develop a nnathematical model that canbeused
to assess the behavior of the system. The de-
velopnnent of connplex models simulating the
relations annong aninnals, plants, their uptake
of materials, and the flow of energy from the
estuarine environment requires the use of
computers. The capacity of computers to in-
tegrate large quantities of diverse data will
make it possible to evaluate new data con-
tinually as they are collected. Also, it will be
possible to resolve nnany problenns that have
proved, thus far, to be too difficult to solve
by methods used in the past.

Facilities

The present laboratory facilities, occupied
in July 1964, consist of three buildings. One

building is a two-story laboratory of about
20,000 square feet, the second is a radiation
laboratory of 1,500 square feet, and the third,
of 1,000 square feet, provides storage and
contains a crematory for ashing radioactive
organisms. The main building has office and
laboratory space for about 16 investigators
and supporting staff, two large salt-water
laboratories, three constant-temperature
rooms, several counting and instrument rooms,
a stockroom, a conference room, and offices
for administrative staff. The radiation build-
ing is divided into three parts: a radiation
room with 3-ft. concrete walls and running
salt water for studies of chronic effects of
low-level irradiation; an instrument room
for the cobalt 60 irradiator. X-ray nnachine,
and neutron generator; and an aquarium room
with running salt water for maintaining ex-
perimental animals.

Figure 8.— View from secretary's desk looking down hall of first floor. Portion of lobby is to the right of the hall.

Figure 9.-Salt-water facilities, showing large fiberglass storage tanks (upper right-hand corner) and three sizes
of fiberglass tanks inside of laboratory. As far as we can determine, this is the first use of large fiberglass tanks
as storage tanks for sea water. Lower right-hand picture shows fiberglass-covered wooden tab^. Salt-water
system consists of a dual set of PVC (polyvinyl chloride) pipes from storage tanks to Inside of laboratory The
dual pipe system is alternated weekly-one system Is used for salt water while the other system Is held as a
standby with fresh water for killing organisms that foul the pipes.

ORGANIZATIGNAL CHART
Bureau of Connnerclal Flsherlea - Region 2
RADIOBIOLOGICAL LABORATOl
Beaufort, N. C.

Laboratory Director

Health Phyalca

AselscanC Laboratory Director

Katntcnance
(Jointly with Biological Laboratory)

Batuarlna Ecology

Productivity 1

Radlo-aasay

Adolnlstraclon
(Jointly with Biological Laboratory)

B 1 ogeoc henl 8 1 r y

1 1

Sedlnent
Mineralogy

Analytical
Chemlatry

Pollution Studies

tebrate Vertebrate

Experlnental
Envlronnenta

Radiation Effecca

Phyalologleal
Bffeccs

Horphologlcal
Effects

Figure 10. — Organizational chart.

Organization

The widespread use of isotopes produces a
host of related problems that can be solved
more easily by investigators in related fields
working in the same laboratory than can be
accomplished by individual investigators work-
ing at separate locations. A group of investi-
gators of varied background can offer (1) a
team approach in solving problems, (2) nnore
efficient use of costly equipment needed for
this work, (3) continuity to the research work,

(4) convenience for sponsors of research, and

(5) a much broader approach in the research
than is available to an individual investigator.
The staff of the Radiobiological Laboratory
has been organized with these points in mind.

The research of the Radiobiological Labora-
tory is divided into the broad areas of estua-
rine ecology, biogeochemistry, pollution
studies, and radiation effects (fig. 10). These
four areas of research are called programs.
Within each program are a number of projects.
The considerable freedom given each project
leader in planning the details of his research
results in a wide variety of studies. For
example, there are projects concerned with
productivity of estuaries, trace elements in
sea water, and mathematical modeling. The
four program chiefs, along with the laboratory
director, consider the broader aspects of the
research program and decide when two or more

programs should cooperate in solving problems
too general to be handled by a single program
project.

RESEARCH ACTIVITIES

The purpose of research at this laboratory
is twofold: (1) to determine the fate (cycling)
of radioactive elements that are released into
the estuarine environment and the effect of this
radioactivity on estuarine plants and animals;
and (2) to develop and apply radioisotopic
methods to studies of estuarine ecology. We
are investigating basic problems in ecology,
radiobiology, biochemistry, and geochemistry
to obtain a more comprehensive understanding
of the accumulation of radionuclides by fishery
organisms. Because ionizing radiations from
radionuclides interact with other environmen-
tal factors to affect the growth and survival
of fishery organisms, we determine the re-
sponses of the biota to radiation under various
environments. Also, radioisotopes are used to
trace the movement of elements in the estuarine
environment. This movement is a cyclic ex-
change between biotic and abiotic phases in the
environment. With radioisotopes we can deter-
mine the rates at which this exchange takes
place and also determine the amounts of ele-
ments concentrated by organisms as the ele-
ments are passed through the food web.

10

MEASURING PRIMARY PRODUCTIVITY IN ESTUARIES

MICROSCOPIC
PLANTS

MACROSCOPIC
AQUATIC PLANTS

SALT MARSH
PHANEROGAMS

HARVESTING MARSH GRASS
TO MEASURE ITS ANNUAL
PRODUCTION

PLACING BELL JARS TO MEASURE
THE PRODUCTION OF ATTACHED
ALGAE

MEASURING PHYTOPLANKTON PRODUCTION

Figure 11. — The amount of energy flow through an ecosystem depends on the sunlight energy fixed by photosynthesis in
producer organisms; all other organisms ultimately depend on this source for food. In the estuarine environment, pri-
mary producers can be separated into three broad categories — microscopic floating plants (phytoplankton), rooted
plants (marsh grass), and macroscopic "attached" plants (benthic algae). Investigators are measuring the amount of
energy (carbon) fixed by these primary producers by: measuring the uptake of radioactive carbon by phytoplankton;
harvesting marsh grass and measuring its annual growth; and measuring rates of photosynthesis of algae attached
to bottom sediments by isolating sediment, algae, and water with a bell jar. Changes in dissolved oxygen in the water
enclosed by the bell indicate rates of photosynthesis.

Research at the laboratory is separated
into four programs --three concerned with
cycling of nutrient elements and their radio-
nuclides, and one with the effects of radiation
on marine organisms,

Estuarine Ecology

The Estuarine Ecology Program investi-
gates the biological productivity of estuaries.
The ultimate aim of this research is predic-
tion of the fate of radionuclides introduced into
the estuarine environment --especially their
accumulation by organisms consumed by
humans. Accuracy in estimating this accumula-
tion in edible species requires, however,
knowledge of the pathways and mechanisms of
accumulation for the entire ecosystem. Shallow
estuaries are different from--and in some
ways more complex than--the open sea, be-
cause of the ea^e with which materials may
move between the water and the sediment, and

the presence of food chains based on primary
producers other than phytoplankton. Work is
being done on the rate of primary production
by phytoplankton, attached algae, and higher
plants, and on transfer of this production to
other trophic levels, because the flow of
energy influences the cycle of materials and
thus the movement of radionuclides.

Biogeochemistry

The rapid accumulation of certain radio-
nuclides by estuarine organisms reflects the
metabolism of trace elements. Complete under-
standing of the cycling of radionuclides in the
estuary requires knowledge of the elemental
composition of estuarine organisms; the trans -
port processes operating in the organism to
incorporate the elements; and the physiological
disposition, i.e., the metabolism, of the ele-
ments.

11

Monitoring Fallout Radioactivity in Estuarine Organisms

Stratosphere Circulation

iWiorldwide Fallout

Collection of Organisms

Sample Preparation

X

leasuremenf of Radioactivil

Z
Z
< ,■'

I ■-'

>

u
o

I i

Gamma Spectral Analysis

Figure 12. — Radioactive materials are added to the estuarine environment through fallout from the explosion
of nuclear weapons. These materials often are accumulated and concentrated by seafood organisms. As
part of a program to study the biological concentration of fallout radioactivity by estuarine organisms,
Investigators collect organisms in the natural environment and take them to the laboratory for analysis.
The amount and type of radioactivity in the organisms are measured with specially designed electronic
equipment. The radioactivity content of some fresh-water and estuarine clams is shown in gamma spectral
analyses.

12

USING RADIOISOTOPES IN FISHERY RESEARCH

MOVEMENT OF TRACE METALS f

I Di»1Mb«l.o" 1l\th tlm« *tl«r l««li« O* lt*«lo(»«lop«*

TRACE METAL METABOLISM

UPTAKE -ACCUMULATION
ABSORPTtON - rON TRANSPORT

1 STUDYING THE PHYSIOLOGY OF FISH

ION PROTEIN tNTERACTIONS
METAH-O- ENZYMES
EXCRETION

DETERMINING FILTERING RATES OF CLAMS

■•Kto)*

W<'»*

»•••»■

'^

■•MB

••• ■•'

W*M 00<*N

I
1

CYCLING OF ELEMENTS

MEASURING PRIMARY PRODUCTIVITY

Figure 13.— New research possibilities have arisen In the field of ecology as radioactive tracers nave become available.
The movement of trace elements through experimental ponds Is followed by using radioactive isotopes of the elements
as tags or labels. The capacity of clams to filter food from water Is measured through the use of algae labeled with
radioactive elements. Also, the rate at which carbon is produced by plants— primary production— can be determined by
rate of uptake of carbon 14 by the plants.

13

STUDYING EFFECTS OF RADIATION

USING COBALT 60 IRRADIATOR INSERTING FISH INTO IRRADIATOR

IRRADIATING MARINE ORGANISMS WITH COBALT 60

BIOCHEMICAL

DETERMINATIONS

MEASURING RESPIRATION

MEASURING TOTAL ELEMENT

DETERMINING PROTEINS

14

ON ESTUARINE ORGANISMS

REMOVING BLOOD

CELLULAR CHARACTERISTICS

COUNTING CELLS

MEASURING PACKED CELL VOLUMES

Figure 14.— The effect of ionizing radiation
on estuarlne organisms is studied at tiie
Radiobiological Laboratory. Organisms
are exposed to gamma radiation from a
cobalt 60 source which is contained in a
specially built irradiator. After exposure
to radiation, the organisms are subjected
to various biochemical and cellular tests.
Often, radiation-induced physiological
changes occur first in the blood.

DETERMINING CELL TYPES

15

We are now studying the trace element
composition of estuarine organisms, with par-
ticular reference to those organisms known
to concentrate envirormnental radioactivity.
Mineral metabolism in the American oyster
is being studied with special emphasis on
protein-metal interactions. Anatomical and
subcellular distribution and the physiological
function of various minerals are being analyzed.
Soluble metalloproteins are chromatographed,
and the protein fractions are characterized by
ultraviolet absorption, nitrogen content, min-
eral content, and enzymatic activity.

Estuarine organisms and sediments must
also be characterized chemically before con-
clusions on accumulation or exchange of radio-
isotopes can be drawn. Estuarine organisms
are being systematically collected and analyzed
for naturally occurring gamma activity; bio-
logical indicators of radioactivity are identified
and studied to determine the physiological
characteristics which cause them to accumulate
specific radionuclides. Environmental samples
collected for radioassay are analyzed for con-
tent of various trace metals by atomic absorp-
tion spectrophotometry. This project is being
expanded to include facilities for additional
elements so that our knowledge of the cycling
of elements and their radionuclides in the
estuarine environment can be correlated with
compositional data.

Pollution Studies

Experiments are conducted in this program
to explore the routes and rates by which radio-
activity released into the estuarine environ-
ment might be returned to man and to deter-
mine the rates by which nutrients move through
the biotic and abiotic phases in the environ-
nnent. Scope of research ranges from experi-
ments in the natural environment with com-
munities of organisms to those conducted
in the laboratory with single species of
organisms maintained in small volumes of
water.

Observations are made on the cycling of
radionuclides released in artificial tidal ponds
and other more natural environments. By fol-
lowing the uptake of the radioisotopes by the
biota, we can compare the rates of accumula-
tion by the different species of organisms be-
cause they are all exposed to the same en-
vironmental factors. The rates should be
approximately those which would occur in the
sea because the physiological condition of the
organisms should be similar to their normal
conditions. Sannples of the biota, sediment,
and water are removed from the pond periodi-
cally and analyzed for radioactivity. Organisms
are analyzed alive and returned to the pond so
that the ecology of the pond will be unchanged.
At the end of the experiment, components of the
pond are analyzed for content of stable ele-

ments so that their specific activity can be
calculated.

All processes in anestuary cannot be studied
in situ; therefore, experiments also are con-
ducted under controlled conditions in the labo-
ratory. For example, the interaction of en-
vironmental factors such as pH, temperature,
salinity, and stable element concentration on
the exchange of radionuclides and nutrients
between sediments and sea water and the
accumulation of these materials by estuarine
organisms is determined by varying one of
these factors while the others remain con-
stant. Other experiments in the laboratory
include studies of the retention of radio-
nuclides by fish and shellfish and the passage
of radionuclides from water to phytoplankton
to organisms of other trophic levels. Analyses
of related stable element content of the orga-
nisms in each trophic level are made so that
the passage of a radionuclide through the food
chain can be related to the specific activity
of the organisms and their environment.

Radiation Effects

Research on the effects of ionizing radiation
on marine organisms is a logical sequel to the
investigations of the fate of radioactive ma-
terials in the marine environment. Our main
objectives are to determine the influence of
environmental factors on the response of
estuarine organisms to ionizing radiation and
to characterize the physiological effects of
radiation on these organisms. We are now in-
vestigating the influences of temperature, sa-
linity, population, number of organisms per
volume, and food on the responses of estuarine
organisms to radiation. In an estuary, salinity
and temperature largely characterize the phys -
icochemical properties of the water and control
the fauna. Effects of temperature upon the re-
sponse of mammals and fresh-water fish to
radiation are well documented, but data are few
concerning the effects of temperature on the
response of marine organisms to radiation and,
to our knowledge, no data exist on the influence
of salinity.

We are describing the interactions of radia-
tion, salinity, and temperature by subjecting
various developmental stages of resident es-
tuarine species to combinations of the three
factors and nneasuring changes in their LD-50's
(dose of radiation (in roentgens) required to kill
50 percent), growth, and respiration. Prelimi-
nary work indicates salinity can modify L.D-50's
of estuarine species. Newly hatched brine
shrimp, exposed to different doses of radiation,
are reared in various combinations of popula-
tion sizes and water volumes to determine the
influence of radiation on their growth and sur-
vival. Similarly designed experiments will test
the influence of food supply. Results fronn
constant low-level irradiation are to be com-
pared with those fronn acute doses.

16

FUTURE RESEARCH

Sufficient capabilities have been developed
to permit the laboratory staff, acting as a
team, to mount an inclusive study of the dynannic
aspects of the radioecology of a specific
estuary--a case history or study in depth.
Our plan of attack is first to complete a pre-
liminary mathematical model of the flow of
energy and specific materials and to begin
studying the standing crop of the estuarine
biota. On the basis of information obtained in
the preliminary studies, an "all-inclusive"
study involving as many aspects of estuarine

ecology as possible will be undertaken. Infor-
mation will be gathered on seasonal and de-
velopmental feeding trends, selective feeding,
and competition for food among species. Data
will be collected also on population dynamics,
including size and composition of estuarine
populations, seasonal abundances, and distri-
bution of various species. From this study we
plan to obtain information necessary to (1) in-
crease the production of organic matter,

(2) channel the available organic matter into
food webs that support fishery organisms, and

(3) predict the routes and rates of movement of
radionuclides in the estuarine environment.

MS. #1789

17

GPO S04-038

,lfl8L WHOI L,b,ary . ser,,-,l>

5 WHSE 00468

As the Nation's principal conservation agency, the Depart-
ment of the Interior has basic responsibilities for water,
fish, wildlife, mineral, land, park, and recreational re-
sources. Indian and Territorial affairs are other major
concerns of America's "Department of Natural Resources."

The Department works to assure the wisest choice in
managing all our resources so each will make its full
contribution to a better United States — now and in the future.

UNITED STATES

DEPARTMENT OF THE INTERIOR

FISH AND \nLDLIFE SERVICE

BUREAU OF COMMERCIAL FISHERIES

WASHINGTON, D.C. 20240

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