Technical Paper No. 44
AN OVERVIEW OF THE INDIAN RIVER CLAMMING INDUSTRY
THE INDIAN RIVER LAGOON
tORIDA SEA GRANT COLLEGE
AN OVERVIEW OF THE INDIAN RIVER CLAMMING INDUSTRY
THE INDIAN RIVER LAGOON
A collection of papers prepared in connection with the Brevard
County Clam Industry Workshop held September 7, 1985 at the
Florida Institue of Technology, Melbourne, FL.
Florida Sea Grant Extension Program
University of Florida
Gainesville, FL 32611
Project No. IR-85-7
Grant No. NA85AA-D-SG059
Technical Papers are duplicated in limited quantities for specialized audiences
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Department of Ccamerce, grant number NA85AA-D-SG059. It was published by the
Sea Grant Extension Program which functions as a component of the Florida
Cooperative Extension Service, John T. Woeste, Dean, in conducting Cooperative
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TECHNICAL PAPER NO. 44-
Overview of the Industry. Derek Busby 1
History of the Indian River Lagoon. Diane Barile 7
Biological and Environmental Factors Affecting the 14
Clamming Industry. Conrad White, John Ryther.
Economics of Clams. Warren Rathjen, Chuck Adams 15
Knowing How Much is There. Forrest Dierberg 23
Clam Mariculture. Mike Castagna, Leroy Creswell 26
Management of the Industry. Mark Berrigan, Patty 29
Carbonara, Robert A. Patterson
Industry's View. Tom Jones 37
Mike Ednoff 39
OVERVIEW OF TBE INDUSTRY
Derek S. Busby
Sea Grant Extension Agent
Brevard County Sea Grant Extension Program
The Indian River is, in fact, a lagoonal system extending one hundred and
forty miles along the eastern coast of central Florida and separated from the
Atlantic Ocean by an extensive series of barrier islands. It is connected to
the ocean by four man-made inlets which exchange same 10 billion gallons (less
than 5% of the Lagoon's volume) of water with each tide (Ryther, 1984). The
fact that the Lagoon is open to the ocean and diluted by freshwater inputs from
natural tributaries (as well as a system of managed canals) qualifies the Indian
River Lagoon as an estuary.
Estuaries, such as the Indian River Lagoon, where freshwater and saltwater
interact, are among the most productive ecosystems on earth. In Florida,
estuaries provide food and shelter for over 70% of the State's catch taken in
ccmnercial and recreational fisheries (Haddad, 1984). Many species are
dependent upon the estuary during sane, if not all, of their life cycle. One
such species which has recently experienced a rapid growth in production and
value is the hard clam, Mercenaria mercenaria.
Generally, the term "clam" is applied to a wide variety of two-shelled
(bivalve) mollusks such as the quahog,- northern hard shell and southern hard
shell or venus clam. A clam is a mollusk with two shells and two abductor
muscles which are used to open and close the shell. Adult clams also have a
muscular "foot" which is used to burrow into sand or mud substrates.
Additionally, clams have siphons or "necks" which draw seawater into their
mouths where microscopic plants, animals, and oxygen are removed through
The northern hard shell clam carries the scientific name of Mercenaria
mercenaria and the southern hard shell is Mercenaria campechiensis. Mercenaria
cones from the Latin word for money or reward. In the past, the shells of these
bivalves had monetary value as Indian wampum. Campechiensis is derived front
Campeche, Mexico where the original specimen used to describe the species was
obtained in the late 1980's (Stewart).
The word "clam" has been derived through time. Early American settlers
couldn't pronounce the name used by the Narragansett Indians, "Poquahock". They
referred to quahogs (a bastardization of "poquahock") as "clamps" which was
later shortened to "clam" (Stewart).
The east coast of Florida comprises the southernmost extent of the range of
the northern quahog which extends as far north as Nova Scotia and the Gulf of
Saint Lawrence. These clams have also been introduced to the waters of
Florida's west coast near St. Petersburg and a small fishery now exists there.
Southern quahogs occur from the Chesapeake Bay to as far south as the St. Lucie
Inlet. They also are found in the Gulf of Mexico, the Yucatan and Cuba.
The Indian River Lagoon provides excellent habitat for clams who prefer
moderately hard sandy bottoms and salinities from 20 to 35 parts per thousand.
The calm, shallow flats of the Lagoon are ideal for the clam which may be found
from just below the surface to depths as great as 50 feet (Stewart).
As the Autumn season approaches and water temperatures within the Lagoon
fall to approximately 23 degrees centigrade (73 degrees fahrenheit) spawning
begins. Females are stimulated to release eggs by the discharge of sperm by the
males. Clams are protandric hermaphrodites meaning that they change sexes
during their lifetime. Approximately 8% of them begin life as males with half
later changing to females (Stewart).
Fertilized eggs quickly produce a free-swimming larvae ringed with tiny
hair-like cilia and within six to ten days the foot, shell and body begin to
develop. The animals are widely dispersed during this free-swimming stage by
wind-driven tides and currents prevalent in the lagoon. As the shell develops,
the young clam (veliger) falls to the bottom where it secretes byssal threads to
allow temporary attachment to seagrasses, algal mats or sediments. Once the
foot is developed, the clam can burrow into the sediment.
Growth rates in Florida waters may be three times that of clams living in
northern waters. In Tampa Bay, clams have attained a size of 2 1/2 to 3 inches
by the end of their second year (Stewart).
Florida, commercial hard clam production was first described in 1880. A
large increase in production was reported in 1908 when extensive beds in the Ten
Thousand Islands area were being harvested. These beds were in excess of 150
square miles. Since then, clam harvests have fluctuated with a low of 4000
pounds being recorded in 1960. Historically, Statewide annual harvests have
averaged around 69,000 pounds with an average dockside value of $53,000
(Stewart). In Brevard County since 1975, landings have averaged 246,785 pounds
worth $786,235 dockside (NMFS). However, changing climactic conditions within
the last few years have contributed to significant increases in clam populations
within the Indian River lagoon. Since 1982, clam harvests have rocketed with
1,708,379 pounds of meats worth $6,130,783 landed value reported for 1984
In the past, increases in the clam population have been attributed to
increased salinities within the Lagoon favorable to clams. Now, however, same
researchers believe that the increase in nutrient level entering the Lagoon, due
to man's influence, may serve as additional food sources allowing for more
mature and young clams (see Ryther in this publication). Also, contributing to
this phenomenal increase in production, is the advent and practical application
of depuration technology.---Depuration is a method which allows for the rapid
cleansing of clams harvested from polluted waters.
The Florida Department of Natural Resources establishes acceptable bacteria
levels for waters from which clams are harvested in line with federal
guidelines. The Department continually monitors harvest areas and establishes
areas from which clams may be sold directly to consumers (approved areas) or
from which clams must be cleansed (unapproved areas or conditionally approved
areas when closed by D.N.R. biologists) prior to sale.
The two methods used to cleanse clams are depuration and relaying.
Relaying consists of transferring clams from polluted areas to areas within
approved zones where bacteria levels are low enough to allow sale of harvested
clams to the public.
Clams are placed within these areas for approximately two weeks on
suhberged lands leased from the State. Presently, there are 96 shellfish leases
covering some 786 acres of State owned bottom in Brevard County. These range in
size from less than 1 acre to 92 acres (Ednoff). Testing by State-certified
laboratories allows harvesters to know when clams have acceptably low levels of
bacteria and are eligible for sale. The relatively slow turnaround time
associated with relaying clams has brought about the application of depuration
methods. Depuration is a process where clams are placed in land-based tanks and
water is pumped through the tanks. The water is cleansed by subjecting it to
ultraviolet light which kills bacteria. Using this method, the clams will
generally purge themselves of undesirable bacteria within 72 hours and actually
be "cleaner" than clams harvested for direct sale or harvested after relaying.
Within the last 2 years, there has been a marked increase in the number of
depuration facilities operating in Brevard County. In 1983, there was only one
such facility operating, whereas there are now five facilities within the
County. This rapid increase in the use of depuration coupled with clam
population increases may be credited for the phenomenal growth in production
since clams may now be harvested from areas unapproved for direct sale and
during times of high rainfall when conditionally approved areas are closed by
This tremendous growth within the. industry has not been without its
accompanying problems. As previously mentioned, the advent of
depurationtechnology has caused nearly relentless fishing pressure to be exerted
on the clam beds. Additionally, the economic success of the clamming industry
in the lagoon has attracted clammers from many other clam producing states.
Daily earnings in excess of $300 have brought clamners from as far away as
Massachusetts. Florida does not have a residency law as do many northeastern
states which would forbid out-of-state clammers from entering the fishery before
first establishing residency. This has allowed large numbers of transient
clamners to cane to Brevard County and harvest clams during the winter months
when northern beds are inaccessible. While same have stayed to make their homes
in the warmth of the Florida climate, many more have taken their harvests and
their earnings back to their home states when beds there reopened. While many
local clammers credit the northerners for their industrious natures and for
introducing more efficient harvesting methods and techniques to Florida, many
also feel a degree of animosity towards these out-of-staters. The locals feel
that these clammers (who do not have a vested interest in the resource) simply
do not care about how it is treated or whether it will continue to provide a
dependable livelihood in the future. They feel that the additional pressure
created by the northerners will cease only when the resource is depleted and the
out-of-staters return to their home states, leaving behind nothing but a memory
of what once was.
This influx of northern clammers has also placed additional burdens on the
enforcement branch of the Florida Department of Natural Resources. The Florida
Marine Patrol is responsible for enforcing rules and regulations relating to
marine resources including clam harvesting and relaying. With a limited number
of officers to patrol the entire length of the lagoon, and with the numbers of
clammers sometimes approaching a thousand during the winter months, the Marine
Patrol has been severely taxed.
A Marine Patrol officer must be present when clams are harvested from
conditionally approved or unapproved waters for the purpose of relaying to
leased areas in approved waters. Even though the "relay teams" will consist
ten or twelve boats, the large numbers of clammers present during the winter
makes it difficult for the Marine Patrol to insure that all clams harvested from
polluted waters are, in fact, relayed or depurated prior to sale. This
situation has necessitated that off-duty officers be employed (at the expense of
the clamners themselves) to monitor these activities.
While this association of clamners and officers is seen by some as
constituting a conflict of interest, others argue that this practice has
actually improved enforcement since the officers have became increasingly
familiar with the clamners, their methods, and the resource itself.
As with any fishery, basic information about the biological functions of
the species involved is needed to make sound management decisions. A basic
problem facing the fledgling Indian River clamming industry is a lack of
knowledge and research applicable to the resource. Information about such
factors as size and locations of beds, migration of beds, survival rates of seed
clams in different habitats, recruitment rates, seeding success and predation
are needed to help understand how much fishing pressure the resource can
Recently, the opening of a flood control canal by one of the water
management districts caused decreased salinity levels in clam harvesting areas
and was sited by industry as causing a 10-20% die-off in harvested clams for a
two-week period following the opening. The water management district has
expressed great concern over the effects of canal openings and has turned to the
scientific community to help determine such effects. Unfortunately, at this
time, that kind of specific information does not exist and serves to illustrate
the need for increased efforts to gather solid background data. Additionally,
an ongoing monitoring system of the size and extent of beds and numbers of clams
would be extremely useful in making management decisions and would play an
important role in protecting the resource from over harvesting.
In attempting to predict what will happen to the Indian River lagoon
clamming industry, it must be remembered that the health of the industry is
intimately tied to the health and well-being of the Lagoon itself. The Lagoon,
and the industry which it nourishes, are now entering a new period in their
history. Awareness about the Lagoon and the natural systems comprising it is on
Serving as a focal point for research and information about the Lagoon, is
the Marine Resources Council of East Central Florida. The MRC has launched the
Indian River Lagoon Initiative to investigate and research the environmental,
social, and management problems facing the Lagoon as a whole and to serve as a
catalyst for present and future research within this region. Funding from State
and local governments, as well as private industry and individuals, is used to
supplement other sources of money and draw attention to ths issues of the
Lagoon. Also, the MRC is involved in educating the public about the Lagoon and
is developing a bibliography of Lagoon-related source materials. These efforts
cannot be completely separated from occurrence in the clamming industry. As
awareness and understanding of the Lagoon increase, people coming into contact
with its resources will, hopefully, obtain a desire to protect the Lagoon and
the resources dependent upon it.
In lieu of a Statewide clamming license, the State Legislature has, within
the last year, approved a Brevard County clam-diggers license to give local
control over clamming activities. This license is only available two months of
the year (in the sunner when northern clam beds are open) and carries an
increased fee of $500 for non-resident clamners. Resident clammers, who have
resided in the State for a year or more, can obtain the license for $100. Money
from the increased licenses is to go to improved research and enforcement
Such legislation is a step forward and it is hoped that it will go a long
way toward alleviating or, at least, aiding in regulating the extreme pressure
now being placed on the resource. However, legislation alone cannot solve the
complex interaction of natural and social systems affecting this industry.
Other management possibilities need to be explored and applied research needs to
be focused on industry-related problems.
One idea under consideration is the application of mariculture techniques
to the production of clams. Sane of this type of work has already begun, but
the potential of mariculture to create a steady supply of high-quality shellfish
to local and, perhaps more importantly, to export markets has yet to be fully
realized. Yet, the knowledge and technology exists. The fast-growing nature of
the clam in southern waters, as well as the pricing structure of the clam
industry (where the smaller "little necks" fetch higher prices than the large
"chowders") lend themselves perfectly to mariculture and fast turnaround times
in production cycles. Additionally, mariculture may be seen as a means of
protecting and even enhancing the resource by channeling the labors of those now
employed within the industry away from the traditional harvesting methods of
raking and treading into the farming-type activities involved in mariculture
activities. This could help alleviate a great deal of the destructive
activities associated with such hunting and gathering techniques and concentrate
production into smaller portions of the lagoon.
This is not to say that mariculture is a panacea for the ills being
encountered by the Lagoon and the industry. The ramifications of widespread
application of these techniques will only be known with time and many social
conflicts must be faced and resolved before the development of mariculture
within the lagoon will be accepted. However, it is another option, another
weapon in an arsenal of management techniques available to us if we keep our
minds open to new ideas and are willing to use these ideas to the betterment of
the resource as well as ourselves.
Florida Sea Grant sponsored a workshop on the clamming industry in the
Indian River lagoon which was held in September of 1985 at the Florida Institute
of Technology. This workshop focused on problems facing the lagoon and the
industry and on research currently addressing those problems. Additionally, the
feasibility of applying mariculture techniques to clam production within the.
Lagoon was explored. This workshop brought together scientists, local and state
regulatory agency personnel, members of the industry and the public to gain a
more comprehensive understanding of the burgeoning industry. The following are
summaries of the proceedings of that workshop.
Barile, D., ed. Proceedings of the Indian River Resources Symposium. 1984.
Sea Grant Project, No. I.R.34-28.
Ednoff, M. Aquaculture and the Clam Industry in Indian River and Brevard
Counties (unpublished). 1984.
Haddad, Kenneth D. "Habitats of the Indian River". Proceedings of the Indian
River Resources Symposium. 1984.
Ryther, John H. "The River That's Not a River". Proceedings of the Indian
River Resources Symposium. 1984.
Stewart, V.N. Clams. Sea Stats No. 7. Florida Department of Natural
Resources. June 1981.
HISTORY OF THE INDIAN RIVER LAGOON
Director, Marine Resources Council of East Central Florida
The ancient Ais Indians navigated the shallow grassflats of the large
estuary isolated from the Atlantic Ocean. Teeming waters provided food and
transportation routes. Villages were marked by tall mounds of discarded shells.
The Ais controlled and were intimately knowledgeable of the secrets of existence
in the long lagoon draping along the east coast of Florida.
The Lagoon through the Spanish, English, and American colonial periods
produced oranges, hides, feathers for ladies' hats, fish and produce including
pineapples. Following the Indian Wars of 1845-1853, homesteaders eager for free
land tilled the flood prone, poor soil along the Lagoon. Many turned to
fishing. In the 1920's, the Drainage Acts of Florida established and encouraged
the drainage of marshes and swamps. A highly speculative real estate market
developed 95 drainage projects in wetlands. Mangrove forests were impounded by
dikes to eliminate mosquito breeding grounds.
With drainage systems in place and the clouds of mosquitoes eliminated,
large scale agriculture developed. By the 1960's, housing developments began to
replace the less profitable agricultural lands.
The Ais people are now gone. Their homeland, the Great Lagoon, is no
longer recognized or understood as a functioning ecosystem. Successively called
the Ais Lagoon, the Indian lagoon, and most recently the Indian River, the
estuary has lost its identity as a productive system, dependent upon the
delicate balance of salt and freshwater. No Ais chief directs the use of its
resources or its management.
The Indian River extends along the east central Florida coastline fran near
Daytona Beach to Hobe Sound in the south. The shallow (three feet average
depth) brackish water has salinities near that of seawater at the inlets and
almost fresh at the mouth of freshwater streams. While nearly as long as
Chesapeake Bay (150 miles vs. 180 miles) the Lagoon varies in width fron less
than a half mile at the Narrows near Vero Beach to 5 1/2 miles at the northern
end. near Titusville. _.The upper linear half of the Lagoon includes two-thirds
of its area and volume. Contrary to its name, the Indian River in no way
behaves or functions as a river flowing to the sea. Movement of water is
directed primarily by wind and by tides near the inlets.
On a yearly average, the amount of rainfall on the Lagoon nearly equals
evaporation. The major source of water is from land drainage via creeks and
streams. The natural drainage area, a narrow band not more than ten miles wide
historically, has been enlarged by extensive drainage systems; one such project
adding more than one hundred square miles to the watershed.
The purpose of the drainage systems, when constructed in the 1920's, was to
drain "useless marshes and swamps" for farming. In recent years, ranch lands
have been converted to residential housing lots as industry and cities expanded
on both the barrier islands and mainland. Water released from the land as
runcff new carries herbicides, pesticides, fertilizer, industrial waste and
sewage effluent into the Lagoon.
The watershed of the Indian River and its shoreline is managed by six
counties, forty cities, two regional planning districts, special taxing
districts including drainage districts, mosquito control districts and inlet
commissions. Each organization manages, regulates, or plans independently as if
the lines drawn on maps were absolute boundaries drawn on the water.
The Indian River, a bar-built estuary, is an active biological system. The
geographic location and confined protected waters provide a stable environment
creating extraordinary diversity of life. Studies at the Florida Institute of
Technology and the Harbor Branch Foundation show that the Indian River has a
greater diversity of plants and animals than any estuary in the United States.
The shallow, warm, nutrient rich waters of the Indian River produce
luxuriant flats of submerged aquatic vegetation, seagrasses, and algae. The
grasses maintain an organic soup of decaying vegetation and a variety of food
sources for an extraordinary variety and number of animals. The seagrasses also
provide hatcheries and protected nursery grounds for oceanic animals. Nearly
sixty percent of the fish caught commercially offshore spend critical portions
of their life cycle in the Indian River Lagoon.
Commercial fishing, both offshore in the Atlantic and in the Lagoon, has
made Brevard County a leader in State fisheries landings. This standing is due
to the expansion of the clam and scallop fisheries. The Lagoon produces 80% of
Florida's clam harvest. Clamners from New York, Rhode Island, and North
Carolina have introduced basket rakes for clamming in shallow water and large
basket rakes and tongs operated from boats in deeper water. Sophisticated
depuration plants and relay techniques purify clams taken from polluted waters.
In the midst of great species diversity, an abundance of rare and
endangered plants and animals are recognized in the Indian River region. The
first national wildlife sanctuary was established on Pelican Island near
Sebastian, Florida by President Theodore Roosevelt. Brown pelicans, roseate
spoonbills, least terns, bald eagles, and ospreys all frequent the Lagoon.
The West Indian (or Florida) manatees are numerous in the Indian River
Lagoon. Of the one thousand believed to exist, three hundred have been counted
in Brevard County alone. The barrier island beaches along the Lagoon are prime
nesting sites for young sea turtles. Populations of immature loggerheads and
green turtles may spend early years in the Lagoon as a developmental habitat.
Today, the Indian River is home to an ever growing population of nearly
600,000 people. In the last six years, an awareness of and a concern for the
future of the Lagoon's natural systems has grown as people find that the economy
and quality of life within the region are based upon this aquatic treasure.
BIOLOGICAL AND ENVIRONMENTAL FACIORS
AFFECTING HE CLA4ING INDUSTRY
Brevard County Environmental Engineering Department
The Indian and Banana Rivers comprise .east-central Florida's
major brackish water systems. These waters lie east of the major
coastal ridge and are separated from the Atlantic Ocean by an
extensive system of barrier islands. The Indian River extends
from Turnbull Creek -in north Brevard County south to St Lucie
Inlet; the Banana River begins as an extension of the Indian
River referred to as Banana Creek within the Kennedy Space Center
and terminates at the southern tip of Merritt Island. The length
of the Indian River is approximately 150 miles (240 km); the
width varies from 10 ft (3 m) to 5.5 mi (8.9 km). In actual
fact, however, the lagoon systems that border the east coast of
Florida extend from Volusia County to Martin County.
These lagoons are shallow, non-tidal, wind mixed, saline systems
that have an average depth of 5 ft (1.5 m) and a depth range of 0
to 13 ft. (4 m); deeper areas occur in the Intracoastal Waterway
channel and in those areas that have been dredged for fill
material and/or marinas. The dominant type of bottom relief is
gently sloping sand-shell-mud areas; in some areas coquina rock
outcrops are present.
Historically, the lagoons had limited exchange with ocean waters.
Small, shallow ephemeral openings in the barrier islands would
occur periodically with turbulent fall and winter storms. For a
long period, Ponce Inlet was the only opening in the northern
Indian River; Sebastian Inlet was dredged in 1921, Ft Pierce
Inlet was dredged in 1921, and the Canaveral Locks were completed
in 1965. Because the lagoons are isolated from direct oceanic
influence (except near man-made inlets) water temperature tends
to mimic air temperature closely; the temperature range recorded
by Brevard County over the past five years varied from 46 F to
Salinity is the other major factor that determines the type of
aquatic system that develops in the lagoons. Salinity can be
influenced by a variety of factors, but the dominant one in the
northern Indian and Banana Rivers is the rainfall-evaporation
cycle (hydrogeological cycle). In this area freshwater
discharges cause decreased salinities in zones near the major
streams, which include the Eau Gallie River, Crane Creek, Turkey
Creek, and Sebastian Creek and near urbanized areas with
significant stormwater runoff. Stratification rarely occurs,
however, except in the Sebastian Creek-Sebastian Inlet area,
where the freshwater from the creek forms a lens on top of the
higher salinity inlet water during high discharge events from the
creek. Salinity ranges recorded for the northern portion of the
Indian River were 14 parts per thousand (ppt) to 44 ppt, with a
mean value of around 22-24 ppt (dependent on station location and
proximity to inlet or stream).
The major biological communities of the lagoons are highly
dependent on the temperature and salinity regimes found in given
area. They are associated with the fringing wetlands and uplands
and/or the submerged areas. The wetlands bordering the rivers
are dominated by mangroves and to a lesser extent by chordgrass
and other emergent vegetation. The submerged areas can be
divided into vegetated and unvegetated zones while other
relatively minor communities are associated with hard bottom and
man-made structures. The communities that are important to this
workshop are the submerged vegetated areas (seagrass and algae)
and non-vegetated areas. The vegetated areas are dominated by
the attached macrophytes manatee grass (Syringodium filiforme),
shoal grass (Halodule wrightii) and turtle grass (Thalassia
testudinum), by the attached algae Caulerpa prolifera, and by
three genera of semi-attached "drift algae" (Gracilaria,
Acanthophora and Hvpnea). While it may appear that certain
submerged zones are monotypic, most areas are a mixture of two or
more species of grass and algae.
In terms of fauna, the Indian and Banana Rivers lie at the
convergence between two large biogeographical zones referred to
as the Carolinian and Caribbean. Those animals labeled as
Carolinian tend to be species found in cooler waters, while those
animals associated with the latter zone tend to be warm water
species. A large percentage of fish and invertebrate species are
found throughout both geographical areas. The importance of cool
water/warm water species can be demonstrated from the fact that a
number of species in this area tend to be existing at either the
northern or southern terminus of their distribution relative to
water temperature; outside disturbances that impact these
sensitive species, such as a sudden elevation of water
temperature above the ambient level can lead to a loss of that
species from the area. Recovery of a sensitive species can be
protracted; the recovery period for seagrasses can be
Four hundred (400) species of fish have been collected from the
Indian River Lagoon. Many of these fish are highly dependent on
seagrass and/or mangrove areas at some point during their life
cycle for breeding, foraging for food, and for protection. Of
the 95 species of-fish that are frequently found within the
lagoon waters, 90 were associated with seaqrasses at some point
in time; 48 were associated with mangrove communities at some
point, 61 were found over or in sand bottom areas, 42 were found
in association with lagoon hard bottom habitats, 51 near canals,
45 near freshwater tributaries and 20 were found within mosquito
control impoundments. These figures serve to illustrate the
importance of seagrasses to the overall quality of the lagoon
In terms of RELATIVE importance to the lagoon, the 10 top ranked
fish collected from the northern Indian River were:
1. bay anchovy
2. silver perch
3. sea catfish
5. striped burrfish
6. southern puffer
8. gulf pipefish
9. code goby
10. Atlantic stingray
The lagoon also supports an extensive invertebrate fauna on which
the fish are indirectly or directly dependent for food. Extensive
invertebrate species lists have been compiled by the County and
other institutions. These lists help point out how important the
seagrass and mangrove habitats are to the stability and
productivity of the lagoon. As with the fish the grass and
mangrove areas serve the invertebrates as places for breeding,
foraging for food, points of attachment for sessel species such
as a number of polychaete worms, amphipod crustaceans and bivalve
molluscs, and as zones of refuge from predators. The ten most
common invertebrates found in the northern Indian River are:
1. Brachidontes exustus small clam
2. Parasterope pollex very small crustacean
3. Cvmoduce faxoni small beach flea type crustacean
4. Limnodriloides winchelmanni very small oligochaete worm
5. ODhiophragmus filograneus small long-legged starfish
6. Axiothella mucosa small fringed polychaete worm
7. Cvmadusa compta small beach flea type crustacean
8. Leptochelia rapax small long-bodied crustacean
9. Phasicolion sp. small worm-like animal
10. Erichsonella attenuata small long-bodied crustacean
The invertebrate fauna also includes commercially valuable
species such as shrimp, blue crabs, stone crabs, and of course
the hard clam, Mercenaria mercenaria.
Without good water quality, however, the biological community of
the lagoon begins a rapid decline. The need for excellent water
quality in the lagoons is more acute than with some other
brackish systems because of their physical configurations. True
estuaries receive significant inputs of freshwater from the major
tributaries that empty into them and at the same time have major
outlets to the oceans; although pollutants can degrade these
systems, there is a flushing mechanism present that can dilute
some of the pollutant's effects. The Indian River is land-locked
and anything discharged into the system either ends up in the
sediments or is taken up into the biological food web. Once a
compound is present in the food web, there is the possibility
that it may be passed to humans. Brevard County's Environmental
Services Division is concerned with the apparent decline over the
past 10 years of "water quality" in large areas of the Indian and
The Environmental Engineering Department's biological laboratory
has monitored surface water quality in the County from 1967 to
the present. The primary focus of the laboratory is toward water
quality 'monitoring via collection of water samples, long-term
invertebrate monitoring, establishment of a bivalve sentinel
program for trace metals and monitoring of seagrass areas. The
programs can be separated into: 1.) long term projects of greater
than two years' duration, 2.) short term projects of less than or
equal to two years, and 3.) interface projects of varying time
intervals. Other functional categories the laboratory provides
for are euphemistically referred to as 4.) "Alarms" and "Panics",
and 5.) other, or better known as "other duties as assigned".
The laboratory programs can also be divided into site and non-
site specific projects. The major water quality monitoring
program of the lab is non-specific and includes 33 permanent
stations located in the Indian, Banana and St. Johns Rivers and
Mosquito Lagoon. Each station is sampled monthly to determine
physical, chemical and biological values. The site specific
projects include 18 stations within the class II waters, 6
stations in the Tortoise Island subdivision, 4 stations in the
Sykes Creek impoundment, 2 stations inside Port Canaveral, 8
stations in the Kiwanis Island basin on Merritt Island, and 2
stations inside the Sands Canal (Lake Washington). In addition
to the long term monitoring water quality projects, the lab
samples 6 sites for benthic invertebrates. These stations have.
been sampled since 1976 and contribute greatly to determining the
relative health of the particular water body.
The lab also has a number of short term programs targeted toward
maintenance and management of the lagoon and adjacent waters.
These include a sentinel program to determine trace metals in the
hard clam, a study of water quality decline within Port
Canaveral, a survey of the water quality within the Merritt
Island barge canal, and a $35,000 grant from the federal coastal
zone management program to map the outlines of the seagrasses in
the lagoon from Turnbull Creek to Sebastian Inlet. The various
interface projects in which the laboratory provides scientific
expertise are planning and zoning ordinances, artificial reef
sites, dredge and fill investigations, and fish kill
Analysis of the data collected by the laboratory to date shows
that water quality is highly variable within the county. In
general, those areas isolated from intensive development, or away
from direct agricultural runoff exhibit good water quality.
Those areas in close proximity to urbanized zones and/or are
subjected to significant agricultural runoff showed degraded
conditions. The degradation can be attributed to the discharge
of water high in macronutrients (nitrogen and phosphorus) which
causes excess phytoplankton productivity, and which in turn can
lead to warm weather dissolved oxygen instability. In addition,
discharges from both wastewater plants and stormwater systems
have led to localized increases in turbidity; the turbidity
increases have in turn decreased light penetration in the photic
zone. The implication of the decreased water clarity is that the
amount of light needed for seagrass growth and reproduction has
been reduced in some areas to the point where significant
seagrass loss has occurred over the past 15 years. The amount of
seagrass loss exceeds 30% in large sections of Florida, and in
Brevard County losses are expected to approach 50% within a short
Areas within Brevard County that have "good" water quality and
appear to have a balanced biological community are:
1. Mosquito Lagoon
2. The Indian River between Turnbull Creek south to the
railroad bridge north of Titusville
3. The Indian River on the east side of the ICW from SR 402
south to the SR 528 Causeway.
4. The Indian River from Malabar Point south to Sebastian
5. The Banana River from the NASA Causeway south to SR 528
Those areas that exhibit "fair" water quality in Brevard County
1. The Indian River other than what was listed as having
good water quality.
2. The Banana River between SR 528 and the Pineda Causeway
3. Newfound Harbor south of the Merritt Island airport to
the connection with the Banana River
4. Sebastian Creek
Those areas that show enriched conditions are:
1. Sykes Creek and the northern half of Newfound Harbor
2. The Banana River south of the Pineda Causeway
3. Turkey Creek
Those areas that are degraded or EUTROPHIC are:
1. Crane Creek
2. Eau Gallie River
3. Numerous residential canal systems throughout the County --
It should be pointed out that the above classifications are not
all-inclusive and that there are areas within most of the
segments that are better, or worse than what was indicated. In
many areas of the lagoon, strides are being taken toward
eliminating the pollutants that have caused the decline of water
quality; many of the wastewater plant discharges into the lagoon
are being taken out. The greatest threat to the lagoon water
quality now appears to be the loss of shoreline habitats to
intense residential and commercial development via the legal
permitting processes, coupled with weak enforcement of existing
rules and regulations by both State and Federal agencies that
govern stormwater and industrial discharges and dredge and fill
John H. Ryther
Harbor Branch Foundation
Fort Pierce, Florida
A single hard clam may release from one to over 20 million eggs per
spawn. If the average clam lives in the river long enough to spawn several
times, it may produce over 100 million eggs, of which only one must survive
to adulthood to maintain the population. If two survive, the population
would double; if 10 of one hundred million survive, a bonanza would result.
Thus very small differences in survival make very large differences in the
The two major factors normally affecting survival are (1) availability
of food (single cell algae or phytoplankton), particularly during the 1-2
week larval stage and (2) predation. As with all organisms that produce
large numbers of young, predation is most severe in the youngest stages
(larvae and newly-set seed) and declines rapidly as the animals reach
commercial size, excluding the affects of man.
Both food availability and predation may be beneficially affected by
rainfall. Land drainage, particularly from fertilized agricultural areas,
brings nutrients to the river and stimulates growth of the. unicellular algal
food of the clams. Freshwater drainage and the resulting reduced salinity
may also kill or exclude predators, as is the case in oyster culture, where
nursery areas are commonly located in the upper, brackish sections of
estuaries for that reason.
It is therefore suggested that the recent success of the Indian River
clam fishery may have resulted from the unusually heavy rainfall during
1982, particularly during the spring and fall spawning seasons, and the
above-normal rainfall during the succeeding two years (1983 and 1984), in
contrast to the prolonged period of several years of below-normal rainfall
prior to 1982. Below-normal rainfall during the spring spawning season of
1985, if followed by similar conditions during the fall of this year, may
herald a return to poor recruitment success.
The above conclusions are theories only, based upon correlations and
indirect evidence. ..A modest, continuing recruitment monitoring program,:
correlated with meteorological data, would confirm or deny the hypothesis,
provide useful predictive information to the industry for planning purposes,
and could lead to water management practices that might prove beneficial to
ECONOMICS OF CLAS
Warren F. Rathjen
Center for Fisheries Engineering Studies
Florida Institute of Technology, Melbourne, Florida
In 1982 "Clams" recorded in world landings totaled
1,303,775 tons. This contrasts with 1973 totals which were
recorded at 822,400 tons or only 63 percent of the 1982 total.
1) In 1982 over half of this catch was taken from the Northwest
Pacific (primarily Japan) almost half of the remainder was
harvested from the Northwest Atlantic (particularly the United
States). The United States East Coast Clam Fishery is dominated
by four species which accounted for a record production in 1984,
see Table 1.
Thus in spite of management and environmental problems the
United States Clam Fisheries are operating at record levels.
The primary species are summarized briefly below.
1) FAO, 1979 (Vol. 48) Yearbook of Fishery Statistics
1982 (Vol. 54) "
U.S. Landings of Clams 1984 2)
* Over Previous Year
** Previous High 1974
70,200,000 $ 34.3
- 121,800,000 pounds
2) Source Fisheries of the United States 1984 (1985)
U.S. Dept. Comm. Natl. Marine Fisheries Service
The surf clam Spisula solidissima, has been an important
fishery in the Mid-Atlantic area since World War II (mid
1940's). The fishery grew steadily through the early 1970's
when some signs of overfishing became apparent. Management
restrictions and expansion of the fishery to offshore areas has
helped to keep production high. Although the surf clam is found
from eastern Canada to the Carolinas most of the significant
production is limited to the area from Georges Bank (off
Massachusetts) to Cape Hatteras, N.C. The surf clam is canned
and sold as strips for frying. Landings are reported in weight
of meats. Surf clams harvested from wild stocks probably have
reached'peak production levels and indeed some decline is
The ocean quahog Artica islandica is, like the surf clam,
taken from ocean waters. The ocean quahog lacked significant
fishing effort until the decline of the surf clam was perceived
by industry in the early 1970's. Increased fishing for the
"OQ's" has accounted for record levels of production in the
1980's; this trend is expected to continue. The resource is
widely distributed from Virginia northwards. Deterrents to
expansion include conservative market interest due to strong
flavor and slow growth rates. Large adult ocean quahogs have
been reported to be very old (up to 100 years); this could
represent resource problems at some point. The ocean quahog is
primarily a northern variety not normally expected in commercial
quantities south of the Carolinas.
The soft clam-Mya arenaria-is the traditional clam of the
New England area which is used as a fried clam and in chowders.
Due to heavy fishing pressure and environmental problems,
including pollution, predation and "red tide", the supply in New
England has been "down"; in recent decades this has been offset
to some extent by production from the chesapeake Bay area. The
Chesapeake production was accomplished by development of
harvesting equipment capable of bringing quantities of clams up
from 10-20 feet below the surface of the bay. This was (and is)
accomplished with "escalator" dredges. The soft clam fishery of
the Chesapeake represents a fishery developed through a
combination of unsatisfied markets and innovative harvest
The hard clam Mecenaria mercenaria is the most valuable of
the four primary east coast species. It is harvested in most
coastal states from Maine to Florida. Some biologists believe a
second species (or variety?) occurs in the southern part of this
animal's range; this aspect needs more study and clarification.
Much of the high value of the hard clam is attributable to its
demand as a raw or "half shell" food item. The production of
hard clams has been under stress in New England and in the
middle Atlantic; however, this has been offset and supplemented
by increased production in the south, particularly in Florida;
(see other material in this publication).
Florida has enjoyed production of hard clams before. A
fishery existed in the Ten Thousand Island area of the Florida
Bay from the late part of the 19th century until after World War
II. Most of the production (up to 200,000 bushels (year) was
taken by mechanical dredges and was subsequently canned, one of
two or more canneries existed at Marco, FLorida. 3)
Early man in Florida also took advantage of the intermittent
abundance of the hard clam. Indian middens (refuse heaps)
around the periphery of the Indian River area, and elsewhere
reveal that hard clams were a major component of the aboriginal
diet. Evidence seen at a "dig" underway at "Honeymoon Hill" on
Merrit Island suggests that clams and other molluscs alternated
with oysters as a primary food source. This suggests that
variable environmental conditions probably occurred, thus making
it more or less favorable for individual species.
Clams are a major shellfish product on the U.S. East Coast
of North America. Changes in environment and resource condition
coupled with market demands allow for adjustment in production
opportunities from.different sectors of the range of the
products. In some cases management and/or culture can be
effected to enhance the access to these valuable and attractive
3) Tiller, Richard E., John B. Glude, and Louis D. Stringer,
1952, Hard Clam Fishery of the East Coast; March Fisheries Revue
Vol. 14 No. 10.
Assistant Professor, Food and Resource Economics Dept.,
and Extension Marine Economist, Florida Sea Grant
Extension Program, Cooperative Extension Service,
University of Florida, Gainesville, Florida
Total U.S. hard clam production in 1984 was reported to be 14.5 million
pounds and valued at $49.8 million dockside. The landings of hard clams (the
colloquial term "hard clam" can actually apply to three genera of commercial
importance Mercenaria, Protothaca, and Saxidanus) represented only eleven
percent of the total domestic clam production, the majority of which was surf
clam landings (70.2 million pounds was valued at $34.3 million). However, hard
clams, which are utilized primarily in whole form (i.e., half-shell, steamed,
etc.) trade rather than in a minced or strip form, were the most valuable
species on a per pound of meat basis. The dockside value of hard clam landings
represented 43 percent of the total dockside value of all species of clams
landed in the U.S. in 1984 (Table 1). The hard clam industry has historically
be centered in the New England and Mid-Atlantic regions, with the majority of
the landings being reported by Maine, New Jersey, Massachussetts, Rhode Island,
New York, and Virginia.
Florida has only recently become a significant producer of the hard clam
Mercenaria mercenaria. Landings in 1984 of hard clams in Florida were reported
to be 1,851,069 pounds on a meat weight basis, with a dockside value of
$6,552,200. Florida generated approximately 13 percent of the total domestic
landings and dockside value of hard clams in 1984. More dramatically, this
represents a 13-fold increase over landings and value reported for 1983 (Table
2). Hard clams were ranked as the eighth most important commercial species in
the state in terms of dockside value (Table 3). In addition, of the ten most
important commercial species in Florida in 1984, hard clams had the highest
un-weighted exvessel price per pound. The price per pound of meat has continued
to increase since 1971 (Table 2). Few species in Florida have exhibited a
comparable increase in production and value in the commercial industry, with the
notable exceptions of calico scallops and swordfish.
The majority of the Florida production for a given year occurs on the east
coast, primarily in the restrictive confines of the Indian River lagoon system.
Brevard County, which borders the Indian River lagoon, accounted for 92 percent
of reported landings and dockside value in 1984 (Tables 4). Prior to 1984,
however, Brevard County landings of hard' clams averaged less than 100,000 pounds
of meats (Table 5). The neighboring Indian River, St. Lucie, and Volusia
counties reported minimal production in 1984, with approximately 5 percent of
the state's landings reported by Gulf County on the west coast. The number of
producers at a given time has varied considerably since 1983, with estimates
ranging from 400 to 1,000. These values most likely include a number of
part-time operators. In addition, many producers have apparently migrated down
from the northeastern regions of production. Accurate estimates of the current
number of producers is difficult to obtain due to the degree of seasonal entry
and exit which had not previously existed in the fishery. The recent initiation
of a "trip ticket" reporting system and a clammers license will undoubtedly
provide for more accurate future estimates of effort and production.
There are approximately 20 major dealers of hard clams in Florida, with an
additional 5 dealers which market depurated clams. Most of the hard clams
produced in Florida are marketed outside of the state, although a percentage are
sold to local wholesalers and restaurants. Florida hard clams are marketed as
shell stock, primarily for the lucrative restaurant trade.
The growth in the hard clam fishery is obviously of importance to the local
eonany, particularly as more producers reside permanently in the region and as
more of the product is sold outside of the region. This ensures the incomes and
expenditures generated through dockside sales and value added from processing
and/or depuration is retained within the local econany. A major obstacle to a
more accurate assessment of the status of the hard clam industry in Florida is
the lack of data at the producer and dealer level. This problem is compounded
by the fishery having only existed as a major commercial industry for 1 1/2
years, with an uncertain future to continue as such. Recent efforts to more
accurately document effort and production should be complemented by attempts to
describe various marketing aspects of the industry, such as ...
(1) describing product distribution and market channels by size class and
(2) documenting production and price by size class at the producer and wholesale
(3) collecting cost and return data at the producer and wholesale level,
(4) describing the seasonal impact on local price from production changes in the
northeast region, and
(5) evaluating the relative economic importance of depurated versus
non-depurated clam production.
Increased knowledge of these various economic aspects of the industry will help
ensure a viable industry will be maintained through efficient management and
Table 1: Total U.S. Clam Landings and Dockside Value, 1984
Pounds Dockside Average % of Total
Species (meat weight) Value $/lb. lbs $
( X 1,000
Hard 14,749 lbs $ 49,849 $ 3.38 11 43
Ocean Quahog 38,812 11,829 .30 29 10
Soft 7,919 19,842 2.51 6 17
Surf 70,243 34,334 .49 53 29
Other Species 1,198 637 .53 1 1
Total 132,921 Ibs $ 116,491 100 100
Source: Fisheries of the United States, 1984, NMFS, NOAA, U.S.
Dept. of Cammerce.
Table 2: Annual Reported Florida Hard Clam Production and
Dockside Value, 1970-1984
Pounds Dockside Average
Year (meat weight) Value $/lb
1984 1,851,069 lbs $ 6,552,200 $ 3.54
1983 142,566 473,108 3.32
1982 145,329 458,562 3.16
1981 117,249 313,458 2.67
1980 61,892 154,856 2.50
1979 71,714 163,756 2.28
1978 126,282 221,183 1.75
1977 147,927 205,172 1.39
1976 60,837 77,338 1.27
1975 73,233 90,394 1.23
1974 94,130 94,258 1.00
1973 139,103 101,257 .73
1972 63,468 39,979 .63
1971 99,264 49,632 .50
1970 60,804 33,171 .55
Source: Published and unpublished Florida Department of
Natural Resources and National Marine Fisheries
Service (NMFS) state and county camnercial fisheries
Table 3: Reported Landings and Dockside Value of Most
Important Ccmnercial Species in Florida, 1984
lbs $ 59,305,342
Source: Unpublished NMFS state canmercial fisheries data.
Table 4: Reported Hard Clam Landings and Dockside Value in -
Florida by County, 1984
Lee and St. Lucie
(meat weight) Value
1,708,378 lbs (92%) $ 6,130,783
1,851,069 Ibs $ 6,552,200
Source: Unpublished MFS county ccmnercial fisheries data.
Table 5: Hard Clam landings and Dockside Value for Brevard
Year (meat weight) Value
1984 1,708,378 Ibs $ 6,130,783
1983 108,332 374,604
1982 136,498 432,542
1981 61,348 171,542
1980 50,816 129,650
1979 37,269 .- 88,650
1978 112,442 203,261
1977 135,198 184,536
1976 50,547 61,144
1975 67,018 85,841
Source: Unpublished NMFS county commercial fisheries data.
1KNI WNG HOW MUCH IS THERE
Department of Environmental Science and Engineering
Florida Institute of Technology
Four transects at each of three sections on the Indian River lagoon were
sampled between April and July 1985. One section (at Grant) represented a
conditionally approved area with a history of heavy clam harvesting; another
section (at Palm Bay) was in closed (restricted) waters and had sane relaying
associated with it; the third section in closed waters with little harvesting
activity was located between Channel Markers 99 and 100 south of the Pineda
Causeway. Bivalves from three of the four transects at each of the lagoon
sanp ing sections have been sorted, identified, measured (along the longest length
of the shell), and enumerated.
Each of the twlve transects were sampled at stations of 200 m (655 ft.)
intervals. A 1/4 m open-ended drum with a 4 inch wide fluorescent strip and a
bevelled edge was pushed to a depth of 4 inches into the sediment. Bottom
substrate along with shellfish were collected with an airlift (suction) dredge (see
figure) with the assistance of SCUBA equipped divers. The suction dredge
operates by a Briggs and Stratton engine which draws water through the intake and
into the pump, expelling it with great thrust. The outflow passes through a long
hose leading to a suction control valve which regulates the amount of water
transmitted and, indirectly, .the force of water movement. The water then passes
through a suction head with a reduction nozzle where the flow of the water is
accelerated and the pressure below the nozzle falls creating suction into the
suction hose. Consequently, a sarpJe is airlifted through the hose and collected
into a 2 mm mesh bag. This dredge along with the aid of SCUBA is believed to be
one of the more accurate and quantitative methods of benthic sampling. In
addition, the researcher is able to observe the bottom morphology and vegetation.
Core samples for particle size fractionation were also taken at each station.
Sorting of the shellfish was done in the lab by sieving through a 2.8 mm screen
sieve (U.S. Standard No.7) and collec-ting the shellfish from the shell fragments
The enclosed table presents the average number of individuals for each size
class of clam and other bivalve shellfish found at each site. The smallest size
class for clams, "seeds" (<1" are the most abundant group of clams at Grant. An
average of 8 clams per 1/4 m (average of 31 stations on three transects)
Jrdicates the Grant area has received a successful set of clam larvae and should
-; : i :i 1~' t,.' e'd substantial quantities of harvestable clams as long as no
significant die-off occurs. Ey contrast, the numbers of "seed" clams at the Palm
Bay and Merritt Island locations are considerably less than those found at Grant.
Whether these differences are due to varying salinities, substrates, depth, food
supply, or competition among the sites is uncertain. The substrate at Grant was
sandy and the water depth shallower than at the other two sites. Merritt Island
had a bottom that was ccrrcs(ed crir.ici: l of shell fragments rc ilt. Also,
r'otice the large runners of nulliia lateralis at the Palm Bay and Merritt Island
locations. The similar sizes of Mulinia and "seed" clams suggest that competition
for food and attachment sites may be part of the explanation why "seed" clams are
more abundant at the Grant site than at the Palm Bay and Merritt Island sites.
For size ranges of clams greater than one inch in length, there are no
obvious differences between sampling locations. Moreover, the number of
individuals at Grant decrease dramatically from the small "seed" clams. There are
two possible explanations for the decrease at Grant of clams greater than one
1. Harvesting in the conditionally approved waters near Grant has reduced
the numbers of larger clams to levels similar to those areas of the lagoon where
the populations are lower.
2. Unsuccessful sets of larvae for a two-year period or mortality of
juveniles reduced the numbers of the larger c -,i ai i-e survivors grew to
marketable sizes. Note that the number of "beans", an illegal size of clam for
harvesting, is present in very low numbers at Grant.
Successful recruitment of juvenile clams in the Grant area should sustain the
supply of harvestable clams for the next two years providing mortality is kept to
a minimum. However, the low recruitment at Palm Bay and Merritt Island locations
suggest that those areas will not provide large numbers of harvestable clams. The
populations of harvestable clams at Grant is considerably lower than the
juveniles, and is comparable to the harvestable clam populations at the other
The sampling methodology (SCUBA assisted suction dredge) provides a
quantitative picture of the shellfish populations, and should prove to be a
valuable tool in future recruitment, growth, and inventory studies on this
valuable resource in the Indian River Lagoon.
i S IP 1ASIt
Sand moar A
Su"tlon head with
Collecting beg Reducidonl nessl A
Figure 2. Airlift suction dredge.
Meani number of individuals per i mn in each size range (shell length in inches)
each of three sections of the Indian River Lagoon.
in transects, A, B, C, of'
Number of stations
Seeds < 1"
Beans 1" 1!"
Buttons 1I1" 2"
Little necks 2" 21"
Top necks 211" 3"
Cherry stones 3" 4"
Chowders > 4"'
"0. 1" 0.4"
SAygd ium pnpyrium
A B C
.(9) (9) (8)
0.0 0.1 0.0
Eastern Shore Marine Research laboratory
Virginia Institute of Marine Science
The hard clam, Mercenaria mercenaria is considered an excellent candidate
species for aquaculture for the following four reasons:
First, the hard clam has a good market demand. A review of the National Marine
Fisheries Service market reports indicates a strong and steady demand for clams
(especially for smaller sizes). There have been few unexplained fluctuations in
demand or price.
Second, M. mercenaria is a hardy, relatively fast growing species with few
Third, the technology for growing this species is available and a number of
successful clam farms are already in operation. Demonstrations of this technology
are available at a number of research centers in the southeast.
The fourth and, perhaps, the most important aspect of clam farming is the
maximum price is offered at the minimum saleable size. In other words, the little
neck clam is worth more than the cherrystone or chowder sizes. Besides, the obvious
cash flow advantage in this, there is also an advantage in growing the product only
through the rapid juvenile growth phase and not after the growth rate slows down as
they reach larger sizes.
Farming of clams is usually divided into three phases. Phase one is the
hatchery stage in which adult clams are induced to spawn, the eggs collected, graded
and fertilized. The fertilized eggs are then cared for while they develop into
free-swimming clam larvae. The larvae achieve metamorphosis and set as small clams
after about 10 days.
During the second or nursery phase, the newly set clams are held in raceways or
upwellers, which exclude predators, and are washed free of silt until they are large
enough to plant on natural bottoms with a reasonably good chance to survive to
market size. Clams set at about a quarter of a millimeter in size, or about the
size of a small sand grain. They can be eaten at this size by a whole array of
predators such as grass shrimp, minnows, etc. When the clams are this small, their
siphon is not completely developed and they are vulnerable to smothering. A nursery
system eliminates these problems and allows the seed clams to grow under careful
Once the clam seed reaches 8 to 10 millimeters (about half the size of a dime)
they are ready for the final field grow out phase. A successful field grow out plot
must have proper salinity (20 o/oo or higher), temperature and food to sustain fast
growth. The clams must be protected in prepared beds which prevent larger predators
from destroying them and also prevent the clams from moving away from the protected
bed. Clams are usually planted in the prepared beds at densities of 100 to 300 per
square foot, dependent on the conditions found in the area. Stone or shell
aggregate for bottom substrate and plastic nets or pens for covers are used for
The field grow out phase requires the lowest investment and has the best cash
flow and profit potential. This phase is reccmnrnded for starting clam growers.
Prcrer sized seed can be purchased from commercial hatcheries.
Division of Applied Biology
Harbor Branch Foundation
Ft. Pierce, Florida 33450
The Harbor Branch Foundation, located in Ft. Pierce, Fl.orida maintains
an on-going research program in mollusc cultivation. The facility includes
a 2,000 sq. ft. greenhouse covered with translucent polyethylene film to
provide illumination for phytoplankton cultures, and chemical laboratories
for algae stock cultures and water quality analysis.
The facility was designed for pilot-scale production of bivalve
molluscs to meet the increasing demand for shellfish products. During the
fall of 1984, the Harbor Branch Foundation, in collaboration with Indian
River Mariculture, Inc. investigated the feasability of providing through
hatchery production juvenile hard clams, Mercenaria mercenaria, for
subsequent planting in the Indian River.
Adult hard clams collected from the Indian River near Grant, Florida
were transported to the laboratory and induced to spawn by thermal shock
(alternately raising and lowering the water temperature) and by adding an
infusion of stripped gametes to the culture'water. The fertilized eyis
developed into straight-hinged veligers within 24 hours.
Clam larvae were cultured in 500 liter cone-bottom fiberglass tanks
following standard techniques for bivalve culture (see Castagna, 1981).
Phytoplankton, unicellular algae which serves as food for larval as well as
adult filter-feeding bivalves, were cultured in 400 liter clear fiberglass
tanks. Unialgal stock cultures were maintained in a temperature and
photoperiod controlled incubation room in test tubes. As culture cell
densities increased, they were transferred to increasingly larger volumes of
enriched seawater until the 400 liter tanks were inoculated. Clam cultures
were fed approximately 10,000 cells/ml daily commencing 48 hours after
fertilization. Food levels were increased to 50,000 cells/ml as the larvae
grow and clear the algae from the culture water.
Larvae were stocked initially at 10 15 clams/mnl i:. 5 iicron, UV
irradiated seawater. The culture water was exchanged daily, tnc larvae being
collected on fine screens as the tanks were drained. During water
exchanges, small larvae were culled from the cultures, and the larval
densities lowered as the clams became larger. Within 10 12 days the clams
were competent to metamorphose (the pediveliger stage); at this stage larval
densities had been reduced to 1 3 larvae/mi.
Pediveligers that were retained on a 110 micron mesh screen were placed
in screened fiberglass cylinders, termed downwellers, and suspended! in the
culture tanks. A gentle flow of water air-lifted from the culture tank
created a downward current forcing the larvae into contact with the screen
on the bottom of the cylinder.
Once all of the clams had set in the downwelling cylinder, they were
transferred to a larger culture tank-(8' diameter) which holds several
cylinders. Cultured phytoplankton were added to the nursery tank, and the
the flow of water through the cylinder was reversed, that is water and food
were pumped upward through the cylinders. As many as 1/2 million juvenile
clams were held in each upwelling cylinder. This technique, termed passive
upwelling nursery systems, is becoming widespread in the culture of bivalves.
The juvenile clams were harvested from outdoor raceways when they
reached 5 to 10 mm in shell length. They were then transported to Indian
River Mariculture for growout in sand-filled trays with protective plastic
mesh covers to deter predation. Clams grow rapidly in growout systems,
reaching marketable size ir about 16 to 18 months.
Preliminary results indicate that hatchery production of hard clams to
provide mariculture' farms in the Indian River is feasable. Several million
clam seed were cultured at the Harbor Branch facility in 1984. This program
has the capability to expand production of clam seed should the demand for
cultured hard clams for mariculture purposes increase.
Castagna, M. and J. N. Kraeuter (1981)
Manual for growing the hard clam Mercenaria. Virgania Sea Grant
Program, Special Report #249. Virginia Institute of Marine Science,
Gloucester Point, Virginia 23062, 105 pp.
(Available from Sea Grant, $3.00)
MANAEMNT OF HE INDUSTRY
Senior Biblogist, Dept of Natural Resources
Management of hard clam resources in Florida has a
short and recent history when compared to more traditional clam
producing states. Although clam landings in Florida have been
recorded for more than 100 years, little resource management has
been directed specifically toward the clamming industry. Hard
clam harvesting has been managed and regulated as an adjunct
to policy developed for oyster resources. Existing policies
dealt more directly with regulating the clamming industry rather
than managing clam resources. However, the goal is the same,
preserve, enhance, and perpetuate shellfish resources.
Recently the need for new regulations arose and a
new mechanism for establishing fishing regulations was adopted.
Hard clam regulatory responsibility in Florida is now shared by
the MFC and the DNR. As of July 1, 1983, a 7 member Marine
Fisheries Commission (MFC), appointed by the Governor has rule
making authority in the following areas; gear specifications,
prohibited gear, bag limits, species that may not be sold,
protected species, closed areas, quality control codes, seasons,
and special considerations relating to egg-bearing females and
oyster and clam relaying.
Florida DNR continues to be the regulatory authority to
enforce the MFC's rules. DNR's Division of Marine Resources,
and more specifically the Bureau of Marine Resource Regulation
and Development, work with the MFC, FDA, NSSP and ISSC to
regulate the shellfish industry and maintain shellfish product
quality assurance. The Division's Shellfish Environmental
Assessment Section (SEAS) and the Shellfish Sanitation Section
(SSS) are instrumental in administering shellfish guidelines and
achieving shellfish management goals. The enforcement authority
for Florida's fishery regulations is the DNR's Marine Patrol
The SEAS section is responsible for designating shellfish
harvesting areas according to established federal guidelines.
Shellfish growing areas in Florida are classified as Approved,
Conditionally Approved, and Prohibited on the basis of
bacteriological and sanitary surveys. Unclassified areas are
closed to shellfish harvesting pending SEAS surveys. Harvesting
shellfish is permitted only in Approved or Conditionally Approved
areas. Shellfish harvesting areas may be designated as Approved
when the Interstate Shellfish Sanitation Conference (ISSC)
standard for fecal coliform densities are met during the most
unfavorable pollutional conditions, and designated as Prohibited
when the ISSC standard is exceeded. Conditionally Approved
areas must meet ISSC standard at all times while areas are
Approved as a source of shellfish for direct marketing. Public
health is protected in Conditionally Approved areas by closing
those areas to shellfish harvesting when the ISSC standard is
exceeded. Harvesting is also permitted in certain unclassified
areas when harvested shellfish are relayed and depurated.
The SEAS section has developed an atlas which defines
shellfish harvesting areas. Brevard County has 162 square miles
of growing waters of which 80 square miles are Conditionally
Approved and 80 square miles are Unclassified. The Conditionally
Approved harvesting area, designated as Body F, is approximately
16.2 square miles and was the location of the highest concentra-
tion of clams in 1984 and 1985.
The Seafood Sanitation Section (SSS) is responsible
for monitoring a comprehensive quality control program which
regulates the production and processing of shellfish. However,
few clams are processed within the state since the primary
product is shipped as shellstock. The Seafood Sanitation
Section also shares responsibility with the SEAS Section. They
determine bacteriological water quality and also monitor process
water and meat quality from depuration and relaying operations.
Meat samples and water samples are forwarded to the SSS
Laboratory, or they are sent to independent laboratories for
bacteriological testing before relaying clams can be approved
for harvest from shellfish leases or depuration plants.
Several requirements must be met in order for clams to
be commerically harvested and sold. Any person or business
harvesting or selling saltwater products to a wholesale or
retail dealer must have a valid saltwater products license.
Also, any harvester selling saltwater products for human
consumption must sell only to a licensed wholesale dealer.
Primary producers must also conform to specific quality
Persons or businesses buying and reselling saltwater
products must have a saltwater products license or obtain a
wholesale dealers licence. Wholesale and retail dealers must
also be in compliance with the Seafood Quality Control Code and
the Comprehensive Shellfish and Blue Crab Control Code. These
Codes give regulatory authority to the Department of Natural
Resources to control seafood quality aboard fishing vessels, in
offloading facilities, during production, handling, processing,
storing, and distribution.
Issued with a wholesale dealers license is a whole-
sale dealer permit number which must accompany all wholesale
transactions. Tags showing the permit number.and certificate
number must also accompany products when sold through licesned
dealers. These tags are used to establish the source and
distributional channels of shellfish.
In addition, all wholesale dealers are required to maintain
records of all purchases and sales, and these records are open
to inspection by the DNR. Records are collected through a newly
established reporting format established by the Marine Fisheries
Information System (MFIS) at the DNR Marine Research Laboratory.
Wholesale fishery transactions and supplemental information
supplied on 'Trip Tickets' should supply fishery scientists with
necessary information for making stock assessments and imple-
menting fisheries management policies to maximize yields and
The Department of Natural Resources also has regulatory
authority in managing shellfish resources through special
permits; including shellfish processing, mechanical harvesting,
relaying, depuration, shellfish leases, and aquaculture leases.
Table 1 represents a summary of management policy and regulatory
authority controlling hard clam resource management. These
policies are promulgated in the Florida Statutes (F.S.) and the
Florida Administrative Code (F.A.C.).
Rules have been adopted to protect clam resources from
over harvesting and depletion. These rules established a minimum
harvesting size of 7/8 inch thickness (across the hinge), protect
the environment by restricting harvesting hard clams in grass-
beds, protect environmentally sensitive areas by regulating
the use of mechanical harvesting gear, and insure public health.
Rules also restrict the time and manner of taking and trans-
porting hard clams. The effect of these newly adopted rules will
be to assure an abundant supply of hard clams in the future,
while protecting seagrasses and other parts of the estuarine
environment. Because some rules only became effective January 1,
1985, it is impossible to determine their impact on clam
resources. However, it is apparent that this action was not
swift enough in coming to sufficiently curtail harvests of
buttons in 1984. The year class, or set which would make up the
most valuable part of the 1985 harvest, the little necks, make
up only a small percentage less than 5% of the present clam
In order to increase shellfish production an extensive
leasing program has been developed. Approximately 2275 acres of
state bottoms have been leased through 194 lease contracts; 99
of these leases are located in Brevard County, totaling 850
acres. Bottoms are presently leased at $5.00 per acre. Over
the years Florida's policy on leasing has fluctuated between
strongly encouraging leasing to suspending new leasing activity.
In earlier years shellfish leases were most commonly used to
cultivate oysters, but more recently, clam production and
relaying to shellfish leases have increased, particularly in
Brevard County. Leased bottoms are designated by corner posts,
but access is not restricted except for harvesting shellfish.
Under Florida Law a lessee must demonstrate that the lease
is being developed to improve productivity to levels suitable for
commercial harvesting. Suitable development for shellfish
leases generally meant providing suitable substrate, or cultch
to promote oyster attachment and growth. Suitable development
of a lease for clam production is much more difficult to define,
and other criteria to demonstrate development,may need to be
The Governor has requested leasing contracts be carefully
scrutinized; attempts are being made to have all public lands
which are leased by the private sector become self-supporting.
Lease contracts and prices, including docks, marinas, and
shellfish leases; would be sufficient to reimburse the state
for all costs incurred in the course of administration and
enforcement. The Department's position has been to restrict
leasing activity until the specific guidelines are enacted. The
Department is also presently investigating alternative shellfish
leasing concepts pertinent to use requirements, compensation,
and fee structures.
Numerous changes have been proposed to improve leasing
concepts. These include 1) revising aquaculture.leasing rules
defined in FAC 160-21, 2) restricting the size of shellfish
leases, 3) changing lease prices, and 4) developing methods of
payment based on production levels. New policies are also being
developed which will pertain specifically to aquaculture leases
and the restricted use of state bottoms and overlying waters.
The clamming industry in Florida, particularly Brevard
County exploded during 1984 after successful sets in 1982 and
1983. Table 2 represents a conservative estimate of the
fishery's landings and values. To appreciate the magnitude of
increase, these figures can be compared with state wide landings
and values of approximately 125,000 lbs and 400,000 dollars in
the proceeding two years (Table .3).
New policies have also been enacted to support and encourage
relaying and depuration activity. Florida's shellfish management
policies are directed toward promoting shellfish production, as
well as, protecting and perpetuating the resource. One method
of increasing production is through relaying clams to depuration
facilities. Depuration has proven to be an effective method
for utilizing a previously rehabilitated resource and insuring
product quality. The DNR has supported the conscientious har-
vesting of clams, from specific areas closed to public har-
vesting, for the purpose of depuration. Individuals or companies
which hold shellfish leases can apply for permits to relay clams.
Harvesting, transport, and relocation are closely monitored
and supervised by law enforcement officers and the DNR. Clams
can be harvested from leases 15 days after relaying has been
officially terminated, if meat samples meet bacteriological
standards (230 standard).
Depuration is typically accomplished in tanks using
recirculated U treated water, water quality paraters are
controlled, and bacteriological concentrations are closely
monitored. Table 4 demonstrates the rapid increase in
relaying and depuration activity in recent years.
Clams Ch. 370.16, F.S.
Harvesting Ch. 16B-28, F.A.C.
Mechanical Harvesting Ch. 370.16, F.S.
Vessel Requirements Ch. 16B-28, F.A.C.
Shellfish Lease Ch. 370.16, F.S. and
Ch. 16B-28, F.A.C.
Aquaculture Lease Ch. 16Q-21, F.A.C.
Relay Permits Ch. 16B-28, F.A.C.
Depuration Permits Ch. 16B-28, F.A.C.
Quality Control Ch. 16N-27, F.A.C.
Enforcement Ch. 370.16, F.S. and
Ch. 16N-27, F.A.C.
and Sales Ch. 370.06, F.S.
Hard Clam Harvests And Values (1984)
Bushels Number/ Number Percent Value Value
Harvested Bushel (millions) Harvest ($0.00) (million $)
Buttons 54,548 1200 65.46 25 0.02 1.30
Little Necks 130,914 700 91.64 60 0.06 5.50
Cherry Stones -26,183 300 7.85 12 0.05 .40
Chowders 6,545 100 0.65 3 0.01 .06
Total 165.&1 7.26
Values Extrapolated From Florida Landings And Industry Surveys
Hard Clam Landing And values
Year Total Brevard County Volusia County Gulf County
Pounds Dollars Pounds Dollars Pounds Dollars Pounds Dollar,
1979 71,714 163,756
1980 61,892 154,856 50,816 129,650 4,149 9,715 262 489
1981 117,249 313,458 61,348 171,404 31,275 94,609 13,735 21,21i
1982 1"45,324 458,562 136,498 432,542 7,971 24,429 790 1,43:
1983 142,566 473,108 108,332 374,604 19,234 59,168 14,033 36,47
1984 1,548059 4,836,684-1,433,295 4,498,611. 14,513 45,851 71,634 154.47
From Florida Landings, NMFS.
Hard Clam Landing And Values
Year Total Brevard County Volusia County Gulf County
Pounds Dollars Pounds Dollars Pounds Dollars Pounds Dollars
1979 71,714 163,756
1980 61,892 154,856 50,816 129,650 4,149 9,715 262 489
1981 117,249 313,458 -- 61,348 171,404 31,275 94,609 13,735 21,217
1982 145,324 458,562 136,498 432,542 7,971 24,429 790 1,433
1983 142,566 473,108 108,332 374,604 19,234 59,168 14,033 36,475
1984 1,548059 4,836,684 1,433,295 4,498,611 14,513 45,851 71,634 154,476
From Florida Landings, NMFS.
Aquatic Preserves Manager
Florida Department of Natural Resources
The Indian River Malabar to Vero Beach Aquatic Preserve
may be the setting for a new industry soon: mariculture. As
those in the shellfish business realize that clams can not
reproduce fast enough to keep up with the increasing demands and
the aquaculture industry improves the technology to cultivate
clams, people are beginning to look towards clam mariculture as
a way to keep production up.
Clam mariculture projects on state-owned submerged lands
will require a lease. Until, recently, aquaculture leases in
this area and around Florida have not been in big demand. In
anticipation of more requests for leases, the Department of
Natural Resources is looking into their leasing policies again.
The Department of Natural Resource's Divison of State Lands has
put a temporary hold on leasing new areas while rewriting
portions of the rule concerning aquaculture leases. They will
resume processing aquaculture lease applications when the rule
has been revised.
If the lease applied for is in an aquatic preserve, it
will also be reviewed by the staff of that preserve. The aquatic
preserve personnel will try to determine if that particular
lease and its mariculture plan are compatible with the goals of
aquatic preserves. Staff will be looking at the lease location,
the types of impacts the project will have on the lagoon's
resources and will try to work with the applicant in developing
environmentally-sound plans. If there is not enough data to
make a thorough evaluation, a small-scale test of the proposal
might be possible first.
Mariculture can be a valuable asset to the shellfish
industry but not if it is done at the expense of the lagoon. A
healthy habitat is needed for the propagation of shellfish.
The Indian River Lagoon is in good condition and with careful
planning we can keep it that way.
Captain R.A. Patterson
Florida Marine Patrol
Prior to the development of the Brevard/Indian River clam industry,
there were few regulations dealing with the harvesting and process
of clams. Rapid growth and large influx of harvesters brought
about many problems.
Through.cooperation with people in the industry, additional
regulations have been instituted and others are in the process
of being updated. Considering that clamming is basically a new
industry to Florida, growth has been orderly. Additional studies
on the resource and the effect on the marine environment needs to
MFC Rule 46-17 Size and Harvesting restriction
Special Act:75-336 Sport bag limit
F.S. 370.16 Shellfish regulations
F.S. 370.06 Saltwater Products License
1985 HB-89 Brevard/Indian River Clam Licen
Adm. Rule 16B28 Shellfish Code and Relaying
Adm. Rule 16N27 Quality Control (Boat Requiremc
Rapid growth of industry
Large influx of clammiers
Size of harvest areas
Control of relay operations
Control of depuration processes
Lack of sufficient regulations
Lack of manpower.- (Activity increase 1983-84. 200%
Illegal operations (harvest/sale)
Courts and fine structure
President, Indian River Clamners'Cooperative Association
The following is a brief description of concerns and recca~endations of the
Indian River Clamners' Cooperative Association which represents approximately
forty clambers now working in the Indian River Lagoon.
1. The current 7/8", across the hinge, size limit is too small and should
be increased to one inch. All clams smaller than 1" should be returned to the
Lagoon for later harvesting. This will protect the industry by protecting the
resource from overharvesting. To aid enforcement and clammers culling for small
clams, the tolerance level for harvested undersized clams should be raised from
the present level of 3% to a 5% level.
Equipment presently in use is designed for the 7/8" size limit (7/8"
between teeth or bars) so that minimal culling by clamners is required. Raising
the tolerance limit to 5% will allow for the increased possibility of undersized
clams being harvested between the 7/8" and 1" size ranges due to human error
introduced in the culling process and save clamers from purchasing expensive
2. The Indian River Lagoon is too small for the intense fishing and
recreational activities presently occurring within it. Submerged lease areas
decrease the size of areas available to the public. Old leases which are not
being used for production purposes (i.e., relaying or mariculture) should be
reissued to persons wishing to participate in productive activities or else
revert back to the people of Florida.
3. The southern clam has a shorter shelf life than does the northern clam.
Due to this fact, it would be preferable to open new harvesting areas within the
Lagoon during the winter months (perhaps on December Ist) when the shelf life of
the southern clam more nearly approaches that of the northern clam.
4. The practice of relaying clams from unapproved or conditionally
approved areas to either leased areas in approved waters or to depuration plants
has positive and negative impacts upon the industry. Smae of the positive
aspects include the creation of a steady market flow by allowing harvest from
unapproved.areas or during-times when conditional areas are closed.
Unfortunately, this also has the effect of creating increased harvesting
pressure on the resource and allows buyers to more easily set prices lower than
fair market value since only buyers with leases or depuration plants can buy
5. Money frcm the newly created "clam diggers license" should go to
purchasing and properly placing seed clams rather than to research which may be
of questionable benefit to the resource. If research is to be conducted, it
should be of a practical, applied nature and be directed at increasing
production. The Florida Marine Patrol or other suitable government agencies
should also be able to use this money to help combat pollution problems facing
6. [This section presented by Mr. Charlie Hotcavig- Indian River clanmer.]
Pollution is the clanmers' biggest enemy. Many people involved in the clamming
industry in other areas of the country have been forced out of these areas by
harvesting area closures necessitated by severe pollution problems. At this
time, approximately 80% of clam harvesting areas in the state of New York are
closed due to pollution. Individuals have the ultimate responsibility for the
health of the Lagoon. However, the state of Florida must aid the people of
Florida in this effort by taking the lead in the fight against pollution of the
Indian River Lagoon.
Aquaculture Development Representative
Florida Department of Agriculture & Consumer Services
The Brevard County Clam Industry Workshop, held September 7, 1985, brought
together a concerned group of people, representing varied interests to talk
about the use, protection and management of a resource of importance to
all. The workshop was a success in that attendees came away with a better
understanding of one another's interests and the overall picture of the
Indian River Lagoonal System. What follows is a summary of some of the
information presented at the workshop, my impressions and some recommended
actions for the future.
Participants heard that over 90% of the clams reported harvested in Florida
came from Brevard County waters. The 1984 statistics showed 1.7 million
pounds of clam meats valued at $6.1.million or a dockside value of $3.54 per
lb. of meat. Since Florida harvests 13% of the nation's total, clamming is
clearly an economically important industry to Brevard County.
Participants learned that the Indian River is more of a lagoon than an
estuary since there is relatively little water exchange between the lagoon
and the Atlantic Ocean. In fact, the term river is a misnomer which adds to
the problems of the lagoon since it implies anything, such as pollutants,
added into the river will merely be carried away. So creating a better
public awareness of the value, function, and fragility of the Indian River
Lagoonal System should be a high priority of all attendees. We learned that
the lagoon is one of the most diverse estuaries in the United States with
approximately 400 species alone of fish collected from the lagoon. The
marine grasses, mangroves, and other marsh plants are very important to the
health of the lagoon-and the overall system directly impacts the commercial
harvests in and outside the lagoon.
The Indian River Lagoon is now an aquatic preserve which is an attempt to
provide more protection to the area. The lagoon has an aquatic preserve
manager and a management plan. The plan is the process by which such a
concerned group as the clam workshop, can work within to eliminate the
pollution sources into the lagoon and protect the clam resource. An aquatic
preserve could accommodate aquatic farming enterprises such as clam culture
if they are designed in an environmentally compatible manner and do not
overly restrict the other users or purposes of the preserve. A
demonstration project was suggested as one possible method to evaluate the
compatibility and impact of a culture operation on the Indian River Aquatic
The audience learned that a great deal of research has been undertaken in
the lagoon,. DNR has contributed through the shellfish assessment program,
aquatic preserve program, and scientists at the Marine Research Lab in St.
Petersburg. The University of Florida, Florida Institute of Technology, and
Harbor Branch Foundation have all undertaken research in the lagoon. FIT
and Harbor Branch have been actively sampling the lagoon to determine clam,
abundance and develop methodology to predict yearly recruitment to the clam
fishery. Recent research suggests that the large 1984 clam harvest may have
resulted from heavy rainfall during the spring and fall spawning seasons in
1982 and the above normal rainfall the succeeding two years, in contrast to
previous' theories of prolonged low rainfall and decreased clam abundance.
Developing the appropriate methodology to predict clam populations on a
yearly basis should be a high research and management priority. A second
observation is that researchers have shown considerable interest in the
Indian River Lagoonal System. Workshop participants should work towards
insuring that these resource persons continue to undertake active research
programs in the lagoon and provide these researchers with direction which
reflects the needs and concerns of the various user groups.
Regulatory issues were discussed and questions answered. One issue which
needs to be clarified is the names for the various sizes of clams harvested.
One speaker suggested sizes should be as follows:
Seed clams less than 1.0 inch
Beans 1.0 1.5 inches
Buttons 1.5 2.0 inches
Little necks 2.0 2.5 inches
Top necks 2.5 3.0 inches
Cherry stones 3.0 4.0 inches
Chowders greater than 4.0 inches
Little necks, top necks and cherry stones were considered the sizes
commercially important. Therefore, one industry need is to standardize the
clam sizes wherever the hard clam can be grown. This will assist both in
managing the resource and marketing the product. The lease moratorium was
briefly discussed. DNR staff stated that even though clams were recognized
in the shellfish lease law (Chapter 370.16 F.S.), that law, when written
(1961), was aimed at oysters since very few clams were harvested at that
time. Staff stated the law was in the process of being revised along with
the aquaculture lease law (Chapter 253 FS). Staff also felt the shellfish
lease law to be too'vague on DNR-recinding idle leases and if challenged,
probably would not stand up in court (i.e. another part of the shellfish
lease law states the leases are granted in perpetuity). Regulators did
state very clearly that industry members must make their needs known and
work with government agencies, legislators, other users, etc. to obtain
their goals and wisely utilize the resource. The Marine Patrol ran through
the current regulations, fielded questions, and expressed a willingness tc
continue to work with workshop participants.
Industry concerns were presented by four speakers. Dealers would like tc
see the industry work together to improve the quality of the product anc
maintain high standards. Marketing is presently no problem as demand
exceeds supply. However, improved methods (which IFAS researchers art
addressing) of handling and storing the product are needed, especially
storage temperatures. The exeuctive director of an industry association
talked about the economic importance of the industry to Brevard County and
the state. He stated very clearly how all groups need to work together,
state their problems and needs clearly, and engage in the political system
to foster change. The only reason no assistance has ever been given to the
clam industry (i.e. in contrast to the oyster industry) is because none has
ever been requested.
Clammers presented eight industry concerns:
1. -The size of clams needs to be standardized. Clams harvested should
be the size worth the most money and not undersized. Undersized clams should
be culled back into the water to be harvested the following season when they
are worth more money.
2. The size of rakes currently have teeth spaced 7/8 inches apart to
coincide with the minimum allowable sized clam harvestable. If the minimum
clam size increases to 1.0 inch, the rakes should be allowed to remain at
the current 7/8 inch spacing.
3. The Marine Patrol presently allows a 3% tolerance of undersized
clams per bag of clams harvested. If the minimum harvestable size is
increased to 1.0 inch, then the tolerance should be increased to 5%.
4. The lease moratorium should be lifted and an equitable system of
leasing instituted. There are many leases not presently being utilized and
this is not fair, especially since the law says these leases should revert
back to the State.
5. The industry needs to have more approved shellfish areas opened.
Presently, the process requires too much time. The state should be doing
all it can to maximize the number and acres approved for shellfish
6. Relaying was viewed as a necessary evil when approved areas were
closed or not producing. Relaying from unclassified waters should be
7. The new license fees are high when compared to other commercial
fishing industries (i.e. saltwater products license) and represents the
money the clammer gives to the state to protect the resource. Clammers
should have a more representative voice -in how the funds are allocated, and
to what types of programs that benefit the needs of the industry.
8. There should be a better effort to stop and abate pollution in the
Indian River Lagoon. The Marine Patrol could take a much more active role.
Many clammecs have moved south as the resource has become polluted along the
eastern seaboard. There is no place further south to go if the Indian River
The majority of the afternoon was devoted to presentations dealing with
clam aquaculture in Virginia and in the Indian River Lagoon. Virginia
researchers have found the hard clam to be an excellent candidate species,
with a good market, a relatively short culture period for the highest priced
market size, a hardy species once the organism is cultured past early life
stages, and culture technology is readily available. There are a minimum of
24 clam farms in operation and most are already earning a profit. While
aquatic farming of clams will never replace the wild catch, it should be
viewed as a supplement to the wild catch which could stabilize supply and
Clams can be induced to spawn through manipulation of temperature and
photoperiod or through injection of hormones such as seratonin. They should
be reared in a hatchery or well protected area until they are a minimum of
9-10 mm in length (7/16 inch). Planting at this size along with some
protection will yield 70-80Z survival.. A simple hatchery and nursery'can be
established for as little as $7000. A number of commercial hatcheries are
in operation and a person with an aquatic farm or lease can send clams from
their waters to these northern hatcheries to be spawned and juvenile clams
shipped back to the farmer. Prices range from $7 per thousand 6mm clams
after August to $14-17 per thousand 9-10 mm clams. A number of growout
techniques can be employed. A manual written for the culturist without a
scientific background was presented. The reference is:
Manual for Growing the Hard Clam Mercenaria
Michael Castagna and John Kraeuter
Special Report in Applied Marine Science and Ocean Engineering
Virginia Institute of Marine Science, No. 249, Spring 1981
Gloucester, Point Virginia 23062 $3.00
Researchers in Virginia have established a cost to the farmer of 3.4
cents per clam from spawning to loading a market sized clam on a truck.
.In Florida, there-is one.commercial farm which has worked closely with
Harbor Branch Foundation developing appropriate clam culture technology for
the Indian River Lagoon. Harbor Branch has established a research hatchery
and is now routinely spawning clams. Genetic selection has yielded a clam
with a. reddish shell and easily distinguished from a wild caught clam.
Researchers have been planting a 4-6 mm clams in 4 x 8 foot covered trays on
leased bottoms. Approximately 50% of these clams will survive to market size
and yield 5 bags per tray. Growout requires 16-18 months with seed clams
planted in the spring and harvested the following year in the fall. The
speaker invited all interested clammers to come to Harbor Branch and view
The workshop and its participants could become the focal point in
developing an industry composed of wild harvesting, relaying and culturing
clams, and in harmony with environmental concerns and other users of the
Indian River Lagoon. The workshop only scratched the surface of the work
which must be carried on by participants to foster change and insure the
continuance of the resource. The major points identified at the workshop
1. The Indian River Lagoon is a valuable resource. It is extremely
productive, biologically diverse and economically important to both
commercial and recreational fisheries within and outside the lagoon. The
wetland (marsh) and aquatic plants (grasses) are directly tied into that
productivity, diversity, and commercial economy, and as a result, must be
protected and well managed. The aesthetics of the area must be maintained
as they are the primary reason for growth in Brevard County. The Aquatic
Preserve designation was made in an attempt to protect and manage the
resource and could be used as a vehicle to achieve commercial needs as well.
2. The Clam resource has problems. The resource is poorly understood
in terms of yearly abundance and recruitment and with what factors (i.e.
rainfall, salinity)it is correlated. Population growth and other sources of
pollution are continuing to further threaten the resource and not enough is
being done to abate or control these sources. The clam industry must share
the resource with other users including other commercial and recreational
fishing, navigation, other recreation, agriculture, and public uses such as
causeways and power lines. In addition, there are unresolved regulatory
problems with relaying, depuration, leases and harvestable sizes of clams
and enforcement of present laws is inadequate.
3. The technology to culture clams commercially on leases exists, such
aquatic enterprises can be profitable, and clam aquaculture would add a new
dimension to the industry. The efficiency of agriculture over a hunting and
gathering technique has been an established fact for over 100 years for
nearly all food consumed. Aquaculture can stabilize and enhance markets
through year round production and availability of a quality product. Such a
program in the Indian River Lagoon could be accomplished in an equitalbe
manner without eliminating the small independent businessman and at the
same time reduce enforcement problems.
Clearly, the participants who gathered at the workshop to discuss problems
and needs of the clam resource and the cooperative spirit of communication
generated at the meeting should be continued. I believe all the necessary
ingredients exist to develop a productive clam industry which will be a
strong economic incentive to protect and manage the resource in an
environmentally sound manner. Therefore, I am suggesting the following
recommendations for consideration as a course of further action.
1. Create an organization of all existing user groups, resource
persons, and private concerns to actively pursue development of a plan of
action to foster needed changes and implement objectives. The organization
can be in the form of a committee, a new incorporated organization, or a
branch of an existing group such as the clammers association, the Marine
Resources Council of East Central Florida, or through the Aquatic Preserve
Management team. The organization should develop clearly defined goals and
plan strategic objectives to obtain those goals. The organization should
also have broad based representation to insure they are managing their own,
future destiny with respect to the Indian River Lagoon. Representation
a) Industry. A member and a non-member of the clammers' association,
a relayer, a depurator, a dealer, a member of the Organized Fisher-
men of Florida, a member of the Southeastern Fisheries Association,
a commercial fisherman directly dependent on the lagoon, a commercial
fisherman indirectly dependent on the nursery function of the lagoon,
a clammer at large, a clam farmer, and a recreational clammer.
b) Conservation and environmental groups such as the Marine
c) Researchers such as Harbor Branch, Florida Institute of
Technology, University of Florida and others.
d) Resource persons such as IFAS and Sea Grant extension and
ocher government agencies, especially regulatory. DNR, for
example, could have members representing shellfish assessment,
Marine Research Lab, State lands, and aquatic preserves.
e) Others including the aquatic preserve manager, chamber of
commerce, local government,.and public at large.
One possible organization could be based on Alaska's Regional Aquaculture
Association's designed to protect and manage the resource, but requiring
legislation. A brief synopsis of the Alaska program is attached.
2. Continue to encourage research in the Indian River Lagoon,
especially as it relates to the clam industry. This would include
continuing monitoring and ecological studies; basic clam biology,
recruitment predicting, handling, storage, shipping, pros and cons of
relaying and deputation, and quality control; culture techniques including
environmental compatibility of aquatic farming enterprises; and
3) Develop an educational program. Informing area residents, industry
members, and other users about the importance of the lagoon, the benefits of
a clam industry which includes aquatic farms, and the long term value of
protecting and managing the resource should be a high priority. This
program should minimally include how the lagoon functions, the economic
importance of users including the clam industry, pollutional threats to the
resource, and what steps concerned citizens can take to insure maintenance
of the resource. News releases, media events, and brochures describing all
the various users and functions of the lagoon are important tools which
numerous government resource persons can assist with in developing. The
long term solution is to develop a comprehensive program within the Brevard
County School District so that hopefully, our children will grow up knowing
how to respect the resource and not make similar mistakes.
4) Develop a dynamic plan of action and systematically implement those
identified actions. This is a key recommendation and may be accomplished
through an existing planning process or developed as an independent plan
from the organization described in recommendation (I). The process should
contain specific elements to manage and enhance the clam resource. The
elements to address should include:
a) Pollution. The sources of pollution, the pollution issues
affecting the shellfish industry, and the approaches currently being taken
to reduce pollution in growing areas.
b) Leases. The issue of creating private property rights in a
publically held natural resource should be resolved one way or the other.
The DNR should begin by plotting existing leases on a map of the Indian
River Lagoon. Industry would then know where the leases were located, who
the owners are, and possibly work a deal to sub-lease or purchase a lease.
Regulators and users could also use the map to assess where additional
leases should or should not be located. Next, DNR should rescind inactive
leases. If the statute is not clear, then testing in court would clarify
the statute by developing case law. The moratorium should be lifted and
new parcels leased. One possible solution to the lease dilemma would be to
use the organization in recommendation (1) to work out a new lease plan with
government regulators satisfactory to both sides. The DNR could then go to
the Legislature with the organization's support to amend existing statute
(s). The paper entitled "Building the Perfect Lease" could be the basis for
fostering a workable solution.
c) Aquatic Preserve. The goals and objectives of the organizations
dynamic .plan of action should be integrated into the aquatic preserve
management planning process.
d) Demonstration. A public or joint public-private demonstration
project on clam aquaculture should be undertaken. Appropriate -technology
will be determined, costs and return data generated, and environmental
compatibility evaluated. Most importantly, skpetical industry members will
have the opportunity to see how such an aquatic farming enterprise is
established and operates.
e) Political Strategy. This is an important element which was
addressed by two speakers. Collect the facts, determine needs and
priorities, and engage in the political system to properly inform the local
Legislative delegation. As both speakers stated, you have to ask for
something in order to get it.
I believe these recommendations could assist the start of a new future for
the shellfish industry in the Indian River Lagoon. The key is to organize
and cooperate. Interested industry persons should not give up if they can't
get all their members to agree. The Industry must adapt to modern times-and
not expect to survive with past methods or technology. Those who do not
participate at first, will participate as changes occur and objectives
achieved. These are the facts of life and are no more evident then in the
competitive nature of our free enterprise system. And the dynamic plan of
attack can be so designed as to never eliminate the small or individual
businessman which presently makes up the majority of this industry. The
keys are communication, cooperation, and compromise.