Florida Board of Conservation
Division of Salt Water Fisheries
CLAMS AND OYSTERS IN CHARLOTTE COUNTY AND VICINITY
Kenneth D. Woodburn
Florida Board of Conservation Marine Laboratory
Maritime Base, St. Petersburg, Florida
Originally Mimeographed 1 August 1962
REISSUED March 1965
FSBCML NO.: 62-12
CS NO.: 62-1
Fishing is Florida's oldest industry, Florida saltwaters produce
a greater variety of marine products, including game and food fishes,
than any other State. The combined value of the commercial and sports
fisheries, established by state-wide professional surveys, is at least
$300,000,000 yearly. The whole State, and all 35 coastal counties in
particular, share in this wealth a gift of Nature so long as they
judiciously exploit their shorelines, saltwaters and submerged bottoms*
The State Board of Conservation has a vested interest in seeing that
this is done. It is charged with the supervision, conservation and
development of the different fisheries through scientific management,
control and aquaculture based on research. The job is difficult.
Problems are acute because rapid urbanization has accelerated lucrative
waterfront development and unfavorable changes in marine environments.
Damage to our multi-million dollar fisheries is not inherent in
urbanization unless planning is poor and short-sighted and destructive
dredging, filling and pollution are condoned because of apathy, ignorance
Coastal, estuarine and island development can be planned to best
serve conservation. The State Board of Conservation stands ready to
aid and advise counties, other governmental units and private interests
in the best known ways to sustain and further marine productivity.
CLAMS AND OYSTERS IN CHARLOTTE COUNTY AND VICINITY
Charlotte is a county of change. Its population has tripled in
the last decade. Most of the new population is concentrated in water-
front communities whose homesites have been created by digging canals
to drain raw upland and provide navigable waterways. This surge of
people makes it imperative that affected shorelines, saltwaters and
submerged bottoms be judiciously exploited. Fortunately, hydraulic
dredging and filling of submerged land to make residential finger fills
has not been widely practiced in Charlotte as in Pinellas, Dade and
Palm Beach Counties where productive bay bottoms have been extensively
As pollution, pests and diseases, and declining yield continue to
plague northern shellfish areas, interest and enthusiasm in Florida as
a commercial shellfish producer grows* In our warm waters, clams and
oysters reach marketable sizes in about one-half the time they do in
New England and the Middle Atlantic States. Charlotte and Okaloosa
Counties have experienced the greatest increase in commercial shell-
fishing activity and interest in Florida. This study has been made in
recognition of the important role Charlotte County is playing in the
Florida seafood industry.
If the present boom in shellfish harvesting and culture is to
continue and succeed, bulkhead lines will have to be set at or near
mangrove shorelines and dredging as well as filling limited by the
bulkhead lines. The most realistic method to assure marine productivity
is to allow those low shorelands lying in the path of urbanization to be
raised to levels suitable for human habitation with fill material ob-
tained from draglining canals inside bulkhead lines.
Scale: 1" = 250,000"
Reference points and bodies of water in
County and gricinity
FSBCML NO.: 62-12
CS No.: 62-1
Field investigations for this report were made intermittently from
June 5 through June 21, 1962 with the assistance of Officers William
King and Luke Wolcott of the Florida Conservation Patrol* Map 1 has
been prepared to orient the reader to reference points and bodies of
water. Water salinities and temperatures, tides, bottom types, abun-
dance and quality of clams &nd oysters, and shellfish predators were
Three species of bivalve mollusks have commercial significance in
Charlotte County and vicinity.
The Southern Quahog or hardshell clam, Mercenaria campechiensis, is
being harvested extensively from productive natural beds along the
inside of Gulf barrier islands.
The eastern oyster, Crassostrea virginica, is the basis for exten-
sive leasing of submerged bottoms especially in Turtle and Bull Bays.
Oyster harvesting has been mostly from natural bars also. These public
bars are closed to oystering from May 1st to September 1st each year so
that now oyster activity is limited mainly to seeding of leases, Coon
oysters refer to oysters that are stunted, poor quality and usually
overcrowded. AS spat or baby oysters, they settle in unfavorable
locations. If culled and moved to favorable environment, they can reach
marketable size and quality.
Large beds of the Rangia marsh clam, Rangia cuneata,in the brackish-
freshwater zones of the Myakka and Peace Rivers have commercial.concentra-
tions if processing proves economically feasible, marketing outlets
materialize and river water is certified for shellfish harvesting,
Recorded hardshell clam production began in Florida in 1880, in-
creased significantly in 1908 with exploitation of large clam beds in
Collier and Monroe Counties near the Ten Thousand Islands, grew steadily
until the peak year of 1932, remained at a high level through most of
World War II and plummeted to a beginning low by 1950, From 1950
production increased modestly, as shown on Table 1, until February 1962
when intensive harvesting of natural clam beds in Charlotte County and
vicinity began. Table 2 showi the dramatic jump in Charlotte County hard-
shell clam production preceded two months earlier by a sharp rise in
oyster production, Development of marketing outlets in Middle Atlantic
States caused the increase in hardshell clam harvesting.
Most shellfish leases have been for oysters, One oyster-shucking
plant operated in Placid this past season. Another is being constructed
nearby. It is very doubtful that production from natural bars in the
area could ever support two oyster houses. Leases will have to be
brought into production where mechanical harvesting is allowed. Oyster
shell planting for cultch was observed in Turtle Bay during field work
for this report. Oyster seed was being collected from coon oyster bars
in Gasparilla Sound.
Florida oysters and hardshell clams follow different paths to the
consumer. The oyster season coincides chiefly with the winter tourist
season. Most local oysters are consumed raw on-the-half-shell. Besides
shucking, and packing and chilling, processing of Florida oysters is
limited. Summer condition is poor because of spawning. The hardshell
clam is usually processed into chowder or a canned minced product. A
spawning condition is not so marked and there is no closed season de-
noting a period of poor quality.
Mechanical harvesting of clams and oysters lying in the path of
the West Coast Intracoastal Waterway is planned after contracts are let
for waterway dredging in Charlotte Harbor, Gasparilla Sound, Placida
Harbor and Lemon Bay. The waterway route generally follows deeper water
where harvesting of clams or oysters by hand or hand implements is
difficult or impossible especially for clams. Mechanical harvesting is
not allowed on public shellfish beds but in this case it would be
permitted because of the
Clam Production in Florida
YEAR EAST COAST WEST COAST TOTAL
18W0 5,000 -..-- 5,000
1903 57,000 182,000 239,000
1923 5,000 602,000 607,000
1930 49,840 661,736 711,576
1932 12,000 1,108,812 1,120,812
1940 6,700 701,100 707,800
1945 3,000 687,700 690,700
1950 900 4,400 5,300
1955 6,300 15,700 22,000
1960 2,134 23,893 26,027
* 5-,0 pounds
of meat per U. S. Standard Bushel (Florida East Coast)
of meat per U. S. Standard Bushel (Florida West Coast)
Commercial hardshell clam and oyster production in Charlotte County
since increased exploitation of natural beds*
DATE HARDSHELL CLAMS OYSTERS
(pounds of meat)
May 1961 ------ Closed
June 1961 ..... season
July 1961 --...- for
August 1961 ..---- Oysters
September 1961 ------ .--
October 1961 ------ 192
November 1961 -..-- 2,204
December 1961 88 24,035
January 1962 ------ ----
February 1962 74,130 15,512
March 1962 22,330 8,524
April 1962 36,960 10,592
*Taken from Florida Landings- compiled by U. S. Fish and Wildlife
Service in cooperation with Florida State Board of Conservation
and the University of Miami Marine Laboratory.
probable destruction of shellfish by dredging, spoiling or siltation.
Special attention was given to waterway considerations during field
studies* The inherent difficulties in mechanical harvesting of shell-
fish before the waterway route is marked for dredging are obvious.
"Discovery" of the large beds of Rangia clams this year has roused
considerable interest in molluscan circles. Dr. Joseph P. Morrison,
Acting Curator, Division of Mollusks, U. S. National Museum, stated in
a letter to Dr. Robert F. Hutton:
"The bivalves you sent for identification, collected north of
Punta Gorda in the Peace River estuary, are readily identifiable
as Rangia cuneata (Gray).
The U. S, National Museum has eastern Florida records of this
species only from the St. Johns River (South of Jacksonville), and
from Lake Worth at Boynton. I have seen specimens from near Stuart,
Florida, in the Museum of Comparative Zoology collection at Cambridge.
On the west coast we have it from the Caloosahatchie River near Fort
Myers; from the East and Wakulla Rivers in the St. Marks region; from
Apalachicola; and from Pensacola.
Your specimens from the Peace River extuary help to fill in the
zoogeographic story of this brackish water species. It should also
be abundant in the lower Myakka River. You may recall that this is
one species that I am still searching for in the Tampa Bay area, to
parallel its fossil occurrence there. Does it live in the Manatee
Rangia cuneata is an edible clam, belonging to the family
Mactridae. It is a close relative of the Hen or Surf Clam, Spisula
solidissima, one of the important clams commercially fished off the
Middle Atlantic States, and canned at Cape May, New Jersey, by the
Snow and other companies. J. A. Singley in 1893 reported that
Rangia cuneata (from the Galveston:region) had been canned and sold
commercially by the Givens Oyster Company under the name of "Little
Neck Clams". This report is in Singley's "Texas Mollusca", a part
of the 4th. Annual Report (1892) of the Geological Survey of Texas.
Rangia cuneata (presumably from Vera Cruz coastal lagoons) is
also served in restaurants in Mexico as far inland as Pachuca,
Hidalgo, in a clams and rice dish called "Paella a Valenciana".
Hydrographic studies (see Map 2 and Table 3):
Water salinity is to the shellfish farmer what soil pH is to the
general farmer, Hardshell clams, oysters and Rangia clams have different
optimal ranges of salinity just as wheat, corn and rye do:for pH. Lime
and fertilizer can alter soil conditions for the land farmer but his
saltwater counterpart can do little to his saltwater except carefully
choose his lease site based on rainfall data, freshwater drainage
patterns, known salinities and species preference.
Bottom samples of water in depths exceeding four feet are always
checked for salinity stratification between a lighter, fresher surface
layer and a heavier, saltier bottom layer. Surface salinity determina-
tions alone may result in the choice of bottom sites where salinities
are high enough to harbor marine predators or lead to the rejection of
suitable bottoms where salinities are actually favorable to oysters.
Ocean salinity is 35-36 o/oo (parts per thousand salt). Near oceanic
salinity is best for the hardshell clam which does not tolerate salini-
ties under 20 o/oo. The oyster has a wider range of salinity tolerance
but it does best where river water and freshwater effluents (vitamins,
nutrients, etc.) are well mixed with ocean water and where the salinity
is low enough to discourage predators and diseases with marine affinities
but still high enough to give the oyster a pleasing salty taste. Zones
of optimum salinities change year to year with rainfall totals and
distribution but a general criterion to follow is to choose sites that
register no more than 30 o/oo during the dry season or less than 8 o/oo
during the rainy season. The best oysters usually come from areas of
small or gradual salinity variations. Of course, salinity determinations
made in years of extreme drouth or rainfall make long-range recommenda-
tions for lease sitesprecarious. Less is known about the optimal
salinity requirements for the Rangia clam, particularly for its upper
ranges. Generally, it seems to thrive best in waters that change from
fresh (o/oo) to brackish from wet to dry season. Rangia clams taste
best from saltier waters, however.
Large canals draining raw upland, creating waterfront real estate and
emptying into the Peace River, Myakka River and Alligator Bay have
resulted in salinities that change more rapidly and go lower tha.i when
freshwater seeped slowly through pine flatlands, marshes add mangrove
swamps into Charlotte Harbor. Attached animals such as the oyster cannot
escape abruptly decreased salinities* They die or deteriorate from
enormous metabolic regulatory problems.
Water temperatures conducive to yearly spawning of the eastern
oyster are never a limiting factor in Florida. Minimum spawning temper-
atures from 60-680F. are common even in winter and optimum spawning
temperatures from 80.5-82.56F. are reached in late spring when shell
plantings for cultch are recommended. Some northern areas fail to have
oyster reproduction because of cold water in spring and summer. Colder
winters with lowered water temperatures are more conducive to oysters
"fattening" up than warm winters. This "fattening" is actually the
storage of glycogen, animal starch.
The combined Peace and Myakka Rivers are one of the major drainage
basins of Florida with a total watershed of approximately 2500 square
miles. Because of this, Charlotte Harbor is one of the major estuaries
where freshwater and ocean water mix but tidal ranges are not great
enough to get any drastic differences in salinities between high and
Initial hydrographic stations were made on June 5 in Charlotte
Harbor, Myakka River and Peace River before a bad drouth was broken by
summer rain. For quick reference, the salinities of June 5 and other
representative ones have been charted on Map. 3. All salinities, temper-
tures and related data for the stations located on Map 2 are given in
Table 3. Seven salinities at correlative stations made during a rainy
period and year (1960) are charted on Map 4 for comparison. Rainfall
for seven months preceding the September 1960 sampling totaled 40.44
inches, for seven months preceding June 1962 only 6.24 inches.Resulting
differences in salinities are extreme. They are discussed in the
sections on bodies of water. -12-
Scale: 1" = 250,000"
Location of hydrographic stations made in Charlotte
County and vicinity (June 5-21, 1962; see Tabe 3)
FSBCML NO.: 62-12
CS No,: 62-1
Scale: 1" w 250,r000"
3 7 6
Representative water salinities (su-face o'/) and depths (ft.) in
Charlotte County and vicinity (June 1962)
FSBCML NO. 68-12
CS NO.: 62-1
Scale: 1" = 250,0004'
Water salinities (su 0fe o0o0) and depth (ft.) taken in
bottom o S1oo
Charlotte County (September 1960)
FPDCML NO.: 62-12
CS NO.: 62-1
z S 4,,
Hydrographic data for stations located on Map 2
STATION DATE TIME TIDE MOON WATER DEPTH BOTTOM
PHASE "C. o/oo (ft.)
1. VI- 5-62 0850 SL NM 29.2 37.5 36 hard
2. 0915 SL NM 29.2 36.5 12 hard
3. 0930 SL NM 28.1 35.5 12 hard
35, 8 sand
4. 0950 SL NM 28,0 35.0 20 hard
5. 1000 SL NM 28.3 33.0 13 hard
6. 1020 SL NM 28.3 31.4 12 soft
7. 1045 SL NM 28.3 28.4 18 sandy
Hydrographic data for stations located on Map 2
12 VI- 5-62
13. VI- 6-62
14. VI- 5-62
14. VI- 6-62
15. VI- 5-62
15. VI- 6-62
16. vi- 5-62
18. VI- 6-62
19. VI- 7-62
20, VI- 8-62
TIME TIDE MOON WATER DEPTH BOTTOM
PHASE o.C .nn (ft.)
1400 F NM 32.0 32.5 12 hard
_ ____~__~_ ___ ____ _IT__~__I _____ __
Hydrographic data for stations located on Map 2
STATION DATE TIME TIDE MOON WATER DEPTH BOTTOM
PHASE 0C. o/oo (ft.)
22 VI- 8-62 1045 SH FQ 32.0 25.3 6 sandy
29. 1100 F FM 29.1 34.5 2 sandy
30. 1200 F FM 30.2 35.0 2 shell
31. 1230 F FM 31.0 35.4 5 sandy
32. 1310 F FM 31.0 35.0 5 shell
33. 1345 F FM 30.9 34.5 6 shell
33. VI-21-62 1110 SH FM 29.0 33.6 7 shell
STATION DATE TIME
data for stations located on Map
TIDE MOON WATER
PHASE oC. o/oo
34. VI-16-62 1155 F FM 29.1 32.7 11 sand &
34. VI-21-62 1130 SH FM 29.0 32.4 6 sand &
, t ,
Tidess E = Ebb
SL = Slack Low
F m Flood
SH = Slack High
. . I I ll
BODIES OF WATER
(see Map 1)
Stations referred to in the following discussions are located on
Map 2 and listed in Table 3.
Oyster growth and condition were disappointing on concrete pilings
at the Punta Gorda highway bridge and the old bridge now used for fish-
ing. Slime and barnacles covered flat oysters of non-marketable sizes.
After summer rains began, salinity dropped from 29.4 to 14.2 at the
bridge with no significant stratification between surface and bottom
samples; in September 1960 shortly after hurricane Donna, the water was
fresh (<1.0 o/oo), As mentioned earlier, 40.44 inches of rainfall in
seven months preceded the 1960 readings and only 6.24 the 1962 readings.
Dense concentrations of Rangia clams were found at Long Island and
Harbor Heights and between these two locations wherever a soft muddy
bottom and black rush (Juncus roemerianus) prevail. Rangia clams are
present from Long Island to the legal freshwater line (Station 16) where
a tidal interface was observed. These clams were salty tasting during
the drouth but lost their tang after summer rains lowered salinities.
Pollution control is vital if Rangia clams from the Peace River are
to be successfully exploited commercially. In the past effluents from
phosphate fertilizer plants have been a problem. Additionally, septic
tank discharges into the river during the summer rainy season must be
The best oysters found during the field survey for this report were
in this small, mangrove-lined bay. They were cupped, clean, good tasting
3 1/2 to 6 inches long. The oysters are mostly around mangroves and o..
a soft, mud bottom. Crown conchs, the most common oyster predator in
south Florida, are scarce or absent. Salinities were 27.9-29.0 o/oo
(Station 18); in September 1960, 6.8 o/oo.
The fate of this area for continued quality oysters rests with
future:real estate development. If Port Charlotte expands to change the
mangrove zones into waterfront real estate by dredging and filling, shell-
fish potential is questionable. Oyster leases have been applied for at
the mouth of Alligator Bay.
Most oysters examined were narrow and flat. Mud bottoms predominate.
The shorelines are dominated by red mangroves with some cordgrass. Good
oysters are reputed to come from this area on the Alligator Bay side
during certain winters.
Fat cup oysters were discovered at the head of the bay. These were
3 1/2 to 4 1/2 inches long and on a soft mud bottom. They were in bars
near;mangroves and also in open water. Few oysters were actually grow-
ing on prop roots of red mangroves. Oysters opened were in good condi-
tion and tasty but somewhat muddy. This small bay should be good for
oyster leases. There is access to its shoreline by road where oysters
could be loaded on trucks or a shucking house could be located.
There is a good set of oysters from the water surface to bottom on
pilings of the El Jobean railroad bridge. These oysters were in good
condition except for fouling organisms on the shells. Oyster set was
much less on the new highway bridge parallel with the railroad brid.e.
El Jobean is a key salinity station (Station 7) like the Punta Gor-da
bridge across Peace River. After summer rains began, the salinity
dropped but did not begin to approach that of September 1960 when the
river was completely fresh. Broken submerged pilings make oyster tong-
ing difficult under the railroad bridge. This station usually should
have good oysters during drouth years. No crown conchs were seen.
Scattered oysters are found north of El Jobean but there pp atred
to be none of any commercial quantity or marketable quality.
The Rangia marsh clam is distributed from about two miles north of
the El Jobean bridges to two miles north of the bridge across Highway
U. S. 41, Densest concentrations are found from Bird Island to Tarpon
Point wherever black rush dominated the shoreline and soft mud the
bottom as in Rangia beds in Peace River.
Alligator Creek (Located south of Punta Gorda):
Drainage canals creating waterfront property have been cut into the
north and south forks of Alligator Creek. Rock has been exposed along
the canal edges where oysters have set and reached marketable size and
quality but oyster shells are brittle contrasted with those in natural
watercourses. The same brittleness has been noted before in Pirate
Harbor under similar conditions. The effect of summer rains on salinity
and stratification showed up well at Station 22 where surface readings
dropped 24.3 o/oo and bottom readings 11.4 o/oo (see Table 3) in 13 days.
Salinities were very high (oceanic actually) compared to
in September 1960. Fat oysters six to eight inches long were harvested
from here in the winter of 1960-61. This year oysters have done poorly
and most have died including ones that Officer King transplanted from
Turtle Bay. Young oysters were also dead. Shells were badly fouled by
mussels. Those oysters still living had a very salty taste.
Cape Haze Bay:
This small bay was checked because its protected water would offer
calm harvesting during northwesterly winds that occur in winter. Only
'coon oysters were found and these confined to mangrove margins* Crown
conch egg cases were present.
Only tcoon oysters attached to mangrove roots were found. Good
quality oysters have been reported in other years but their absence
here while being found in Tippecanoe and Alligator Bays is difficult
Oysters of marketable size and quality seem to be missing from this
large estuary. Hydrographic conditions should be favorable for oysters
from the confluence of Myakka and Peace Rivers south to Cape Haze Bay.
The lack of suitable bottom materials (rock,planted cultch) is probably
the limiting factor. One oldtimer reported a deepwater bar northwest
of Pirate Harbor in former years but there is no evidence of it now.
Upper Charlotte Harbor would merit some experimental cultch planting
to substantiate oyster culture potential. Any plantings, public or
private, would be best off the Cape Haze peninsula where they would be
in the lee of northwesterlies during the winter harvesting season.
This bay and Bull Bay are the scenes of most oyster lease activity
in Charlotte County. When sampled, salinities decreased from oceanic to
about one-half that of seawater from lower to upper Turtle B.y. One
large public oyster bar lies at the mouth of Turtle Bay. Oyster growth
and quality are best along the north or deep water side of this bar.
Only *coon oysters growing on or near red mangroves were found in upper
Turtle Bay and these were scarce. Mud overlying rock typifies most of
the upper bay bottom. Rock becomes exposed toward the head of the bay.
Crown conchs are plentiful especially near the mouth of the bay. A
moderate set of young oysters was observed on shell cultch planted two
months before this survey. Shell for cultch was being planted during
this survey by blowing it off a small barge with water pressure.
The shell was being mounded in rows on a grassy bottom. Screened
rack culture of seed oysters is being tried to control predations by
'Coon oysters are abundant near mangrove islands. One public bar
in open water near a red mangrove tuft has been heavily harvested. Most
oysters were heavily fouled by barnacles. Dense tunicate (sea squirt)
growth indicated prevailing high salinities. Crown conchs and their egg
cases are abundant.
Sea urchins (pincushions) and crown conch eggs were abundant and
a sign of prevailing high salinities. #Coon oysters covered by barnacles
predominated. One submerged open water bar about one-third up Catfish
Creek had a few commercial quality oysters. This 'coon oyster area would
be a good source of seed for leases.
A dense set of oysters, mostly $coon but some cupped were attached
to pilings of the railroad bridge. Oyster set was much less at the
highway bridge. The upper end of Coral Creek is dammed to provide fresh-
water reservoir for the Cape Haze development. Coral Creek could be
another source of seed oysters for leases.
Twelve spoil banks will be placed east of the intracoastal waterway
route which runs the length of Gasparilla Sound. Hardshell clams are
most concentrated along the inside of Gasparilla Island wherever a firm,
sticky mud bottom with seagrass is found. Most of the clams are west of
the waterway route on shoals where hand harvesting has been productive
but there are probably enough in the deeper water with a sand bottom to
justify mechanical dredging when waterway dredging is imminent.
The Grouper Hole, a small embayment formed by a mangrove projection
of Gasparilla Island, supports one of the best hardshell clam beds in
Florida. Hundredaof bushels of clams have been taken from its muddy,
grassy bottom by tonging in recent months and there are still many clams
to harvest. This site was checked in February 1961 during a bulkhead line
survey when large clams were growing three and four thick in many spots
with 15 to 20 clams per square yard. Thinning them out would improve
individual quality but it will be important to study long-term effects
of intensive harvesting on this clam population.
Very stunted 'coon oysters grow on top of Three Sisters reef which
has shell at least two feet thick. This crowded oyster bar lies in the
path of the waterway and is a potential source of seed and shell for
oyster leases. Most oysters found in Gasparilla Sound are around mangrove
islands especially on the mainland side where oyster seed was being
collected during this survey.
Hardshell clams are abundant at the island side of the Placida-Boca
Grande railroad trestle but less so than farther south in Gauparilla
sound. Many clams were killed and their shells exposed in dred'i.ng and
filling the Gasparilla Island causeway approach to the new highway
bridge to Placida, Oyster set is slight on the highway bridge but be-
comes dense on the railroad trestle at the mainland end where freshwater
and upland effluents are less diluted by strictly saline waters. This
same effect, but less pronounced, was noticed at the El Jobean railroad
trestle across Myakka River. Tunicates were very common at the Placida
end of the railroad bridge.
Northerly fPmthe highway bridge, hardshell clams are found mainly
near the barrier island side of Placida Harbor with scattered quantities
found ai deeper water the waterway route follows near the mainland,
Scattered hardshell clams are found near Little Gasparilla Pass which
was badly silted by Hurricar Donna; oysters are not significant in this
The Narrows (from Placida Harbor to southern Lemon Bay):
Large hardshell clams have been heavily harvested just north of
the Cape Haze development bridge at the widest part of the Narrows.
Clams are still abundant. Oysters, mostly coon, are limited to the red
mangrove margins. This is primarily a tonging area because water depths
average about 5 ft. M.L.W, Dredging of the intracoastal waterway will
probably do more proportionate damage to shellfish in this narrow section
than anywhere else because of this narrowness and of the restricted tidal
flushing of silt that can be expected. Water turbidity was great during
the study. A narrow dredge cut has been made northerly to Lemon Bay for
navigational purposes. Salinities were near-oceanic and bottoms predom-
inantly sand mud with attached seagrass.
This bay has been noted along the Florida Gulf coast for its hard-
shell clams and oysters. During the survey, six boats with 10 hand-
clammers were working productive clam beds. south of Stump Pass on the
barrier island side of the bay. Clams are found from Stump Pass north
to the Englewood Beach bridge in the shallow seagrass beds also on the
barrier island side. *Coon oysters are plentiful near mangroves at the
mouths of Gottfried Creek and several smaller creeks that flow into
Lemon Bay on the mainland side.
Hardshell clams are;tound in water five to eight feet deep north of
the Englewood Beach bridge. These have been heavily tonged in recent
months. Clams are also present in shoals north of the bridge but not in
such dense concentrations as farther south where freshwater flow is not
prominent during the rainy season.
A large oyster bar with commercial quality oysters but also many
dead one lies about 300 yards southwest of the Lemon Bay Fisheries
Company at Englewood. This bar is mostly subtidal. It had the best
oysters found besides those in Tippecanoe and Alligator Bays. *Coon
oyster bars with many dead oysters were found along the mainland side of
the bay at a mangrove point midway between Englewood and Forked Creek
and at Forked Creek. These bars would probably have marketable oysters
in the deeper water around their peripheries in years with adequate
rainfall. 'Coon oysters and some cupped three-inch oysters were attached
to pilings of the Manasota Key bridge where salinities had decreased to
22.0 o/oo from near-oceanic in lower Lemon Bay. Many more oysters were
living in the reduced salinity. One more hydrographic station (42) was
made;at the head of Lemon Bay where the salinity was less than one-
The intracoastal waterway alignment proceeds through approximately
the middle of Lemon Bay north of the Englewood Beach bridge where the
bay narrows and clams and marketable oysters lie in the path of dredging.
South of the Englewood Beach bridge, the waterway alignment lies east
of commercial clam beds but most spoiling will be west of the waterway
route on mangrove islands or in open water.
Because of a bad drouth preceding field investigations for this
report water salinities in clam and oyster habitats were abnormally high,
Several locations that were fresh (<1.0 o/oo) in September 1960 had
readings near that of full strength seawater.
The Peace River bridge at Punta Gorda and the Myakka River bridge at
El Jobean are two of the most strategic spots in checking salinities for
stratification and the influence of upland watershed and freshwater flow
into an estuary (Charlotte Harbor).
The best quality oysters of marketable size found during this
survey were in Alligator Bay, Tippecanoe Bay, Lemon Bay near Englewood
and Alligator Creek.
More young oysters were alive in those areas where freshwater con-
centration can discourage marine predators and diseases such as apper
Lemon Bay, Coral Creek and Myakka River at El Jobean.
The crown conch, locally the most important oyster predator was
observed to be the most abundant in Bull Bay and Turtle Bay. The two
bays are eenterof oyster lease and culture activities.
Heavily populated beds of Rangia marsh clams in the Peace and Myakka
Rivers could probably support a commercial fishery if processing proves
economically feasible, marketing outlets develop and sources of river
pollution are controlled.
Rangia clams seem to do best where the freshwater-brackish water
zone shifts back and forth from rain to drouth.
Hardshell clams are most plentiful on the Gulf side of Gasparilla
Sound, Placida Harbor andsouthern Lemon Bay where seagrasses grow on
soft, sticky, sandy mud bottoms along the barrier islands. These clam
concentrations lie west of the intracoastal waterway alignment and are
shallow enough for hand digging or tonging.
Less dense concentrations of hardshell clams are found in deeper
water on harder, sandier bottoms in Gasparilla Sound and Placida Harbor.
These areas would be most affected by dredging and spoiling for the
waterway. Oysters involved are mostly Icoon but suitable for seeding
Commercial hardshell clams would be most affected by the intra-
coastal waterway development in the Narrows between Placida Harbor, where
large clams are plentiful and Icoon and some cup oysters lie along the
mangrove shoreline, and in Lemon Bay in deeper water (six to eight feet)
just north of the Englewood Beach bridge. The only oyster bar with
significant commercial quantity and quality of oysters subject to the
effects of waterway development was in Lemon Bay off Englewood.