Northeast Fisheries Science Center Reference Document 03-10
Comparison
of invertebrate abundances in four bays
of the northeastern United
States: two bays
with sparse quahogs and two bays with
abundant quahogs
by Clyde L. MacKenzie, Jr.
National Marine Fisheries Serv., James J. Howard Lab., 74 Magruder
Rd., Highlands, NJ 07732
Print
publication date August 2003;
web version posted August 29, 2003
Citation: MacKenzie, C.L., Jr. 2003. Comparison of invertebrate abundances in four bays of the northeastern
United States: two bays with sparse quahogs and two bays with abundant quahogs. Northeast Fish. Sci.
Cent. Ref. Doc. 03-10; 25 p.
Download complete PDF/print version
INTRODUCTION
Northern quahogs, Mercenaria mercenaria,
have been harvested in eastern North America for centuries (MacKenzie
and Burrell, 1997). The bays from Rhode Island through New Jersey
have been principal harvesting areas (Figure
1). In the 1960s and 1970s, Great South Bay in Long Island, New
York, accounted for around half the total U. S. production of quahogs,
as many as 700,000 bushels a year (Anonymous, 1987). In 1879, Barnegat
Bay, New Jersey, produced 150,000 bushels of quahogs (Ingersoll,
1887), and as late as the early 1970s it yielded as many as 100,000
bushels (Ford, 1997). Since then, quahog landings in Great South
Bay and Barnegat Bay have fallen sharply, and in 2000 Great South
Bay produced about 3% (20,000 bushels of quahogs) of peak harvests
in the 1960s and 1970s (D. Barnes1), and Barnegat Bay
produced 0.6% (600 bushels) of the harvest in the early 1970s (P.
Lauer2). In contrast, quahog harvests/fisherman from Point
Judith Pond, RI, have been large because the pond has large stocks
of quahogs, and in the 1990s and through 2002, quahog landings from
Raritan Bay, NY and NJ, actually rose to about 150,000 bushels/year
(MacKenzie and Pikanowski, 1999; MacKenzie et al., In Press; and
recent data). The quahogs in Point Judith Pond (12-15 fishermen year-round)
and Raritan Bay (180 fishermen) have been heavily harvested.
People have been attempting to explain the causes of the
declines in the quahog stocks in Great South Bay and Barnegat Bay. Fishermen
and hatchery operators (C. Strong3, J. Zatilla4)
on Long Island and fishermen (J. Harry5, W. Jenks6)
in New Jersey believe a prime factor has been a decline in water quality,
because brown tides in the two bays first appeared almost consistently
at the time the quahog seed started to become scarce and their quahog
harvests began to decline. In addition, the meats of market-sized quahogs
have since been thin and gray. The thin, gray meats of adult quahogs
suggest they have difficulty feeding during the blooms and also that
the picoplankton accumulates on the surfaces of their meats. Another
cause of the quahog declines may be a steep rise in the abundance of
blue crabs, Callinectes sapidus, in New York (Briggs, 1998) and
New Jersey beginning in the 1970s (Stehlik et al., 1998). Yet another
cause of the declines may be overharvesting of the quahogs.
Before implementing the current project, some information was collected
concerning the possible importance of predation on quahog abundances.
In June 2002, the manager of the Bluepoints quahog-oyster hatchery in
West Sayville, New York, informed me that if he planted seed quahogs
then in Great South Bay blue crabs or lady crabs, Ovalipes ocellatus, would
destroy them within a few days. This hatchery had been planting hatchery
quahog seed in the bay since the 1960s. Quahog farmers in Barnegat Bay
were placing screens over the seed quahogs they had purchased from local
hatcheries to prevent blue crabs from destroying them. In July 1986,
we obtained 15,000 quahogs 4-5 mm in length from the Tuckerton quahog
hatchery. They were divided into five groups of 3,000 quahogs each and
then spread in five scattered sites around Barnegat Bay. When the planted
sites were examined about 30 days after the planting, all but 4-5 quahogs
had been crushed and eaten by crabs, presumably blue crabs, at every
site.
In the current project, abundances of benthic invertebrates that inhabit
the quahog beds were surveyed in the four bays above: Point Judith Pond,
Great South Bay, Raritan Bay, and Barnegat Bay. If invertebrate abundances
were much lower in Great South Bay and Barnegat Bay than in Raritan Bay
and Point Judith Pond, the cause of the quahog scarcity was unlikely
overharvesting of the quahogs, but was more likely related to poor water
quality and predation.
HABITAT
CHANGES IN GREAT SOUTH BAY AND BARNEGAT BAY SINCE
THE 1970s
Great South Bay and Barnegat Bay have relatively narrow openings to
the Atlantic Ocean, and thus water exchanges with ocean water is limited.
The residence time of water in Great South Bay is 8-12 weeks (anon. 1978),
and in Barnegat Bay, in the summer, it is about 10 weeks (Guo et al.
1997). In contrast, Raritan Bay has a wide opening, 9 km, and resident
time of its water is 2 weeks (Jeffries, 1962). The residence time of
water in Point Judith Pond is unknown.
Great South Bay and Barnegat Bay have had major environmental changes
in the past 30-40 years, that coincided with the quahog declines. Their
shorelines have experienced extensive residential development followed
by excess nutrient loadings, which are diluted only slightly by ocean
waters due to the narrow openings. Another change has been an extension
of municipal sewerage lines that once emptied treated freshwater into
the bays to the far side of their barrier beaches where they empty the
freshwater into the ocean. This change resulted in raised salinities
in the bays. Concurrently, dense blooms of Aureococcus anophagefferens, a
coccoid picophytoplanktonic alga, and other algae, including the
chlorophyte Nannochloris atomus and the dinoflagellate Alexandrium fundyense, have
developed in the bays during summers. A. anophagefferens requires
salinities above 22 ppt to grow (Olsen and Mahoney, 2001). They are the
causative agents of "brown," "green," and "red" tides, respectively.
Blooms of A. anophagefferans cause high mortalities to quahog
larvae and prevent the growth of juvenile quahogs (Greenfield and Lonsdale,
2002), and laboratory studies demonstrated that monospecific cultures
of N. atomus do not support growth of larval or juvenile quahogs
(Tiu et al., 1989; Bass et al., 1990). A. anophagefferens has
small cells (about 2um in diameter) (Grizzle et al, 2001), that
the quahogs cannot filter (Tracy, 1988). In excised quahog gill tissues,
these cells have been shown to inhibit their ciliary beats (Gainey and
Shumway, 1991).
The increase in blue crab abundances occurred during and after the
1970s. New York landings of blue crabs increased from about 1,000 pounds/year
during the 1960s and 1970s to 513,000-1,215,000 pounds/year during the
early 1990s (Briggs, 1998). In New Jersey, blue crab landings increased
from less than 1 million pounds/year during the 1960s to nearly 8 million
pounds in 1993 (Stehlik et al., 1998). Substantial portions of the landings
were from Great South Bay and Barnegat Bay, while most New Jersey landings
were from Delaware Bay. Blue crabs are a devastating predator of juvenile
quahogs when abundant (Kraeuter, 2001; MacKenzie et al., in press). They
also feed on a wide array of invertebrates that are associated in the
bottom with quahogs (Stehlik et al., 1998). Lady crabs and rock crabs
are also present in Great South Bay and Barnegat Bay.
DESCRIPTIONS
OF THE BAYS' HABITATS AND
QUAHOG FISHERIES
Point
Judith Pond (Figure 2)
Point Judith Pond, 5 km long and about 1 km wide, has a relatively
wide, deep inlet to the Atlantic Ocean, and there is little shoaling
on its inside or outside. The rise and fall of tide inside the pond is
the same as it is outside in Block Island Sound, which suggests a large
exchange of pond and ocean waters. There has been little obvious pollution
in the pond, and as it has few noticeable plankton blooms the water is
relatively clear (MacKenzie et al., In Press).
Point Judith Pond is a productive quahog-producing area in Rhode Island.
Year-round, the pond usually has 12-15 quahog diggers, each harvesting
about 1400 quahogs/day, over 90% of which have been littlenecks (1.75-2.25
in. in diameter), the size that brings the highest landed price (about
20 cents ea.). The diggers have seen large numbers of quahog seed in
the beds and have not mentioned any scarcity of quahogs (MacKenzie et
al., In Press).
Great
South Bay (Figure
3)
Great South Bay, along the south side of Long Island, N.Y., is about
50 km long, 10 km wide, and has an area of about 50,000 acres. The public
bottoms of the bay extend for nearly 50,000 acres and comprise about
55% of the total extent of quahog harvesting area; the reminder has been
privately owned or leased. The bay has one major inlet, Fire Island Inlet,
an opening to the Atlantic Ocean, at its southwestern end. This opening
is rather narrow and is shoaled on its inside, which limits the rise
and fall of tide in the bay is about 60 cm. Two other inlets to the ocean,
Jones Inlet located farther west, and Moriches Inlet in Moriches Bay
at the east end of Great south Bay, are much smaller than Fire Island
Inlet. The bay's bottom is mostly fine sand with oyster shells occurring
in small zones. Its water depth throughout is 2-3 m.
The percentage of total U.S. landings of M. mercenaria coming
from New York (mainly Great South Bay) reached about 50% in 1947, but
it dropped afterward to just under 20% in 1954. In 2 years in the late
1950s and early 1960s, quahog juveniles set densely throughout most of
Great South Bay. In 1958 Moriches Inlet was widened and deepened by dredging,
and it led to an increase in water exchange with the ocean and an increase
in salinity. This opening apparently set the environmental stage for
the boom in quahog abundance in Great South Bay in the 1960s and 1970s.
Because the bay's quahogs grow slowly, they remained as seed and littlenecks
for several years (MacKenzie et al., 2001; MacKenzie et al., in press).
By the mid-1960s, a few thousand fishermen were harvesting the quahogs
on the bay's public bottoms; most were landing 5-10 bushels/day. Quahog
production from the bay rose steadily to slightly above 60% of the U.S.
total in 1978 and remained slightly above 50% of the total until 1980
(McHugh 1991). Afterward, the bay's landings fell sharply. In 1999, only
about 50 men raked quahogs on the public bottoms of the bay. Each usually
harvested 1.5-2 bushels of quahogs/day. Since then, the quahogs have
become even scarcer, and in 2002 each raker landed only about 500 quahogs
(slightly less than a bushel per raker/day) (MacKenzie et al., In Press).
A Great South Bay survey of quahog abundance in 1975
showed there were relatively few seed under the length of 40 mm (Figure
4). This shows that little setting had occurred for 4 to 5 years
before that, i.e., 1971-1975. Normally there would be far more seed in
each length grouping than in the groupings between 40 and 55 mm. A glance
at Figure 4, upper panel, shows quahog landings in that period were between
570,000 and nearly 700,000 bushels/year, about the most ever produced
from the bay. The bay obviously had a large quantity of mature quahogs,
enough to produce huge quantities of quahog larvae.
Summer blooms of N. atomus and A. anophagefferens were
documented in the 1950s and in 1985, respectively, in Great South Bay
(Cosper et al., 1987). Both have reappeared in them nearly every summer
since about 1985 (Bricelj and Lonsdale, 1997). In the continued presence
of A. anophagefferens in Great South Bay, the meats of
quahogs are thin and gray and the quahogs grow slowly (D. Relyea7,
C. Strong3).
Raritan
Bay (Figure
5)
Raritan Bay is triangular-shaped and about 19 km long. Its deeper areas
in New Jersey consist of mud, the shallower areas of sand. Raritan Bay
has an opening to the ocean that is 9 km wide, allowing a large exchange
of its waters with ocean waters. The rise and fall of tide (2 m) are
about the same inside the bay and in the nearby ocean. The bay is polluted
with nutrients, but the large tidal exchange prevents nearly all deleterious
blooms from developing in it. Newell (2003) stated Raritan Bay waters
have four times the quantity of chlorophyll as Great South Bay, but does
not have its picoplankton.
In recent years, Raritan Bay has been a large producer of quahogs.
But in 1990, only about 15 men were digging clams in the southeastern
part of the bay and the harvesting was limited to 3-4 small areas. The
quahogs were relayed to Barnegat Bay for depuration. During the 1990s,
quahog abundance increased sharply over about 6,000 acres. The quahog
harvesting fleet swelled to about 100 bull rakers by 1999. Two quahog
depuration plants began operations and they purchased most quahogs landed;
the remainder were relayed to Barnegat Bay. Each fishermen harvested
4-8 bushels of quahogs/day (MacKenzie and Pikanowski, 1999). The New
Jersey fishermen were not harvesting the quahogs fast enough to keep
up with quahog growth. Consequently, the littlenecks and topnecks (about
2.3-2.8 cm long, a market size slightly larger than littlenecks), the
two quahog sizes that bring the highest market prices, grew to the cherrystone
and chowder sizes before the fishermen could harvest them, and now the
bay has mostly the larger quahogs. The fishermen usually return the chowders
to the bottom because they sell for low prices, $3.00/bushel (J. Harry5).
Barnegat
Bay (Figure
6)
This paper will consider the sections of New Jersey's coastal bays
known as Barnegat Bay and Little Egg Harbor. Collectively, they span
a longitudinal distance of 62 km and they range from 1.5 to 6.5 km in
width. As in Great South Bay, most of their bottoms consist of fine-grained
sand, but some consist of mud. Barnegat Bay has one opening directly
to the ocean, Barnegat Inlet, located in the southern part of the bay.
The bay also has a narrow inlet, the Point Pleasant Canal that connects
with the Manasquan River, at its north end, and it is connected with
Little Egg Harbor though Manahawkin Bay, that is slightly less than 2
km wide at its southern extremity. Barnegat Inlet is relatively narrow
(340 m wide) and extensive shoaling with a narrow winding channel (185
m wide) snaking through the shoal. The rise and fall of tide in the bay
is about 20 cm (Chant, 2001) vs. 2 m on its outside beaches. Little Egg
Harbor also has one opening, Beach Haven Inlet, at its south end. This
inlet also has extensive shoals in its inside with a channel 8-9-km long
running through it; in places it is 170 m wide.
During summers in the 1950s when quahogs were abundant, about
250 fishermen were harvesting quahogs in Barnegat Bay and Little Egg
Harbor. Most used tongs and short rakes for harvesting, while some used
bull rakes and some treaded (MacKenzie et al., In Press). A 1969-73 survey
of the invertebrates in Barnegat Bay showed the abundance was about 2,775
invertebrates/m2 (Loveland and Vouglitois, 1984)
After the late 1970s, the numbers of fishermen fell when the quahogs
became scarcer, and from 1998 to 2002 only about 8 men were digging quahogs
in the summer (P. Lauer2). They observed little seed in the
beds (J. Chadwick7). As in Great South Bay during the late
summer, the meats of most quahogs in Barnegat Bay have been gray: The
mantles, gills, and soft parts of the clams' bodies were so colored,
and they became darker when cooked. The meats have been much thinner
than meats of normal quahogs. When quahogs have been transferred from
Raritan Bay to Barnegat Bay for depuration, after 6 months their meats
have become thinner (they usually are harvested in 1-2 months)(J. Harry5).
Dense picoplankton blooms in Barnegat Bay and Little Egg Harbor are
fairly widespread and prolonged. The distance between Barnegat Inlet
and Beach Haven Inlet is about 32 km. The blooms are concentrated over
a distance of 20-22 km roughly mid-way between the two inlets. They are
dominated by N. atomus, but A. anophagefferens has had
a similar abundance at times. The first occurrences of dense picoplankton
blooms causing brown water discoloration in the summer were observed
in 1985, but they may have occurred and been unnoticed before that (Olsen
and Mahoney, 2001).
METHODS
In 2001, densities of benthic invertebrates in Point Judith Pond, Great
South Bay, Raritan Bay, and Barnegat Bay were sampled with a Petite Ponar
grab with an opening of 15 X 15 cm; the mesh openings of the sieve used
wwere 0.25 um. The grab was operated by hand from small boats.
The bottoms sampled all had sand sediments. Two or three grab samples
were taken at each station. One station was sampled in Point Judith Pond
at a distance of 3.75 km from its inlet; two stations in Great South
Bay, both 25 km east of Fire Island Inlet; three stations in Raritan
Bay, 5 km south, 5 km west, and 15 km west of its inlet; and three stations
in Barnegat Bay, 3 km south, 7 km north of Barnegat Inlet, and another
opposite the inlet. All invertebrates initially were preserved in formalin
and within 4 days the formalin was replaced with 70% alcohol. The animals
then were identified in broad groupings and counted.
Statistical Analysis
Estuary-specific differences in invertebrate community assemblages
were identified by constructing station by species Bray-Curtis similarity
matrices from the log transformed mean numbers of individuals at each
of the stations. A 1-way analysis of similarity (ANOSIM) test, with estuary
as a factor, was applied to the matrices to test for significant differences
(p<0.05) in assemblage structure. The species responsible for differences
in assemblage structure were determined by performing the SIMPER analysis.
Non metric multidimentional scaling was also performed to visualize similarities
in community structure at the stations in the estuaries. All analyses
were performed with Primer Software (Clarke, 1993).
RESULTS OF
INVERTEBRATE SURVEYS
Mean numbers of invertebrates found
in the four bays are shown in Figure 7. The
samples from all four bays contained a fairly broad array of invertebrate
groups: mollusks, crustaceans, polychaetes, and nemerteans, and also
a few anemones in Great South Bay and Barnegat Bay (Table
1 and Table 2). Nearly all invertebrates were
juveniles (young-of-the-year). Point Judith Pond and Raritan Bay grab
samples had an average of about 1,200 invertebrates, whereas the grab
samples from Great South Bay and Barnegat Bay had far fewer. The Great
South Bay samples had an average of 186 invertebrates, or 15.5% as many,
and the Barnegat Bay samples taken at a distance from the inlet had about
365 invertebrates, or 30% as many. The densities of Barnegat Bay invertebrates
apparently have fallen sharply since the Loveland and Vouglitios (1984)
survey in 1969-73.
The 1-way ANOSIM test showed that community structures
in the 4 estuaries were significantly different (R 0.621, P= 0.001).
In addition, pairwise comparisons tests showed all the estuaries, except
for Point Judith Pond and Raritan Bay (R=0.095, P=0.225)(Table 1), had
significantly different community structures (R>0.661, P<0.018)
(Figure 8). Shallow coastal bay (Barnegat and
Great South bays) stations had low scores on axis 1 of the non-metric
multidimentional structure plot while those in Raritan Bay and Point
Judith Pond had high scores. Point Judith Pond and Raritan Bay had far
more polychaetes (779/grab, both bays together), clams (39 clams/grab,
both bays together), and Crepidula (8.5/grab, both bays together)
than were in Great South Bay and Barnegat Bay. The latter had a combined
194 polychaetes/grab, 1.5 clams/grab, but no Crepidula. The grab
samples did not collect quahogs in Point Judith Pond, Great South Bay
and Barnegat Bay, but they were present in Raritan Bay (3.7/grab).
Differences in community structures at stations in Great South Bay
and Barnegat Bay were distinguishable on axis 2 of the ordination plot
in Figure 8. The Barnegat Bay samples had more
phylogenetic groups than Great South Bay (10 vs. 7), and it had over
40 times more amphipods (353.8 vs. 8.33/grab) and about 3 times as many
polychaetes and nemerteans. There are two differences in the habitats
where the stations were located in Great South Bay and Barnegat Bay.
The stations in Great South Bay were 25 km from Fire Island Inlet, its
nearest inlet, whereas the stations in Barnegat Bay were 1 to 7 km from
Barnegat Inlet, its nearest inlet.
The other difference is in the orientation of the bays. Great South
Bay is oriented in an almost east-west direction. During the summer,
wind speeds usually are low in the morning, but they are brisk in a southerly
direction most every afternoon. Because of the bay's orientation, the
afternoon breezes blow across the bay and would likely have relatively
little effect on the bay's water currents. On the other hand, Barnegat
Bay is oriented in a north-south direction, and the afternoon breezes
from the south blow up the bay and likely have a strong effect on the
bay's water currents. The stronger water currents in Barnegat Bay might
bring more food to its benthic invertebrates.
CONCLUSION
The survey reveals the benthic invertebrate densities in Great South
Bay and Barnegat Bay, where quahogs have become scarce, were much lower
than they were in Point Judith Pond and Raritan Bay, where quahogs are
abundant. The declines in quahog abundances in Great South Bay and Barnegat
Bay probably were related to poor water quality and crab predation. Their
brown tides likely interfere with egg production, spawning, and larval
development of their invertebrates. Little quahog harvesting has occurred
in Great South Bay and Barnegat Bay in the past twenty years, yet abundances
of quahogs and invertebrates have not rebounded. Thus, it is unlikely
the declines were related to harvesting.
ACKNOWLEDGMENTS
I thank Charles Balsamo, D. G. McMillan and Karen A. Tammi for
manning survey vessels. John Manderson provided advice on the statistical
analyses and reviewed an earlier draft of the manuscript. Joseph Vitaliano
ran the ANOSIM calculation, D. S. Haven and R. N. Reid critically reviewed
an earlier draft of the manuscript, and T. Finneran produced the maps.
REFERENCES
Anonymous. 1978. Long Island Comprehensive Waste Treatment Management
Plan. Vol. 1: Summary Plan, prepared by the Nassau-Suffolk Regional Planning
Board.
Bass, B. L., R. E. Malouf, and S. Shumway. 1990. Growth of northern
quahogs (Mercenaria mercenaria [Linnaeus, 1758]) fed on
picoplankton. J. Shellfish Res. 9: 299-307.
Briggs, P. T. 1998. New York's blue crab (Callinectes sapidus)
fisheries through the years. J. Shellfish Res. 17(27):487-491.
Bricelj, V. M., and D. J. Lonsdale. 1997. Aureococcus anophageffefens:
Causes and ecological consequences of brown tides in U.S. mid-Atlantic
coastal water. Limnol. Oceanogr. 42: 1023-1038.
Chant, R. J. 2001. Tidal and subtidal motion in a shallow bar-built
multiple inlet/bay system. Pages 102-114 in: M. J. Kennish (editor),
Barnegat Bay-Little Egg Harbor, New Jersey: estuary and watershed assessment.
Jour. Coastal Res., Spec. Issue 32.
Clarke, K. R. 1993. Non-parametric multivariate analysis of changes
in community structure. Australian Journal of Ecology 18: 117-143.
Cosper, E. M., E. J. Carpenter, and M. Cottrell. 1987. Recurrent and
persistent brown tide blooms perturb coastal marine ecosystems. Estuaries
10: 284-290.
Ford, S. E. 1997. History and present status of molluscan shellfisheries
from Barnegat Bay to Delaware Bay. In C. L. MacKenzie, Jr., V.
G. Burrell, Jr., A. Rosenfield, and W. L. Hobart, (eds.). The history,
present condition , and future of the molluscan fisheries of North and
Central America and Europe, Vol. 1, Atlantic and Gulf Coasts. U.S. Dep.
Commer., NOAA Tech. Rep. 127, p. 119-140.
Gainey, P.M., and S. E. Shumway. 1991. The physiological effect of Aureococcus
anophagefferens ("brown tide") on the lateral cilia of bivalve
mollusks. Biol. Bull. 181: 298-306.
Greenfield, D. I. and D. J. Lonsdale. 2002. Mortality and growth of
juvenile hard clams Mercenaria mercenaria during brown tide.
Marine Biology 141:1045-1050.
Guo, Q., N. P. Psuty, G. Lordi, and C-S. Tsai. 1997. Circulation studies
in Barnegat Bay. Pages 17-29 In Flimlin, G. E. and M. J. Kennish
(eds.). Proceedings of the Barnegat Bay Ecosystem Workshop. Rutgers Cooperative
Extension of Ocean County, Toms River, New Jersey.
Jeffries, H. P. 1962. Environmental characteristics of Raritan Bay,
a polluted estuary. Limnol. Oceanogr. 7:21-31.
MacKenzie, C. L., Jr., and V. G. Burrell, Jr. 1997. Trends and status
of molluscan fisheries in North and Central America and Europe--a synopsis. In C.
L. MacKenzie, Jr., V. G. Burrell, Jr., A. Rosenfield, and W. L. Hobart
(eds.). The history, present condition, and future of the molluscan fisheries
of North and Central America and Europe, Vol. 1, Atlantic and Gulf Coasts.
U.S. Dep. Commer., NOAA Tech. Rep. 127, p. 1-14.
MacKenzie, C. L., Jr., and R. Pikanowski. 1999. A decline in starfish,
Asterias forbesi, abundance and a concurrent increase in northern quahog,
Mercenaria mercenaria, abundance and landings in the northeastern United
States. U.S. Dep. Commer., Mar. Fish. Rev. 62(2):66-71.
MacKenzie, C. L., Jr., A. Morrison, D. L. Taylor, V. G. Burrell, Jr.,
W. S. Arnold, and A. T. Wakida-Kusunoki. In Press. A history of quahoging
in eastern North America: Canada, The United States, and Mexico. Mar.
Fish Rev.
MacKenzie, C. L., Jr., D. L. Taylor, and W. S. Arnold. 2001. A history
of hard clamming. In J. Kraeuter and M. Castagna (eds.). Biology of the
hard clam. Elsevier. p. 671-673.
Olsen, P.S. and J. B. Mahoney. 2001. Phytoplankton in the Barnegat Bay-Little
Egg Harbor estuarine system: Species composition and picoplankton bloom
development. J. Coastal Res. Spec. Iss. 32:115-143.
Stehlik, L. L., P. G. Scarlett, and J. Dobarro. 1998. Status of the
blue crab fisheries of New Jersey. J. Shellfish Res. 17(2):475-485.
Tiu, T. A., D. Vaughan, T. Chiles, and K. Bird. 1989. Food value of
eurytopic microalgae to larvae of Cyrtopleura costata (Linnaeus,
1758), Crassostrea virginica (Gmelin, 1791) and Mercenaria
mercenaria (Linnaeus, 1758), J. Shellfish Res. 8: 399-405.
Tracy, G. A. 1988. Feeding reduction, reproductive failure, and mortality
in Mytilus edulis during the 1985 "brown tide" in Narragansett
Bay, Rhode Island. Mar Ecol. Prog. Ser. 50: 73-81.
Personal Communications
1D. Barnes, New York State DEC, Shellfish Division, East
Setauket, New York.
2P. Laurer, quahog dealer, Barnegat, New Jersey.
3C. Strong, Manager Bluepoints quahog farm, West Sayville,
New York.
4J. Zatilla, F. M. Flower and Sons, Bayville, New York.
5 J. Harry, President of Monmouth County Clammers Association.
6W. Jenks, former State of New Jersey shellfish warden and
quahog fisherman, Brick, New Jersey.
7D. Relyea, F. M. Flower and Sons, Bayville, New York.
