Part
2, Sec. 2B2d
Sanctuary Resources - Natural Resources
Fishes
d.
Fishes
The
overall Gulf of Maine, encompassing Stellwagen Bank, supports
a very wide variety of pelagic and demersal fish and shellfish
species. Pelagic species include herring, mackerel, sharks,
swordfish, bluefish, bluefin tuna, capelin, and menhaden. Demersal
species include cod, haddock, hake, pollack, whiting, cusk,
and several species of flatfish such as flounders and halibut.
This
notable variety of species results from the geographic and thermal
transition zone occurring at Cape Cod, which separates the Gulf
of Maine from the Mid-Atlantic region. The transition zone exhibits
both varying composition and abundance of fish fauna; and is
the cause of substantial seasonal variation of species. Most
of the pelagic species exhibit clear seasonal migratory movements
in response to changes in water temperatures. Seasonal movements
among several demersal species are generally confined to shifts
within the overall Gulf of Maine area, although some species,
such as pollack, are migratory.
Generally,
the Gulf of Maine is dominated by boreal, non-migratory species;
and the Mid-Atlantic is largely populated by warm-water, migrating
species. Spring bottom trawl surveys conducted between 1968
and 1981 indicate over 86% of species in the Gulf of Maine are
boreal, or cold temperate. Autumn surveys also indicate the
majority of Gulf fish species are cold temperate (79.5%) (NMFS,
1982). Typically, warm temperate species, such as bluefish (Pomatomus
saltatrix), will migrate southward during cold months
of the year; while some cold temperate species, such as cod
(Gadus morhua), retreat northward during warm
months.
Although
considerable information is available on commercially-important
fish fauna of the Gulf of Maine, relatively few studies have
been conducted on fish fauna as a whole (Azarovitz and Grosslein,
1987). Inventory activities conducted over the larger Georges
Bank area during 1968-1981 employed otter trawls, to which not
all species are vulnerable (in particular, large pelagics such
as tuna and billfish); therefore, the listings below of fish
and invertebrate species are not complete. The diversity of
fish and invertebrate fauna is highest during autumn months;
approximately 100 species have been identified over the Georges
Bank-Gulf of Maine area (Grosslein and Azarovitz, 1987).
Seasonal
distribution and movement of fish and migratory invertebrate
species are explained generally by classification of abundant
species into four groups which demonstrate particular movement
patterns. Groupings are based on seasonal movements within the
60-fathom (110 meter) contour.
Group
l: Residents Found in All Seasons
Little
Seasonal Movement (1A)
Little
skate
Winter skate
American sand lance
Sea raven
Longhorn sculpin
Windowpane flounder
Yellowtail flounder
Winter flounder
Sea scallop
Seasonal
Shifts (1b)
Spiny
dogfish
Atlantic herring
Goosefish
Atlantic cod
Haddock
Ocean pout
American lobster
Group
1 species are typically found in the overall Gulf of Maine-Georges
Bank area throughout the year. Within this group, there are
some species (1b) which demonstrate seasonal shifts within the
general area, but not away from the Georges Bank vicinity.
Group
2: Seasonal Migrants Found Only in Warm or in Cold Month
Common
in Warm Months (2a)
Silver
hake
Red hake
White hake
Butterfish
Fourspot flounder
Shortfin squid
Longfin squid
Common
in Cold Months (2b
Pollock
American plaice
Group
2 fishes are seasonal visitors; they are consistently found
in the Gulf of Maine-Georges Bank area during one or two seasons.
Those species listed as common in warm months (2a) typically
move further offshore or south when temperatures cool; those
species listed as common in cold months typically demonstrate
opposite behavior and move north or east into deeper waters
in the summer.
Group
3: Mid-Atlantic Species That Migrate to the Georges Bank - Gulf
of Maine During the Warm Season
Summer
flounder
Bluefish
Bluefin Tuna
Scup
Group
3 species are common to the Mid-Atlantic area, and migrate north
to the Gulf of Maine-Georges Bank area during late summer to
early autumn, usually in low numbers (Azarovitz and Grosslein,
1982).
Group
4: Cold Water Species Common in the Gulf of Maine/Deep Water
Areas, But Rare on Georges Bank
Smooth
skate
Thorny skate
Redfish
Cusk
Witch flounder
Species
listed in Group 4 are common to deeper waters of the Gulf of
Maine, or those surrounding Georges Bank. They are not normally
abundant on Bank areas, but do visit in the cold season.
Spawning
areas for several fish species occur generally within the southwestern
Gulf of Maine, including those for pollack, Atlantic cod, herring
and squid. There is also particularly strong evidence that Stellwagen
Bank provides spawning habitat for the American sand lance (Ammodytes
americanus), a primary forage species for humpback and
fin whales. (Sherman, et al., 1981; Sherman, et
al., 1984; Richards, 1965).
Many
of the identified Gulf of Maine species have been traditionally
important commercially, and continue to provide an important
economic resource to the New England region. Commercially important
species include:
Common
Nam /Scientific Name
American
plaice(sand dab) Hippoglossoides platessoides
American lobster Homarus americanus
American shad Alosa sapidissima
Atlantic herring Clupea harengus
Atlantic mackerel Scomber scombrus
Atlantic wolffish Anarhichas lupus
Atlantic cod Gadus morhua
Black sea bass Centropristis striata
Bluefin tuna Thunnus thynnus
Bluefish (snapper) Pomatomus saltatrix
Butterfish Peprilus triacanthus
Cusk Brosme
Dogfish Squalus acanthias
Haddock Melanogrammus aeglefinus
Little skate Raja erinacea
Northern shrimp Pandalus borealis
Ocean pout Macrozoarces americanus
Ocean quahog Arctica islandica
Pollack Pollachius virens
Red hake Urophyucischuss
Redfish (Ocean perch) Sebastes spp.
Scup (Porgy) Stenotomus chrysops
Sea scallop Placopecten magellanicus
Silver hake (Whiting) Merluccius bilinearis
Squids Illex spp.
Striped bass (Rockfish) Morone saxatilis
Summer flounder Paralichthys dentatus
White hake Urophycis tenuis
Winter flounder Pleuronectes americanus
Winter skate Raja ocellata
Witch flounder Glyptocephalus cynoglossus
Yellowtail flounder Pleuronectes ferrugineus
(NMFS,
1988)
System
boundaries for many fish species may be provided by Gulf circulation
patterns which carry eggs and larvae. Many gadoid species, such
as cod, haddock, silver hake, sand dabs, and witch flounder
breed on Stellwagen Bank (or in nearshore coastal waters), but
not over deeper Gulf waters.
Due
to its location at the southwestern end of the coastal circulation
pattern, all of Massachusetts Bay acts as a "catch basin" for
a variety of species. Several of these demonstrate somewhat
localized distributions within the Gulf of Maine, including
cod, haddock, pollack, hake, and herring.
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