New England
Whales, dolphins and porpoises are among New England’s
most famous visitors. At least seventeen different species
of cetaceans (the order of mammals which includes all whales,
dolphins, and porpoises) are known to visit the Gulf of
Maine throughout the year. Read on to learn why whales return
year after year to the cold waters of the Gulf of Maine.
The Gulf of Maine is a 36,000 square mile body of water
that extends from the Bay of Fundy in Canada through Cape
Cod Bay and about 200 miles to the east of Cape Cod. Currents,
nutrients and the shape of the seafloor all help produce
concentrations of plankton and small schooling fish in and
around Browns Bank, Cashes Ledge, Cape Cod Bay, Cultivator
Shoal, Georges Bank, German Bank, Great South Channel, Jeffreys
Ledge, Platts Bank, Schoodic Ridges, and Stellwagen Bank,
the only National Marine Sanctuary in the northeast U.S.
These locations are important seasonal feeding areas to
a number of different marine species.
One of the Gulf of Maine’s most prized locations is
Stellwagen Bank, an underwater gravel hill left behind as
glacial debris some 18,000 years ago with the retreat of
the last glaciers. Located approximately 6 miles north of
Provincetown, Stellwagen Bank extends 19 miles north toward
Gloucester. At its most shallow, Stellwagen Bank is 65 ft.
below the surface, while the water depths surrounding it
can exceed 300 ft. The diversity of the marine life and
the concentration of whales on Stellwagen Bank are two of
the reasons this 638-square mile area was designated as
a National Marine Sanctuary in 1992.
Upwelling and other water movements around the banks and
ledges of the Gulf of Maine bring nutrients up into the
sunlit waters to support a rich mix of plankton, which in
turn attracts a diversity of marine life. Georges Bank has
a long and storied history as one of the world’s most
productive fishing ground. Other areas, such as Stellwagen
Bank and Jeffreys Ledge, are important destinations for
fishing vessels, pleasure craft, and whale watchers.
Although whales can be found year round within the Gulf
of Maine, the bulk of the large whale sightings occur from
April through November, when this area becomes a seasonal
feeding area for these amazing mammals. Scientists believe
that most large whales spend the summer preoccupied with
feeding and foraging (looking for food). Some whales gain
up to seven tons during a single feeding season in the Gulf
of Maine. They survive the winter by depleting fat reserves
(blubber) during the winter breeding months in the Caribbean.
Caribbean
In November, the Humpback whales of the Gulf of Maine begin
their annual migration south to the warm tropical waters
of the Caribbean to breed and give birth to their calves.
The one-way trip south may span over 1,500 miles and take
about 40 days to complete.
By January, the Humpback whales begin arriving in the West
Indies, more specifically on: Silver Bank, off the northeast
coast of the Dominican Republic; Mouchoir Bank, south of
the Turks and Caicos Islands; and Navidad Bank, off the
western coast of Puerto Rico.
In particular, the shallow coral reefs of Silver Bank are
the largest breeding and calving grounds for Humpback whales
in the world. As such, the Silver Bank Humpback Whale Sanctuary
was established in 1986.
Over 3,000 Humpback whales have been reported on Silver
Bank during the winter breeding season. Besides the Gulf
of Maine whales, there are Humpback whales from Newfoundland,
Greenland, Iceland and Norway who make the long journey
to the Caribbean every winter.
During the Humpback whales four-month winter visit to the
tropics, scientists believe that little or no feeding takes
place. The whales are sustained during this time by their
fat reserves (blubber).
In March or April, Nature calls and the spring migration
north begins once again for the Humpback whales of the Gulf
of Maine.
Alaska
The Whale Adoption Project’s West Coast Humpback whales
take very different routes for their annual migrations than
the East Coast Humpback whales. Researcher Jan Straley has
been studying the Humpback whales of southeastern Alaska
for over 20 years. The Humpback whales spend the summers
and autumns feeding in these cold, productive waters.
Jan’s research base is in Sitka, Alaska, which is located
midway between Juneau and Ketchikan. Southeastern Alaska
is an extensive archipelago, with a complex network of spectacular
glacial fjords, sounds, inlets, bays and straits located
between the Gulf of Alaska and the Canadian Coast Mountains.
The areas where Jan most often sights the Humpback whales
are Sitka Sound, Salisbury Sound, Frederick Sound, and Seymour
Canal.
Sitka Sound and Salisbury Sound are two principle entrances
to the inside waters of southeastern Alaska and are bounded
by Baranof, Kruzof and Chichagof Islands. Frederick Sound
is centrally located within the archipelago and is a confluence
of two major waterways, Stephens Passage and Chatham Strait.
Seymour Canal is a long, narrow fjord along the eastern
side of Admiralty Island, connecting with Stephens Passage
to the south.
The outer coast of the archipelago, including Sitka and
Salisbury Sounds, is a transition zone between the inside
waters and the Gulf of Alaska. As such, these areas are
exposed to rougher seas and more severe weather than the
bays, inlets, and straits in the relatively protected inside
waters.
The primary prey of Humpback whales in southeastern Alaska
is small, schooling fish including herring, capelin, sandlance,
and juvenile Pollock, and euphausiids, which are small,
shrimp-like crustaceans.
Frederick Sound and Seymour Canal can be a mix of prey types,
but the target prey is usually euphausiids during late summer
and autumn.
Sitka and Salisbury Sounds are primarily herring grounds.
Herring spawn in the early spring along the coastline and
then move offshore to feed during the summer months. In
late summer or early autumn, herring move near shore again
to winter in the deep glacial fjords.
