American Shad (Alosa Sapidissima)



American shad are anadromous fish (moving from the
Lake Surveys sea to spawn in freshwater) found along the Atlantic
coast of North America from Newfoundland to Florida.
Stocking Program Large spawning runs used to occur in the Shubenacadie
and Annapolis rivers (also Saint John, Petitcodiac
Extension Info. and Miramichi), but they are found in many Maritime
coastal rivers. They have been introduced along the
Species Pacific coast and now range from Alaska to
Factsheets California.
[Image]

Physical Characteristics

The American shad, like the alewife (gaspereau), is a member of the
herring family with the following characteristics:

* slender and silvery-coloured with a blue-green metallic hue on
the back;

* has a black spot, similar to the alewife, located on the side,
just behind the head - on the shad, this spot is followed by
several smaller dark spots;

* the eye has an obvious eyelid;

* a row of scales known as scutes form a sharp "sawbelly" edge
along the midline of the belly;

* there is no lateral line.

* American shad can grow to 76 cm (30 in) and weigh 6.8 kg (15 lb).
However, adults found in Canadian rivers are usually 45-50 cm
(18-20 in) long and weigh from 1.4-2.7 kg (3-6 lb).

Facts About Shad

American shad can migrate up to 3,000 km in one season!

The flesh of the American shad is very tasty. Did you know the
scientific name for shad comes from the Saxon word "allis", an old
name for the European shad, and the Latin sapidissima meaning "most
delicious"?

The French common name for this fish is alose savoureuse or
"savoury shad".

The world angling record for American shad weighed 5.1 kg
(11.2 lb) and was caught in the Connecticut River, Massachusetts, in
1986.

Scientific studies show that shad from all eastern U.S. rivers
spend some time in the Bay of Fundy.

Fishing Facts

American shad were much more abundant
in the past. During the 1800s a thriving
fishery for shad existed along the Atlantic
coast supporting an annual catch as high as
23,000 tons (50 million pounds). Today, small
commercial fisheries exist but numbers have
greatly declined due to over-fishing and
changes in our rivers. Dams often block access
to vast areas of spawning habitat. Even where
fishways provide access, many young shad may
not survive the downstream migration.

[Image] Shad are fished commercially in rivers
during their spawning runs. The eggs (roe) are
considered valuable, so large numbers of
mature females are taken. The flesh is sold
fresh and salted. Shad are angled and
considered a fine gamefish.

Natural History

The American shad lives for several years at sea before returning to
spawn in the stream or river where it hatched. Shad avoid cold
temperatures, preferring to stay in water that is 80C or warmer. Much
of their migration and behaviour is determined by water temperature
and currents.

Each spring, schools of shad, using their sense of smell, begin to
migrate up coastal rivers and tributaries when water temperatures
reach 12C.

Spawning in the Maritimes occurs during June and July in water
temperatures of 13-20C. Migration stops in temperatures over 20C.
American shad do not usually travel upstream as far as the alewife.

They spawn in rivers at night in mid-water areas with a wide range of
bottom types. The eggs are about 3 mm across and drift along with the
current to hatch in 8-12 days, depending on the temperature.

A female can produce anywhere from 60,000 to 600,000 eggs. Shad in
Canadian rivers usually produce about 130,000 eggs. Many shad in the
Maritimes are repeat spawners, however southern populations of shad
die after spawning.

Young shad spend their first summer in the river feeding on insects
and crustaceans. They swim near the bottom in water as deep as 3.7-4.9
m (12-16 ft), but at night they are found near the surface. When they
migrate to sea in the fall, they have grown to a size of 7.5-12.5 cm
(3-5 in). They migrate to the sea as river temperatures drop.

At sea, shad live in schools moving to areas with bottom temperatures
that are 7- 13C. They stay near the bottom during the day, dispersing
at night to all depths. Immature and spawned-out adults remain
offshore in areas like the Bay of Fundy until winter, when they move
farther out to sea in order to stay in preferred water temperatures.
At sea they eat zooplankton (tiny invertebrates that live in the
water), small bottom crustaceans, and occasionally small fish. Most
shad mature at age 4 or 5 when they are about 48-53 cm (19-21 in)
long. Shad can live up to 13 years.

Although not a major food source for other animals, shad are eaten at
sea by seals, sharks, blue-fin tuna, kingfish, and porpoises. Young
shad in freshwater are eaten by bass, American eels and birds.