For inquiries contact Jill
Leonard or Joseph
the Conte Anadromous Fish Research Ctr., Turners Falls, MA 01376
The American shad, the largest of the herrings, is the most
abundant anadromous fish on the east coast
of the United States. These sleek, silver, schooling fish are
unique inhabitants of our local rivers. Large populations
support growing commercial and sport fisheries. American shad
have even been successfully introduced to the west coast where
they are also fished by commercial and recreational fishermen.
Anglers can finds themselves in the midst of vast rafts of these
silver fish providing an experience unequalled in freshwater
fishing. Historically, the American shad has been an important
food fish earning the title of "poor man's salmon", while the
eggs, or 'roe', are considered to be a delicacy.
American shad enter rivers in the early
spring and can travel hundreds of miles upstream to spawn. This
energetically taxing migration allows juveniles to hatch and be
reared in an advantageous freshwater environment since larval
development cannot occur in salt water. American shad spawn in
open waters and do not often move up into the tributaries of the
large rivers that they ascend. During the evening, spring
boaters can find themselves surrounded by schools of splashing,
spawning shad. A large female is usually chased by a group of
several eager males. The female releases her eggs into the water
column and they are then fertilized by her accompanying males. A
single female may spawn several times during her migration and
produce as many as 200-250,000 eggs during a single year. The
eggs hatch after 4-9 days in early summer and metamorphose into
juveniles approximately a month later. These young are important
ecologically since they provide food for a number of piscivorous
sport fish including large- and smallmouth bass, walleye and
Juveniles remain in the river until fall when they migrate
downstream to the ocean when they are approximately 2-3 inches
long (less than 0.5 oz.). These migrating juveniles are preyed
upon by numerous ocean fish, including striped bass and bluefish.
After entering the ocean, these planktivores take advantage of
the abundant food resources available and quickly grow to adult
size in 2-3 years. During this period of ocean growth, American
shad migrate south during the winter to areas off North Carolina
and north during the spring to summer feeding grounds in the Bay
of Fundy . It is during this spring migration that
reproductively mature fish will make their way back to their
natal river to spawn and thus complete their life cycle. Unlike
Pacific salmonids, a freshwater spawning migration does not
necessarily end the life of an American shad. A proportion of
the Connecticut River population survives spawning and returns to
the ocean to enjoy the productivity of the sea; 30-50% of
spawning adults will successfully return to spawn in another
year. Interestingly, southern populations (Florida, Carolinas,
etc.) do not have this "iteroparous" life style and are, in fact,
"semelparous" like the Pacific salmon and do not survive
spawning. In rivers north of the Carolinas, post-spawning
survival increases so that in the Delaware River 10-20% survive
to spawn a second time while 80% spawn more than once in the St.
Johns River in Canada. Small adults are approximately 2 pounds
while large females commonly attain 6-7 pounds and historically
have reached 13 pounds.
In the Connecticut River, American shad
were important to the indigenous peoples of the area and likewise
comprised a large proportion of settlers' diets. Some of the
best fishing areas were deemed neutral territories for local
tribes and during the spawning run hundreds of people would
congregate in these areas to spear and net migrating fish.
However, the industrial revolution, and the building of river
dams, drastically reduced the number of shad, and other migratory
fish, in the river. A large dam was built in 1798 at Turners
Falls and this dam eliminated all spawning habitat for shad
beyond 120 miles upriver. The dam at South Hadley Falls in
Holyoke, constructed in 1849, severely restricted the shad's
spawning habitat to the lower 87 miles of the river. Finally, in
1880 the habitat was further restricted by the construction of a
low-head dam at Enfield Falls in Enfield, CT. Following this
construction, shad were limited to the lower 68 miles of the
river during periods of low water. While spawning habitat was
not completely eradicated by these manmade obstacles, the
population was drastically reduced by these intrusions.
Subsequently, however, changes in legislation and in public
opinion focussed attention on the problem and placed the
responsibility for fish passage on the owners of the dams.
Fish passage devices, such as ladders
and fish elevators, were constructed on the five main stem dams.
The first attempts at building fish ladders occurred in 1893 at
Holyoke Dam; however, few fish successfully ascended this
structure. During the late 1800s there was also a growing
movement artificially to rear shad and other anadromous species,
but these attempts met with varied success. In the early 1900s
further modifications of the main stream dams were made; however,
passage was still limited. In the early 1950s the primary
construction of a fish elevator at Holyoke Dam was completed by
the power company and federal personnel. This fish elevator
became operational in 1955 and allowed some access above the
facility. More improvements in the 1970s finally allowed
substantial passage past Holyoke dam. During this same period,
fish ladders were constructed at the Turners Falls dam complex.
The current structures were built in the late 1970s and early
1980s. The Enfield Dam was also breached by the river prior to
this period, so that by the 1980s there was functional fish
passage for American shad in the lower 144 miles of the river.
Currently, American shad migrate as far as Bellows Falls, VT (174
miles upriver), which is thought to be close to the historical
upriver range of the population. Although much attention has
focussed on upstream migration, it has only been in recent years
that the welfare of downstream migrants has been addressed
seriously. Downstream migrants approaching hydropower facilities
are small enough to pass easily through turbine gates and
mortality due to turbines can be considerable. Currently, there
are modified log sluices that direct juveniles away from the
turbines and around the dam; however, the turbulent environment
may also lead to mortality. Additionally, the delay of
downstream migration caused by dams results in a pooling of
downstream migrants which attracts predators both above and below
the dams: the effect of predation at the dams on these migrants
Currently, the Connecticut River
American shad population is estimated at 1-2 million returning
adults each year with between 2-600,000 passing through the
Holyoke Dam fish passage elevator. While in many rivers along
the eastern coast populations of American shad were extirpated
and restoration efforts have proved problematic, the outlook for
the Connecticut River American shad is bright. There have been
slow, but consistent, improvements to water quality, fish passage
and management practices all contributing to the return of the
Poor Man's Salmon. The cooperation of state and federal
agencies, utility companies and the public is leading to the
restoration of this native, New England fish.
You might enjoy this old fish tale or learning about the great shad war.
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sapidissima) in fresh water. Ecology 32(3):556-557.
Chittenden, M.E.J. Weight loss, mortality, feeding and
duration of residence of adult American shad, Alosa
sapidissima, in freshwater. Fisheries Bulletin 74(1):
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Influences of origin, life history and chance on the Atlantic
coast migration of American shad. American Fisheries
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