Striped Bass
by Amanda Argentieri
P1413
The
striped bass, Morone saxatilis, has long been one of the most important
commercial and recreational species found along the Atlantic coast. Also
known as the striper, rockfish, linesider, and roller, the striped bass
has been a sought-after finfish since the colonial era. New England Indians
and European settlers caught and dried the fish in abundance. Along with
cod, striped bass was one of the first natural resources to be regulated
by early conservation measures. For example, in 1639, the Massachusetts
Bay Colony passed a law that neither species could be sold as fertilizer.
By 1776, New York and Massachusetts prohibited all sales of the fish in
the winter months. Continuous harvesting of striped bass continued into
the 20th century, but a severe decline in total landings experienced in
the 1970s resulted in the development of increased regulation and conservation
actions. Today, the striped bass is still a popular species fished both
commercially and recreationally. However, preservation and protection
remain primary issues in the management of this fishery.
Physical Characteristics
The adult striped bass, known for its size and fighting ability, weighs
on average 4 to 7 kilograms (kg) (8 to 15 pounds (lbs)). However, bass
exceeding 23 kg (50 lbs) are caught every year. The length of the fish
also varies considerably from 46 to 140 centimeters (18 to 55 inches (in)).
Its coloring can be light green, olive, steel blue, black or brown, with
a white or silver iridescent underside. This stout-shaped fish also can
be identified by its seven to eight continuous horizontal stripes on each
side of the body from gills to tail.
Distribution
The striped bass is found along the western Atlantic coast from the
St. Lawrence River in Canada to the St. Johns River in Florida. The species
also inhabits the waters west of the Swanee River, Fla. to Lake Pontchartrain,
La. In addition, striped bass has been successfully introduced along the
Pacific coast and to inland reservoirs and lakes nationwide. Striped bass
is classified as an anadromous fish, meaning it migrates from salt water
to fresh water during the spawning season. North of Cape Hatteras, some
striped bass stocks participate in coastal migrations—north in the summer,
and south during the late fall and winter.
Habitat
Striped bass prefer large bodies of deep, clear water with a temperature
between 65F and 70F (18C and 21C). Mature bass can be found in a variety
of inshore, estuarine, and freshwater habitats depending on the location
and season. Most striped bass remain in inshore waters, and are not usually
found more than eight kilometers (five miles) from the coast. Young bass
are typically found in river systems and estuaries, which are critical
spawning and nursery grounds for the species.
Reproduction
The spawning activities of striped bass are triggered by an increase
in water temperature, and occur near the surface in fresh or slightly
brackish waters. Depending on the latitude, adult striped bass travel
inland to their natal rivers to spawn during the late spring or early
summer. Male bass reach sexual maturity at two years, while females usually
do not spawn until age four. During the spawning process, the female releases
her eggs into the water column to be fertilized by the males. The fertilized
eggs must remain in the water column—any that settle to the bottom are
smothered and killed. Depending on the water temperature, the eggs can
hatch 25 to 109 hours after fertilization. The larvae are 2.0 to 3.7 millimeters
(0.08 to 1.5 in) at hatching. The duration of the larval stage is 23 to
68 days, depending on water temperature. The larvae begin feeding after
6 to 8 days. By day 30 to 50, the larvae have transformed into juvenile
fish, taking the body shape of an adult bass.
Diet
Striped bass are nocturnal feeders. Larval striped bass feed on zooplankton,
while the diet of juvenile bass consists of insect larvae, small crustaceans,
mayflies, and other larval fish. Adult bass are considered piscivorous
(fish-eating). They eat almost any kind of small fish as well as several
invertebrates, particularly crabs and squid.
Fishery
Striped bass are caught commercially using gill nets, pound nets, hook-and-line,
and haul seines. Both the commercial and recreational striped bass fisheries
rely heavily on the production from populations spawning in the Hudson,
Delaware, and Roanoke rivers, and the Chesapeake Bay system. Historically,
Chesapeake Bay has produced the majority of the striped bass found along
the Atlantic coast. However, poor juvenile production in the 1970s and
1980s caused a severe decline in commercial and recreational landings.
The cause of this sudden decline has been attributed to several factors,
including overfishing, poor water quality in spawning and nursery areas,
contaminants, natural stresses, and pollution.
Protection & Management
The rapid deterioration of the striped bass fishery was addressed at both
the state and federal level through legislation and management plans.
In 1984, Congress passed the Striped Bass Conservation Act, which allowed
the Atlantic States Marine Fisheries Commission to develop an Interstate
Fisheries Management Plan for Striped Bass. Under the plan, states along
the eastern seaboard were required to comply with certain size limits,
seasonal closures, recreational daily bag limits, and annual commercial
catch quotas to help rebuild the stocks. In 1995, Atlantic striped bass
was officially declared a restored stock, and the strictest regulatory
measures were relaxed.
Other methods of conservation include water pollution control, artificial stocking, and the use of hormones to promote female ovulation. Also employed are fishways, a device that allows striped bass to swim past dams and other obstructions while migrating upstream to spawn. In addition, scientists and aquaculturists have successfully crossed the striped bass with white bass to create a silvery hybrid with dark, broken lines. This hybrid is raised in fish farms and sold in fish markets.
The striped bass fishery is thriving once again, but under tight regulation. Scientists, fishermen, and state and federal governments continue to examine methods to protect this species by improving conservation techniques and enforcing proper management measures.
References
Collette, B.B., and G. Klein-MacPhee (eds.). 2002. Bigelow and Scroeder's Fishes of the Gulf of Maine, Third Edition. Smithsonian Institution Press, Washington.
Groman, D.B. 1982. Histology of the Striped Bass. American Fisheries Society, Bethesda.
Setzler, E.M. et al. 1980. Synopsis of Biological Data on Striped Bass, Morone saxatilis (Walbaum). Dept. of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Washington.
Wirtanen, L.J., and R.H. Ray. 1970. Striped Bass Morone saxatilis (Walbaum): 1970 Report on the Development of Essential Requirements for Production. U.S. Dept. of the Interior, Fish and Wildlife Service, Bureau of Sport Fisheries and Wildlife, Division of Fish Hatcheries, Atlanta.
Websites
NOAA Fisheries Northeast Fisheries Science Center
Chesapeake Bay Program: Striped Bass
Illustration courtesy NOAA.
Printed September 2002.