by G. Shepherd
Table
The striped bass, Morone saxatilis, is an anadromous species
distributed along the Atlantic coast from northern Florida to the St. Lawrence
estuary. It has been successfully introduced in numerous inland lakes and
reservoirs and to the Pacific coast, where it now occurs from Ensenada,
Mexico to British Columbia. Striped bass spawn from mid-February in Florida
to late June or July in Canada. Spawning occurs at or near the surface
in fresh or slightly brackish waters at temperatures ranging from 10o to
23oC; peak spawning activity is observed between 15o and 20oC. Larvae range
from 2.0 to 3.7 mm in total length at hatching and initiate feeding after
4 to 10 days. At about 13 mm in length, larval striped bass form small
schools and move inshore; juvenile striped bass move downriver into higher
salinity waters during their first summer or autumn.
Most striped bass along the Atlantic coast are involved in two types
of migrations: an upriver spawning migration from late winter to early
spring, and coastal migrations that are apparently not associated with
spawning activity. Coastal migrations may be quite extensive; striped bass
tagged in Chesapeake Bay in winter and spring have been recaptured during
the summer in the Bay of Fundy and fish tagged in the Hudson in spring
have been recaptured off the coast of North Carolina during the winter.
Coastal migratory behavior appears to be limited to stocks north of Cape
Hatteras and is related to sex and age.
Atlantic coastal fisheries for striped bass rely primarily on production
from populations spawning in the Hudson River and in tributaries of Chesapeake
Bay. Chesapeake Bay has historically produced most of the striped bass
found along the coast. However, during most of the 1970s and 1980s, juvenile
production in the Chesapeake Bay was extremely poor, causing a severe decline
in commercial and recreational landings during the mid-1970s. Poor recruitment
for Chesapeake Bay was probably due primarily to overfishing; but poor
water quality in spawning and nursery habitats likely also contributed.
During the mid-1980s, stringent management measures were adopted by states
from North Carolina to Maine in an attempt to rebuild the Chesapeake stocks.
These measures, aimed at protecting 1982 and subsequent year classes until
females could spawn at least once, were effective in increasing spawning
stock size and recruitment. Signs of improved recruitment in Chesapeake
Bay have appeared as well. Since 1987, indices of juvenile production in
Virginia's Chesapeake Bay tributaries have been at or near record high
levels in all but one year. High juvenile production in Maryland has begun
to occur at regular frequencies as seen during the 1960s and early 1970s.
Maryland's 1989 index was the fourth highest on record, and exceeded management
criteria for relaxing fishery regulations in 1990. The 1993 and 1996 indices
were the two highest on record with good production throughout the Chesapeake
Bay estuary. As recruitment has improved, stock biomass has increased substantially
and is expected to increase further over the short term under current levels
of exploitation.
In recent years, recreational landings of striped bass have substantially
exceeded commercial landings. In 1996, the estimated recreational harvest
(6,700 mt) was over 3 times the commercial landings level. During 1996,
an estimated 14.0 million striped bass were caught by recreational anglers;
over 90 percent of these were released alive.
In 1995, Atlantic striped bass were formally declared to be a restored
stock, and commercial and recreational management restrictions were relaxed
somewhat. The stock has been managed at a target fishing mortality of 0.31
(25% exploitation rate), with overfishing defined as Fmsy = 0.38 (29% exploitation
rate). Fishing mortality in 1996, as determined from aged based analyses
and tagging data, was estimated as 0.30 (24% exploitation rate).
For further information
Richards, R.A. and D.G. Deuel. 1987. Atlantic striped bass: Stock status
and the recreational fishery. Mar. Fish. Rev. 49(2):58-66.
USDOI and USDOC. 1996. Striped bass research study. Report for 1994.
U.S. Department of the Interior, U.S. Department of Commerce, Washington,
D.C.
NEFSC [Northeast Fisheries Science Center]. 1998. [Report of the] 26th
Northeast Regional Stock Assessment Workshop (26th SAW): Stock Assessment
Review Committee (SARC) consensus summary of assessments. Woods Hole, MA:
/NOAA/NMFS/NEFSC. NEFSC Ref. Doc. 98-03.
