The Atlantic 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 Mexico to British
Columbia. The Atlantic coast (Figure
40.1) stocks, which originate in the Chesapeake Bay, Delaware
River and Hudson River, undergo seasonal coastal migrations ranging
from North Carolina to Nova Scotia, whereas stocks to the north
or south remain within their natal rivers or estuaries. Recreational
fishing on the coastal migratory stocks occurs year round, with
peak activity occurring during the spring and fall migrations.
Commercial fisheries are conducted seasonally, primarily with
hook and line and gillnets.
Striped bass may attain
lengths of up to 150 cm (59 in.) and weights of 25 to 35 kg (55
to 77 lb) (Collette and Klein-MacPhee 2002). Maximum age is in
excess of 25 years and sexual maturity is attained between ages
2 to 4 for males and 5-8 for females (ASMFC 1990). Spawning occurs
in the migratory stocks during April to June as fish migrate into
fresh or brackish water. Water temperatures during spawning may
range from 10° to 23° C; peak spawning activity is observed
between 15° and 20° C (Hardy 1978). After spawning, most
large females leave the estuaries and participate in coastal migrations.
Males also leave the spawning grounds but may remain within the
estuaries throughout the year. Striped bass are omnivorous, feeding
on a variety of invertebrates and fish species (Walter et al.
2003), particularly clupeids such as menhaden and river herring.
Coastal migratory stocks of striped bass
are managed under a fishery management plan developed by the
Atlantic States Marine Fisheries Commission (ASMFC) under the
authority of the Striped Bass Conservation Act. During the mid-1980s,
stringent management measures were adopted by states from North
Carolina to Maine in an attempt to rebuild the depleted Chesapeake
striped bass stocks. Recruitment in Chesapeake Bay improved
and moderate to strong year classes begun to occur at regular
intervals similar to the1960s and early 1970s (Richards and
Rago 1999). In 1995, Atlantic striped bass were formally declared
to be restored, and commercial and recreational management regulations
were relaxed. Current management measures include size limits,
seasonal closures, recreational daily bag limits and annual
commercial catch quotas. Fisheries are limited to state waters
due to the continued moratorium on fishing for striped bass
within the EEZ.
in 2004 were 2.5 million fish or 11,874mt, almost 20% above the
average tonnage landed during 2001-2003 and twice as high as in
1995 when the stock was declared restored (Table
40.2 Data]). Recreational fisheries accounted
for 72% by weight of the 2004 landings of the Atlantic stocks.
Four states, Massachusetts, New Jersey, Maryland and Virginia,
accounted for 70% of recreational striped bass landings between
2000 and 2004. The recreational fishery has generally been dominated
by 7 to 9 year old fish ranging on length from 28 to 40 inches.
This is in part due to size regulations as well as the strong
Chesapeake Bay 1996 cohort which has contributed heavily to the
coastal fisheries. Within Chesapeake Bay the size limit is 18”
and the 2000 year class is the predominate cohort. The level of
striped bass fishing effort, combined with size limits and a catch
and release ethos, results in large numbers of discarded striped
bass. Average hooking mortality has been estimated as 9% (Diodati
and Richards 1996), which equates to over 1.3 million recreational
discard mortalities in 2004.
occur in 8 of the 14 states/jurisdictions with striped bass fisheries.
Total landings in 2004 were 3,290 mt, considerably below such
landings of nearly 6,000 mt landed in 1973. Current size restrictions
of 18” in Chesapeake Bay and 28” along the coast are
higher than early 1970s when size limits ranged from 12”
to 24”. Since 2000, Maryland and Virginia have accounted
for 56% of commercial landings (by weight) followed by Massachusetts
with 14%. In 2004, 4 and 5 year old striped bass accounted for
a third of the total commercial landings. Commercial discards
in 2004 were estimated to be 10% of the total striped bass catch
in number. Seasonal concentrations of migrating striped bass in
the EEZ, an area currently closed to all striped bass fishing,
tend to be more susceptible to incidental capture in commercial
fisheries, which results in discarding.
NEFSC spring research survey
abundance indices for striped bass in the Middle Atlantic area
have varied annually with the appearance of large cohorts entering
coastal waters. The index increased in 1994, 1997 and 2001 due
to large Chesapeake Bay year classes in 1993, 1996 and 2000.
The index also increased in 2000 (Figure
40.3 Data]), due to the large 1999 year class in
the Hudson River stock. Fishery independent indices of abundance
for striped bass are also available from state surveys of juvenile
and adult fish. Maryland Department of Environmental Protection
(DEP) survey indices of striped bass show a steady increase
in abundance since 2001. A haul-seine survey conducted by the
state of New York along southern Long Island indicated increasing
abundance since 2002. Juvenile surveys in the Hudson River,
Delaware River and Chesapeake Bay exhibit moderate to strong
year classes every 2 to 3 years. This pattern of successful
year classes is similar to that which occurred in the 1960s
when the Chesapeake stock was considered to be highly productive.
Average fishing mortality (ages 8-11, unweighted)
exceeded 0.3 prior to1984 (Figure
40.4 Data]) when a moratorium was imposed in the
Maryland portion of Chesapeake Bay. During the Maryland moratorium
years (1984-1989), restrictive striped bass regulations or
moratoriums were also enacted in other states and fishing
mortality declined to about 0.15. From 1990, when the fishery
re-opened, until 2003 fishing mortality averaged 0.23. In
2004 fishing mortality increased to 0.40, although estimates
of F for ages 7-11 from tag recovery results show a smaller
increase to 0.29. Spawning stock biomass of age 4 and older
striped bass increased from about 1,300 mt in 1982 to 27,500
mt in 2002, but has since declined to 24,900 mt in 2004 (Figure
40.5 Data]). Overall, population numbers increased
from 4.8 million fish in 1982 to 60.1 million fish in 1997
and have since fluctuated between 53.9 million and 66.6 million
fish.Since 1982, recruitment at age
1 from the three major coastal stocks combined has ranged
from less than 1.5 million fish (1981 year class) to 22.3
million fish (2003 year class) (Figure
40.6 Data]). Over the 1982-1992 period, geometric
mean recruitment for the 1981-1991 year classes was 4.6 million
fish. In 1993, the Maryland juvenile striped bass index was
the highest in the time series which began in 1957 and marked
the beginning of a series of strong cohorts. The 1993 year
class was estimated at 16.6 million fish at age 1 and was
followed by the strong year classes of 1996, 2000, 2001 and
2003. The initial estimate of the 2004 year class at age 1
was 12.7 million, which is average strength for the period
Fishing mortality and
spawning stock biomassbiological reference points were
calculated in 2003 as part of the development of Amendment
6 to the ASMFC Striped Bass FMP (ASMFC 2003). The spawning
stockbiomass target (17,509 mt) and threshold (14,016 mt)
only pertain to female striped bass. The fishing mortality
associated with Fmsy is 0.41 and is considered
the threshold level of mortality. The fishing mortality
targeted by management is 0.30 (Table
The relationship between spawning stock
biomass and recruitment for Atlantic striped bass over the period
covering the 1981-2004 year classes is illustrated in (Figure
40.6 Data]). The spawning biomass threshold
of 14,016 mt was determined based on the mature female biomass
in 1995 when the stocks were considered restored. The target
SSB of 17,509 mt is 125% of the 1995 spawning biomass. Spawning
biomass in 2004 (24,900 mt) was 42% greater than the target
Atlantic striped bass spawning
stock biomass increased since the 1980s when restoration efforts
commenced and by 1995, SSB was high enough for the stock to
be declared recovered. The spawning stock has continued to increase
and in 2004 was well above the threshold and thus the stock
complex is not overfished. Fully recruited fishing mortality
(ages 8-11) has remained below the target F since 1984. Fishing
mortality estimates from tag recapture models suggest 2004 estimate
of fishing mortality from the catch at age model (F = 0.40)
may be an over-estimate.
Assessment results indicate
that the stocks of striped bass on the Atlantic coast are attaining
their production potential and are generally being fished at
or below their target fishing mortality. Concern expressed in
public and scientific communities that the abundance of striped
bass in Chesapeake Bay now exceeds the carrying capacity of
this system. Continued work will be required to fully determine
the optimal abundance of striped bass in the Bay.
ASMFC, 1990. Source document for the
supplement to the Striped Bass Fisheries Management Plan-Amendment #4.
States Marine Fisheries Commission, Washington, D.C. Fisheries Management
ASMFC, 2003. Amendment 6 to
the Interstate Fishery Management Plan for Striped Bass. Atlantic
States Marine Fisheries Commission, Washington, D.C. Fisheries
Management Report # 41. 63 p.
Collette, B.B., and G. Klein-MacPhee
(ed.). 2002. Bigelow and Schroeder’s Fishes of the Gulf
of Maine. 3rd edition. Smithsonian Inst. Press. Washington, D.C.
Diodati, P. and R.A. Richards,
1996. Mortality of striped bass hooked and released in salt water.
Transactions of the American Fisheries Society. 125: 300-307.
Hardy, J.D. 1978. Development of fishes of the Mid-Atlantic
Bight: An Atlas of Juvenile stages. Vol III. Aphredoderidae through
Rachycentridae. Biological Services Program, Fish and Wildlife Service,
U.S. Dept. of the Interior, FWS/OBS-78/12.
Richards, R.A., and P.J. Rago,1999.
A case history of effective fishery management: Chesapeake Bay
striped bass. North American Journal of Fisheries Management 19:
Walter, J.F.III, A.S. Overton,
K.H. Ferry, and M.E. Mather. 2003. Atlantic coast feeding habits
of striped bass: a synthesis supporting a coast-wide understanding
of trophic biology. Fisheries Management and Ecology 10: 349-360.