Striped Bass Assessment

  • img_3977.jpg
       
  • img_3984.jpg
       
  • img_4008.jpg
       
  • img_4030.jpg
       
  • img_4076.jpg
       
  • img_4099.jpg
       
  • img_4106.jpg
       
Photo - of -

The Striped Bass Program of the Virginia Institute of Marine Science (VIMS) has monitored the size and age composition, sex ratio and maturity schedules of the spawning striped bass stock in the Rappahannock River since 1981. In conjunction with the monitoring studies, VIMS established a tagging program in 1988 to provide information on the migration, relative contribution to the coastal population, and annual survival of striped bass that spawn in the Rappahannock River.  This program is part of an active cooperative tagging study that currently involves 15 state and federal agencies along the Atlantic coast. The Atlantic States Marine Fisheries Commission (ASMFC) and the U.S. Fish and Wildlife Service (USFWS)coordinate the program.

Life History
Striped bass distribution map. © Aquamaps
Striped bass distribution map. © Aquamaps

On the Atlantic coast, striped bass range from the St. Lawrence River in Canada to the St. John’s River in Florida. Migratory populations under management of the Atlantic States Marine Fisheries Commission range from Maine through North Carolina. This fish is a long-lived species (at least up to 30 years of age) that normally spends the majority of its adult life in coastal estuaries or the ocean, migrating north and south seasonally, and ascending rivers to spawn in the spring.

Mature female striped bass (age 4 and older) produce large quantities of eggs (up to 500,000), which are fertilized by mature males (age 2 and older) as they are released into riverine spawning areas. The fertilized eggs drift downstream with currents while developing, eventually hatching into larvae. The larvae and post-larvae begin feeding on microscopic animals during their downstream journey. 

Striped bass larval development. *Scotton, L.N., R.E. Smith, N.S. Smith, K.S. Price and D.P. de Sylva, 1973. Pictorial guide to fish larvae of Delaware Bay: with information and bibliographies useful for the study of fish larvae

After their arrival in the nursery areas, located in river deltas and the inland portions of coastal sounds and estuaries, they mature into juveniles.

Striped bass remain in coastal sounds and estuaries for two to four years, before migrating to the Atlantic Ocean. In the ocean, fish tend to move north during the summer and south during the winter. Important wintering grounds for the mixed stocks are located from offshore of New Jersey to as far south as North Carolina. With warming water temperatures in the spring, the mature adult fish migrate to the riverine spawning areas to complete their life cycle.

 

Seasonal Striped Bass Migration Map
Map courtesy of the Massachusetts Division of Marine Fisheries.

 


In general, Chesapeake Bay spawning areas produce the majority of coastal migratory striped bass. Atlantic coast migratory striped bass use coastal rivers as spawning sites and the lower portions of the rivers and their associated bays and estuaries as nursery areas. Adult habitats include coastal rivers and the near-shore ocean. These habitats are distributed along the coast from Maine through North Carolina. Use of these habitats by migratory striped bass may increase or decrease as the size of the population changes.


 

Monitoring Program

Striped bass collected from the monitoring sites are measured and weighed on a Limnoterra FMB IV electronic fish measuring board interfaced with a Mettler PM 30000-K electronic balance.  The board records lengths (FL and TL) to the nearest mm, receives weight (g) input from the balance, and allows manual input of sex and gonad maturity into a data file for subsequent analysis.  Scales were collected from between the spinous and soft dorsal fins above the lateral line for subsequent ageing, using the method established by Merriman (1941), except that impressions made in acetate sheets replaced the glass slide and acetone.

Cooperative Tagging Program

Commercial and recreational anglers that target striped bass are encouraged to report all recovered tags to the U.S. Fish and Wildlife Service (USFWS).  Although the initial purpose of the coast-wide tagging study was to evaluate efforts to restore Atlantic striped bass stocks, tagging data are now being collected to monitor striped bass mortality rates in a recovered fishery. Each year since 1991, during the months of March, April and May, VIMS scientists obtained samples of mature striped bass on the spawning grounds of the Rappahannock River. Samples were taken twice-weekly from pound nets owned and operated by a cooperating commercial fisherman.   The pound net is a fixed trap that is presumed to be non-size selective in its catch of striped bass, and has been historically used by commercial fishermen in the Rappahannock River.

Annual Reports & Publications
wmscholarworksimage.png

Funding

The Striped Bass survey is currently funded by the Virginia Saltwater Recreational Fishing Development Fund - VMRC.

vsrfdflogo-1_130.jpg VMRC Logo