Established in 1973, the Longline Survey at the Virginia Institute of Marine Science is the world's longest running fishery independent monitoring program for sharks, skates, and rays. Each month from June to September, survey scientists visit 8 fixed longline stations in Chesapeake Bay and coastal Virginia waters to monitor the distribution, abundance, and biology of adult sharks, which use these waters during seasonal migrations along the U.S. eastern seaboard. VIMS scientists monitor the population of juvenile sharks in the related COASTSPAN survey.
The results of the VIMS Longline Survey provide the standardized, fishery-independent data needed to effectively manage these long-lived species. Standardized longline methods allow scientists to detect population trends by comparing survey results from year-to-year and decade-to-decade, while fishery-independence precludes the biases inherent in catch data from shark fisheries, which are influenced by market conditions, advances in fishing gear, regulatory changes, and other factors.
Survey results are used directly by the
- National Marine Fisheries Service for its stock assessment of Atlantic shark species,
- Atlantic States Marine Fisheries Commission in its Shark Management Plan, and
- Virginia Marine Resources Commission to establish fishery regulations for sharks in Commonwealth waters
Shark populations were severely overfished by both recreational and commercial fisheries from the late 1970s to the early 1990s. Data from the VIMS Shark Survey show that sandbar sharks were reduced by 65%, and dusky sharks by 80%. The implementation of shark management measures in Virginia in 1990, and by the Federal Government in 1993, have led to a slow but steady recovery in most mid-Atlantic shark stocks.