Horseshoe Crab Benchmark Assessment

The following is from the text of a news release from the Atlantic States Marine Fisheries Commission. A more detailed overview of the horseshoe crab stock assessment is available as a pdf document on the Commission website www.asmfc.org under Breaking News (Horseshoe Crab Stock Assessment Overview).

In its report to the Commission's Horseshoe Crab Management Board, an independent panel of scientists endorsed the use of the 2009 horseshoe crab benchmark stock assessment and its accompanying multispecies Adaptive Resource Management (ARM) framework for management use.

The assessment indicates abundance has increased in the Southeast and Delaware Bay Region (New Jersey through coastal Virginia), and decreased in the New York and New England. In the Delaware Bay Region, increasing trends were most evident for juveniles, followed by adult males. An increase in adult females is now beginning to be observed in the Virginia Tech Benthic Trawl Survey. These patterns are indicative of population recovery, given that horseshoe crab females take longer to mature than males.

In contrast, declining abundance was evident in New York and New England. Declines in the New England population were also apparent in the 2004 assessment; however, declines in New York represent a downturn from the 2004 assessment. The Technical Committee believes decreased harvest quotas in Delaware Bay encouraged increased harvest in nearby regions. The Technical Committee recommends continued precautionary management to address effects of redirected harvest from Delaware Bay to outlying populations.

The ARM framework includes modeling that links management of horseshoe crab harvest to multispecies objectives, particularly red knot shorebird recovery. It was developed jointly by the Commission, U.S. Fish and Wildlife Service, and U.S. Geological Survey in recognition of the importance of horseshoe crab eggs to several shorebird species in the Delaware Bay. Within the ARM framework, a set of alternative multispecies models have been developed for the Delaware Bay to predict the optimal horseshoe crab harvest strategy that would address the needs of red knot population as well as the fishing industry. Both the peer review panel and Horseshoe Crab Management Board accepted use of the ARM framework as a tool to provide guidance for the multispecies management of horseshoe crab.