An Adaptive Multispecies Approach to Managing the Horseshoe Crab Fishery in Delaware Bay

The Atlantic horseshoe crab fishery is managed by the Atlantic States Marine Fisheries Commission. A traditional single-species assessment is not sufficient for managing harvest of the Delaware Bay horseshoe crab population given their ecological connection with migratory shorebirds which feed on horseshoe crab eggs. In response, a multi-species management framework was developed via a structured decision making process involving shorebird and fishery managers, scientists, and stakeholders. Harvest level recommendations are produced by a complex suite of integrated fishery and red knot models that characterize the ecologic link between the two disparate taxa. Stochastic dynamic programming was used to incorporate uncertainty and select an optimum harvest strategy for horseshoe crabs, constrained by shorebird trophic needs, when forecasting is over an effectively infinite time horizon. This effort is the first to quantitatively link the two species and provide fishery management recommendations in an adaptive, multi-species management framework.