Adaptive management of horseshoe crabs and red knots in Delaware Bay

Each spring millions of horseshoe crabs spawn on the beaches of Delaware Bay, which is the epicenter of the American horseshoe crab distribution.  Density-dependent quantities of eggs are brought to the beach surface and consumed by migrating shorebirds.  Until recently management of Delaware Bay horseshoe crabs and migrant shorebirds had followed traditional species-specific assessments with only qualitative linkages between them.  During that time the management process has been marked by dispute and ad hoc decision making.  Recently, a group of managers and researchers developed an adaptive management framework that explicitly accounts for multispecies linkages and uncertainties.  The decision is now structured as a harvest problem with conservation constraints defined by horseshoe crab and red knot population size.  Predictive multispecies models have been developed to predict consequences of harvest actions under uncertainty.  Optimal harvest actions are being identified through stochastic dynamic programming.  Recently, the Atlantic States Marine Fisheries Commission has endorsed the adaptive management framework.  In this talk, we highlight the successes and challenges encountered, as well as the challenges that lie ahead.