NMFS issues this final rule to prohibit fishing for horseshoe crabs and limit possession of them in an area in the exclusive economic zone (EEZ) encompassing a 30-nautical mile (nm) radius (in a shape roughly equivalent to a rectangle) seaward from the midpoint of the territorial sea line at the mouth of Delaware Bay. The intent of this final rule is to provide protection for the Atlantic coast stock of horseshoe crab and to promote the effectiveness of the Atlantic States Marine Fisheries Commission's (Commission) Interstate Fishery Management Plan (ISFMP) for horseshoe crab.