Protecting Horseshoe Crab Habitat

Each spring adult horseshoe crabs migrate from deep bay waters and the Atlantic continental shelf to intertidal sandy beaches to spawn. Horseshoe crabs are an important food source for migrating shorebirds that feed on the eggs, for migrating fish that feed on the eggs and larvae and for Atlantic loggerhead turtles that feed on horseshoe crabs while using the Chesapeake Bay as a summer nursery area. In addition, horseshoe crabs are critical to the biomedical industry that uses their blood. A chemical obtained from horseshoe crab blood (Limulus amebocyte lysate or LAL) is used to determine the safety of medical products for human use. Horseshoe crabs are slow to mature and can be easily harvested during the spawning season. As such, they may be susceptible to overharvest. Horseshoe crab harvesting for bait in other fisheries such as American eel and conch as well as evidence of localized population declines occurring within Delaware Bay in the late 1990’s raised concerns about the status of horseshoe crabs. As a result, the Atlantic States Marine Fisheries Commission (ASMFC) developed an interstate Fishery Management Plan (FMP) to conserve and protect the horseshoe crab resource. Since the plan’s approval in 1998, states have implemented mandatory reporting of horseshoe crab landings, reduced harvest of horseshoe crabs, initiated long-term monitoring programs necessary for stock status information, and made progress in identifying important horseshoe crab habitat. This article focuses on the progress made by Atlantic states in identifying important spawning and nursery habitat of horseshoe crabs.