Horseshow Crab

7 Pages 1869 Words

What factors are responsible for the decline in the horseshoe crab (Limulus polyphemus) population in the Delaware Bay, USA?

ABSTRACT
The North Atlantic Horseshoe crab (Limulus polyphemus) is found all along the North American coast, with its greatest numbers concentrated in the Delaware Bay area (the southern coast of New Jersey and the northern coast of Delaware) (ASMFC 1998; Shuster 1985). The population of horseshoe crabs in the Delaware Bay has been experiencing a steady decline since 1990 (University of Delaware 2000). Several factors are responsible for this decline, including a decrease in the number of suitable spawning beaches due to beach erosion and development (ASMFC 1998), pollution of the Delaware Bay (Burger et al 2002), biomedical harvesting for LAL, and commercial harvesting for bait in the American eel and conch fisheries (ASMFC 1998; Berkson and Shuster 1999). While some legislation has been introduced calling for a monitoring of the population as well as landing caps for commercial fisheries, more steps need to be taken in order to more sustainably exploit the population. Regulation and standardization of the biomedical fisheries is suggested, as well as increasing the funding for research to determine an artificial bait source for commercial fisheries.
INTRODUCTION
The North Atlantic Horseshoe crab (Limulus polyphemus) has been thriving for millions of years. They were once widespread, but now their habitat is limited to the North American Eastern coast, primarily from Maine to Florida in the USA (Burger et al 2002; Berkson and Shuster 1999). The horseshoe crab is a generalist species, and can survive in a variety of conditions. The adults live in shallow coastal waters and come up onto the shore for 2 months in the summer every year to spawn. The female lays eggs and buries them in the sand where they are safer from predators. The larvae migrate into the sea and develop into juveniles. Juveniles ...