Effects of Blood Extraction on the Mortality of the Horseshoe Crab, Limulus polypliemus

Horseshoe crabs (Limulus polyphemus) are bled by biomedical companies for the extraction of Limulus Amoebocyte Lysate (LAL), a clotting agent used in the detection of endotoxins. In 1998, the Atlantic States Marine Fisheries Conunission mandated tliat all biomedical companies collecting horseshoe crabs for the production of LAL study tl1e horseshoe crab mortality rates resulting from the company's blood extraction process. BioWhittaker, a Cambrex Company is one of tl1e largest producers of LAL in the world. During the sununer of 1999, bled and unbled horseshoe crabs were transported from Bio Whittaker's bleeding facility in Chincoteague, Virginia to tl1e Virginia Seafood Agricultural Research and fa.1ension Center's aquaculture facility in Hampton, Virginia. At the aquaculture facility, they were kept in a tank and their survival was monitored for a period of two weeks. Mortality for bled crabs was 15%, while mortality for unbled crabs was 0%. Because of the importance of horseshoe crabs to a wide variety of interests, proper management requires monitoring and consideration of mortality effects on the population. INTRODUCTION Horseshoe crabs (Limulus polyphemus) are the target of a large commercialfishecy that provides bait for the American eel (Anguilla rostrata), whelk (commonly referred to as conch Busycon spp.), and, to a lesser e:\1ent, catfish fisheries (HCTC, 1998). The horseshoe crab fishery has been increasing rapidly (Loveland et al., l 996~ Berkson and Shuster, 1999) and is the subject of much controversy (Berkson and Shuster, 1999). Biomedical companies also catch horseshoe crabs to produce Limulus Amoebocyte Lysate (LAL), a clotting agent used to detect the presence of endotoxins patl1ogenic to humans in injectable drugs and all implantable devices (Novitsky, 1984~ Mikkelsen, 1988). The LAL test is now a standard used to protect human health around the world, and horseshoe crabs are the only source of LAL. The Food and Drug Administration (FDA) mandates tliat biomedical companies release tl1eir horseshoe crabs alive after they liave been caught and bled. Because mortality rates in tl1e capture and bleeding processes are poorly understood, the Atlantic States Marine Fisheries Conunission mandated in 1998 tliat all biomedical companies actively bleeding horseshoe crabs estimate mortality rates resulting from their bleeding process. Proper management of the resource requires infonnation on all human induced sources of mortality. Bio Whittaker, a Cambrex company, is tl1e largest producer of LAL in the world. In response to the ASMFC mandate, Bio Whittaker requested Virginia Tech to conduct 196 VIRGINIA JOURNAL OF SCIENCE the mortality study. TI1e objective of the study was to evaluate the mortality rates between bled and unbled crabs in a controlled holding facility .