293 



Potential causes of mortality for horseshoe crabs 

 (Limu/us polyphemus) during the 

 biomedical bleeding process 



Lenka Hurton 



Department of Fisheries and Wildlife Sciences 



and 



Horsesfioe Crab Research Center 



Virginia Polytechnic Institute and State University 



Blacksburg, Virginia 24061-0321 



Jim Berkson 



National Marine Fisheries Service-Virginia Tech RTR Unit 



Fisheries and Wildlife Sciences 



and 



Horseshoe Crab Research Center 



Virginia Polytechnic Institute and State University 



Blacksburg, Virginia 24061-0321 



E-mail address (for J Berkson, contact author) Jim Berkson g noaa gov 



Biomedical companies catch and 

 bleed horseshoe crabs for the pro- 

 duction of Limiilus amebocyte lysate 

 (LAL), a product used for protecting 

 public health (Berkson and Shus- 

 ter, 1999). LAL is a clotting agent, 

 derived solely from horseshoe crab 

 blood cells, which is used to detect 

 the presence of pathogenic gram- 

 negative bacteria in injectable drugs 

 and implantable medical and dental 

 devices (Mikkelsen, 1988; Novitsky, 

 1991). In addition, LAL is used in 

 many diagnostic tests for such ill- 

 nesses as gram-negative bacterial 

 meningitis and typhoid fever (Ding 

 and Ho, 2001). Because the LAL test 

 allows one to detect femtogram levels 

 of endotoxin (Ding and Ho, 2001), it 

 is the most effective test for detect- 

 ing endotoxin contamination, and its 

 increasing use in medical and phar- 

 maceutical laboratories makes it a 

 highly valued product. 



The biomedical industry harvest- 

 ed approximately 260,000 horseshoe 

 crabs in 1997 (HCTCi) for the pro- 

 duction of LAL. By 2000, the number 

 of horseshoe crabs bled had increased 

 less than 1% (ASMFC-). However, 

 approximately 25% of the horseshoe 

 crabs landed for biomedical purposes 

 were rejected for use, and about 45% 

 of those rejected were rejected be- 



cause they were injured (ASMFC-). 

 Some mortality is likely related to 

 harvest injuries, but this rate of mor- 

 tality is unknown. At current har- 

 vest levels, mortalities from biomedi- 

 cal collection and bleeding methods 

 may not be negligible. Mortalities in- 

 flicted by the biomedical industry on 

 the horseshoe crab population come 

 in addition to mortalities caused by 

 the commercial fishery, where horse- 

 shoe crabs are harvested for use as 

 bait for eel [Anguilla rostrata) and 

 whelk (Busycon spp.) fisheries (Walls 

 et al., 2002). Furthermore, numer- 

 ous migratory shorebird species 

 feed on horseshoe crab eggs (Clark, 

 1996) and adults (Botton and Love- 

 land, 1989, 1993) to fuel their migra- 

 tion from South American winter- 

 ing grounds to their Arctic breeding 

 grounds (Clark, 1996). Concern has 

 arisen over horseshoe crabs, in part 

 because of local population declines, 

 increased catch and effort, and the 

 need for a superabundance of horse- 

 shoe crab eggs for shorebirds, all of 

 which necessitate a conservative, 

 risk-averse management approach 

 ( ASMFC- ). It is important to not only 

 investigate the effects of the com- 

 mercial fishery harvest and natural 

 predation on horseshoe crab stocks 

 but to comprehensively assess the 



impact of the biomedical industry 

 take on horseshoe crab population 

 viability. Reducing mortalities from 

 the biomedical industry may aid in 

 conserving the horseshoe crab pop- 

 ulation, as well as in reducing the 

 magnitude of conflict between this 

 industry, the commercial fishery, and 

 environmentalists. To achieve this 

 goal, further investigation into the 

 biomedical bleeding process and its 

 effects is required. 



Throughout the typical biomedi- 

 cal bleeding process, horseshoe crabs 

 are subjected to a variety of potential 

 stressors (i.e., air exposure, increased 

 temperature, handling, blood loss, 

 trauma, etc.). Each LAL producer has 

 its own bleeding process involving 

 different methods of capture, distance 

 and method of travel to the bleeding 

 facility, different holding times and 

 conditions, different bleeding meth- 

 ods, and methods of returning bled 

 crabs that are most appropriate to 

 that company's location and facility 

 set-up (Walls and Berkson, 2003). 

 An example of one version of the bio- 

 medical bleeding process begins with 

 the collection of the horseshoe crabs 

 by trawling, dredge, or hand-harvest 

 methods (HCTC). Animals may be 

 held on the deck of a boat or in con- 

 tainers for several hours during col- 

 lection, transported to the bleeding 

 facility in trucks (that may or may 

 not be air-conditioned), held in the 



1 HCTC (Horseshoe Crab Technical 

 Committee). 1998. Status of the 

 horseshoe crab tLimulus polyphemus) 

 population off the Atlantic Coast, 9 p 

 -I- figures and tables. Horseshoe Crab 

 Technical Committee, Atlantic States 

 Marine Fisheries Commission, 1444 Eye 

 Street, NW, Sixth Floor, Washington, 

 DC 20005. 



- ASMFC (Atlantic States Marine Fisher- 

 ies Commission). 2002. Review of the 

 fishery management plan for horseshoe 

 crab iLinutlus polyphemus). Horseshoe 

 Crab Plan Review Team, Atlantic States 

 Marine Fisheries Commission, 1444 Eye 

 Street, NW, Sixth Floor. Washington, 

 DC 20005. 



Manuscript submitted 17 May 2004 

 to the Scientific Editor's Office. 



Manuscript approved for publication 

 21 July 2005 by the Scientific Editor. 



Fish. Bull. 104:293-298 1 2004). 



