The Effects of Biomedical Bleeding Practices on Daily Activity of the American Horseshoe Crab, Limulus polyphemus

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Chris Chabot Plymouth State University Principal Investigator
Rebecca Anderson Plymouth State University Co-Principal Investigator
Winsor Watson UNH - Department of Biological Sciences Collaborator
Journal Article Published

Anderson, R., W. Watson and C. Chabot (2013). Sublethal behavioral and physiological effects of the biomedical bleeding process on the American horseshoe crab, Limulus polyphemus. Biological Bulletin 225(3):137-151, December 2013.

2014 Accomplishment

Story featuring N.H. Sea Grant research on horseshoe crabs gains worldwide attention

In 2014, N.H. Sea Grant staff wrote a story about the effects of biomedical bleeding of horseshoe crabs. The story, based on research sponsored by a NHSG development grant, gained worldwide attention through social media. The topic was mentioned on Twitter by eight other individuals or organizations and was retweeted 21 times, including by NOAA Research and EcoWatch, with a total potential reach of almost 160,000 Twitter users. The NHSG story also spurred a number of related articles in media outlets including The Atlantic and Huffington Post Green. The reach of this story has helped to bring NHSG-sponsored research to the national media spotlight.

2012 Accomplishment

Biomedical Bleeding of Horseshoe Crab Causes Temporary Behavioral Changes
The blood of the American horseshoe crab is harvested to produce a reagent used in a variety of biomedical applications, but it is unknown whether the bleeding process causes behavioral and physiological changes in the crabs. Using NHSG development funds in 2012, researchers examined the effects of the bleeding procedure on mortality, behavior, hemocyanin concentration and heart rate in horseshoe crabs. They determined that the bleeding process caused several significant behavioral effects, including decreased linear and angular velocity, reduced overall activity and diminished expression of circatidal behavioral rhythms. Although the behavioral changes were temporary, they could potentially lead to decreased fitness and spawning rates in the wild, potentiality compounded by the high level of harvest that occurs during the horseshoe crab spawning season. These results provide an improved understanding of the possible impacts of the biomedical bleeding process and may influence how resource managers monitor and regulate the biomedical harvest to ensure sustainable horseshoe crab populations.


We are seeking development funds to perform preliminary research on the sub-lethal effects of bleeding on horseshoe crabs. Our proposed research stands to facilitate both the development of sustainable harvest practices and effective regulations throughout New England.

The stability of the horseshoe crab fishery is an issue of significance to the entire northeast region, and most closely impacts the fishing community and the biomedical industry. Fishermen are increasingly turning to whelk fishing throughout New England and the Gulf of Maine; the whelk fishery offers struggling fishermen a much-needed income source, one that depends on a viable horseshoe crab fishery. Declining population abundance suggests that better management techniques are required to create a sustainable fishery that can accommodate the needs of both stakeholders: the fishing community and biomedical industry.  Current regulations throughout the northeast only take into account the impact of the bait fishery, disregarding the impacts of the biomedical industry. As a result, fishermen shoulder an additional burden, subject to catch limits and area closures, while the biomedical industry is allowed access to an unrestricted harvest.  In order to best manage the fishery, the full impact of the biomedical industry on horseshoe crab populations needs to be understood.        

The high female mortality rate of the biomedical bleeding procedure suggests that the process may need to be improved. Determining how physiology and behavior are affected by bleeding is a necessary first step in devising strategies to minimize the impact of the biomedical industry on horseshoe crab populations. The Great Bay, N.H., horseshoe crab population is a unique resource: an unadulterated specimen pool that has not been harvested for biomedical bleeding. We hope that the preliminary research outlined in this proposal will extend to future research on the effects of bleeding on horseshoe crabs in the natural environment, for which Great Bay offers an optimum study site. We also intend for this project to lay the foundation for future collaboration with Massachusetts and/or Connecticut Sea Grant and potentially for an NSF proposal.