The Horseshoe Crab Ranch & Blood Institute, a new project by Kepley BioSystems, represents a novel new way to source a substance critical to human health while simultaneously conserving and protecting the natural resource that it stems from. The blue blood of the Atlantic horseshoe crab (Limulus Polyphemus) provides the medical industry with one of the most accurate methods of testing for dangerous endotoxins; however, industrial usage of this ecologically important creature cannot be sustained at current levels. Kepley BioSystems believes that engaging in thoughtful husbandry and careful harvesting approaches to these creatures will ensure their well-being as well as an increased supply of a much-needed medical substance.
Since the 1970’s, the pharmaceuticals industry and in turn, millions of patients, have depended on Limulus Amebocyte Lysate (LAL), a substance derived from Atlantic horseshoe crab blood, which is indispensable for sterility testing in drug and medical device safety. This special amebocyte blood cell, key to the horseshoe crab’s own immune system, is responsible for detecting endotoxins, such as potentially lethal e. coli and salmonella, in human vaccines, drugs, implants, and other medical devices.
The LAL assay works in the same manner as it does in the horseshoe crab’s immune system. When the amebocytes are exposed to dangerous bacterial endotoxins at levels up to parts per trillion, the cells instantaneously clot around the bacteria. The ability of LAL to detect these deadly endotoxins is so precise that the assay is the only testing methods approved by the US Food and Drug Administration for drug and implant certification.
Some 600,000 horseshoe crabs are taken from the Atlantic seaboard each year for harvesting of their blood; typically removed from the water for extended periods, they suffer severe hypoxia while being transported in piles on open boats, then in vehicles in uncontrolled temperatures, and most are eventually returned to the water, without feeding or further care to ensure their well-being - resulting in an estimated mortality rate of up to 30%. In fact, these practices have become entirely unsustainable, as the impact on horseshoe crab reproduction and behavior has been compounded by such mortality rates and inexorable industry growth. Factoring in that the Asian horseshoe crab populations are near collapse, driving global demand even higher for LAL from US sources.
In addition to a global medical need for more LAL, the Atlantic horseshoe crab remains an ever-important keystone species to the US Eastern coast. The population levels of horseshoe crabs invariably affect the well-being of a multitude of other native species along the food web, but none so much as the migratory Red Knot bird. The Red Knot is entirely dependent on the egg-laying cycles of the horseshoe crab, such that as the horseshoe crab population declines, so to does the Red Knot. So much so, in fact, that they are now considered threatened by the US Endangered Species Act as of December 2015.
While alternative solutions remain problematic, an accountable and thoughtful solution must be found soon. The Kepley BioSystems Horseshoe Crab Ranch and Blood Institute innovation would validate a sustainable, humane approach to horseshoe crab blood harvest from controlled aquaculture in a protected estuary/site; wherein, horseshoe crabs would be fed, monitored, and carefully bled within the habitat. By establishing optimal protocols for horseshoe crab husbandry, bleeding, to tracking critical parameters to optimize diet, water quality, and density for successful horseshoe crab “ranching,” this approach would aim to reduce physiological and environmental stress and mortality rates, compared to traditional practices of wild capture and harvest. This project would also study horseshoe crab amebocyte production, an as yet, poorly characterized body of research. Ultimately, the outcome of the project would be to establish a sustainable, humane, and scalable horseshoe crab ranching approach that could replace wild capture; thereby averting threats to horseshoe crab populations and to the well-being of millions of patients and birds that depend on them, worldwide.