Horseshoe crabs are harvested by the millions for biomedical blood extraction, raising significant welfare concerns alongside threats to migratory shorebirds that depend on their eggs.
Horseshoe crabs occupy an uncertain position in welfare discussions — their neurological complexity is debated, but their haemolymph system means significant bleeding causes physiological stress measurable through activity and survival changes. The practice of stacking hundreds of crabs in transport trucks and holding them out of water for extended periods before and after bleeding causes additional stress. Sub-lethal effects in surviving crabs include impaired locomotion and altered spawning behaviour. The ecological cascade — reduced eggs threatening migratory shorebird populations — multiplies the welfare impact beyond the crabs themselves. Adoption of rFC would eliminate the need for animal-based testing and protect both horseshoe crabs and dependent species.