Horseshoe crabs are harvested in their millions for biomedical blood extraction to test vaccines and medical products for bacterial contamination, raising significant welfare and conservation concerns about current practice.
Horseshoe crab biomedical harvesting causes welfare harm through the bleeding process itself and through post-release mortality. The extraction process involves stacking crabs in transport trucks without water, transporting them to biomedical facilities, restraining them on racks in a novel environment, and puncturing the cardiac membrane to draw blood — a procedure that causes stress responses measurable through behavioural and physiological markers. The 30% blood volume extraction is substantial, and the combination of transport stress and blood loss explains the significant post-release mortality. Crabs are ectotherms with limited homeostatic capacity — high ambient temperatures during summer harvesting compound physiological stress. The availability of a synthetic alternative (rFC) that has been validated for equivalence to LAL in pathogen detection removes the necessity for continued animal harvesting. The primary barrier to adoption is regulatory inertia and industry conservatism rather than any scientific evidence of rFC inferiority. Transitioning to synthetic alternatives would eliminate the welfare harm to hundreds of thousands of animals annually.