Horseshoe crabs are harvested by the millions each year for their blood — used to detect bacterial contamination in medical products — with welfare and conservation implications that are increasingly debated.
Horseshoe crabs harvested for bleeding experience significant welfare costs: transport, handling, puncture for blood extraction, and release without recovery time all cause physiological stress. Post-release mortality of 10-30 percent means hundreds of thousands die annually from the harvest process. Those that survive show impaired spawning behaviour, reducing reproductive contribution. While horseshoe crabs are arthropods whose sentience is less certain than vertebrates, the precautionary principle and scale of harvest justify concern. The availability of rFC as a validated alternative means continuation of live crab harvest is increasingly a commercial choice rather than a necessity, making transition to synthetic alternatives a priority for both animal welfare and conservation.