Marine Invertebrate Welfare

Horseshoe Crabs and Biomedical Bleeding

Horseshoe crabs are harvested annually for their blood, which is used in medical testing, raising significant welfare and conservation concerns.

Key Facts

Approximately 500,000 horseshoe crabs are collected annually in the US for biomedical limulus amebocyte lysate (LAL) production
Crabs are bled of up to 30% of their blood volume before being returned to the ocean
Mortality rates of returned crabs are estimated at 15 to 30% due to bleeding stress
Horseshoe crab eggs are the critical food source for red knot shorebirds during spring migration
A synthetic alternative (rFC) has been approved in some markets but has not fully replaced LAL

Welfare Considerations

Horseshoe crab bleeding causes physiological stress measurable in blood chemistry and behavioral changes. Released crabs show disorientation and altered behavior. Mortality adds to the welfare concern. The development and adoption of synthetic alternatives would eliminate the welfare cost entirely while meeting the same medical safety requirement.

What You Can Do

Support pharmaceutical companies adopting rFC synthetic alternative to horseshoe crab LAL
Advocate for regulatory approval of synthetic alternatives across all national markets
Donate to horseshoe crab conservation organizations monitoring population health and migration