Answer
Their blue blood contains LAL used to test vaccines and medical devices for bacterial contamination—regulated fisheries bleed a portion and return many crabs alive. Visitors learn this at Coastal Bays outreach events rather than handling crabs for souvenirs. Respect spawn beaches that support both ecology and research.
Sources: Maryland DNR · Maryland Coastal Bays Program
Editorial visitor guidance for Ocean City, Maryland. Confirm current Town of Ocean City, Maryland DNR, NPS Assateague, and NWS rules when regulations or safety apply.
