These crabs play an essential role in the safety of biomedical products

The bright blue blood of horseshoe crabs have been essential for testing the safety of biomedical products for the past half-century. — AFP

On a bright moonlit night, a team of scientists and volunteers head out to a protected beach along the Delaware Bay to survey horseshoe crabs that spawn in their millions along the US East Coast from late spring to early summer.

The group make their way up the shoreline laying a measuring frame on the sand, counting the individuals inside it to help generate a population estimate, and setting right those unfortunate enough to have been flipped onto their backs by the high tide.