Emerging issues in horseshoe crab conservation: A perspective from the IUCN species specialist group

Abstract

Horseshoe crabs are valued in the production of the Limulus and Tachypleus amoebocyte lysate test for bacterial contamination, as bait in several fi sheries in the U.S. and Mexico, and for human consumption in Southeast Asia. Increasing commercial exploitation of horseshoe crabs, coupled with losses of essential spawning and nursery habitats, particularly in Southeast Asia, has raised concerns about the efficacy of current fi sheries regulations and coastal management practices. By the mid-2000s, a critical mass of scientific research coupled with widespread concerns about population declines, provided momentum for a series of international meetings, leading to the 2012 formation of the Horseshoe Crab Specialist Group within the IUCN (International Union for the Conservation of Nature). The Specialist Group is an advocate for science-based conservation of horseshoe crabs and their habitat, with a priority to update the Red List status for the three Asian horseshoe crab species, which are currently regarded as ‘data defi cient’ based largely on outdated information. A troubling and unexpected new issue in horseshoe crab conservation is the importing of Asian horseshoe crabs to supply the U.S. bait market. This practice is an economic incentive to overharvest Asian stocks that may also introduce diseases and invasive organisms into U.S. waters. Illegal fi shing activity in the U.S. and Southeast Asia, driven by the high market value of the crabs, also appears to be increasing. The Specialist Group has taken important actions to support internationally collaborative research and education activities that will increase awareness of and curtail these emerging threats to horseshoe crab populations before local population extinctions are inexorable.