February 14, 2024 — Ancient creatures with 12 legs, 10 eyes, and blue blood were once so prevalent on southern New England beaches that people, including children, were paid to kill them.
Their helmet-like bodies can still be seen along the region’s coastline and around its salt marshes, but in a fraction of the numbers witnessed seven decades ago. There are many reasons why.
In the 1950s coastal New England paid fishermen and others bounties to kill the up to 2-feet-long arachnids — horseshoe crabs are more closely related to spiders, scorpions, and ticks than to crabs — because they interfered with human enjoyment of the shore and were viewed as shellfish predators.
People, not just fishermen, were reportedly encouraged to toss horseshoe crabs above the high-tide line, so they would dry out and die. They were labeled “pests” and ground up for fertilizer. Beachfront property owners were apparently concerned the creature’s presence and their decaying death would impact real estate values.
Those ignorant days may be over, but horseshoe crabs are facing other threats to their existence.
The Center for Biological Diversity, an Arizona-based nonprofit, and 22 partner organizations recently petitioned NOAA Fisheries to list the Atlantic horseshoe crab as an endangered species under the Endangered Species Act. Horseshoe crab populations have crashed in recent decades because of overharvesting and habitat loss, according to the petitioners.
“Horseshoe crabs are imminently threatened by habitat loss, overexploitation, inadequacy of existing regulatory mechanisms, and other natural and manmade factors, including climate change,” according to the 142-page petition. “They are in danger of extinction across a significant portion of their range, and threats are likely to persist and worsen in the foreseeable future.”
The body-armored arthropods — also known as the American horseshoe crab, because they are the only living species of horseshoe crab native to the Americas — are used by the biomedical industry, which takes the animal’s copper-based blood for tests to ensure that medical devices, vaccines, and intravenous solutions are free of harmful bacteria.
Horseshoe crab blood harvests have doubled since 2017, with nearly a million horseshoe crabs harvested for their blood in 2022, according to the Center for Biological Diversity. The petition noted synthetic alternatives to horseshoe crab blood tests are already being used in Europe, but companies in the United States have been slow to adopt the alternatives.