Center for Biological Diversity

For Immediate Release, February 12, 2024


Will Harlan, Center for Biological Diversity, (828) 230-6818,
Annie Chester, American Bird Conservancy,
Emily Snow Ehrhorn, The Humane Society of the United States, (202) 779-1814,
Tim Dillingham, American Littoral Society,

Endangered Species Act Protections Sought for American Horseshoe Crabs

23 Organizations Urge Listing for Ancient Creatures Disappearing From Atlantic Shores

VIRGINIA BEACH, Va.— The Center for Biological Diversity and 22 partner organizations petitioned NOAA Fisheries today to list the American 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.

“We’re wiping out one of the world’s oldest and toughest creatures,” said Will Harlan, a senior scientist at the Center for Biological Diversity. “These living fossils urgently need Endangered Species Act protection. Horseshoe crabs have saved countless human lives, and now we should return the favor.”

Horseshoe crabs are brown, body-armored arthropods with 10 eyes and a long, spiked tail. Despite their intimidating appearance, they are completely harmless to humans. Each spring along the Atlantic and Gulf coasts, horseshoe crabs lay their eggs in massive beach spawning events.

Nearly twice as old as the dinosaurs, horseshoe crabs have been crawling ashore for more than 450 million years. In the past three decades, however, horseshoe crab populations have declined by two-thirds in the Delaware Bay, their largest population stronghold.

Horseshoe crabs are harvested for use as bait by the commercial whelk and eel fisheries. Even though horseshoe crab populations have fallen to historic lows, regulators have increased horseshoe crab harvest quotas.

Biomedical companies also harvest horseshoe crabs and drain their blue blood, which is used to detect toxins in drugs and medical devices. Horseshoe crab blood harvests have virtually doubled since 2017, with nearly 1 million horseshoe crabs harvested for their blood in 2022. Synthetic alternatives to horseshoe crab blood tests are already being used in Europe, but companies in the U.S. have been slow to adopt the alternatives.

“The continued reliance on horseshoe crab blood by pharmaceutical manufacturers has led to a rapid decrease in the population of this important species,” said Kathleen Conlee, vice president for animal research issues at the Humane Society of the United States. “Fortunately, there are non-animal alternatives that can replace the use of horseshoe crab blood and help protect these amazing animals from further overharvest.”

Habitat loss is another dire threat to horseshoe crabs. Spawning beaches across their entire range are being destroyed by development, shoreline hardening, and sea-level rise.

As horseshoe crabs have declined, so have other species, such as endangered sea turtles, fish and birds. Most notably, the rufa red knot, a shorebird species that feeds on horseshoe crab eggs during its 19,000-mile migration from South America to the Arctic, was listed as threatened under the Endangered Species Act in 2015. The listing decision cited the horseshoe crab harvest as one of the contributing factors to the red knot’s decline.

“Horseshoe crab eggs are incredibly nutrient dense, sustaining the federally threatened red knot on their long migratory journey,” said Steve Holmer, vice president of policy at American Bird Conservancy. “Greater protection of the horseshoe crab is needed to fully recover the red knot, as well as conserve other shorebird species, such as the ruddy turnstone and semipalmated sandpiper.”

A sister species to the American horseshoe crab — the tri-spine horseshoe crab in Asia — faces similar threats and is nearly extinct.

“It is clear from the available science that the current fisheries management policies are failing to protect and sustain these ancient mariners,” said Tim Dillingham, executive director of the American Littoral Society. "We must do more to keep them and the red knots and other life that depend on them from disappearing from this Earth.”

Joining the Center for Biological Diversity, the Humane Society of the United States and American Bird Conservancy in petitioning for the horseshoe crab are the American Littoral Society, New Jersey Audubon, Delaware Audubon, Delaware Ornithological Society, Healthy Gulf, Humane Society Legislative Fund, League of Women Voters of New Jersey, Maryland Ornithological Society, Revive & Restore, One Hundred Miles, The Safina Center, Wild Cumberland, Forest Keeper, Coastal Expeditions Foundation, Mobile Baykeeper, Shark River Cleanup Coalition, Southeastern Massachusetts Pine Barrens Alliance, Save Coastal Wildlife, New Jersey League of Conservation Voters and the Delaware Riverkeeper Network.

Horseshoe crab populations have crashed and their habitat is disappearing. Endangered Species Act protections are urgently needed. Please credit: Gregory Breese/USFWS. Image is available for media use.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.

The Humane Society of the United States fights the big fights to end suffering for all animals. Together with millions of supporters, they take cruel industries, rescue and respond to thousands of animals in need every year, and fight all forms of animal cruelty to achieve the vision behind their name: a humane society.

American Bird Conservancy is dedicated to conserving wild birds and their habitats throughout the Americas. With an emphasis on achieving results and working in partnership, they take on the greatest problems facing birds today.

American Littoral Society is a coastal conservation organization which leads the largest community horseshoe crab tagging program in the country, promotes the study and conservation of marine life and habitat, defends the coast from harm, and empowers others to do the same.

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