Center for Biological Diversity

For Immediate Release, October 19, 2023


Will Harlan, (828) 230-6818,

Female Horseshoe Crabs Spared for Another Year in Delaware Bay

Overharvesting Continues to Threaten Crabs, Endangered Shorebirds

DOVER, Del.— The Atlantic States Marine Fisheries Commission decided this week to forgo a 2024 bait harvest of female horseshoe crabs in Delaware Bay, where the crabs’ eggs provide a critical food source for endangered migratory shorebirds.

But the commission still upheld an intrinsically flawed computer model that increases horseshoe crab harvests and allows female horseshoe crab harvests in future years.

“I applaud the commission for not authorizing female horseshoe crab bait harvests for another year, but these animals urgently need longer-term protections,” said Will Harlan, a senior scientist at the Center for Biological Diversity. “The iconic horseshoe crabs that once blanketed Atlantic coast beaches are vanishing, and so are the shorebirds, turtles and other species who depend on them.”

Horseshoe crab populations have crashed in recent decades and not recovered because of overharvesting. Eel and whelk fisheries use horseshoe crabs for bait, and biomedical companies harvest horseshoe crabs for their blood, which can be used to detect toxins. Horseshoe crab populations remain at historically low levels.

As a result, several imperiled migratory shorebirds have also suffered significant population declines. The endangered red knot depends on horseshoe crab eggs to fuel its annual journey from the tip of South America to the Canadian Arctic — one of the longest migrations on Earth. With fewer horseshoe crab eggs on beaches, endangered red knot populations have declined by 84% since the 1980s.

The commission received more than 34,000 public comments opposing the harvest of female horseshoe crabs. Leading scientists also have denounced the commission’s seriously flawed computer model, which recommends harvesting 175,000 female horseshoe crabs and 500,000 male horseshoe crabs for bait annually.

Nearly 1 million horseshoe crabs are also harvested each year by the biomedical industry for their blood, which provides a rapid test for bacterial contamination. A synthetic alternative to horseshoe crab blood was recently approved by the U.S. Pharmacopeia.

“Horseshoe crabs have survived for a half-billion years, but now they face their greatest threat yet: overharvesting,” said Harlan. “These ancient creatures have helped save countless human lives. Can we return the favor?”


Nearly twice as old as the dinosaurs, horseshoe crabs are one of the most ancient animals on Earth. These brown, body-armored beasts with a long, spiked tail gather in late spring for massive beach orgies. Under a full or new moon, females crawl ashore and bury masses of eggs, and mobs of males battle to fertilize them.

The federally endangered red knot times its annual 17,000-mile roundtrip migration to coincide with the horseshoe crabs’ mass spawning. Red knots gorge on protein-rich horseshoe crab eggs, providing an essential refueling for the beleaguered birds on their long journey north. Red knots that miss the egg feast usually die or fail to breed. The Center for Biological Diversity helped secure Endangered Species Act protections for the red knot in 2014.

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Red knot. Credit: Brett Hartl/Center for Biological Diversity. 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.

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