"Environmental groups on Monday petitioned the U.S. government seeking endangered species protection for the American horseshoe crab, a "living fossil" under threat from commercial harvests for bait and biomedical use as well as from habitat loss and climate change.

These spine-tailed sea creatures named for the shape of their body shells have been crawling ashore since long before the age of dinosaurs, and in modern times were a familiar sight to summer beachgoers along the U.S. mid-Atlantic and Gulf Coasts.

But horseshoe crab populations have crashed in recent decades, with spawning numbers down two-thirds from 1990 in the Delaware Bay estuary that was once their biggest stronghold, according to conservation groups. Research also shows their egg densities falling more than 80% in the past four decades.

Those trends are tied to stress on other marine species that feed on their larvae and eggs, including the rufa red knot, a migratory shorebird whose own 2014 threatened-species listing cited horseshoe crab harvests as a contributing factor."

Steve Gorman reports for Reuters February 13, 2024. [2]