Bad News for Shore Birds

Two adult red knots in Delaware Bay: emaciated new arrival (left) and fattened adult ready for departure (right). Red knots rely on abundant horseshoe crab eggs in the Delaware Bay to fatten up on their long migration. Overharvesting of horseshoe crabs for bait has imperiled red knots.

Photo: New Jersey Division of Fish and Wildlife

related articles

The inter-state council that regulates fishing on the East Coast has voted to continue allowing fishermen to kill horseshoe crabs for bait, despite overwhelming evidence that the loss of crabs is leading to an ecological collapse.

The red knot, a shorebird that needs a big feast of horseshoe crab eggs to fatten up for its migration, is so critically endangered that it needs emergency protection, conservation groups argued in February.

But the Atlantic States Marine Fisheries Commission decided to maintain current levels of horseshoe crab harvests, rather than impose a temporary moratorium.

“By maintaining harvest levels rather than adopting a temporary moratorium on all horseshoe crab take, the Commission has dangerously underestimated the needs of both the crab and the Red Knot,” said Darin Schroeder, vice president for conservation advocacy at American Bird Conservancy. “The ASMFC Management Board has failed to live up to its responsibility as an environmental steward, and ignored the Red Knot’s economic benefits. Each year birdwatchers flock to beaches in Delaware, New Jersey, and Virginia to see the staging birds. Soon, there could be no more knots to watch, and it will be too late to act.”

At issue is how many horseshoe crabs are harvested from the waters of Delaware Bay. The annual and amazing migration of red knots sees flocks descend mid-way on their 9,300-mile one-way journey from Chile to the Canadian Arctic to eat the ancient crab's eggs. As horseshoe crab numbers have declined, so have red knot numbers. Studies have shown red knots don't fatten up as much as they used to there, and as such, are too weak to complete their migration and reproduce successfully. Conservation groups have argued for additional fishing restrictions for horseshoe crabs, which are harvested in small numbers for medical uses and larger numbers for bait to catch other fish.

Horseshoe crabs are themselves a marvel of evolution, having survived on earth far longer than humans. Their evolutionary path has, however, been useful to humans, as their odd immune system has provided medical science compounds that have proved both unique and useful. Whether or not the red knot, too, with one of the most impressive migrations in the animal kingdom, holds some special compound that might aid humanity is unknown.

COMMENTS ()