To set the record straight, conservation organizations aren't the only ones that believe red knots should be protected under the Endangered Species Act ("Counting crabs," June 20). The U.S. Fish and Wildlife Service agrees, which is why it placed the shorebird on the ESA candidate list in 2006. And we are not alone in supporting a moratorium on the harvest of horseshoe crabs; leading red knot scientists from the U.S., Canada, Argentina, Chile, Uruguay and Brazil also support a timeout on the take of crabs of Delaware Bay origin — particularly after observing a 5,000 bird drop in wintering locations this year. The Sun ignored that fact, among others, in favor of dated information supporting your view that a horseshoe crab moratorium is unnecessary.

A moratorium on the fishery would not include a ban on the biomedical use of crabs. But there is a growing concern — shared by the Atlantic States Marine Fisheries Commission — that the use of crabs for biomedical purposes is not as benign as previously thought. A new scientific study reveals at least 30 percent of crabs bled may die each year — not the 15 percent stated in your editorial. That's 150,000 dead crabs. We agree that medical purposes should be the priority use of this animal. But steps can be taken to reduce that mortality, and if coupled with a moratorium on the fishery, could recover the species and the red knot that depends on it.

After more than 20 years of intensive study, the horseshoe crabs and red knots of Delaware Bay are among the most studied animals on earth. Without action, we'll study them into extinction.

Caroline Kennedy,Washington, D.C.

The writer is senior director of field conservation for Defenders of Wildlife.