Horseshoe Crabs' Decline Further Imperils Shorebirds

"It's appalling that you would destroy one of the great wildlife spectacles in the world so a few guys could make money scooping up horseshoe crabs for bait," said David S. Wilcove, a professor of ecology and evolutionary biology and public affairs at Princeton University.

Watermen in 15 states along the Atlantic coast, on the other hand, resent the regulators who have limited their horseshoe crab take since 1998. Last year, they landed less than a fourth of the number they took before the state restrictions were imposed.

"It has ruined people's lives," said Frank Eicherly IV, who has spent more than three decades fishing for conch and horseshoe crabs in Delaware. Eicherly has been tracking crabs for the federal government for the past few years, and said he has detected indications that the population is poised for an upswing. "More restrictions is not what we need," he said.

Braddock Spear, who coordinates horseshoe crab management for the Atlantic states, said it would be unfair to make watermen such as Eicherly "take the full burden" for the shorebirds' fate, because regulators have cut their crab catch severely.

For years, people paid little attention to the lowly horseshoe crab, which is related to spiders, not crustaceans, and slithers along beaches from northern Maine to the Yucatan Peninsula and the Gulf of Mexico. Regulators call the species, which dates back at least 200 million years, a "trash fish."

Horseshoe crabs were used as fertilizer and livestock feed until the 1920s but then fell out of commercial favor until the late 1980s, when locals began harvesting them for bait and a source of LAL, a clotting agent that can reveal toxins in medicines and intravenous devices. About 90 percent of the crabs harvested for LAL are returned to the sea after the a portion of their blood is extracted.

Sen. Frank Lautenberg (D-N.J.), who oversees endangered species as a member of the Environment and Public Works Committee, said he is worried about the tourist dollars his state could lose if the shorebirds disappear. Last month, New Jersey officials closed parts of 15 beaches to try to ensure the birds had a decent chance of unearthing horseshoe crab eggs.

Lautenberg said he is trying to persuade his colleagues to pay attention to the red knot's potential demise, but it is hard to get them to focus on an ecosystem's gradual decline: "If it takes place after the next election, in most cases, it doesn't get a lot of attention around here."

Some uncertainty still surrounds the shorebirds' plight, especially since scientists have only recently begun to track the horseshoe crab population. Jim Berkson, a population biologist who helps assess the crabs for state and federal regulators, said as many as 10 million swim in the ocean surrounding Delaware Bay. But a recent trawl survey by Virginia Tech University showed the number of newly matured females, which are crucial in spawning, had dropped by 86 percent between 2001 and 2003.

"They've been fished hard," Berkson said, adding that he is still not convinced crabbing is the "sole or primary factor" explaining the birds' decline.

Regulators' decisions about what to do next are complicated by the uncertainties. Horseshoe crabs take 10 years to reach sexual maturity, and large females make the most desirable bait, so it could take years for the population to rebound despite restrictions. Red knots and other species are also encountering breeding problems, in part because in recent years they have arrived in the Arctic underfed and ill-prepared for the cold.

While some birds have sought food elsewhere -- red knots have stopped off in North Carolina and Florida, for example -- these spots often do not give them the needed sustenance. Perry Plumart, who directs conservation advocacy for the American Bird Conservancy, compared it to "removing the bowl of pasta" from a marathon runner just before a big race.

"This train has been coming down the track for a long time, and regulators said they didn't have enough data," Plumart said, as he looked out at Slaughter Beach. "I've been here when this beach has been crawling with horseshoe crabs, and thousands of birds."