Become a digitalPLUS subscriber. $12 for 12 weeks.
Sports Outdoors and Recreation

Red knot population continues to dwindle

COOK'S BEACH, N.J. — The small bird sitting along this sandy spit of land is starving and dinner offerings are slim.

Having flown 5,000 miles from South America and with 5,000 to go to its Arctic breeding ground, the red knot needs to fatten up along Delaware Bay or die. For tens of thousands of birds over the last decade, death has been inevitable. The red knot population, scientists believe, may be down to its last 25,000.

Two weeks ago, bird experts and environmentalists called on the federal government to accelerate the review process for placing the red knot on the endangered species list. The U.S. Fish and Wildlife Service has proposed a schedule that could begin as early as this fall.

Those same groups urged Maryland and Virginia to ban the commercial harvesting of horseshoe crabs, whose fat-filled eggs are the primary food source for the red knots as they migrate north but are no longer abundant.

"What Maryland is doing is not scientifically defensible from our perspective. Maryland is part of the problem," said Caroline Kennedy, vice president of the Defenders of Wildlife. "We need a moratorium."

Maryland fisheries officials say they have reduced harvests, especially of female horseshoe crabs, and put the crabs off limits for the first six months of the year to protect spawning adults.

"We feel we are managing crabs for a sustainable population," said Mike Luisi of the Department of Natural Resources.

The Atlantic States Marine Fisheries Commission, the primary authority overseeing the health of horseshoe crabs, is updating a plan to provide options for a Delaware Bay management program. The commission's horseshoe crab experts will be meeting in Annapolis on June 24.

Wave-side feast

Each May, an international team of biologists and birders gathers at this ramshackle house on Delaware Bay just north of Cape May to capture red knots in an attempt to understand the birds' decline and, perhaps, reverse it.

With evidence of stormy May weather on the horizon, the team gathered anxiously behind a sand berm, waiting for the "pop" of a small cannon that released a net to capture several hundred birds feeding near the waterline.

Men and women dashed from cover, plucked the birds from the netting and began separating them by species to get blood and feather samples and to band them for identification in the Arctic and in South America. Some birds are outfitted with geolocators to track their flights.

Their concern goes beyond red knots. Many migrating shorebirds — sanderlings, ruddy turnstones and semipalmated sandpipers — also rely on horseshoe crab eggs to energize them for the breeding season to come. The number of those birds has "declined significantly," said Kennedy as she helped with the sorting.

As home to one of the world's largest populations of horseshoe crabs, Delaware Bay had long been a gigantic bird feeder for red knots. In mid- to late-May, migrating red knots — about the size of robins — show up famished, weighing about half their normal weight. For a week or so, they gorge all day long on BB-sized horseshoe crab eggs, each consuming 18,000 or more, until their weight doubles to give them the fuel needed to fly nonstop to the Arctic.

But in the mid- and late-1990s, commercial fishermen scooped up millions of horseshoe crabs to sell to the bait industry, using pitchforks and snow shovels to pile the helmet-shaped creatures into pickup trucks. At the height of the harvest, more than 2 million crabs a year were being taken in the Middle Atlantic states.

By 1997, regulators finally stepped in, but the damage was done. A horseshoe crab takes nine to 13 years to reach sexual maturity so although the population is stable, it's in no position to feed the red knot.

As a result, scientists and birders who used to see 100,000 red knots feeding on the Delaware Bay in the 1980s saw a rapid decline. In 2001, they counted 45,000 birds passing through. Five years later, the count was down to 15,000.

Scientists say fewer and fewer red knots are making weight before their biological clock tells them to head north. The malnourished birds are no match for harsh Arctic conditions.

In August 2006, the red knot was designated a candidate for possible addition to the federal list of endangered species. It hasn't made any progress on a list that now numbers 251 species.

Earlier this month, the U.S. Fish and Wildlife Service settled a number of lawsuits brought by environmental groups by promising to clear the backlog over the next six years.

In a letter to environmental groups, Eric Davis, the agency's point man on the six Northeast candidate species, said the "short-term goals of the Service include preventing further declines in populations and stabilizing or increasing numbers by reducing the magnitude and imminence of habitat-based and human-disturbance threats to red knot at wintering and migration areas."

The assessment on the bird's status, complete with public review and comment periods, will begin in fiscal year 2012, which begins in October, but the determination probably won't be published until the following fiscal year.

Not far enough

The red knot can't wait, argue bird experts, who want Maryland, Virginia and Delaware to join New Jersey in banning commercial horseshoe crab harvests.

"The shorebirds have shown the ability to recover, but we need to act right now," said Mike Parr of the American Bird Conservancy. "The knots are long-lived and 25,000 should be enough, but things have got to stop to let the knots recover. Otherwise, we're going to lose the bird."

But Delaware's environment secretary imposed a two-year ban on the harvest of horseshoe crabs in 2006 only to have the moratorium successfully challenged in court by the commercial industry. Instead, the state now has a male-only 100,000 crab annual quota.

Maryland bans horseshoe crab harvesting from Jan. 1 to June 7 and sets the catch ratio of 2 to 1, males to females, said Luisi. Ten commercial entities have permits to catch a total of 170,653 horseshoe crabs annually for bait and one company has a scientific permit to collect up to 150,000 horseshoe crabs for biomedical applications.

"With the reductions we're making we're seeing the continual growth of horseshoe crabs and the juvenile and adult level," said Luisi. "All signs look good for the horseshoe crab and our management of the species."

Back on the Delaware Beach, surrounded by boxes of shorebirds and busy team members, Larry Niles, leader of the 14-year-old Shorebird Project and lead biologist with the Conserve Wildlife Foundation of New Jersey, disagreed.

The former chief of New Jersey's endangered species program noted that while horseshoe crab harvests are down from the frenzy of the late 1990s, the harvests are still considerably higher than the early 1980s. In fact, Maryland's current commercial and biomedical quota of 320,653 crabs exceeds the entire East Coast harvest in any year from 1980-88.

"The overharvest of crabs caused the Delaware Bay collapse," said Niles as he held a skinny red knot that just arrived on the beach. "If anything else happens to these birds — red tide, tropical storms, loss of habitat — the population doesn't have the elasticity to come back. Close the harvest of the crabs and give these birds a chance."

candy.thomson@baltsun.com

Copyright © 2014, The Baltimore Sun
Related Content
Comments
Loading