Sandy Damage Threatens Horseshoe Crabs and Migratory Shorebirds

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Trucks haul about 42-thousand cubic yards of sand onto the beaches on the Delaware Bay where horseshoe crabs come to lay their egg.

The numbers of horseshoe crabs laying eggs this spring in New Jersey could be lower than normal, after Sandy destroyed more than 70-percent of the crab’s nesting grounds along the Delaware Bay.

The storm dispersed what horseshoe crabs need most to lay eggs – sand.

“Sandy was so violent that it pushed sand well in, or out to sea,” said independent biologist Larry Niles, working with the American Littoral Society.

Without abundant levels of horseshoe crab eggs, migratory birds that eat the eggs during spring stopovers to Arctic breeding grounds will suffer.  Especially the threatened Red Knot.

The shorebird has a reddish breast and head.  It stops along the Bay side of the Jersey Coast on its way from South America to fatten up before making another marathon flight north.  On the Delaware Bay, the birds can gain between 8 and 15 grams of fat a day.

“The eggs, they’re so soft, it’s like putting cheesecake on your hips.  Metabolically, [the eggs] can be eaten and right away goes to fat,” said Amanda Dey, principal zoologist with the New Jersey Department of Environmental Protection.

Dey is married to Niles. The couple are leading a $1 million effort to restore Delaware Bay beaches before the horseshoe crabs arrive in May, and the Red Knots soon after.

The project is being funded with a grant from the National Fish and Wildlife Foundation, the New Jersey Recovery Fund, the New Jersey Natural Lands Trust and the New Jersey Corporate Wetlands Partnership.

The numbers of Red Knots stopping on the Delaware Bay have dropped from about 95,000 in 1989 to just over 12,000 in 2007, according to the American Bird Conservancy.

The decline began in earnest around the same time that the fishing industry started hunting horseshoe crabs for bait, and the pharmaceutical industry started using crabs for their lysate rich blood, conservationists say.

“Horseshoe crabs were an unregulated fishery, so the harvest went from 100,000 to 2.5 million in just a few years, and almost immediately the number of eggs started to decline dramatically,” said Niles.

The Atlantic States Marine Fisheries Commission mediates between all these competing interests – the birds, the biomedical and the fishing industries, and sets quotas for horseshoe crab catches. 

The commission allowed New Jersey to harvest 162,136 horseshoe crabs this year.

But the state has instituted a moratorium on killing horseshoe crabs for bait.  The 15 states that are part of the Commission can be more conservative than the Commission’s plan for horseshoe crab harvests, but cannot be more lenient.

Officials representing the fishing industry would like to see that moratorium lifted.

“The Delaware Bay has seen some very good signs of abundance.  It was assessed in 2012 and the region had an increasing trend of juveniles and adult males,” said Greg DiDomenico, Executive Director of the Garden State Seafood Association, a trade group.

But biologists dispute the recovery.  Some studies show the female horseshoe crabs failing to recover.

“Somebody is killing a lot of [horseshoe] crabs and they’re not owning up to it.  Because recovery is not happening,” said Larry Niles, the independent biologist.

There is no limit on the numbers of crabs that can be taken by the biomedical industry. Companies pluck the crabs off the beach,  drain of a portion of their blood, and then put them back into the ocean.  Between 5 and 30 percent of the crabs die in the bloodletting process, according to a 2012 review prepared by the Atlantic States Marine Fisheries Commission’s Horseshoe Crab Plan Review Team.

The horseshoe crab is even being taken from a reserve meant to protect it, where horseshoe crab harvests have been closed since 2001.

The National Marine Fisheries Service (NMFS), and National Oceanic and Atmospheric Administration (NOAA) allow Limuli Laboratories to harvest up to 10,000 horseshoe crabs from the Carl N. Shuster Jr. Horseshoe Crab Reserve for biomedical purposes. A small portion of the crabs, at least 15-percent, are required to be tagged for research.

It’s unclear why the federal reserve allows a harvest of an animal that it’s supposed to protect.

“It’s a valid question,” said Fionna Matheson, with NOAA.  “Part of it is they get (useful) data from the labs.” 


Photos and video by Amy Pearl