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Alternative bait aims to protect horseshoe crab population

A new product may reduce harvesting of horseshoe crabs from the Delaware Bay for use as bait by commercial fisherman.

Horseshoe crabs, which are actually more closely related to spiders, are used to catch eel and whelk, a culinary staple in Asia and used domestically in chowders and fritters.

Officials announce new horseshoe crab-based bait alternative.

Officials announce new horseshoe crab-based bait alternative.

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The bait alternative is the result of work by Dr. Nancy Targett, dean of the University of Delaware's College of Earth, Ocean and Environment, who's been working for years to determine why horseshoe crabs are effective as bait for eel and whelk.

Her research led to the bait alternative: a mixture of crushed horseshoe crabs and a geletin-like substance made from alginates - compounds found in brown seaweeds and kelp - that allows the bait to be cut into cake-like pieces and placed into traps called "pots".

It took some time. Trying to isolate the attractor proved too difficult, so research efforts were refocused on making the most of smaller amounts of horseshoe crab tissue.

"We know the [horseshoe crab] tissue has the [baiting] activity," said Dr. Targett, "and maybe there were ways we could preserve that activity but use much less tissue, so that we can take some of the pressure off of the horseshoe crabs."

"It was a different outcome than we expected, but it was still a successful one in that we were able to reduce the amount of horseshoe crab tissue. It's now 1/24th of what it originally took."

Strict quotas were established in the 1990's after crab populations dropped considerably due to over-harvesting and diminishing coastlines.

The large horseshoe crab population hosted by Delaware's estuaries is critical to shorebirds who feast on the eggs during their migrations. They also provide food the loggerhead sea turtle and numerous species of sharks.

"The horseshoe crab is the lynchpin of the ecosystem," says DNREC secretary Colin O'Mara. "Anything we can do to reduce their demand by having a synthetic alternative that requires a lot less horseshoe crab is good for the harvest, good for the nesting, good for the birds and good for the whole ecosystem."

The research that created the alternative bait was funded by Delaware Sea Grant, DENREC and DuPont Chemicals and Flouroproducts.

"This is a great example of the way corporations, universities and governments can collaborate to promote sustainable solutions," said senior vice president of operations at DuPont, Gary Spitzer.

Even though her initial research was aimed at identifying the "silver bullet" chemical that makes the horseshoe crab so successful as bait, Dr. Targett is satisfied with the end result.

"I'm satisfied that we got to an outcome that is a positive outcome, that gets to a product that really can be used by the fisherman, and used in a positive way," said Targett.