Abandoned Crab Pots Threaten Diamondback Terrapins (Herpdigest)

Abandoned Crab Pots Threaten Diamondback Terrapins
Starnewslonline, Wilmington, NC

By Gareth McGrath
Gareth.McGrath@StarNewsOnline.com
May 11, 2010
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Andy Wood shook his head as he looked inside the half-submerged crab pot, its crumpled sides, slashed buoy line and barnacle-coated webbing reflecting its age and abandoned status.

"This is just want we don't want to find," said the educator director for Audubon North Carolina as he hauled the cage-like wire trap out of the shallow water and onto the bow of the researchers' small skiff. "We've got at least three dead terrapins in here."
Actually there had been four - along with four mature and still living blue crabs - Woods found after examining the shell fragments that had fallen to the bottom of the mud-splattered pot.

The discovery underscored a worrisome trend for one of North Carolina's most distinctive coastal residents, the diamondback terrapin.

Considered a gourmet treat a century ago, the terrapins were rapidly depleted in much of their range along the country's East and Gulf coasts.

But the smallish turtle, which is unique in being the only turtle species in North America that lives in brackish waters, is now threatened by man's attraction to another coastal delicacy, the blue crab.

Diamondback terrapins are identified as a "species of special concern" in North Carolina, which means populations are declining at a rate that may require conservation efforts in the future.

Data from neighboring states along with some research taking place in Southeastern North Carolina show that a few "ghost pots" coupled with the terrapin's propensity to stay close to home can be a deadly combination.

"There's compelling data in other states, including South Carolina, that crab pots are a significant problem," said Amanda Southwood, a biologist at the University of North Carolina Wilmington.

Fishermen have always found "bycatch" in their crab pots. But the problem today, Woods said, is that vinyl coatings used on the pots slow their breakdown and allow them to keep catching and killing critters for years after they're lost or abandoned.
An estimated 15 percent of the more than 1 million pots soaking in state waters every year are lost.

Working toward a solution that balances the needs of the turtles with those of the fishermen, a trio of Audubon researchers found themselves scouting the shallow waters of the Intracoastal Waterway just south of the Surf City swing bridge for derelict pots on a sunny, but blustery, Monday morning.

One option could be to require crab pots to have turtle-excluder devices, basically a small plastic rectangle with an opening too small for mature terrapins to get through while still allowing crabs access.

Another idea, borrowed from other coastal states, could be to declare any pots not removed after the crabbing season to be litter and allowed to be removed.
Southwood said research into the life cycle of the terrapins also shows that they don't venture too far from shore, possibly making a requirement that pots not be placed in shallow waters in known turtle "pockets" a simple solution for everyone involved.

But you can't approach regulators or legislators asking for a change without data showing the extent of the problem, and hunting for lost pots isn't as easy as it might sound.

To help with the search, the Audubon team uses side-scan sonar to map the bottom of the waterway.

But recognizing a pot's echo among the blips and other shadows on the screen and then actually recovering it from deep water are two different things.
"We've spent 40 minutes trying to get a pot," Wood said. "It's right there, and we still couldn't find it."

The team is also very careful to avoid interfering with active pots.

"We don't touch a pot with a buoy," Wood said, eager to calm any fears commercial crabbers might have.

But, he added, derelict pots are a significant threat to fishermen since they catch crabs that could go into active pots or at least help support the local population.

"We just want to get these derelict pots out of the water," Woods said. "That's all."

Using a small grant from the National Oceanic and Atmospheric Administration, the Audubon team is in its second field season surveying the waterway and back channels between Topsail Island and up and around the Cape Fear River. Other researchers are scouting other areas of the state's coastline.

The findings have been stark and eye-opening.

"In some areas we've found five derelict pots for every one active one," Wood said.
And turtles?

"We had one behind Masonboro Island that had 28 turtles in it, all dead," Wood said.

He added that no one was interested in putting a dent in the state's most lucrative fishery.

"But we know we can do better," Wood said as he waded out to recover yet another wayward pot marooned in the muck, its crumpled and weathered upper half visible at low tide.