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'Tow-time logger' may become a better way to protect rare turtles

UNITED States fishery managers trying to protect rare sea turtles from dying in fishing nets in Bourne, Massachusetts, have tapped a Cape Cod company to build a device they think can help balance turtle protection with profitable fishing.

The "tow-time logger" is a 18-centimeter, silver cylinder that attaches to fishing nets and records how long the net stays underwater.

That time is crucial if a turtle gets snared in the nets dragged behind fishing trawlers. Federal research indicates the vast majority of sea turtles survive entanglement -- but only if the net is pulled up in less than 50 minutes.

With the logger, regulators can avoid other, potentially more onerous, restrictions on perpetually struggling fishermen -- such as shutting down fishing areas or requiring turtle-saving gear that doesn't work well in all nets. In fisheries where they decide time limits would work best, they wouldn't have to depend on an honor system to enforce time limits meant to protect the struggling turtle.

"Turtles have also been around since the time of the dinosaurs," said Elizabeth Griffin of the environmental group, Oceana. "They're cool animals that I think most people want to see continue to exist."

The logger was built under a US$25,000 federal contract with the National Oceanic and Atmospheric Administration (NOAA) by Onset Computer Corp, a Bourne-based supplier of data loggers for energy and environmental monitoring.

Successful tests

It starts recording water depth every 30 seconds once the net drops below 2 meters. If the net stays under beyond a preset time limit, the logger records it, and the infraction can be discovered when regulators download its data.

The device's early tests at sea have been successful, and work is ongoing to toughen it for the real-life rigors, such as being banged on fishing boat decks.

The company expects it to cost between US$600 and US$800, an expense that would fall to fishermen.

Even when the logger is perfected, regulators know limiting how long the nets stay underwater is no cure-all as they devise rules, which they hope to complete by 2010, to meet a new federal law to protect sea turtles from trawler fishing nets.

Some environmentalists say turtles shouldn't be kept underwater at all because even relatively short times of being trapped without oxygen hurt them.

Fishermen are skeptical. They say short tows aren't practical in most fisheries, such as those in deeper waters, where a worthwhile catch is impossible if the nets must constantly be pulled up.

"Nobody's going to love the idea," acknowledged Henry Milliken, a biologist with the National Marine Fisheries Service, which is part of NOAA.

But he said fishermen might prefer limits on how long a net can be underwater to alternatives, such as closing fishing areas.


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