Ocean power projects raise concern about salmon

Posted: Tuesday, December 28, 2010

TACOMA, Wash. - The quest for green energy is increasingly focused on ocean power such as tidal and wave generators. But some scientists are raising concerns about whether those projects could interfere with salmon and other species with sensitive internal compasses.

Pacific Northwest National Laboratory oceanographer Andrea Copping tells The News Tribune of Tacoma that scientists believe salmon, like sharks and sea turtles, might sense the Earth's magnetic fields as they navigate back to their natal streams.

Some scientists worry that the power-generating devices and the cables that bring their electricity to shore can create electromagnetic fields that could interfere with the salmon. Copping's lab in Sequim on the Olympic Peninsula is studying the reactions of salmon, dungeness crab, halibut and American lobsters when copper wiring near their tanks is energized.

"Before we put these power-generating devices in the water, we need to know how they will affect the marine environment," Copping said.

Even so, several projects are under way in the Northwest. The Snohomish Public Utility District has received a $10 million grant from the federal Department of Energy to install two tidal turbines in Admiralty Inlet west of Whidbey Island in Puget Sound. The Navy has also explored the possibility of placing generators in the Sound, though Copping said that project is on hold.

A company has a license to move forward with a commercial-scale wave project off the Oregon coast, Copping added.

Wave generators off the coasts of Washington, Oregon and Northern California could eventually produce 50,000 megawatts of electricity, or roughly the output of 50 nuclear power plants, the Northwest Power Planning Council has estimated.

In the Sequim lab, aquarium tanks filled with marine species are placed near two large coils, each containing about 200 pounds of copper wiring. Electricity is fed into the coils and an electromagnetic field is created with a magnetic flux equal to the power of a small bar magnet. Scientists study the reaction of the marine animals when the coil is energized.

Copping said preliminary results from her lab's experiments should be available in the coming weeks.

Stephen Kajiura, an associate professor at Florida Atlantic University, has studied how underwater electric cables can affect a shark's behavior. The cables can create electromagnetic fields.

He said sharks will bite the cables, thinking they are prey. "The cables may very well produce magnetic fields that could disrupt behavior," Kajiura said.

Both he and Copping said it's important to have scientific guidance on the subject.

"It's coming so fast, regulators are asking questions we don't have answers to," Kajiura said. "It would be nice to have some baseline research before we move ahead."

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