Bird-tracking study reveals some migration paths cross areas slated for offshore wind farms

If wind farms are built off of Maryland's coast, turbines will be spinning in areas where many seabirds cross — but few linger — during annual migrations, according to a bird-tracking study.

Researchers spent the past five years tagging more than 400 birds with tiny transmitters and watching their movements. The exercise has produced the most detailed picture to date of the territories crossed by three common species of seabirds.

“We were able to get a much better sense of where these birds are,” said Caleb Spiegel, a wildlife biologist for the U.S. Fish and Wildlife Service.

The maps the researchers created will inform decisions on whether and where to permit construction of wind turbines from North Carolina to New York.

Two companies are vying to build more than six dozen wind turbines at least 17 miles off the coast of Ocean City, Md., though the projects are not certain. They cleared a major hurdle when state energy regulators approved ratepayer subsidies for them in May, but officials in Ocean City and U.S. Rep. Andy Harris are fighting to limit the turbines’ visibility from beaches.

The federal Bureau of Ocean Energy Management, the agency that oversees any offshore wind development, funded the bird study. A spokesman for the agency said the research “will be used to avoid and minimize the impact of future offshore wind energy development.”

In the past, biologists’ best guesses for seabird migration patterns and wintering habits have come from surveys. Researchers would physically count birds they could spot or identify from a boat or an airplane, Spiegel said. But that work had its limitations — darkness and bad weather, specifically.

To instead track the birds’ patterns using $1,800 satellite transmitters, researchers from the U.S. Geological Survey’s Biodiversity Research Institute and the U.S. Fish and Wildlife took many overnight boat trips stalking the birds. They captured them and either surgically implanted the tracking devices or attached them like backpacks. Three species were targeted: Red-throated loons, surf scoters and Northern gannets.

The researchers found that all three species were more likely to enter areas the government has established for offshore wind development during migration than during the winter.

The gannets, in particular, trafficked the wind development areas most extensively while heading to or from breeding grounds in eastern Canada or wintering spots as far south as the Gulf of Mexico. But the wind farm zones made up a relatively small portion of the areas that gannets frequently travel, the researchers said.

Researchers were surprised to learn that when seabirds spent their winters in the mid-Atlantic, they mostly clustered in the Chesapeake and Delaware bays and ventured off the coast less often, Spiegel said.

David Bigger, an environmental protection specialist in the federal bureau’s office of renewable energy programs, said the new data helps fill in gaps in understanding how widely the birds travel. Wildlife impact has been a key concern as the country explores turning coastal winds into a source of domestic, renewable energy.

There is currently only one wind farm off the U.S. coast, near Block Island, R.I. But other projects are being planned, including the two off Maryland’s coast.

Skipjack Offshore Wind LLC, a subsidiary of the developer behind the Block Island project, is planning to build 15 turbines off the coast by 2022. U.S. Wind, a subsidiary of Italian company Toto Holdings SpA, plans to build 62 turbines by 2020.

U.S. Wind officials could not be reached for comment. Skipjack CEO Jeffrey Grybowski said the research provides “useful new data” as the company’s project prepares for “extensive environmental review” that will consider wildlife and other impacts.

“Much global experience demonstrates that a properly sited wind project can be a significant benefit to the environment,” Grybowski said.

The Maryland Public Service Commission in May approved ratepayer subsidies for the projects that would add $1 a month to the average residential electricity bill. The subsidies are allowed under a state program designed to encourage renewable energy development. The offshore wind developers said they considered the ratepayer money key in making the projects financially viable.

But as the wind farm proposals move forward, bird safety is not the only concern. Ocean City officials have hired top Annapolis lobbyist Bruce Bereano to help them lobby the federal government to keep wind turbines as far from shore as possible. Many in the resort town fear they will be eyesores that discourage tourism.

Ocean City officials hope to exert pressure when the time comes for federal regulators to consider permit applications for the wind farms. Harris amended an appropriations bill in July that would prevent the projects from being evaluated unless they are at least 24 miles from shore, several miles farther than proposed for the U.S. Wind project.