If wind farms are built off 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, 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 Service 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.