Patuxent Wildlife Refuge scientists study how wind farms affect sea ducks

Patuxent Wildlife Research Center scientist Sara Therrien conducts research on a captive colony of sea ducks held in diving tanks.

Close to 1 million waterfowl spend their winters in the Chesapeake Bay, providing recreational hunting and bird watching for locals and visitors.

But the call for construction of wind farms of more than 100 turbines about 10 miles offshore presented a question scientists could not answer: Will the turbines affect the birds?


With funding from theU.S. Department of the Interior's Bureau of Ocean Energy Management, or BOEM, scientists at Patuxent Wildlife Refuge Center are pioneering studies to understand the lifestyle of East Coast sea ducks to try to answer this question.

"We are spending millions of dollars to figure out where the birds are on the Atlantic coast … so that, to the best of our ability, we can locate wind farms where the fewest birds are," said Jim Woehr, who has been an avian biologist for more than 30 years and is a member of BOEM's Division of Environmental Assessment.


"No one's ever looked at this before," said Alicia Berlin, a scientist at the Patuxent Wildlife Research Center who has been with the Atlantic Seaduck Project since 2009. "It's groundbreaking research."

The seaduck study began as BOEM and U.S. Fish and Wildlife Service officials starting discussing Cape Wind, the first planned offshore U.S. wind farm, Woehr said.

He said planners were concerned about disrupting the "interstate skyway" birds travel during migration from the mid-Atlantic states to their summer breeding grounds in Canada.

"It became obvious that the concerns weren't just with Cape Wind, but up and down the (Atlantic) seashore," he said.

BOEM is now funding a multi-year study conducted by the Fish and Wildlife Service, in partnership with theU.S. Geological Survey, Sea Duck Joint Venture, Biodiversity Research Institute and Memorial University of Newfoundland, to map out the birds' migration paths and uncover their behaviors.

The information will factor into BOEM's decision about where wind can be built, Woehr said.

Collecting baseline data before the construction of wind farms provides a "unique opportunity" to see how the turbines will affect the birds, said Sara Therrien, a doctoral candidate in neuroscience and cognitive science who is a part of the seaduck project.

"We don't know much about their lives," Therrien said.


Captured seaduck colony

Berlin's team of scientists has been on the Chesapeake Bay at night, collecting ducks with nets and high-powered flashlights. Veterinarians at Patuxent implant captured ducks with transmitters that send back information on the birds' movement, Berlin said.

Research is already showing behaviors unique to East Coast flocks, like the division of long-tail ducks into two unique migration routes, one crossing the Great Lakes and the other flying through Nantucket on their way to Canada, Berlin said.

Most information on sea ducks was gathered on the West Coast before this study, she said. Other researchers are examining what the birds eat, their hearing and ways to improve the tracking devices.

Therrien has spent the last three years working with Patuxent's captive seaduck colony to understand how the birds respond to sound. No one has studied birds' ability to hear underwater, where sound travels about four times faster than in air, she said.

Therrien raised and trained a group of lesser scaup ducks to respond to sound by tapping on a sensor that releases mealworms — what she calls "duck candy."


Two 2,000-gallon tanks allow her to test their hearing up to 7 feet deep, though they can dive 60-plus feet in the wild, Therrien said.

"If I find that the birds are very sensitive to noise underwater… the wind turbines' construction probably would have an affect on them," she said.

Other research on Patuxent's ducks works to improve the transmitters used to send data from tagged ducks to the lab. Scientists have to balance battery size, which determines the life span of the transmitter, with creating transmitters that are small enough for the ducks to fly and dive, Berlin said.

A new type of solar-powered "backpack" transmitter may be tested this summer, allowing for a longer battery life and more data from each tagged bird, she said.

Four years of data

The seaduck project will amass about four years of data on the birds' migration patterns, Woehr said. He does not expect that scientists will find that the birds fly far enough off shore to be impacted by wind farms, but will not know until results are compiled.


Though the number of ducks on the eastern seaboard is unknown, their populations have declined, Berlin and Therrien said.

If wind farms are built in their migration route, it could increase stressors the ducks face.

"If they have to fly around one farm, that's not a big deal," Therrien said. "But say there's wind farms up and down the coast. … It could be another factor that will add to the physiological stress of the birds" and increase mortality.

To learn more about the Atlantic Seaduck Project, go to