Increasing interest in offshore wind development, driven in large part by rising energy demands and concerns about climate change, necessitates research on potentially affected natural resources that will provide data that informs the permitting and siting process. Federally-designated wind energy areas (WEAs) in the mid-Atlantic region overlap with the ranges of many marine bird species, including the Northern Gannet (Morus bassanus).
The Northern Gannet is the largest breeding seabird in the North Atlantic Ocean, distributed along the continental shelf waters on both sides of the Atlantic. Northern Gannets are opportunistic and effective predators, foraging on small to mid-sized surface-schooling fishes in dramatic plunging dives from the air, as well as diving directly from the surface of the ocean.
Lead Investigator: Iain Stenhouse
On migration, Northern Gannets move widely down the east coast of Canada and the U.S. to winter in the shelf waters of the mid-Atlantic region, the South Atlantic Bight, and the northern Gulf of Mexico. A very small proportion of the birds that breed in Newfoundland are known to cross the Atlantic to winter off of West Africa. Like many seabirds, Northern Gannets display a low rate of reproduction and delayed maturation, initiating breeding at around 5 years of age and laying only one egg per year. They are long-lived, with some birds known to have survived at least 20 years, making them vulnerable to increases in adult mortality. This species is also considered to be vulnerable to offshore wind development in European waters, due to their relatively poor maneuverability and their habit of flying and plunge-diving from heights within the rotor-swept zone of wind turbines.
In order to assess the population impacts of offshore wind development on Northern Gannets, basic information must be collected on their distribution and behavior, including flight pathways and timing of habitat use, within the WEAs. BRI is working with multiple collaborators to accomplish these goals and meet the following objectives: (1) determine if Northern Gannets could be captured during the winter, non-breeding season, (2) tag individuals with satellite tracking devices, (3) define the timing of their annual migrations to and through the study area, and (4) track the fine-scale winter movements of Northern Gannets in the mid-Atlantic region.
In this study, Northern Gannets were successfully captured for the first time in winter using night-lighting techniques. These efforts, conducted in 2012, 2013, and 2014, resulted in the deployment of 46 satellite tags.
In general, winter-caught Northern Gannets demonstrated regional-scale movements along the Atlantic coast during winter, and around mid-April began a more consistent migration northward toward their breeding colonies in eastern Canada. During the return fall migration, Northern Gannets moved from shelf to coastal waters, as they travelled to the mid-Atlantic region, or passed through it on their way to the South Atlantic Bight or Gulf of Mexico. The use of coastal waters appears to be more pronounced among females.
The mid-Atlantic region and the Gulf of Mexico were hotspots for Northern Gannet activity during winter. The Bureau of Ocean Energy Management has provided additional funding for a fourth field season in 2015, extending what was initially a 3-year study. This additional year of tracking will serve to strengthen the study by increasing the overall sample size.
Iain Stenhouse, Ph.D., Senior Science Director, Marine Program Director
Field Crew Leader
Carl Anderson, Associate Wildlife Biologist
Contributing BRI Staff
Andrew Gilbert, Data Management Director
Wing Goodale, Deputy Director, Center for Ecology and Conservation Research Director
Carrie Gray, Wildlife Research Biologist
Lucas Savoy, Waterfowl Program Director
Kate Williams, Wildlife and Renewable Energy Program Director
Our research partners include:
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