Populations of the bald eagle continued to make a comeback across the Bay watershed last year, as biologists counted 760 nests occupied by the once-endangered bird.

The figures, released by the Bay Program, showed a tenfold increase from the record low of 74 nests counted in 1977, when the population hit its all-time low.

Last year, 396 nesting pairs were counted in Virginia’s portion of the watershed, 338 pairs in Maryland’s portion, 25 in Pennsylvania, and one in the District of Columbia.

Historically, scientists believe more than 3,000 pairs once inhabited the Bay watershed, but populations dropped over the centuries, the result of water pollution—fish are a favored food—and loss of habitat near waterways.

But the primary cause of the decline was the widespread use of the pesticide DDT, which caused the shells of eggs to become too thin to withstand incubation.

The banning of DDT in 1972, along with curbs on water pollution, habitat restoration and programs that released eagles into the wild, are credited with helping with the population’s recovery.

The Bay region is considered to be home to some of the most productive nesting grounds in the nation. Bald eagles prefer to nest in mature trees adjacent to open water, where they can survey feeding and hunting opportunities over a large area.

Bay Program goals to restore forest buffers along streams and shorelines, preserve open spaces and reduce water pollution will help to preserve habitat and ensure the long-term health of the species.

“Restoration of vital habitat and improvements in water quality will provide bald eagles the greatest opportunity to thrive throughout the the Bay watershed,” said Rebecca Hanmer, director of the EPA’s Bay Program Office. “The strong rebound of the bald eagle is both an encouraging sign and a real impetus for all of us to redouble our efforts to restore the Chesapeake Bay.”

In 2002, 687 occupied bald eagle nests were counted.

Data for the Baywide survey was collected by the U.S. Fish and Wildlife Service, the Maryland Department of Natural Resources, the Pennsylvania Game Commission, and the Center for Conservation Biology at the College of William & Mary for the Virginia Department of Game and Inland Fisheries.