Ted Ames, a Stonington-based fisherman and scientist, has won “genius” grant from the John D. and Catherine T. MacArthur Foundation in recognition of his innovative fisheries research in the Gulf of Maine. The $500,000 award has no strings attached. Ames said he hoped it would allow him to complete several research projects he has in mind.

Ames is one of 25 winners of MacArthur Fellowships for 2005.

“His studies,” stated the MacArthur Foundation in announcing the grant, “draw distinctively from the anecdotal experiences of aging fishermen to map historical patterns and chart the evolution of current conditions. His work paints a scientifically compelling picture of the complexity of the fish population structure in the Gulf and identifies new strategies for individual and institutional marine management in the region.”

Ames, 66, is a former staff member of the Island Institute, which published his “Cod and Haddock Spawning Grounds in the Gulf of Maine” in 1997. The booklet described Ames’s two-year effort to gather information from older fishermen about “ripe and running” cod that once spawned in the inshore waters of Maine and Massachusetts.

In a somewhat unusual departure from ordinary scientific publishing, the 1997 booklet included a powerful narrative, also by Ames, describing a “run” of giant cod encountered by a Jonesport fisherman, Roger Beal, Sr., on April 7, 1942. “I’d heard the story before,” Ames wrote, “but had always taken it with a grain of salt.” But in the course of his interviews for the spawning grounds project, he encountered Beal, who “finally put the issue to rest. The Machias Bay spawning run of giant cod had actually happened.” Ames’s account appeared first in Island Journal, and was then incorporated in the 1997 booklet, which also featured maps and statistics on historic inshore cod spawning areas.

“Ted Ames is a home-grown genius who has developed a whole new methodology for understanding the ecology of groundfish,” said Philip Conkling, president of the Island Institute. In 2004, following Ames’s nomination for the MacArthur grant, Conkling was asked to write an evaluation of Ames’s contributions to marine ecology.