PORTLAND, Maine — Valuable species of shellfish have become harder to find on the East Coast because of degraded habitat caused by a warming environment, according to a pair of scientists that sought to find out whether environmental factors or overfishing was the source of the decline.
The scientists reached the conclusion in studying the decline in the harvest of four commercially important species of shellfish in coastal areas from Maine to North Carolina — eastern oysters, northern quahogs, softshell clams and northern bay scallops. They reported that their findings came down squarely on the side of a warming ocean environment and a changing climate, and not excessive harvest by fishermen.