Long Island Sound

Long Island Sound, arm of the Atlantic Ocean, c.90 mi (145 km) long and 3-20 mi (5-32 km) wide, separating Long Island, N.Y., from the SE New York mainland and Connecticut. On the W the East River joins it with New York Bay. The sound is fed from the north by the Housatonic, Connecticut, and Thames rivers. The Long Island Sound is a popular leisure-boating center. New Haven, New London, and Bridgeport, Conn., are the largest port cities; many residential communities line the sound. Federal and state environmental studies in the mid-1990s identified serious problems in the sound and recommended a massive cleanup.