Before dawn, Jerry Leeman churned through inky black waters, clutching the wheel of the fishing vessel Harmony. The 85-foot trawler, deep green and speckled with rust, was returning from a grueling fishing trip deep into the Atlantic swells. Leeman and his crew of four had worked 10 consecutive days, 20 hours a day, to haul in more than 50,000 pounds of fish: pollock, haddock and ocean perch, a trio known as groundfish in the industry and as whitefish in the freezer aisle.