The giant weathervane scallops (Patinopecten caurinus) are found only in the northeastern Pacific Ocean where they are the targets of a small fleet of commercial trawlers that fish from Yakutat to the eastern Aleutians. Many of these fishermen are descendants of the members of the original fleet, which came to the Pacific from traditional Atlantic scallop grounds off New England in the early 1960s, some of whom were the founders of the modern king crab pot fishery. Scallops are bivalves, like clams and oysters, with paired shells joined by a muscular hinge, and they are the only bivalves capable of actively evading predators by ejecting water from their shells and fleeing twenty feet or more. They are found in large beds on gravel, rock, and sand bottoms at depths from 120 to 600 feet. Weathervanes are the largest scallops, growing to shell diameters of eight inches and more.