High Densities of Juvenile Sea Scallop (Placopecten magellanicus) on Banks and Ledges in the Central Gulf of Maine

Abstract

A video survey was conducted from August 10–14, 2009, to estimate sea scallop density, abundance, and size distribution on Platts Bank, Fippennies Ledge, Jeffreys Bank, Jeffreys Ledge, and Cashes Ledge in the central Gulf of Maine. Of the 298 km2 surveyed, 134 km2 (45%) had scallops present. Scallop density was estimated using only stations containing at least 1 scallop. High densities of small scallops occurred on all but Jeffreys Bank, where no scallops were observed. Densities ranged from 1.56 scallops/m2 on Jeffreys Ledge to 4.70 scallops/m2 on Platts Bank, equaling an estimated abundance of 470 million scallops. Less than 1% of scallops were larger than 100 mm. Explanations for the lack of large individuals may include sporadic recruitment, high natural mortality from predation, or environmental influences. If these scallops were to survive to harvestable size (approximately 102 mm), they could provide an important commercial resource worth approximately USS124 million.