Mortality Assessment of Atlantic Sea Scallops (Placopecten magellanicus) from Gray-Meat Disease

Abstract

ABSTRACT The sea scallop Placopecten magellanicus (Gmelin, 1791) fishery is the most valuable wild scallop fishery in the world. Landings are primarily adductor muscles, which are ideally creamy white and firm. Recently, an increasing number of dark brown to gray, flaccid, and stringy meats have been caught in areas of Georges Bank and the mid-Atlantic, causing concern in industry and management. The mortality of gray-meat scallops was investigated, and an anesthetization procedure was developed allowing assessment of meat color in live scallops for laboratory experiments. The mortality rate of gray-meat scallops compared with white-meat scallops was tested. Gray-meat infection was swift and fatal; 26 of the original 28 gray-meat scallops died, whereas only 1 of 28 white-meat scallops died. The gray-meat condition was clearly associated with apicomplexan parasite infection intensity. Gray-meat scallops were identified visually, with image analysis computer software, and cell counts of apicomplexan nuclei....