Convergence of a Disease and Litigation Leading to Increased Scallop Discard Mortality and Economic Loss in the Georges Bank Fishery

Abstract

Rotational management in the Atlantic sea scallopPlacopecten magellanicus fishery has focused on closing areas to fishing when a high proportion of small scallops is observed in a discrete area, but less attention has been paid to reopening closed areas to prevent poor meat quality. In this fishery there are several large marine protected areas, including Closed Area I of Georges Bank. Intense drop camera surveys of Closed Area I in 1999 led to incorporating a 700-km 2 area into the rotational management scheme. There was a larger abundance of scallops to the south of this area, and these were made available for harvest in 2005, but this fishery was closed in 2006 when the management plan was overturned by a federal court decision. When the area was reopened again in 2011, however, the expected harvest was not achieved. Although fishermen harvested the scallops and opened the shells to extract the meat, they found that many of the meats were gray and not of marketable quality and so they discarded them. The gray meats were linked to a highly pathogenic apicomplexan infection. There was a 52% decline in exploitable biomass between 2011 and 2013 (7,300 metric tons, representing a gross revenue of US$170 million) that could not be attributed to a reduction in landings, resulting in a failure to complete the allotted trips. The scallop rotation management plan has been extremely successful overall, with 69 of the access area trips harvesting over 80% of the allocation; however, increased monitoring of meat quality would further improve management.