Final Report An Assessment of Sea Scallop Abundance and Distribution in the Nantucket Lightship Closed Area

For the sea scallop, Placopecten magellanicus, the concepts of space and time have emerged as the basis of an effective management tool. The strategy of rotational area management has aided in the sustainability of the resource. Since 2003 with the adoption of Amendment 10 to the Fishery Management Plan (FMP), rotational area management has provided a mechanism to protect juvenile scallops from fishing mortality by closing areas based on scallop abundance and observed length distributions. Approximately half of the sea scallop industry’s current annual landings are attributed to areas under this rotational harvest strategy. While this represents a management success, it also highlights the extent to which landings and management are dependent on the effective implementation of this strategy. The continued prosperity of scallop spatial management is dependent on both periodic and large incoming year classes, as well as a mechanism to delineate the scale of a recruitment event and subsequently monitor the growth and abundance of these scallops over time. Current and accurate information related to the abundance and distribution of adult and juvenile scallops is essential for managers to respond to changes in resource subunits, especially as the resource is being managed at finer-spatial scales. Acknowledging the importance of accurate, timely, and meaningful information necessary to meet the management needs, the Virginia Institute of Marine Science (VIMS) conducted a stratified random survey of the Nantucket Lightship (NL) and the South Channel (SC) in the summer of 2020 and the NL in 2021. The primary objective of these surveys was to assess the abundance and distribution of sea scallops in these areas, culminating with spatially explicit annual estimates of total and exploitable biomass by Scallop Area Management Simulator (SAMS) Area. Secondary project objectives for each year included: 1. Finfish bycatch species composition and catch rates, 2. Scallop biological sampling (length:weight relationship, disease, product quality, and shell samples for ageing), and 3. Sea scallop dredge performance (commercial and survey dredges)