Abstract
The Georges Bank yellowtail flounder (Limanda ferruginea) fishery was once vibrant in the 1960s and 1970s with annual landings reaching 15,000 MT but has since collapsed to only 6 MT landed in 2020. Despite reductions in the total allowable catch for two decades, biomass estimates from federal fisheries independent trawl surveys are at historical lows, suggesting biotic and abiotic factors are influencing abundance. The stock has become concentrated in Closed Area II Access Area, an area closed in 1994 to protect groundfish but is rotationally opened to the Atlantic sea scallop fishery, resulting in bycatch of yellowtail flounder. Working collaboratively with fishermen, we conducted a seasonal video trawl survey from 2013 to 2021 to estimate yellowtail flounder population size and condition factor within the Access Area. Yellowtail flounder and the physical and biological variability of its environment in Closed Area II Access Area were characterized using our video trawl survey data, drop camera scallop survey data and finite-volume coastal ocean model (FVCOM) temperature data. This yellowtail flounder aggregation declined over the video trawl time series, while the Access Area has experienced changes in substrate composition, fluctuating seasonal temperatures, and strong increases in skate and dogfish density across the time series. These variable physical and biological processes are expected to affect yellowtail recruitment success and the rebuilding capacity of this stock, in turn affecting how we manage bycatch of yellowtail flounder in the sea scallop fishery.