Spatial and Temporal Variability in Sex-At-Length of Summer Flounder Landed in the Commercial and Recreational Fisheries from Massachusetts to Rhode Island

Summer flounder females grow faster than males and may experience a lower natural mortality rate.  Sex-structured assessment models have been developed for other fishes with sexually dimorphic characteristics to more appropriately account for the population dynamics of those species.  However, while a desire exists to develop similar assessment techniques for summer flounder, some prerequisite data needed to develop a sex-structured model are not available, including the sex of fish landed in the recreational and commercial fisheries.  We collected sex and length data from summer flounder landed in the recreational (n=6,494) and commercial (n=11,090) fisheries in 2010 and 2011.  In the recreational fishery, significantly more females were landed at a given size than in the commercial fishery.  The sex structure of landed summer flounder was variable in time and space in both fisheries.  Females were present at higher proportions at a given length in southern regions and at shallower depths in the recreational fishery.  In the commercial fishery, inshore landings were more likely to be female at a given length than fish landed offshore.  Evidence of fishery-dependent, seasonal, and spatial variability in sex-at-length in both fisheries suggests an annual monitoring program may be required before sex-specific data can confidently be incorporated into an assessment.