Abstract
•The first study to describe the spatial extent of B. undatum along the Mid-Atlantic.•Largest abundance of whelk per m2 found in depths between 40 and 75m in the Mid-Atlantic Bight.•Size of sexual maturity ranges from 56 to 73mm and varies among regions and sex.•Relative abundance per m2 estimates provided for whelk in Mid-Atlantic via dredging.•Meta-analysis of whelk literature to examined trends in size of maturity.
Recent expansion of the unmanaged waved whelk (Buccinum undatum) fishery within the United States Mid-Atlantic continental shelf region has prompted investigation into local life history parameters. Limited adult dispersal and lack of a planktonic larval stage has the potential to create spatially distinct populations with respect to size of sexual maturity and size frequency. During the summer of 2015, a comprehensive survey was undertaken to evaluate population structure, sex ratio, relative abundance, and size of sexual maturity for whelk in the Mid-Atlantic. Samples (n=228) were collected from Georges Bank through the DelMarVa region using a modified scallop dredge at depths ranging from 27.4 to 112m, with most whelk caught between 40–75m, and peak abundances at 51–60m. All whelk collected (n=3877) were sexed, weighed, measured, and assessed for maturity. Sex ratios were skewed in favor of females in the south and balanced through the rest of the regions. Size of maturity ranged from approximately 56–73mm and varied among regions and sex. Estimates of size of sexual maturity for B. undatum from other regions of the world were compiled, demonstrating that the size of maturity for this species is highly variable, and current minimum landing size regulations tend to fall below the estimated size of sexual maturity, potentially increasing the risk of recruitment overfishing. Overall, spatial variation in whelk phenotype suggests local adaptation in this species, indicating that regional management would be most appropriate.