Population Genetic Structure in Channeled Whelk Busycotypus canaliculatus along the U.S. Atlantic Coast

Abstract

Globally, commercial fisheries for whelk (family Buccinidae) generally exhibit a boom-and-bust cycle that fuels overexploitation of resources. Channeled whelk Busycotypus canaliculatus is a commercially important species that supports a valuable fishery along the Atlantic coast of the United States. The fishery is managed at the state level, with minimum landing size varying by state. Biological studies of channeled whelk in New England and the mid-Atlantic region have indicated that females have a low probability of maturity upon entering their respective fisheries. The life history characteristics of channeled whelk, including slow growth, late maturation, and direct development paired with unsuitable minimum landing size, make this species vulnerable to overexploitation. Currently, the population genetic structure of channeled whelk is unknown, impeding the ability to appropriately inform management. This study used 2,570 single nucleotide polymorphisms to elucidate the population genetic structure of channeled whelk sampled from 10 locations ranging from Massachusetts to South Carolina. The data indicated seven genetically distinct populations across the sampled region of the U.S. Atlantic coast. Estimates of genetic divergence among populations spanned an order of magnitude (FST = 0.017–0.582), with higher levels of divergence observed when comparing populations separated by biogeographic barriers. Based on the magnitude of observed genetic differences, five regional management units are suggested. The results of this study will aid discussions among fisheries managers in Atlantic states aimed at the development of appropriate management plans. The complex population genetic structure revealed by this study underscores the need for more comprehensive sampling, including between fishing locations sampled in this study and among offshore locations, to better understand the population genetic structure of channeled whelk.