Population Structure of Surf Smelt in Puget Sound, Washington

Surf Smelt Hypomesus pretiosus are commonly encountered, and seasonally abundant, throughout the nearshore marine waters of Washington, from the Columbia River to the Canadian border and into southernmost Puget Sound and Hood Canal.  Surf smelt are the target of significant commercial and recreational fisheries and are an important prey item for numerous fish, bird, and mammal species.  Fishery effort and harvest are often concentrated in relatively small geographic areas, making local depletion a potential concern. Little is known about surf smelt population structure but limited genetic research to date has suggested that, despite their rather broad distribution, surf smelt occupying Puget Sound and the Salish Sea represent a single stock.  Here we present microsatellite data from over 700 samples collected over a wide portion of Puget Sound from beach seine research studies, recreational fisheries, and commercial fisheries.  Using this robust collection of samples we demonstrate that very little genetic disequilibrium exists and conclude that the population is, in fact, a single stock.  The implications of this finding for fishery management will be discussed.