Microsatellite DNA reveals population genetic differentiation among sprat (Sprattus sprattus) sampled throughout the Northeast Atlantic, including Norwegian fjords

Abstract

Sprat (Sprattus sprattus), small pelagic shoaling fish, were sampled from the Celtic, North, and Baltic seas, and 10 Norwegian fjords. Significant overall genetic differentiation was observed among samples when analysed with eight microsatellite DNA loci (Global F ST = 0.0065, p < 0.0001). The greatest genetic differences were observed between the Baltic and all other samples (largest pairwise F ST = 0.043, p < 0.0001). No significant genetic differentiation was observed between a sample from the Celtic Sea (CEL) and the North Sea (NSEA; F ST = 0.001, p = 0.16), but variable levels of genetic differentiation were observed among samples collected from Norwegian fjords (pairwise F ST ranging from 0 to 0.0096, most non-significant). All fjord samples were significantly differentiated to NSEA and CEL samples. Further, all fjord samples displayed reduced allelic richness compared with NSEA and CEL samples. Clearly, sprat display population genetic differentiation throughout the Northeast Atlantic, and there may be limited connectivity between Norwegian fjord and sea-going populations. © 2011 International Council for the Exploration of the Sea.