title: Identifying patterns of dispersal, connectivity and selection in the sea scallop,Placopecten magellanicus,using RADseq-derived SNPs.
abstract: Understanding patterns of dispersal and connectivity among marine populations can directly inform fisheries conservation and management. Advances in high-throughput sequencing offer new opportunities for estimating marine connectivity. We used restriction-site-associated DNA sequencing to examine dispersal and realized connectivity in the sea scallopPlacopecten magellanicus, an economically important marine bivalve. Based on 245 individuals sampled rangewide at 12 locations from Newfoundland to the Mid-Atlantic Bight, we identified and genotyped 7163 single nucleotide polymorphisms; 112 (1.6%) were identified as outliers potentially under directional selection. Bayesian clustering revealed a discontinuity between northern and southern samples, and latitudinal clines in allele frequencies were observed in 42.9% of the outlier loci and in 24.6% of neutral loci. Dispersal estimates derived using these clines and estimates of linkage disequilibrium imply limited dispersal; 373.1 ± 407.0 km (mean ± SD) for outlier loci and 641.0 ± 544.6 km (mean ± SD) for neutral loci. Our analysis suggests restricted dispersal compared to the species range (>2000 km) and that dispersal and effective connectivity differ. These observations support the hypothesis that limited effective dispersal structures scallop populations along eastern North America. These findings can help refine the appropriate scale of management and conservation in this commercially valuable species.
authors.affiliation: Department of Biology Memorial University of Newfoundland St. John's NL Canada.
authors.forename: Mallory
authors.initials: M
authors.lastname: Van Wyngaarden
authors.affiliation: Department of Biology Memorial University of Newfoundland St. John's NLCanada; Department of Ocean Sciences Memorial University of Newfoundland St. John's NL Canada.
authors.forename: Paul V R
authors.initials: PV
authors.lastname: Snelgrove
authors.affiliation: Bedford Institute of Oceanography Dartmouth NS Canada.
authors.forename: Claudio
authors.initials: C
authors.lastname: DiBacco
authors.affiliation: Aquatic Biotechnology Lab Bedford Institute of Oceanography Dartmouth NS Canada.
authors.forename: Lorraine C
authors.initials: LC
authors.lastname: Hamilton
authors.affiliation: Marine Research Division AZTI Technalia Sukarrieta Bizkaia Spain.
authors.forename: Naiara
authors.initials: N
authors.lastname: Rodríguez-Ezpeleta
authors.affiliation: Fisheries and Oceans Canada Northwest Atlantic Fisheries Centre St. John's NL Canada.
authors.forename: Nicholas W
authors.initials: NW
authors.lastname: Jeffery
authors.affiliation: Bedford Institute of Oceanography Dartmouth NS Canada; Faculty of Computer Science Dalhousie University Halifax NS Canada.
authors.forename: Ryan R E
authors.initials: RR
authors.lastname: Stanley
authors.affiliation: Department of Ocean Sciences Memorial University of Newfoundland St. John's NL Canada; Fisheries and Oceans Canada Northwest Atlantic Fisheries Centre St. John's NL Canada.
authors.forename: Ian R
authors.initials: IR
authors.lastname: Bradbury
keywords: RADseq; connectivity; dispersal; outlier loci; population genomics; population structure; sea scallop; single nucleotide polymorphism