MEPS prepress abstract   -  DOI: https://doi.org/10.3354/meps14776

ABSTRACT: Climate-driven warming and changes in major ocean currents enable poleward larval transport and range expansions of many marine species. Here, we report the population genetic structure for the gastropod Kelletia kelletii, a commercial fisheries species and subtidal predator with top-down food web effects, whose populations have recently undergone climate-driven northward range expansion. We genotyped 598 adults from 13 locations spanning approximately 800 km across the species’ historical and expanded range using reduced representation genomic sequencing (RAD-seq). Analyses of 40,747 SNPs show evidence for long-distance larval dispersal of K. kelletii larvae from a central historical range site (Point Loma, CA) hundreds of km into the expanded northern range (Big Creek, CA), which seems most likely to result from transport during an El Niño Southern Oscillation (ENSO) event rather than consistent on-going gene flow. Furthermore, the high genetic differentiation d among some sampled expanded-range populations and their close genetic proximity with distinct populations from the historical range, suggest multiple origins of the expanded-range populations. Given the frequency and magnitude of ENSO events are predicted to increase with climate change, understanding the factors driving changes in population connectivity is crucial for establishing effective management strategies to ensure the persistence of this and other economically and ecologically important species.