ESR 26:1-12 (2014)  -  DOI: https://doi.org/10.3354/esr00624

ABSTRACT: We used variation at microsatellite loci and in mitochondrial DNA (mtDNA) to detect and quantify (1) hybridization between the harbour porpoises Phocoena phocoena and the Dall’s porpoises Phoconoides dalli and (2) the genetic population structure of harbour porpoises in British Columbia (BC), Canada. We assayed variation across 262 individuals (204 putative harbour, 44 putative Dall’s, 9 putative hybrids, and 5 unidentified porpoises) obtained primarily from strandings and initially identified morphologically. Our assays identified 198 pure (probability ≥0.95) harbour porpoises, 37 pure Dall’s porpoises, and 27 individuals of mixed ancestry, and we found that hybrids between the 2 species occurred over a larger geographic range than previously known. Analysis of 8 microsatellite loci was used to estimate a value of F_ST between the Strait of Georgia region and waters outside this area that was low and non-significant (F_ST = 0.0025, p > 0.25). Cluster-based Bayesian analysis of population structure in harbour porpoises suggested a single genetic population across our sample area. Within the harbour porpoise, there were 50 mtDNA haplotypes that differed from each other by an average of 0.015 substitutions per nucleotide site. Hierarchical AMOVA indicated that there was no significant divergence between the waters within and the waters outside the Strait of Georgia region (Φ_ST = -0.022, p > 0.9). Our findings suggest that harbour porpoises inhabiting coastal waters of southern BC constitute a single genetic population, which should be reflected in management decisions. Our data also suggest that these management efforts should take into account occasional hybridization with sympatric Dall’s porpoise.

KEY WORDS: Harbour porpoise · Dall’s porpoise · Population structure · Hybridization · Species at risk · Microsatellites · D-loop

Full text in pdf format Supplementary material

Cite this article as: Crossman CA, Barrett-Lennard LG, Taylor EB (2014) Population structure and intergeneric hybridization in harbour porpoises Phocoena phocoena in British Columbia, Canada. Endang Species Res 26:1-12. https://doi.org/10.3354/esr00624 Export citation Share:    Facebook - - linkedIn