Genetic population structure of harbour seals in the United Kingdom and neighbouring waters

Abstract

In the United Kingdom (UK), several harbour seal (Phoca vitulina) populations have been declining over the past decade. In order to understand the effect of these changes in abundance, this study seeks to determine the population structure of harbour seals in the UK, and in Scotland in particular, on a wider and finer spatial scale than has previously been reported. Harbour seals were genotyped from 18 different localities throughout the UK and neighbouring localities in mainland Europe, at 12 microsatellite loci. Results from Bayesian and frequency based tests of population structure suggested an initial structural division into two main groups consisting of localities in northern UK and southern UK–mainland Europe, respectively. These two clusters were further divided into four geographically distinct genetic clusters. An overall agreement between the genetic results and the existing management areas for UK harbour seals was observed, but it is also clear that an adaptive management approach should be adopted, in which the delineation of the current management areas is maintained until further genetic and ecological information has been accumulated and analysed.