A population on the edge: genetic diversity and population structure of the world's northernmost harbour seals ( Phoca vitulina )

• Published in: Biological Journal of the Linnean Society
• Main Authors: Andersen, Liselotte Wesley, Lydersen, Christian, Frie, Anne Kirstine, Rosing-Asvid, Aqqalu, Hauksson, Erlinggur, Kovacs, Kit M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2011
• Subjects: Greenland; Norway; Svalbard; harbour seal; Iceland; Northern Norway; Phoca vitulina
• Online Access: https://pure.au.dk/portal/en/publications/96a645f0-bf37-11df-8cb9-000ea68e967b; https://doi.org/10.1111/j.1095-8312.2010.01577.x

It is crucial to examine the genetic diversity and structure of small, isolated populations, especially those at the edge of their distribution range, because they are vulnerable to stochastic processes if genetic diversity is low and isolation level high, and because such populations provide insight into consequences of population declines in a broader conservation context. The harbour seal population at Svalbard is the world's northernmost harbour seal population. Nothing is known about the genetic diversity, distinctiveness or origin of this small, marginalized mammalian population. Thus, the present study investigated its genetic status in the context of nearby harbour seals in Iceland, Southeast Greenland and Northern Norway; this species is depleted/threatened in all of these regions. A total of 174 samples distributed between the four locations were analysed using 15 polymorphic microsatellites and variation in the D-loop. Each of the four locations was a genetically distinct population. The Svalbard population was highly genetically distinct, had reduced genetic diversity, received limited gene flow, had a rather low effective population size and showed an indication of having experienced a bottleneck resulting from a recent population decline. The significant heterozygote excess observed in the Svalbard sample might be attributed to the low effective population size, which could initiate future population inbreeding effects. This phenomenon has not been reported earlier from other harbour seal populations, but if it the Svalbard population is experiencing inbreeding, this could reduce its resilience to climate change, disease outbreaks or other perturbations. Udgivelsesdato: 2010