Combined Genetic and Telemetry Data Reveal High Rates of Gene Flow, Migration, and Long-Distance Dispersal Potential in Arctic Ringed Seals (Pusa hispida)

Micaela E Martinez-Bakker,David A Tallmon,Stephanie K Sell,Brendan P Kelly,Bradley J Swanson,Neil John Gemmell

doi:10.1371/journal.pone.0077125

Abstract

Ringed seals (Pusa hispida) are broadly distributed in seasonally ice covered seas, and their survival and reproductive success is intricately linked to sea ice and snow. Climatic warming is diminishing Arctic snow and sea ice and threatens to endanger ringed seals in the foreseeable future. We investigated the population structure and connectedness within and among three subspecies: Arctic (P. hispida hispida), Baltic (P. hispida botnica), and Lake Saimaa (P. hispida saimensis) ringed seals to assess their capacity to respond to rapid environmental changes. We consider (a) the geographical scale of migration, (b) use of sea ice, and (c) the amount of gene flow between subspecies. Seasonal movements and use of sea ice were determined for 27 seals tracked via satellite telemetry. Additionally, population genetic analyses were conducted using 354 seals representative of each subspecies and 11 breeding sites. Genetic analyses included sequences from two mitochondrial regions and genotypes of 9 microsatellite loci. We found that ringed seals disperse on a pan-Arctic scale and both males and females may migrate long distances during the summer months when sea ice extent is minimal. Gene flow among Arctic breeding sites and between the Arctic and the Baltic Sea subspecies was high; these two subspecies are interconnected as are breeding sites within the Arctic subspecies.

Highlights

IntroductionThe unprecedented melting rate of Arctic sea ice has resulted in elevated mortality of ice-adapted marine mammals such as the polar bear and ringed seal [3,4,5,6]
Warming climate is an imminent threat to the persistence of Arctic fauna [1,2]
We investigated genetic variation and spatial structure of ringed seal populations to evaluate their susceptibility to population declines and local extinction driven by diminishing snow and ice cover

Summary

Introduction

The unprecedented melting rate of Arctic sea ice has resulted in elevated mortality of ice-adapted marine mammals such as the polar bear and ringed seal [3,4,5,6]. The potential of these species to adapt to their changing environment will depend largely upon the spatial structure of their populations and the amount of gene flow [7]. Saimensis) which are listed as threatened (Arctic and Baltic subspecies) or endangered (Lake Saimaa subspecies) under the U.S Endangered Species Act [10,11]. We quantified gene flow between breeding sites (i.e. tentative populations) and dispersal potential, essential parameters in developing effective conservation strategies

Methods

Results

Conclusion