Walruses (Odobenus rosmarus rosmarus) in the Pechora Sea in the context of contemporary population structure of Northeast Atlantic walruses

TY - JOUR

T1 - Walruses (Odobenus rosmarus rosmarus) in the Pechora Sea in the context of contemporary population structure of Northeast Atlantic walruses

AU - Andersen, Liselotte Wesley

AU - Jacobsen, Magnus W.

AU - Lydersen, Christian

AU - Semenova, Varvara

AU - Boltunov, Andrei

AU - Born, Erik W.

AU - Wiig, Oystein

AU - Kovacs, Kit M.

PY - 2017/12

Y1 - 2017/12

N2 - Identifying genetically different groups of animals, occupying specific geographical areas, is a prerequisite for conservation and management priorities. In the present study, the genetic structure of Atlantic walruses (Odobenus rosmarus rosmarus) occupying the Pechora Sea (PEC) in the western Russian Arctic, including walruses from Svalbard-Franz Josef Land (SVA-FJL) and East Greenland (EGR) regions, was investigated using 14 microsatellites (N = 159) and mtDNA sequences (N = 212). Bayesian-based clustering analysis identified two clusters: EGR and the other Northeast Atlantic areas. Pairwise F ST analyses based on microsatellites revealed low but significant genetic differences between walruses from the PEC and SVA-FJL groups, which was supported by mtDNA analysis. F ST was not significant for all sampling years, indicating a temporal effect or male-biased gene flow. Extended Bayesian Skyline Plots suggested a constant female subpopulation size (N ef) for EGR and an increase for the SVA-FJL and PEC groups that commenced around 40-30 Kyr ago, indicating different demographic histories for walruses in the EGR. Further, the evolutionary phylogenetic relationship between Atlantic and Pacific walruses (O. r. divergence), based on mtDNA sequences, showed a monophyletic Atlantic clade, suggesting that Atlantic and Pacific walruses diverged ~949 Kyr. The principal finding suggests that PEC walruses show low, but significant genetic distinction from walruses in SVA-FJL and should be managed conservatively, as a separate, small population.

AB - Identifying genetically different groups of animals, occupying specific geographical areas, is a prerequisite for conservation and management priorities. In the present study, the genetic structure of Atlantic walruses (Odobenus rosmarus rosmarus) occupying the Pechora Sea (PEC) in the western Russian Arctic, including walruses from Svalbard-Franz Josef Land (SVA-FJL) and East Greenland (EGR) regions, was investigated using 14 microsatellites (N = 159) and mtDNA sequences (N = 212). Bayesian-based clustering analysis identified two clusters: EGR and the other Northeast Atlantic areas. Pairwise F ST analyses based on microsatellites revealed low but significant genetic differences between walruses from the PEC and SVA-FJL groups, which was supported by mtDNA analysis. F ST was not significant for all sampling years, indicating a temporal effect or male-biased gene flow. Extended Bayesian Skyline Plots suggested a constant female subpopulation size (N ef) for EGR and an increase for the SVA-FJL and PEC groups that commenced around 40-30 Kyr ago, indicating different demographic histories for walruses in the EGR. Further, the evolutionary phylogenetic relationship between Atlantic and Pacific walruses (O. r. divergence), based on mtDNA sequences, showed a monophyletic Atlantic clade, suggesting that Atlantic and Pacific walruses diverged ~949 Kyr. The principal finding suggests that PEC walruses show low, but significant genetic distinction from walruses in SVA-FJL and should be managed conservatively, as a separate, small population.

KW - ALLELE FREQUENCY DATA

KW - DEMOGRAPHIC HISTORY

KW - ELEPHANT SEAL

KW - FRANZ JOSEF LAND

KW - GENETIC DIVERSITY

KW - MICROSATELLITE VARIATION

KW - MOLECULAR EVOLUTION

KW - MULTILOCUS GENOTYPE DATA

KW - STATISTICAL TESTS

KW - TIME DEPENDENCY

KW - climate change

KW - conservation

KW - divergence

KW - genetics

KW - management

KW - microsatellites

KW - mtDNA

UR - https://www.scopus.com/pages/publications/85052522950

U2 - 10.1093/biolinnean/blx093

DO - 10.1093/biolinnean/blx093

M3 - Journal article

SN - 0024-4066

VL - 122

SP - 897

EP - 915

JO - Biological Journal of the Linnean Society

JF - Biological Journal of the Linnean Society

IS - 4

ER -