Micro-evolutionary Effects of Annual Sea Ice Conditions on Ringend Seal (Phoca hispida)

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

Sea ice constitutes a dominant and highly dynamic physical feature of marine polar environments with significant effects on species distribution. While much attention has been directed towards correlating present species distribution with annual ice conditions, no study has yet focused on the micro-evolution of marine fauna in the polar regions as a function of annual sea ice dynamics. This study aims specifically at testing the hypothesis that annual sea ice conditions have significant micro-evolutionary effects in ringed seal (Phoca hispida), a phagophilic species that is highly dependant on specific annual sea ice and snow dynamics. The genotype at 96 nuclear SNPs (Single Nucleotide Polymorphisms) loci and the nucleotide sequence of the maternally inherited mitochondrial control region will be determined in 1,379 ringed seal samples collected in areas around Greenland where annual sea ice regimes are highly heterogeneous in space and time. The proposed study is unique by specifically focusing on the interaction between a dynamic physical feature of the Polar environment and the micro-evolution of a polar fauna. An understanding of such micro-evolutionary effects of sea ice conditions on polar fauna is important in terms of enhancing our predictive capabilities regarding the long-term effects of climate change in polar regions. The ringed seal is centrally placed in the Arctic food web and any processes that affect ringed seals cannot be viewed in isolation, but are likely to extend to other species to which the ringed seal is ecologically linked. The proposed high-resolution population genetic approach taken is novel and unprecedented in a study aimed at natural populations of a non-model species. The study extends the application of genetic analyses to a detailed tempo-spatial scale where current and traditional approaches so far mostly have proven insufficient. The comprehensive collection of samples available for other marine species provides a unique opportunity to later extend the proposed study above from single-species to a comprehensive ecosystem level analysis. The results of the proposed study will have relevance in terms of formulating management policies for ringed seals and those species that are part of the same food web. Ringed seals are harvested for local subsistence in many areas in the Arctic and understanding the processes that limit or facilitates dispersal is central in defining sound management policies. The proposed study enhances international research by international collaboration between a US education and research institution and a Danish governmental research institution. The project involves training of a postdoctoral researcher in state-of-the-art genetic analyses of natural populations, and will serve as an example of the application of high-throughput SNP genotyping in the study of natural populations, where this approach yet has to take footing. In addition to publication of the results in scientific journals, and the establishment of a dedicated web site to present the data and results, a poster for wide distribution will be published in Greenlandic and Danish presenting the findings of the study in layman's terms. The aim of the poster is to relay the concept of the high degree of connectivity among distant geographic locations as well as the long-term influence of sea ice upon Arctic fauna. The proposed work builds upon and extends the principal investigator's current research program which focus on population structure and connectivity in natural animal populations, in particularly marine mammals.