Exploring Long-Term Variation in Arctic Marine Ecosystems through Stable Isotope Analysis and Fatty Acid Biomarkers

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The Arctic is changing rapidly and there is growing concern about how these changes may impact various species that are endemic to this region and are of tremendous economic and cultural importance to the indigenous peoples of the north. Long-term studies of the impacts of climate change on marine mammals are typically limited to a few years or at most a few decades, but we know that the environmental conditions in the Arctic have varied substantially through the Holocene and particularly in the last few hundred years. This research program will reconstruct long-term variation in the ecology of Arctic marine mammals (polar bear, ringed seal, walrus, bowhead whale, narwhal, beluga whale) from Baffin Bay and East Greenland over the last 12,000 years by analysing the bulk and compound-specific stable isotope compositions (13C and 15N) of the proteinaceous component of bone samples (collagen) from natural history collections (materials collected from palaeontological and archaeological sites as well as tissue samples archived by museums). These data will provide insight into variation in the trophic position of these animals and the relative importance of sea ice algae supporting marine food webs. Unlike most palaeoenvironmental reconstructions, these data will shed light on how organisms at or near the top of the food web have responded to long-term environmental variation, a perspective that cannot be accessed except through these unique natural history collections. We cannot adequately address how climate change influences these species today if we lack a long-term perspective. This research program also seeks to develop new biomolecular techniques for studying ancient bones. Past ancient biomolecular research has focused on proteins (isotopic analysis, radiocarbon dating, palaeoproteiomics) and nucleic acids (ancient DNA) and this program seeks to explore the use of lipids extracted from ancient bones as markers of ecological variation. Fatty acid biomarkers from adipose and other soft tissues provide valuable insights into the ecology of modern animal populations and this program will explore the feasibility of applying similar techniques to the lipids preserved within the ultrastructure of dense, cortical bone.