An Urgent Replacement and Upgrade in Isotope Ratio Mass Spectrometry at Trent's Water Quality Centre

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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. My research program reconstructs long-term variation in the ecology of Arctic marine mammals (polar bear, ringed seal, walrus, bowhead whale, narwhal, beluga whale) over the last 12,000 years by analysing the bulk and compound-specific stable isotope compositions 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 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 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. The equipment requested in this proposal (a new elemental analyzer and isotope ratio mass spectrometer capable of measuring d13C, d15N, and 34S on small solid organic samples) represents an urgent upgrade to our existing instrumentation that is incapable of generating all of the isotopic measurements needed to complete this research. This new equipment will increase the resolution with which we can address the causes and consequences of long-term environmental variation in the foraging ecology of Arctic marine mammals, minimizing the equifinality that often plagues these kinds of data. It will provide excellent opportunities for undergraduate and graduate students to become highly competent in the field of isotope ratio mass spectrometry and ensure equitable access to this instrumentation for all members of the university community.