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

北极正在迅速变化，人们越来越担心这些变化可能会影响该地区特有的各种物种，这些物种对北方土著人民具有巨大的经济和文化重要性。关于气候变化对海洋哺乳动物影响的长期研究通常仅限于几年或最多几十年，但我们知道，北极的环境条件在整个全新世，特别是在过去几百年中发生了巨大变化。我的研究项目重建了北极海洋哺乳动物生态的长期变化（北极熊，环斑海豹，海象，弓头鲸，独角鲸，白鲸）在过去的12年里，通过分析骨骼样本中蛋白质成分的整体和化合物特异性稳定同位素组成，从自然历史收藏品（从古生物和考古遗址收集的材料以及博物馆存档的组织样本）中提取胶原蛋白。这些数据提供了深入了解这些动物的营养地位的变化和海冰藻类支持海洋食物网的相对重要性。与大多数古环境重建不同，这些数据揭示了食物网顶部或附近的生物如何对长期环境变化做出反应，这一观点只能通过这些独特的自然历史收集来获得。如果我们缺乏长远的眼光，就无法充分解决气候变化如何影响这些物种的问题。 本提案中要求的设备（能够测量小固体有机样品上的d13 C、d15 N和34 S的新元素分析仪和同位素比质谱仪）是对我们现有仪器的紧急升级，现有仪器无法产生完成本研究所需的所有同位素测量。这种新设备将提高我们解决北极海洋哺乳动物觅食生态长期环境变化的原因和后果的分辨率，最大限度地减少经常困扰这些数据的等同性。它将为本科生和研究生提供极好的机会，使他们在同位素比质谱领域具有很高的能力，并确保大学社区的所有成员都能公平地使用这种仪器。

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.