Chapter 7 - Distribution of Freshwater Ostracods in the Canadian North and Implications for Palaeoclimate Reconstructions

Abstract

A new modern freshwater ostracod calibration set spanning Northern Canada was compiled to explore relationships between ostracods and their environment for the ultimate purpose of the quantification of past environments. Environmental data were available for 91 lakes; however, 31 ostracod species representing 9 genera were present in only 68 of these lakes. Variables contributing significantly to species distributions across the region were mean July air temperature, lake water alkalinity–calcium ratio and water depth. Application of the dataset included the calculation of 22 species optima and tolerances to mean July air temperature and the reconstruction of mean July air temperature from a fossil ostracod record at Upper Fly Lake in the southwest Yukon Territory. Ostracod-inferred mean July air temperatures corresponded with reconstructions using other proxies from the same site, indicating the utility of a calibration set from the Canadian North to provide modern analogues during the Late glacial–Early Holocene.