High latitude ecosystems are particularly sensitive to environmental change and are undoubtedly facing challenges due to modern climate change as ecological thresholds are surpassed. Within these regions, lakes offer a unique utility by acting as sentinels of environmental change by archiving past biogeochemical conditions in their sediments. The lakes surrounding Clements Markham Inlet are amongst the highest latitude lakes in the world; however, the biogeochemical functioning of these ecosystems is mostly unknown. My project will reconstruct the past environmental conditions of lakes along an altitudinal transect to understand not only how they respond to climatic variation, but also to determine if high altitude lakes may be more sensitive to climatic shifts.
The goal of this project is to reconstruct the past environmental conditions of multiple lakes along an altitudinal transect around Clements Markham Inlet to identify the biogeochemical responses of lacustrine systems to climate change. By comparing diatom assemblages, I will determine if shifts in aquatic biota are more pronounced with increasing altitude, potentially indicative of a heightened sensitivity to environmental change. More broadly, this project will contribute to a more comprehensive understanding of High Arctic environments and past climate change in general by placing current limnological conditions within a long-term context.
Clements Markham Inlet, located within the Tuvaijuittuq Marine Protected Area on the northern coast of Ellesmere Island, Nunavut, has experienced significant climatic variability during the Holocene. Most lakes around Clements Markham Inlet have yet to be studied; however, they are expected to contain valuable information about past biogeochemical changes in response to climatic variation. Multiple lakes with similar characteristics will be chosen along an altitudinal transect to reconstruct past environmental conditions and explore the importance of altitude in this already sensitive region.
During the summer of 2022, water column samples and short sediment cores, representing approximately 3000 years of environmental change, will be taken from each lake. Diatom assemblages will be compared to elucidate past environmental conditions and regional climate along a temporal scale determined through radiometric dating.
This paleoclimate reconstruction using diatom assemblage data will provide a detailed understanding of how lakes at various altitudes have responded to past climatic variation. The specific focus on diatoms as a biological indicator of past environmental change will also contribute to refining the taxonomy of this region, which is relatively unknown due to the logistical difficulties of sampling. By selecting sites along an altitudinal transect, I expect to determine if there is an increased sensitivity to climatic shifts at higher altitudes, which has yet to be explored in high Arctic regions.