Arctic biodiversity responses to climate change impacts in the Canadian Beaufort Sea

The Arctic is experiencing unprecedented rates of warming. Arctic coastal environments are particularly vulnerable to the consequences: thawing of permafrost, decline of sea ice, and increased fluxes of sediment, organic carbon and nutrients across the land-ocean interface. These effects of global climate change drive significant transformations in coastal biogeochemistry and ecosystems, with severe implications for local communities. However, the responses of nearshore Arctic ecosystems to these changes, as well as involved mechanisms and driving forces, remain poorly constrained. The 'Fluxes from Land to Ocean: How Coastal Habitats in the Arctic Respond' (FLO CHAR) project focuses on the Mackenzie Delta region of the Beaufort Sea and asks the question: How does modern climate change alter land-ocean dynamics and the biodiversity of coastal ecosystems? A key objective is to explore biodiversity shifts and ecosystem functioning over the past millennium, to gain long-term perspectives of ecosystem dynamics in response to climate-driven changes. This is achieved through marine sedimentary ancient DNA (sedaDNA) analyses, utilizing state-of-the-art metabarcoding approaches and shotgun metagenomics. Establishing baseline data of coastal biodiversity in the Beaufort-Mackenzie region during the Late Holocene will allow to put modern biodiversity and ecosystem dynamics in a long-term context. Further, key diversity shifts will be assessed in the context of paleoenvironmental and -geochemical records to assess potential responses to climate change impacts, such as sea ice dynamics and land-ocean organic matter fluxes. The outcomes of the project will offer a critical framework for assessing future directions of Arctic coastal environments, and developing sustainable management and adaptation strategies.