Subtle response in Arctic coastal benthos to environmental change - a case study from NE Kalaallit Nunaat (Greenland)

Climate change is rapidly altering the environment in the Arctic with large implications for marine life. This study presents the first time-series analysis of epibenthic community structure in Young Sound, NE Kalaallit Nunaat (Greenland), aiming to assess the structural and functional changes over time in response to climate-driven environmental change. Using data collected by drop cameras and ROVs at depths of 20m to 60m, from years 2003–2010 and 2021-2022, we evaluated the taxonomic and functional composition of the benthic community. Brittle stars and bivalves were the most common taxa, altogether comprising 95% of total abundances, and they displayed fluctuating temporal trend, with a significant reduction in bivalve abundances in the later years. Dissimilarities in the benthic communities were primarily driven by differences in depth and secondly by the length of the open water period. Longer ice-free period led to an increase in the large and small size classes, short-lived and filter/suspension feeding taxa, which may impact higher trophic levels in the fjord. This shift indicates that ecosystem changes are also occurring in the outflow region of the Arctic, underscoring the vulnerability of Arctic benthic ecosystems to climate change.