Epibenthic food web structure across the Northeast Greenland seascape

The Arctic is in a state of rapid transformation driven by climate change and other anthropogenic stressors, making it essential to establish reference values for diversity, including trophic structure and variability of stable isotope values. Here, we use stable isotopes of carbon (δ¹³C) and nitrogen (δ¹⁵N) to characterize the trophic structure of epibenthic faunal communities across the Northeast Greenland seascape, covering coastal, shelf, shelf-break and upper-slope habitats in this under-explored region. We found that epifauna communities show wide occupancy (niches) in stable isotope space, with relatively high overlap among habitats. Among the studied seabed habitats, the differences in consumer δ¹³C were relatively minor, and no dominance of terrestrial input (highly depleted values) was evident even at coastal sites. However, epifauna in coastal habitats (fjord and bay) showed higher δ¹⁵N values, which may indicate a reliance on more degraded organic matter. We did not find consistent trajectories in stable isotope values across feeding groups along the inshore-to-offshore gradient, suggesting multiple parallel feeding strategies and realized diets of generalist consumers across the seascape. Continued research on the structure of marine food webs can provide an important understanding of the development of ecosystem functioning in a future Arctic.