Environmental DNA metabarcoding reveals seasonal and spatial variation in the vertebrate fauna of Ilulissat Icefjord, Greenland

A combination of environmental DNA (eDNA) metabarcoding, local ecological knowledge, and hydrographic data reveals significant seasonal and spatial variation in the vertebrate fauna of Ilulissat Icefjord, Greenland. The study finds that Arctic char migrate to the southern fjord during summer, while harp seals forage in large herds within the system. Polar cod emerges as the dominant prey fish, whereas Greenland shark is notably absent, likely contributing to larger ringed seal and Greenland halibut populations due to reduced predation pressure. Summer conditions show a more diverse vertebrate community and distinct water masses in the southern branch compared to the northern branch and main fjord, indicating a time lag in inflow dynamics. This research underscores the value of integrating local knowledge with scientific methods to monitor biological responses to climate-induced changes in this UNESCO World Heritage Site.

Schiøtt, S., Jensen, M., Sigsgaard, E., Møller, P., Avila, M., Thomsen, P., & Rysgaard, S. (2023). Environmental DNA metabarcoding reveals seasonal and spatial variation in the vertebrate fauna of Ilulissat Icefjord, Greenland. Marine Ecology Progress Series, 706, 91–108. https://doi.org/10.3354/meps14250