The interview survey conducted in Ilulissat, Ilimanaq, and Qasigiannguit in Greenland during March–April 2019 showed that the local fishers are changing fishing strategies and adapting to a changing environment caused by climate change. The main fjord of Ilulissat Icefjord is usually filled with icebergs year-round, making it impossible to navigate. Currently, there are more ice clearing events in Ilulissat Icefjord during the winter than previously. The traditional pattern of going fishing using dogsled is changing and fishing from boats occurs, whenever the main fjord clears of ice. The poorer sea ice conditions in the southern branch of the fjord system, combined with the fact that it is increasingly challenging to reach fishing sites, have resulted in fishers from Qasigiannguit not going to the Icefjord as much as they used to. Ilulissat Icefjord is by any means considered important fishing and hunting ground by locals, as both Greenland halibut and ringed seals are known to be of larger size inside the fjord system, when compared to those caught in Disco Bay. The locals use Ilulissat Icefjord during a limited period of the year, and the fjord is therefore said to be protected from overexploitation. They observe the immediate effects of climate change from changes in the ice conditions, a change in the fjord's accessibility, and the occurrence of Atlantic cod, which were not present in the fjord system in such numbers before.

Ilulissat Icefjord in Greenland is experiencing the effects of climate change, with the Sermeq Kujalleq glacier being one of the fastest-moving and most productive ice streams in Greenland. This is likely affecting the distribution of species in the fjord, including those important to local fisheries. Due to heavy ice conditions, few studies on environmental and ecological conditions exist from the fjord. However, new techniques such as environmental DNA (eDNA) metabarcoding now allow deeper insight into the fjord system. Here, we combine local ecological knowledge with data on hydrographic conditions, stable isotopes (δ18O), and eDNA metabarcoding to investigate the spatial and seasonal distribution of marine fish and mammals inside Ilulissat Icefjord. Our eDNA results support local observations that Arctic char migrate to the southern fjord during summer, harp seals forage in large herds in the fjord system, polar cod is the dominant prey fish in the area, and Greenland shark likely does not reside in the fjord system. Lower predation pressure in the Icefjord, due to the absence of Greenland shark and polar bears as well as limited fishing/hunting, is presumably one of the reasons why ringed seals and Greenland halibut are larger in the Icefjord. Furthermore, our results indicate that in summer, the southern branch of the fjord system has a more diverse community of vertebrates and different water masses than the northern branch and main fjord, indicating a time lag between inflows to the different branches of the fjord system. Our approach highlights the value of combining local ecological knowledge with scientific research and represents a potential starting point for monitoring biological responses in Ilulissat Icefjord associated with climate-induced changes.