Inuit and Local Knowledge on the Marine Ecosystem in Ilulissat Icefjord, Greenland

Abstract

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.

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

“…Until now, ice conditions have prevented scientific field surveys of the marine ecosystem of the Icefjord, although locals from the interview survey have described changes related to season and climate change (Schiøtt et al 2021). For example, locals report that (1) Arctic char migrate to the southern fjord during the summer; (2) large herds of harp seals come to feed on capelin in the main fjord; (3) Greenland halibut are larger in the main fjord of the Icefjord compared to Disco Bay and the northern and southern branch of the Icefjord; and (4) Greenland halibut are larger the further one moves into the main fjord, where the fish community is also less diverse (Table S1).…”

“…Onethird of all Greenland halibut caught in the Disco Bay area are caught within and just outside the Icefjord (Nygaard 2019). Both Greenland halibut and ringed seals generally have a higher body mass inside the Icefjord compared to those caught in Disco Bay (Schiøtt et al 2021), suggesting especially high productivity and growth in this area. Despite the importance of the Icefjord for fisheries and wildlife, and the rapid changes currently induced by climate change, few studies have investigated environmental and ecological conditions inside the fjord.…”

“…Selected results from this survey -specifically knowledge about the fish and marine mammal community -are included here for comparison with the results from eDNA metabarcoding. Detailed descriptions about the interview setup, their observations of changes in biological and environmental conditions, and the adaptation of the locals to these changes can be found in Schiøtt et al (2021).…”

“…It is locally known that both Greenland halibut and ringed seals are generally larger inside the Icefjord compared to those caught in Disco Bay (Schiøtt et al 2021). The reason for this difference might be due to (1) absence of the Greenland shark, (2) absence of polar bears, and (3) fishing and hunting activities being limited to the winter and spring.…”

“…Predation from polar bears on ringed seals would have required at least 43 seals annually per bear to sustain their survival (Kingsley 1998) and their absence would relieve a large number of seals in the Icefjord from predation. The third limited predation factor in the Icefjord is from human activities, which are limited to the winter and spring (Schiøtt et al 2021), giving both seals and fishes a refuge from human predation from late spring until late autumn inside the Icefjord. The limited seasonal (fishing/hunting) activities or total absence of apex predators (polar bear and Greenland shark) could suggest that the Icefjord is a refugium during part of the year for both ringed seals and Greenland hali but that reside in the Icefjord, placing them at the top of the local food chain, allowing them to grow older and larger.…”