Updated: 2 Apr. 2019
Killer whales (Orcinus orca) in the Arctic are known to avoid ice, only migrating from North Atlantic waters up to the Arctic ocean in the summer, when sea ice levels are low. However, recent sea ice loss has led to increasing presence and abundance of killer whales in the Canadian Arctic. Their migration patterns are poorly known, making it difficult to predict what are the ecological implications of this new top predator in Arctic ecosystems.
A group of Canadian scientists interviewed Inuit hunters from different communities in the Canadian Arctic to better understand the ecological impacts of killer whales in the Arctic. Inuit are the Indigenous people living in Nunavut regions of the Canadian Arctic, and they rely on marine mammals and other available local species for food. Their traditional knowledge is therefore extremely valuable to study marine mammal ecology.
Inuit describe killer whales as fast swimmers that don’t spend much time in the same place, moving around fast. Their relative abundance varies by region but may be higher in North Baffin waters than in other regions. Killer whales in groups of up to 10 individuals were observed following their marine mammal prey, such as beluga whale (Delphinapterus leucas) and bowhead whale (Balaena mysticetus), more frequently through Hudson Strait and Lancaster Sound. Most hunters confirm the increasing abundance of killer whales in the Canadian Arctic, and even suggest it may be also related to the increasing bowhead population.
Inuit are concerned with the presence of this top predator, especially regarding competition for the same food resources. These movements of killer whales in the Canadian Arctic are one of the many ecosystem changes occurring in this region with potential implications for marine mammal populations.
Source: Higdon JW, Westdal KH, Ferguson SH (2014) Distribution and abundance of killer whales (Orcinus orca) in Nunavut, Canada-an Inuit knowledge survey. J Mar Biol Assoc United Kingdom 94:1293–1304. doi: 10.1017/S0025315413000921
Author: Sara Pedro