Species spotlight: Orca
Common name: Orca, or Killer Whale
Latin name: Orcinus orca
Status under SARA: There are several populations of Orca found in Canadian waters, some of which are considered “transient” and others that are “resident”. BC’s Northeast Pacific southern resident population is Endangered; BC’s Northeast Pacific northern resident, transient and offshore populations are each listed as Threatened. The Northwest Atlantic/Eastern Arctic population has been proposed for listing as Special Concern.
Range: Members of the various populations are found in Canada’s Pacific, Arctic, and Atlantic oceans both in deep offshore waters and in near shore, coastal and estuarine areas. Orcas are not known to occur in the waters of the central Arctic where sea ice is more persistent.
Population Estimate: Fewer than 78 individuals are thought to remain in BC’s Pacific southern resident population, while up to 200 individuals could remain in BC’s Pacific northern resident population. Both populations have experienced steady declines in recent years.
Size: On average less than 9 m in length for adult males, and less than 7.7 m for adult females. The prominent dorsal fins of adult males can stand up to 1.8 m tall, while the dorsal of females and juveniles are about 1 m in height and tend to appear more hook-like in shape.
This iconic marine species is well-known among Canadians and are easy to recognize given their black and white pattern and tall dorsal fin. British Columbia’s resident populations are unique in that they tend to travel in larger groups, or “pods”, than their transient and offshore cousins, and they show unique behaviours and dietary preferences. Resident populations predominantly feed on fish and not marine mammals, and as such their numbers seem to fluctuate with the availability of their prey – the five different salmon species on BC’s coast (i.e., Sockeye, Pink, Chum, Coho and Chinook salmon). As a result, BC’s resident killer whale populations are critically linked to the fate of salmon, whose own numbers have been declining in recent years. The 2012 Cohen Commission of Inquiry was even formed to investigate the decline of Fraser River Sockeye Salmon. And it doesn’t stop there – impacts on the food supply and habitat that Pacific salmon rely upon can ultimately impact BC’s resident Orcas.
Given the intricacy of linkages between BC’s freshwater salmon spawning grounds and the coastal and near shore waters where adult salmon serve as food for resident Orca populations, we need to be prudent and conservation-minded with industrial developments and other human activities that could disrupt nature’s balance in BC – and elsewhere. To provide a voice for nature in these matters, Nature Canada and BC Nature are working with the UVic Environmental Law Centre, as interveners in the hearings for the TransMountain project. This project which would see large increases in oil tanker traffic – and the risk of one or more serious oil spills – throughout the range of BC’s southern resident Orca population. Under SARA, both the critical marine habitat of these Orcas, and the individual whales themselves, are protected from harassment, harm and destruction.
Let’s hope that nature’s voice makes a positive difference for BC’s southern resident and other Orca populations!