Biodiversity

Trends in Abundance of Killer Whale Populations Along the B.C. Coast.

Southern resident killer whale population trends.

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Northern resident killer whale populations trends.

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Transient killer whales and resident killer whales live in B.C. coastal waters. The resident whales are divided into distinct northern and southern populations.

Photo credit: Department of Fisheries and Oceans Canada

Since 1973, annual counts have showed that:

• Both southern and northern resident killer whale populations have increased.

• In contrast to the southern population, the northern resident population grew steadily to 1991. The northern whales may have fared better because there were more of them originally and they are generally less exposed to disturbance. Also, fewer northern whales (14 individuals) were captured for aquariums before 1974, compared to the estimate of 47 southern resident whales captured (about 40% of the population then).

• Population declines for both populations in the late 1990s may be related to a reduction in numbers of a key prey species for resident whales, the Chinook salmon, along the west coast.

• Southern resident killer whales appear to be the most endangered, but all killer whale populations along the B.C. coast are considered to be at risk. A species recovery strategy has been drafted for the northern and southern resident populations.

For detailed information, including graph data, see In-Depth report [pdf].

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