Exotic species alert

Abnormally high water temperatures experienced by BC this past summer are another example of a changing global environment. Extreme algae blooms, drought-like conditions, and enhanced predation are all deleterious effects of increased local temperatures. Furthermore, with changing temperatures, species can change their native range, including parasites and predators.

For salmon farmers, climate change poses a new set of challenges. Higher water temperatures can support higher growth rates for fish, but are also accompanied by lower dissolved oxygen which has a negative effect on physiological parameters. For example, little information is available on how Atlantic salmon will cope with infectious diseases with the added pressure of higher water temperatures. 

Marine Harvest Canada’s Sarah Harding took a picture of a large sunfish (Mola mola) swimming in Quatsino Sound this September. Over the last few years, the company's staff have reported seeing many exotic species swimming in Quatsino Sound, including large Humboldt squid, which are thought to have negative consequences for migrating juvenile sockeye salmon.