Killer whales are at the top of a complex food web. (Credit: iStock)
Welcome to the killer whales page of the 'I Am Fish' tour. These three guiding words, I am fish, appear simple. But they reflect an ancient and extraordinary web of biological activity that connects humans with the ocean.
I am killer whale
There are two distinct types of killer whale that use the Pacific North Coast Integrated Management Area (PNCIMA): the salmon eating 'residents' and the marine mammal eating 'transients'. Both are top of their respective complex food webs. Near the southern boundary of PNCIMA is the best place in the world to observe the resident killer whales as returning salmon are funneled through the narrow passage that separates Vancouver Island from the rest of Canada. The transients are known to eat pretty much any warm-blooded mammal in PNCIMA including harbour seals, porpoises, dolphins, minke whales, humpback whales, Stellar sea lions, grey whales and sea otters.
Why are killer whales important to humans?
Each year thousands of people come to PNCIMA for the opportunity to see killer whales in the wild. The economic value of killer whales to the whale watching industry is in the millions of dollars per year, but the monetary value is simply the result of capitalizing on the true human value placed on killer whales. That is, the value humans hold for the biology of the animal: its social behaviour, its intelligence and its strength. We carry such powerful aesthetic and intrinsic values for killer whales that many people travel long distances and dispense considerable money to see them. From the logo of the Vancouver Canucks to Miga, the half-whale Olympic mascot, killer whales are emblematic of British Columbia.
What can we do to protect them?
Every aspect of our modern lifestyle impacts the health of killer whales. Airborne pollutants from Asia, sewage contaminants from Victoria, and toxins in runoff waters from Vancouver all find their way into the flesh of killer whales. Both types of killer whales are top predators, and as such they require a robust and clean ecosystem to support their lifestyle.
The transient killer whale is the most contaminated marine mammal on the planet. The combined effects of elevated PCBs, fire retardants (PBDEs), and other contaminants transported from both local and global sources are thought to have serious impacts on the killer whales' reproduction and immunity.
Both types of killer whales are presently at risk due to a combination of factors including toxic contamination and a decline in prey. The residents feed almost exclusively on Chinook salmon, a species prized by both commercial and recreational fisheries. Protecting resident killer whales requires conserving Chinook salmon.
If we succeed in protecting killer whales, then we have likely succeeded in protecting other lifeforms in PNCIMA.
