Re: “Ottawa cutting chinook catch to save orcas,” May 25.
The article concerning the decline of chinook salmon and orca populations fails to mention the influence of seals.
According to the University of British Columbia marine mammal research unit, seal numbers in the Strait of Georgia increased from about 5,000 to more than 40,000 from 1970 to 2008, and now kill about half of the juvenile coho and chinook. Reducing the salmon sport catch without addressing the exploding numbers of seals will not help the orcas much.
Is it possible that seal numbers are unsustainably high because they were severely culled prior to 1970, which in turn eliminated their natural predators, the transient killer whales? The transients have not yet returned in sufficient numbers to adequately control the seal population.
If it is now politically incorrect to kill seals directly, perhaps ways might be explored to increase the transient killer whales, which would also support the whale-watching industry.
The salmon also have a new predator to deal with — California sea lions, which have recently invaded in large numbers. I understand transient killer whales find this U.S. invader tasty, as well as seals.
Bruce Pendergast
Victoria
