Re: “Ottawa spending millions to help endangered orcas” and “Washington state moves to protect endangered southern residents,” March 16.
These articles failed to address a couple of noteworthy things regarding prey availability for resident orcas, more resources for local salmon enhancement being one of them.
The southern resident orcas are facing increased competition for salmon in large part due to the increase in harbour seal and California sea lion populations since the enactment of the Marine Mammal Protection Act in 1972. California sea lions populations that once numbered fewer 10,000 have now increased to more than 300,000.
According to the National Oceanic and Atmospheric Administration, pinnipeds, including orcas, consumed five million chinook salmon from California to Alaska in 1975. By 2015, the numbers rose to about 31.5 million. By contrast, recreational and commercial fisheries harvested 3.6 million chinook salmon in 1975, declining to 2.1 million fish by 2015.
In the Salish Sea, harbour seals alone consumed 68 tonnes of chinook salmon in 1970. By 2015, they were consuming 625 tonnes, double the amount consumed by orcas in the same location, and six times the volume caught by commercial and recreational fishermen.
This speaks volumes about our disappearing salmon.
Apart from the numbers thing, the lack of abundant forage fish, such as herring impacted by a century of industrial fishing, is cited as a major factor in the increased predation of juvenile and adult salmon by harbour seals and sea lions.
Allan Crow
East Sooke
