September 10, 2018 — Decades of politics and foot-dragging have stymied the recovery of threatened and endangered Chinook salmon, while an iconic population of killer whales that depends on them veered toward extinction. Now, a last-ditch effort to save the whales may also be what thwarts the recovery of Chinook.
The Southern Resident killer whales are dying. An extended family of 75 orcas living year-round in the sea surrounding the San Juan Islands near Seattle, their numbers never fully rebounded since aquariums that later became SeaWorld captured a third of them in the late 1960s.
And there are other culprits.
Cargo ships and whale-watching boats zip through the Salish Sea, adding noise that interferes with the whales’ ability to locate each other and their prey. The water they live in is toxic. The Puget Sound outside Seattle is tainted with flame retardant, and PCBs and pollutants gush from nearby rivers into the sea.
The Chinook salmon they eat to live are contaminated with mercury, lead and organic compounds like PCBs. The Washington state Department of Health advises humans to limit their consumption of Chinook salmon to eight ounces per week. But Southern Residents eat dozens of the fish per day.
Not only is their food toxic, there’s also less of it than ever before. Five populations of Chinook the whales depend on are listed as threatened; a sixth is endangered. And they’re smaller, declining in size by 10 percent since the late 1970s, according to research published February in the scientific journal Fish & Fisheries.