August 7, 2018 –A multitude of factors are harming Puget Sound’s local population of endangered orcas: water pollution, noise, loss of habitat.
But topping that list right now for many scientists is recovery of their primary food source: Chinook salmon.
The tragic scenes captured on the water over the past week – of the grieving orca J35 incessantly carrying her deceased calf, and of 4-year-old J50 ill and starving – are sad events, but not surprising to scientists working on orca recovery.
They say they established years ago that when Chinook salmon are scarce, local orcas become sick and unable to effectively reproduce.
“This is just a really conspicuous example of it,” said Sam Wasser, who directs the Center for Conservation Biology at the University of Washington.
He’s part of a team of scientists that has done DNA and hormone analysis of orca scat collected by sniffer dogs. They’ve proved that when pregnant orcas are low on food and start metabolizing their blubber, toxins are released into their bloodstream that cause them to miscarry.