Scientists unravel the mysteries of the Salish Sea

Pilot Stockton Rush emerging from the hatch atop the OceanGate submarine in the San Juan Islands, in the north-western part of the US state of Washington. He is also CEO of Everett-based OceanGate.

By now, the millions of people around the world who followed the saga of a mother orca carrying her dead calf know that the endangered southern-resident orca whales exclusively eat chinook salmon. But what do the chinook eat?

A team of research scientists climbed into a small submarine and plunged to the bottom of the Salish Sea off San Juan Island two weeks ago, in search of the forage fish that are a staple of the chinook’s diet.