Research team in U.S. buys `salmon ranch' to feed orcas

An American group that has studied the decline of the southern resident orca population for more than four decades has acquired land on either side of a Washington state river with hopes it can restore chinook salmon runs for an “ecosystem approach” to feeding the whales.

The Center for Whale Research, based in Friday Harbour, Wash., said chinook salmon are the main food source for the resident orcas, whose numbers have been squeezed to 74 largely because of dwindling salmon stocks in the Salish Sea. The centre has acquired 45 acres on the Elwha River near Port Angeles on the Olympic Peninsula, where native chinook salmon spawn. They've dubbed the property Big Salmon Ranch.

The U.S. government in 2014 removed two hydroelectric dams that blocked salmon runs on the Elwha, and fish populations are improving, said Ken Balcomb, the centre's founder and senior scientist.

“The salmon are coming back in greater numbers each year and in 20 more years they may reach historical population levels,” he said. “Restore the ecosystem and the salmon will recover. We decided to champion a good example as a model for other river ecosystems that can ultimately provide food for the southern resident orcas.”

Balcomb said the group will keep its Elwha ecosystem habitat in an undisturbed, non-resource-extraction condition in perpetuity so that chinook salmon can recover to pre-dam levels of 25,000 to 33,000 returning adults in the coming decades.

The 7,400 chinook that recently returned to the Elwha created about 900 redds, or spawning nests, each containing about 5,000 fertilized eggs.