Orcas growing factor in Columbia River salmon management

There was fascinating news last week about southern resident killer whales that have an extensive connection to the Columbia River. These scientific findings could have a major impact on salmon management and the hydroelectric system.

For many years there were occasional reports of orcas being seen by fishermen working offshore in the Columbia River plume. Starting in 2013, a satellite-tracking program showed how they also range up and down the outer coast. They appear to bide their time, waiting for returning Chinook salmon to begin congregating near the Columbia’s mouth.

Last week’s most attention-grabbing orca news involved a different new technology — use of a camera drone this fall to conduct a thorough survey of the J, K and L pods in Washington’s Puget Sound. Photos reveal the orcas’ everyday behavior, without the drone appearing to disturb them in any way. The 82 famous killer whales are doing very well, with new 2015 calves fattening and additional females showing signs of pregnancy. This is extraordinarily promising news for animals that are counted among the eight most endangered species in the U.S.

This comes in a year of healthy Chinook salmon runs, especially to the Columbia-Snake system. The annual count is now above 1.3 million returnees to Bonneville Dam. Unlike transient killer whales that range around the North Pacific hunting smaller marine mammals, the Puget Sound orcas are strictly fish-eaters, strongly preferring Chinook. This abundant year has clearly set off an enthusiastic round of baby-making.

An unfortunate fact of life for orcas — and everything else that relies on salmon — is that runs fluctuate. This year’s extreme Pacific Northwest drought and the warm El Niño waters now dominating the Pacific may mean a sharp decline in salmon two to four years from now.

A thorough report by The Seattle Times explores the Puget Sound orcas’ strong Columbia River connection:

• “Scales and fish tissue samples from fish kills by orcas has enabled researchers to trace those fish to Canada’s Fraser River in the summer, and the Upper Columbia and Snake River in the winter.”

• “A conservation biologist at the University of Washington … has noticed in his research on orcas that thyroid hormone levels that set metabolic rates are highest when the orcas arrive in late spring, suggesting the whales are arriving in Puget Sound after feeding on a rich food source: spring runs of Columbia Chinook salmon.”

This news is bringing a renewed interest in returning the Snake River to a natural-flow regime, something that would require bypassing four hydroelectric dams. This has been a nonstarter for regional politicians for years. But the amazing popularity of orcas and stringent federal legal protections conferred on them could be a game-changer.

While dam removal could eventually enhance salmon runs, the orca-Columbia connection could also bring additional fishing restrictions, notably in years when salmon are in short supply.

It is anybody’s guess how all this orca news will balance out for local fishermen. But it’s still fun knowing our local waters play such a key part in the lives of this iconic Northwest species. We look forward to many more sightings this winter and next spring.