Orca survival may be impossible without Lower Snake River dam removal, scientists say

Southern resident orcas that frequent Puget Sound may not survive without breaching the Lower Snake River dams to help the salmon the orcas live on, scientists say.

Leading killer-whale scientists and researchers are calling for removal of four dams on the Lower Snake River and a boost of water over the dams to save southern resident killer whales from extinction.

The scientists sent a letter Monday to Gov. Jay Inslee and co-chairs of a governor’s task force on orca recovery.

The whales need chinook — their primary prey — year round, scientists state in their letter, and the spring chinook runs in particular returning to the Columbia and Snake are among the most important. That is because of the size, fat content and timing of those fish, making them critical for the whales to carry them over from the lean months of winter to the summer runs in the Fraser River, the scientists wrote.

The need for Columbia and Snake river fish is so acute, “we believe that restoration measures in this watershed are an essential piece of a larger orca conservation strategy. Indeed, we believe that southern resident orca survival and recovery may be impossible to achieve without it.”

Based on the science and the urgency of the current threats confronting the southern residents, the scientists recommended two top priorities for the task force in its recommendations for orca recovery: Immediately initiate processes to increase the spill of water over the dams on the Columbia and Snake, to create more natural river conditions, and to breach the Lower Snake River dams.

The letter comes as the death of three southern resident orcas in four months last summer, one from L pod and two in J pod, have added fuel to the long running-campaign to free the Snake. Read full article.