Can Columbia Basin Sockeye Salmon Adapt to a Changing Environment?

Columbia Basin sockeye salmon have adapted to one of the most changed environments of that of any salmon run in the world.  Prior to white settlement of the region, perhaps three to four million or more sockeye salmon returned to eight subbasins.  By the late 20^th century, the run reached a low in 1995 of fewer than 10,000 fish returning to the Wenatchee and Okanagan subbasins combined, and none returning to the Snake Basin.  Impassible dams, overfishing, water diversions, habitat destruction, and mainstem passage issues all contributed to this decline.  Sockeye salmon were seemingly doomed, done in by their inability to adapt to a changed environment. 

However, in less than 20 years, there has been a remarkable resurgence to the point where last year’s run of over 385,000 fish was the largest recorded since the mainstem dam fish counting program began in the 1930’s.  The reasons for this are unclear and controversial, likely including improved ocean conditions, improved passage through the hydrosystem, and improvements in freshwater habitat.  It is also unclear whether this is a temporary blip in the long term decline of the stock, or a permanent turnaround.  Reasons for optimism include

1.)     The remarkable work going on in the Okanagan, including habitat restoration, sockeye reintroduction, and an innovated water management tool

2.)    Increased Snake and Wenatchee Basin sockeye runs and better understanding of the stocks,

3.)    Programs to restore sockeye salmon to the Yakima and Deschutes basins and the push to start similar programs for the Wallowa and Canadian Columbia River lakes. 

Looming over Columbia Basin sockeye salmon restoration efforts is the effects of climate change on the world’s southern most sockeye stocks with some of the world’s longest migrations through what is already one of the world’s warmest salmon rivers.  Climate change will not only increase water temperatures, but along with an increasing human population, decrease water flows upon which sockeye salmon depend.  

This presentation will serve as a keynote address for the Columbia River portion of the symposium, raising some of the issues that will be addressed in subsequent presentations.