Columbia River sockeye salmon have once again broken records by returning past Bonneville Dam in numbers not seen since the dam was completed in 1938. While most of the estimated 600,000 adult sockeye are heading to spawning lakes on the upper Columbia in Washington and British Columbia, the boom is also good news for endangered Snake River sockeye salmon. Enough Snake River sockeye have reached Lower Granite Dam so far this year to make it the third strongest return since 1975.
During some years in the 1990s, fewer than 10 Snake River sockeye returned past Lower Granite. As of July 21, nearly 1,900 sockeye have passed the dam – this passage rate was exceeded only by the totals in 2010 – and we expect more adults to return as the season progresses. Most of the fish migrated downriver as juveniles in 2012, when the abundance of juvenile migrants was well above the ten-year average. They likely benefited from above-average river flows and improved passage conditions at federal dams. In addition, several ocean indicators, including the Pacific Decadal Oscillation (PDO) and food availability, were favorable in 2012.
The surge of sockeye coincides with our release of a proposed recovery plan under the Endangered Species Act for Snake River sockeye. The proposed plan serves as a roadmap to recover these fish, which declined very close to extinction in the 1990s. We worked with federal, state, and tribal biologists and managers, as well as local stakeholders to develop the proposed plan. Implementation of the final plan, once completed, is voluntary and relies on the collective efforts of all partners and stakeholders.
The proposed plan lays out actions to recover the species best known for returning more than 900 miles up the Columbia, Snake, and Salmon rivers to spawn in Redfish Lake, high in the mountains of central Idaho. Though still supported by hatchery production, it’s only in recent years that significant numbers of fish have begun spawning in the wild again.
The recovery actions include steps to restore sockeye habitat and improve their survival through federal dams, as well as further research to help inform recovery strategies. For example, we are investigating the likely causes of unusually high numbers of juvenile sockeye that disappear on their way down the Salmon and Snake rivers before they ever reach the first dam they pass, Lower Granite.
The proposed plan also includes several “modules” that reflect the latest science on each part of the species’ life cycle, such as their time in river, estuarine, and ocean habitats. NOAA Fisheries and our partners may adjust the implementation of the plan over time based on research and monitoring that indicates which recovery actions are most effective.
Implementation of the final plan will rely heavily on the support and involvement of the Idaho Department of Fish and Game, Shoshone Bannock Tribes, the U.S. Forest Service, Bonneville Power Administration, and NOAA Fisheries’ Northwest Fisheries Science Center, among others.
“There’s a long history of really strong partnerships that we’ve built on in developing this recovery plan,” said Rosemary Furfey, NOAA Fisheries’ Snake River Sockeye Recovery Coordinator. “That means we have good support from many stakeholders who want to see this plan – and this species – succeed.”
A sockeye hatchery operated by the Idaho Department of Fish and Game just opened in 2013 and will boost the number of juvenile sockeye salmon migrating to the ocean, where they can take advantage of good conditions such as those that have prevailed in recent years.
An analysis of 25 years of sockeye returns by the Northwest Fisheries Science Center found that strong sockeye returns are most closely related to April upwelling of cold, nutrient-rich water from the deep ocean and a regional climate index that serves as a barometer of ocean conditions.
The conclusion likely applies to this year’s returns as well and indicates that ocean conditions have been favorable for juvenile sockeye, said John Williams, a former NOAA Fisheries researcher and lead author of the paper describing the analysis that was published in Fisheries Oceanography. The authors concluded that sockeye may benefit from productive ocean conditions earlier than other salmon species because they feed lower on the marine food chain and so would more quickly experience improving conditions.
Snake River sockeye and sockeye returning to the Upper Columbia should both benefit from the same favorable ocean conditions, said Rich Zabel, director of the Fish Ecology Division at the Science Center and a coauthor of the paper. Upper Columbia sockeye have also benefited from restoration and reopening of historic habitat on both sides of the U.S.-Canada border. The habitat improvements may have translated into more robust juvenile fish that have a greater likelihood of surviving their years at sea, Williams said.
The draft Snake River Sockeye Recovery Plan is now open to public comment for 60 days. NOAA Fisheries West Coast Region will accept comments through September 19, 2014. The proposed plan and accompanying documents are available at: http://www.westcoast.fisheries.noaa.gov/protected_species/salmon_steelhead/recovery_planning_and_implementation/snake_river/current_snake_river_recovery_plan_documents.html
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