COLUMBIA RIVER SPRING-SUMMER CHINOOK STUDIES

Columbia River Studies

Kintama’s previous work on spring-summer Chinook has focused on resolving two key policy issues:

(1) “Delayed Mortality” – that Snake River dam passage reduces smolt survival later in life.

(2) “Differential Delayed Mortality”  – That smolt transportation reduces smolt survival later in life.

We use our array design to directly test the theory that increased dam passage or barging reduces smolt survival.  We do this by comparing survival of smolts subject to contrasting experimental treatments (passage through 4 vs 8 dams, or 8 dams vs barge transport).

See applications pages for more information

So far, we have found that lower river & early ocean survival is indistinguishable between release groups, and therefore ther is no evidence to support either theory.    What is most remarkable about our work is that it demonstrates that we can now (a) do rigorous experimental science directly in the ocean and (b) follow smolt migrations for thousands of kilometers.  These are the animations.

Click on the box in the lower right corner for the full-screen animation.

Columbia River 2011

In 2011, all tagged smolts were released below Bonneville Dam (avoiding the 50% in-river mortality loss that the smolts would otherwise experience). Upstream sub-arrays in the Columbia River were removed, as was the sub-array near Graves Harbor AK, and the remaining cross-shelf marine sub-arrays were extended out to 500m water depths. We also deployed a line of receivers south of the Columbia River near Cascade Head, Oregon, in case any smolts migrated in that direction. Smolts were collected at the dams, tagged, and tissue samples collected for subsequent genetic analysis to identify where the tagged smolts originally came from. You can see that from the animation that only one Snake Run of River (ROR) smolt migrated south – and it turned around and headed north again afterwards at about twice the speed of the other smolts, suggesting that it was trying to make up for lost time on its migration!. Also note that some smolts hung around the river mouth for a long time. (2011 report currently in preparation).

Columbia River 2010

We found no difference in survival between Snake & Yakima River hatchery reared spring Chinook smolts in 2006-2009, so we moved tagging locations to Lower Granite & John Day dams in 2010.  Here are the animations of mixed release groups of hatchery and wild-origin spring Chinook tagged at these dams.  Note the smolts migrating to Alaska, 2500 km distant from the release point and the smolts re-entering the river & migrating back upstream!  Read the report.

Columbia River 2008 vs 2009

A comparison of the migrations of Kintama’s acoustically tagged Yakima & Snake River spring Chinook smolts in 2008 & 2009.  Despite the differences in dam passage history, lower river & early ocean survival was nearly identical, as was the survival of transported smolts. Read the multi-year report

Columbia River 2009

An expanded animation, showing more clearly the smolt movements in 2009.  Note the smolts migrating to Alaska, 2500 km distant from the release point.  The “clock” (bottom left on screen) shows that the 2,500 km migration took 3 months. Read the report

Columbia River 2008

An expanded animation, showing the smolt movements in 2008.  Note the smolts migrating to Alaska, 2500 km distant from the release point.  The “clock” (bottom left on screen) shows that the 2,500 km migration again took 3 months. Read report

Columbia River 2006

Smolt movements in 2006. Note the smolts migrating to Alaska, 2500 km distant from the release point.  The “clock” (bottom left on screen) shows that the 2,500 km migration again took 3 months.