Important findings from the 2011 Columbia River Chinook salmon survival study

Kintama has released preliminary results from the 2011 study: Estuarine and Early Marine Survival and Movements of Yearling Chinook Salmon funded by Bonneville Power Administration (BPA). Kintama’s Research Manager, Dr. Erin Rechisky, presented the results at the Anadromous Fish Evaluation Program (AFEP) forum on December 1, 2011. The study included tagging of approximately 800 Chinook yearlings, a portion of these were captured at the Lower Granite Dam and then transported to below Bonneville Dam, and another portion was collected, tagged, and released at the Bonneville Dam. DNA samples were collected from each fish to ascertain stock origin. The major findings, some expected and some not so, included:

  • Yearling Chinook smolts migrate north upon ocean entry more than 95% of the fish detected in the ocean were detected on our acoustic sub-array north of the Columbia River mouth
  • Smolts migrate farther offshore at Willapa Bay, WA, but are closer to shore off of Lippy Point, BC
  • Smolt survival in the lower Columbia River and estuary was high, while survival in the coastal ocean and particularly the plume, was lower.
  • Post-Bonneville Dam survival was similar for Snake River and Columbia River yearling Chinook tagged and released at Bonneville Dam. We found no evidence of delayed mortality for smolts migrating through Snake River dams
  • Post-Bonneville survival in the lower Columbia River and estuary was similar for Run Of River and Transported Snake River yearling Chinook