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Investigations of Adult Salmonids at Bonneville Dam for Gas Bubble Trauma, 1995

Nov 4, 2019


Since 1987, the Columbia River Inter-Tribal Fish Commission’s (CRITFC) Stock Assessment Project has conducted research on adult salmon runs at Bonneville Dam. These studies were established to monitor the age and length-at-age composition of Columbia Basin salmonids and to design and develop salmon stock identification techniques. In 1995, the National Marine Fisheries Service (NMFS) requested that CRITFC increase its sampling effort at Bonneville Dam an additional two-days-per week (14 May 1995 through 24 June 1995) to evaluate the effect of increased spill over mainstem dams on adult migrating salmon. NMFS was particularly concerned whether elevated nitrogen levels in the water might result in gas bubble trauma in fish. CRITFC agreed to perform the requested studies using methods employed in its Stock Assessment projects to examine and evaluate the physical condition, level, and nature of any injuries noted among fish sampled.



Pederson, D., L. Gramman, and J.K. Fryer. 1995. Investigations of adult salmonids at Bonneville Dam for gas bubble trauma, 1995. Columbia River Inter-Tribal Fish Commission Technical Report 95-05. Portland, OR. 9p.



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CRITFC Technical Report