Effects of dissolved gas supersaturation on fish residing in the Snake and211 Columbia rivers, 1997

摘要

Large amounts of spill at dams has commonly generated levels of dissolved gas211u001esupersaturation that are higher than levels established by state and federal 211u001eagencies setting criteria for acceptable water quality in the Columbia and Snake 211u001eRivers. Large spill volumes are sometimes provided voluntarily to increase the 211u001eproportion of migrating juvenile salmon that pass dams through nontubine routes. 211u001eHowever, total dissolved gas supersaturation (TDGS) resulting from spill in past 211u001edecades has led to gas bubble disease (GBD) in fish. Therefore, during the period 211u001eof high spill in 1997, the authors monitored the prevalence and severity of gas 211u001ebubble disease by sampling resident fish in Ice Harbor reservoir and downstream 211u001efrom Ice Harbor and Bonneville Dams.