Gas Bubble Trauma Observed in Fish – Preliminary Analysis
Margaret J. Filardo
"Fish were sampled at Lower..."
Fish were sampled at Lower Granite, Little Goose, Lower Monumental, McNary, Bonneville and Rock Island Dams.
Over 9000 fish were examined for GBT during the spring migration season.
COE Waiver Conditions for GBT are 15% of fish showing signs of GBT in non-paired fins.
At tailrace TDG levels near 120% the incidence of GBT in migrating salmonids was minimal.
Project operations limitations at Lower Granite Dam resulted in higher TDG levels that showed effects of GBT in fish over long periods of time.
Operations for management of excess market spill resulted in elevated levels of GBT in migrating salmonids.