|Document Type:||Chapter or Section|
|Type of Book:||Technical|
|Section or Chapter Title:||Effects of long-term exposure to supersaturation of dissolved atmospheric gases on juvenile Chinook salmon and steelhead trout in deep and shallow test tanks|
|Book Title:||Gas bubble disease: proceedings of a workshop held at Richland, Washington, 8-9 October 1974|
|Author:||Earl M. Dawley, Michael H. Schiewe, Bruce H. Monk|
|Editor:||Duane H. Fickeisen, Mark Joseph Schneider (Eds.)|
|Publisher:||Energy Research and Development Administration, Technical Information Center Office of Public Affairs. Oak Ridge, Tennessee|
Bioassays in shallow (0.25 m) and deep (2.5 m) tanks with dissolved atmospheric gas concentrations ranging from 100 to 127% of saturation in water at 10°C were conducted to determine the lethal and sublethal effects on juvenile fall chinook Oncorhynchus tschawytscha and steelhead trout Salmo gairdneri. Juvenile fall chinook (38.7-41.3 mm) were much more resistant to supersaturation than juvenile steelhead (164-196 mm). Chinook tested in the shallow tanks at 120% of supersaturation incurred 50% mortality after 22 d, whereas steelhead tested at the same level incurred 50% mortality in 30 hr. Gas bubble disease signs were noted on mortalities and on live subsamples taken every 28 d. Vertical distribution of both chinook and steelhead groups in the deep tanks appeared to compensate for about 10 and 10 to 15%, respectively, of effective saturation. Average depths of the fish tested in deep tanks increased with increased gas concentration. Significant differences in growth and condition factor were not found between stressed and control fish during the test period.