Preface 



Gas bubble disease resulting from exposure of 

 aquatic organisms to water supersaturated with 

 dissolved gas was described some 100 years ago, 

 but only in the past decade has a serious problem 

 been recognized in a natural river system. Opera- 

 tion of spillways at hydroelectric generating facili- 

 ties on the Columbia River and its major tributaries 

 results in entrainment of air into the river water, 

 increasing the dissolved gas content to supersatu- 

 rated levels. The resulting gas bubble disease is a 

 factor contributing to observed declines in salmo- 

 nid fish stocks. Even more recently, a widespread 

 gas bubble disease problem has been realized with 

 fish kills in steam generating station discharge 

 plumes, both at freshwater and marine sites. In 

 these cases, supersaturation is caused by the de- 

 crease in gas solubility which accompanies heating 

 of water used to cool condensers. 



In the past several years, intensive research 

 efforts have been undertaken by several agencies 

 in the Pacific Northwest. These projects have been 

 broadly scoped with major goals of prediction of 

 gas levels and their effects, reduction of impacts 

 on populations of aquatic biota, and development 

 of national water quality criteria and standards. 

 Many of these studies have progressed to a point of 

 having a sufficient data base to begin drawing 

 major conclusions and we have been encouraged 

 by work in other regions. The Nitrogen Task Force 

 has served as an informal forum for exchange of 

 ideas and development of plans for future work, 

 but we felt a need for a Gas Bubble Disease Work- 

 shop to draw together on-going research within the 



Pacific Northwest as well as other regions. The 

 workshop format included formal presentation of 

 papers printed herein and a series of informal 

 round table discussions charged with determining 

 research needs in specific areas of interest. Notes 

 of the round table discussions are also included 

 herein. It is with the hope of stimulating further 

 research efforts and providing a comprehensive 

 view of on-going projects that we present these 

 proceedings. 



The success of the Gas Bubble Disease Work- 

 shop was certainly due to the efforts of participants 

 for which we thank them. Those who accepted our 

 invitations to co-chair round table discussions con- 

 tributed significantly to the workshop. Additionally, 

 many Battelle-Northwest staff members contributed 

 significantly to the workshop, and their aid is also 

 appreciated. In particular, J. C. Montgomery, R. W. 

 Hanf, Jr., J. C. Mourich, and J. L. Helbling deserve 

 special recognition for their hard work. 



Duane H. Fickeisen 



Mark J. Schneider 



Richland, Washington 



November 1975 



For Battelle-Northwest and the Division of Bio- 

 medical and Environmental Research of the Energy 

 Research and Development Administration. 



