Gas Bubble Disease Monitoring and Research
of Juvenile Salmonids

The Problem

Spill at Bonneville Dam.

A management decision was made in 1994 to increase survival of migrating juvenile salmon by increasing the proportion of river water and fish passed via spill at Snake and Columbia river dams. One result of this action was an increase in dissolved gas supersaturation, which can lead to gas bubble disease in fish. This disease can lead to impairment or death of fish due to gas emboli in the gills and tissues. Indirect mortality can also occur through increased susceptibility to predators or disease, but little is known about other sub-lethal effects. Concerns about the risk of gas bubble disease in fishes in the Columbia Basin have heightened with the recent increased use of spill. This project is funded under reimburseable customer agreement number 96AI93279 (BPA).

Objectives

The objectives of this research are to: (1) determine the progression of signs of gas bubble disease and their usefulness as monitoring tools; (2) provide training and quality control for a biological monitoring

Gas bubbles in gill filaments.

program; and (3) identify the risk of juvenile chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) fish to gas bubble disease based on their vertical and horizontal location relative to ambient dissolved gas in the Columbia and Snake rivers (fish are less susceptible to gas bubble disease at depth). Beginning in 2000 this project has provided assistance to regional fisheries managers by training people to monitor fish for signs of gas bubble disease and providing quality assurance/quality control (QA/QC) of these monitors during spring and summer. Current tasks involve maintaining dissecting microscopes, training other agencies' personnel and providing QA/QC during the spring and summer emigrations of juvenile salmon.

Highlights and Key Findings

Bubbles in the lateral line.

All data collection on this project has been completed and the final report to the funding agency was completed in 2000. Beginning in 2000 through 2003, we provided training, QA/QC, and equipment maintenance (microscopes etc.) for the agencies involved in monitoring fish for signs of gas bubble disease as part of the Biological Monitoring Program on the Columbia and Snake rivers.

Where Are We Headed In 2003

In FY2003, this project will continue to provide assistance to regional fisheries managers by maintaining dissecting mircoscopes, training people to monitor fish for signs of gas bubble disease and providing QA/QC of these monitors during spring and summer.

Project Contact

Alec G. Maule
U.S. Geological Survey
Western Fisheries Research Center
Columbia River Research Laboratory 5501-A Cook-Underwood Rd.
Cook, WA 98605-9717

Email: alec_maule@usgs.gov
Phone: 509-538-2299
Fax: 509-538-2843

Publications