BPA Fish and Wildlife FY 1998 Proposal

Section 1. Summary
Section 2. Goals
Section 3. Background
Section 4. Purpose and methods
Section 5. Planned activities
Section 6. Outcomes, monitoring and evaluation
Section 7. Relationships
Section 8. Costs and FTE

see CBFWA and BPA funding recommendations

Section 1. Summary

Title of project
Effects of Dissolved Gas Supersatuaration on Resident Fish

BPA project number   9602200

Short description
Evaluate the effects of dissolved gas supersaturation on resident fish downstream from Bonneville and above and below Ice Harbor Dams.

Business name of agency, institution or organization requesting funding
National Marine Fisheries Service

Proposal contact person or principal investigator

Section 2. Goals

General
Supports a healthy Columbia basin; adaptive management (research or M&E)

Section 3. Background

Stream area affected

Stream name   Lower Snake, Lower Columbia
Stream miles affected   SRm 1-15, CRm 130-140
Hydro project   Effects from spill produced by all projects.
Subbasin   Mainstem
Habitat types   Riverine, Reservoir.

History
In 1993, fish and invertebrates were sampled and examined for gas bubble disease (GBD) downstream from Bonneville Dam during the spring freshet; funded by the U.S. Army Corps of Engineers (COE) $15K. In 1994, fish and invertebrates were sampled and examined for GBD, then held in net-pens for 4 days to evaluate changes in GBD signs and survival in the lower and mid-Columbia River and the lower Snake River. Evaluations were continued throughout the period of spill provided for passage of juvenile salmonids; funded by the COE $132.5K. In 1995 and 1996, sampling and holding activities similar to 1994 were conducted; funded by the COE $188.2K, and BPA $205.5K, respectively.

Biological results achieved
Impacts of GBD to the aquatic biota in the reaches of highest dissolved gas have been evaluated by spill managers. Dissolved gas levels and durations of exposure which cause signs of GBD and mortality in captive fish and invertebrates have been documented and have been incorporated into a predictive model.

Project reports and papers
Schrank, B. P., B. Ryan, and E. M. Dawley. (in preparation). Evaluation of the effects of dissolved gas supersaturation on fish in the mainstem Columbia and Snake Rivers, 1996. Report to the Bonneville Power Administration, Contract # 96-BI-93605, Project No. 96-022, 49p. (Available from Northwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA 98112-2097.)
Schrank, B. P., E. M. Dawley, and B. Ryan. 1996. Evaluation of the effects of dissolved gas supersaturation on fish and invertebrates in Priest Rapids Reservoir, and downstream from Bonneville and Ice Harbor Dams, 1995. Report to the U.S. Army Corps of Engineers, Contract E96940029, (Available from Northwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA 98112-2097.)
Toner, M. A., E. M. Dawley, and B. Ryan. 1995. Evaluation of the effects of dissolved gas supersaturation on fish and invertebrates downstream from Bonneville, Ice Harbor, and Priest Rapids Dams, 1994. Report to the U.S. Army Corps of Engineers, Contract E96940029, 43p. (Available from Northwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA 98112-2097.)
Toner, M. A., and E. M. Dawley. 1994. Evaluation of the effects of dissolved gas supersaturation on fish and invertebrates downstream from Bonneville Dam, 1993. Report to the U.S. Army Corps of Engineers, Contract DACW57-85-H-0001, E96940029, 23p + Appendix. (Available from Northwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA 98112-2097.)

Adaptive management implications
During periods of high spill over dams on the Columbia and Snake Rivers, results from this study may be used as an index to assess the impacts of gas supersaturation on salmonid (Oncorhynchus spp.) and resident nonsalmonid fish.

Section 4. Purpose and methods

Specific measureable objectives
During the periods of high spill, we will monitor the prevalence and severity of GBD by sampling resident fish downstream from Bonneville and Ice Harbor Dams and upstream from Priest Rapids Dam. The long-term goal of this study is refinement of a multiparameter model relating dissolved gas supersaturation levels (related to water flow and spill volumes) to signs of GBD and mortality in shallow-water fishes. Using regression analysis, we will compare duration and concentration of exposure to ambient dissolved gas levels with signs of GBD and mortality in organisms sampled from the river and held in net-pens.

Critical uncertainties
Impacts to resident fish from GBD may be inconsequential or difficult to assess. Criteria based on faulty conclusions from resident fish sampling data could cause negative effects on measures taken to improve survival of migrating juvenile salmon.

Biological need
To determine the relationship between the supersaturated dissolved atmospheric gases and the prevalence and severity of GBD in resident salmonid and nonsalmonid fish. Provide spill managers an index on impacts of GBD on resident fish during the spill season.

Hypothesis to be tested
Specific levels of supersaturation of dissolved atmospheric gasses cause gas bubble disease (GBD), which may be lethal to resident fish.

Alternative approaches
Effects on resident fish could be ignored and effects of GBD on salmonids used as the only criterion for regulating spill at dams. We believe that the effects on resident fish are different and often greater than salmonids because of the duration of exposure to dissolved gas supersaturation. Severe impacts to resident fish populations could result from this narrower management perspective. A resident fish model relating dissolved gas levels to signs and mortality from GBD has been developed. However, confidence intervals are still quite broad for the mortality evaluation. More data are necessary to develop a more comprehensive and robust model.

Justification for planning
The potential of mortality unidentified by other means is a serious and unacceptable risk.

Methods
Weekly from each river reach (downstream from Bonneville Dam and Ice Harbor Dam and upstream from Ice Harbor Dam), up to 100 individuals of a targeted resident fish species will be collected and examined for signs of GBD. In some shallow areas, a 7.5-m 2-stick seine with 12.7-mm webbing will be used to collect fish. Along shorelines with a steep gradient, a 3.4-m-deep, 50-m variable-mesh beach seine will be used for sampling. In mid-channel, a purse seine will be used. The primary sampling method will be electrofishing using a boat equipped with a pair of adjustable booms fitted with umbrella anode arrays. All fish will be anesthetized, identified, measured to the nearest millimeter, and examined for external injuries and signs of GBD (subcutaneous emphysema on fins, head, eyes, and body surface). Fish will then be examined within 15 minutes of collection using a dissecting microscope with 15- to 40-power magnification. Specimens collected from each river reach will be held in net-pens and cages for 4 days, and then reexamined for prevalence of GBD. Analysis of variance will be used to determine relationships between dissolved gas levels, exposure duration, GBD signs, and GBD-related mortality.

Section 5. Planned activities

Constraints or factors that may cause schedule or budget changes
Changes in state water quality waivers might change the dates and amounts of spill. If in 1997, the refinement of the resident fish GBD model increases the precision of mortality predictions to an acceptable level, that model may replace the need for subsequent sampling and holding research. Handling mortality to juvenile salmonids of about 0.5% and to resident species of about 5%.

Section 6. Outcomes, monitoring and evaluation

SUMMARY OF EXPECTED OUTCOMES

Expected performance of target population or quality change in land area affected
Development of predictive model to index impacts to resident fish from dissolved gas supersaturation.

Present utilization and convservation potential of target population or area
N/A

Assumed historic status of utilization and conservation potential
N/A

Long term expected utilization and conservation potential for target population or habitat
N/A

Contribution toward long-term goal
Development of a predictive model for impacts to resident fish from dissolved gas supersaturation.

Indirect biological or environmental changes
Cessation of sampling for effects of GBD.

Physical products
NA

Environmental attributes affected by the project
Reevaluation of requests for voluntary spill at dams.

Changes assumed or expected for affected environmental attributes
N/A

Measure of attribute changes
N/A

Assessment of effects on project outcomes of critical uncertainty
Continued refinement of the model--at lease one additional year of data--will protect against the potential of drawing faulty conclusions.

Information products
Prevalence of GBD in resident fish populations that inhabit shallow water areas of the mainstem river, and an estimate of mortality from GBD.

Coordination outcomes
Re-evaluation of spill volumes/dissolved gas levels in the mainstem river.

MONITORING APPROACH
(See Methods section)

Provisions to monitor population status or habitat quality
The COE will be monitoring levels of dissolved gas.

Data analysis and evaluation
Through statistical analyses comparing data sets from previous years and other locations.

Information feed back to management decisions
Re-evaluation of recommendations to use model in lieu of continued sampling and testing .

Critical uncertainties affecting project's outcomes
Research could be conducted to evaluate the abundances of resident fish species, thus evaluate impacts from GBD by examination of fluctuations in the population.

Evaluation
Weekly reports of GBD in resident fish. Confidence limits on model parameters.

Incorporating new information regarding uncertainties
Through discussions with investigators and contracting officer's technical representative.

Increasing public awareness of F&W activities
Through dissemination of results.

Section 7. Relationships

Opportunities for cooperation
None at this time

Section 8. Costs and FTE

1997 Planned  $180,000

Other non-financial supporters
None