BPA Fish and Wildlife FY 1997 Proposal

Section 1. Administrative
Section 2. Narrative
Section 3. Budget

see CBFWA and BPA funding recommendations

Section 1. Administrative

Title of project
Evaluating Effects of Dissolved Gases on Resident Fish

BPA project number   9602200

Business name of agency, institution or organization requesting funding
NMFS

Sponsor type   WA-Federal Agency

Proposal contact person or principal investigator

BPA technical contact   , EWP

Biological opinion ID   

NWPPC Program number   

Short description
Evaluation of the effects of dissolved gas supersaturation on fish in Priest Rapids Reservoir, and downstream from Bonneville and Ice Harbor Dams.

Project start year   1996    End year   1999

Start of operation and/or maintenance   0

Project development phase   Maintenance

Section 2. Narrative

Related projects
GBD monitoring of juvenile salmonids under FPC.

Project 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 US 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, sampling and holding activities similar to 1994 were conducted; funded by the COE $188.2K.

Biological results achieved
Impacts 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 are being incorporated into a predictive model.

Annual reports and technical papers
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.)

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.

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 to develop a multiparameter model relating dissolved gas supersaturation levels (related to water flow and spill volumes) to signs of GBD and mortality in shallow-water organisms. 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 at the three river sections.

Testable hypothesis
Specific levels of supersaturation of dissolved atmospheric gases cause gas bubble disease (GBD), which is lethal to resident fish.

Underlying assumptions or critical constraints
Spill will be used to increase survival of juvenile salmonids passing through Columbia and Snake River dams. Many studies have concluded that spill provides the safest passage route through dams on the Columbia and Snake Rivers. Increased spill has raised concern that a subsequent increase in dissolved gas levels of the water may be detrimental to the aquatic biota.

Methods
Weekly from each river reach (downstream from Bonneville Dam, downstream from Ice Harbor Dam and downstream from and in the reservoir of Priest Rapids 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. 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.

Brief schedule of activities
Starting the last week in March, fall chinook salmon emigrating from Spring Creek Hatchery will be sampled along with resident fish during the period of spill for fish passage. Thereafter, at the onset of spill in the three river reaches, resident salmonids and non-salmonids will be collected and examined for GBD on a weekly basis. Most of the resident non-salmonids will be collected and examined for GBD on a weekly basis in the three river reaches. Most of these organisms will be placed in net-pens and examined for GBD after a 4-day holding period. This will also be performed on a weekly basis. The 1996 field season is expected to be completed about mid August.

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.

Critical uncertainties

Impacts to resident fish from GBD may be inconsequential or difficult to assess.

Summary of expected outcome
Development of predictive model to index impacts to resident fish from dissolved gas supersaturation.

Dependencies/opportunities for cooperation

Risks
Handling mortality to juvenile salmonids of about 0.5 % and to resident species of about 5 %.

Monitoring activity
Weekly sampling results distributed through FPC and annual presentation and written reports will provide results of this study for review by outside agencies.

Section 3. Budget

* For most projects, Authorized is the amount recommended by CBFWA and the Council. Planned is amount currently allocated. Contracted is the amount obligated to date of printout.

Funding recommendations

CBFWA funding review group   Mainstem

Recommendation    Tier 1 - fund

Recommended funding level   $180,000

BPA 1997 authorized budget (approved start-of-year budget)   $180,000