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
Allowable Gas Supersaturation at Dams

BPA project number   9300800

Business name of agency, institution or organization requesting funding
Montgomery Watson

Sponsor type   WA-Consultant

Proposal contact person or principal investigator

BPA technical contact   Bill Maslen, EWI 503/230-5549

Biological opinion ID   NMFS BO RPA Sec. 16 + waivers

NWPPC Program number   5.6E.1

Short description
Determine the potential threshold level of total gas supersaturation in combination with turbine/bypass passage that may be associated with increased susceptibility of juvenile salmonids to predation mortality. Additional tasks have involved evaluation of smolt monitoring programs and examination protocols.

Project start year   1993    End year   1996

Start of operation and/or maintenance   

Project development phase   Implementation

Section 2. Narrative

Related projects

Project history
Task 3
Turbine and Bypass Passage Simulation
The interaction between dissolved gas supersaturation (DGS) and juvenile salmonids passing through hydroelectric kaplan turbines or juvenile fish bypass systems is not well understood. This experimental work was developed to determine if juvenile salmonids exposed to elevated DGS are more susceptible to predation after exposure to simulated turbine or bypass passage than fish that were not exposed to DGS conditions. Potential threshold levels of DGS in combination with turbine/bypass passage that may be associated with increased susceptibility of juvenile salmonids to predation mortality would provide valuable insight on operation of the hydrosystem for the benefit of outmigrating juvenile salmonids.

Potential increase in mortality of juvenile fish exposed to elevated levels of DGS were assessed in a laboratory. Juvenile salmonids were exposed to elevated levels of DGS ranging from 115% to 130% and the environments associated with passage through turbines and juvenile fish by systems. Turbine conditions were simulated in test chambers with pressure drops from several atmospheres to close to the vapor pressure of water (from 100' to approximately -31' in 0.25 seconds; cavitation, turbulence, shear layers, and blade strike were not simulated. Bypass conditions were simulated by water velocities similar to that of existing bypass collection channels (2-2.5 body lengths/second). Experimental controls involved duplicate conditions but without exposure to elevated DGS conditions. Predation rates were used as a measure of total impact on fish as a result of exposure protocols.

Task 5
Review of Monitoring Plans for Gas Bubble Disease Signs and Gas Supersaturation Levels on the Columbia and Snake Rivers.

The overall purpose of this project was to review the current monitoring program for dissolved gas supersaturation and GBT and to evaluate its validity. The results of the review of the monitoring program will provide the basis for improving protocols for future monitoring efforts.

Task 7
A Review of Historic Levels of Dissolved Gas Supersaturation in the Columbia and Snake Rivers and Its Effect on The Survival of Juvenile and Adult Anadromous Salmonids.

At present, there is considerable uncertainty as to the effects of dissolved gas supersaturation (DGS) and Gas Bubble Trauma (GBT) on the survival of anadromous fish populations of the Columbia and Snake Rivers. This has led to questions concerning the appropriate river management options which should be pursued in order to optimize fish survival. Since the early 1960's, a variety of data have been collected by regional state, tribal, and federal agencies and by universities which may provide insight into the relationships between fish survival and DGS. These data include information on river flow conditions, dam operations, dissolved gas levels, fish introductions, species and stock composition, fish passage routing, adult returns, and other related factors. To date, no attempt has been made to examine these data for possible relationships between dissolved gas supersaturation and the survival of Columbia-Snake River steelhead trout and Pacific salmon. If these data could be compiled into a database management program which was regionally accessible, fisheries and other experts could perform analyses which would identify any relationships which may be present. This could help fisheries managers in their decisions regarding the selection of appropriate river flow and fisheries management alternatives in relation to DGS.

The purpose of this work is to bring together, into a Microsoft Access IBM PC database application, appropriate data which may relate the survival of anadromous fish populations to river DGS levels, flow conditions, dam operations, fish introductions, species and stock composition, fish passage routing, and other related factors. Once these data are developed into a database application, perform a preliminary analysis to establish if relationships exist between the survival of Columbia-Snake River steelhead trout and Pacific salmon and river dissolved gas levels.

Task 8
Bubble Reabsorption In A Simulated Smolt Bypass System - Concept Assessment.

The monitoring program for examining the prevalence of gas bubble trauma (GBT) in Snake and Columbia river salmonids has been questioned. Dr. Larry Fidler in a letter to Mr. Ted Bottiger of the Pacific Northwest Power Planning Council suggests that the current monitoring program may be “invalid” because clinical signs of GBT may disappear during a fishes’ passage through the fish bypass system at dams. Only fish that pass through the bypass system are examined for GBT. Based largely on theoretical work, it appears that the high hydrostatic pressures experienced by the smolts as they pass through the smolt bypass system could quickly reabsorb any bubbles that had formed due to dissolved gas supersaturation.

Our objective for the tests recorded here was to examine the validity of Dr. Fidler’s suggestion. We subjected fish (fingerings spring chinook salmon (Oncorhynchus tshawytscha)) to dissolved gas supersaturated water to develop signs of GBT and then exposed them to pressures that could occur during passage through a smolt bypass system.

Task 9.1
Inspection of the 1995 Gas Bubble Biological Monitoring and Research on the Columbia and Snake Rivers.

Because of the importance of the smolt monitoring program, the NMFS/EPA Gas Bubble Disease Technical Working Group (TWG) requested an independent review of the biological monitoring on the river for the 1995 spill period. This review included a review of the existing protocols, inspections of monitoring sites, observation of examination procedures, and review of the reporting methods. The inter-disciplinary team includes personnel for NMFS, the USF& WS and non-agency members of the 1994 QA/QC review team.

Task 9.3b
Comparison Of Clinical Signs Of Gas Bubble Disease In The Gills Of Smolts Using Both Compound And Dissecting Microscopes.

The total dissolved gas levels in the Columbia and Snake Rivers were comparable during the 1994 and 1995 spill periods. The observed incidence of gill bubbles was significantly lower during the 1995 spill. In the 1994 spill, observation of gill bubbles were made using a compound microscope. In contrast, in the 1995 spill, dissecting microscopes were used. Because of the differences in incidence of bubbles between 1994 and 1995 spill periods, the impact of two these two protocols on the detection of bubbles has been questioned. The differences in these protocols involved not only magnification but the examination procedures. The compound microscope requires the excision of the gill arches while the dissection microscope examination can examine intact gills. Task 9.3b was directed toward the resolution of the question of the impact of gill examination protocols on bubble detection.

Task 9.5
Research Priorities Related to Gas Bubble Monitoring Needs in the Columbia River Basin.

The NMFS/EPA Gas Bubble Disease Technical Work Group requested an independent QA/QC review of the monitoring program for gas bubble disease. As part of this review, the 1995 QA/QC Study Team reviewed the long-term research needs of the gas bubble disease monitoring program. A report documents that portion of the 1995 QA/QC Study Team's work.

Biological results achieved
Task 3
Turbine and Bypass Passage Simulation
Laboratory experiments are complete. Results indicated for turbine passage simulation, predation rates were significantly higher for fish exposed to DGS levels of 125 and 130%. For bypass passage simulations, predation rates were significantly higher for fish exposed to DGS levels of 130%.

Task 5
Review of Monitoring Plans for Gas Bubble Disease Signs and Gas Supersaturation Levels on the Columbia and Snake Rivers.

Thirty-one specific recommendations were developed. The smolt and adult monitoring programs should be reviewed in terms of the data requirements and procedures which are needed to make the program statistically valid. The skin peel procedure used for observation of bubbles in the lateral line does not appear to be valid. Some of the observations for gas bubble trauma were subjective and should be omitted from future programs. Experimental validation of the gas bubble trauma protocols and scoring criteria are needed. Problems occurred with the distribution of both biological and dissolved gas data during parts of the spill period. Formal policies on data reduction, quality assurance, and data distribution are needed for both the biological and physical monitoring programs.

The current level of accuracy and reliability of the dissolved gas monitoring program on the Columbia and Snake rivers may not be adequate for real-time management of the spill program. This is related to the lack of Standard Operating Procedures (SOPs) for the operation of dissolved gas monitoring equipment, the lack of SOPs for the overall monitoring program, and the lack of a Quality Assurance Program. Input on potential changes to the dissolved gas monitoring program is needed from the fisheries and regulatory agencies.

Task 7
A Review of Historic Levels of Dissolved Gas Supersaturation in the Columbia and Snake Rivers and Its Effect on The Survival of Juvenile and Adult Anadromous Salmonids.

This work is still on-going. A preliminary interim draft report has been submitted. The final report and Microsoft Access database will be completed by June 30, 1996.

Task 8
Bubble Reabsorption In A Simulated Smolt Bypass System - Concept Assessment.

Separate groups of fish were examined for clinical signs of GBT prior to pressurization and after pressurization. Four pressurizations ranging from 5 to 120 minutes were tested. The test fish were spring chinook fingerlings (Å 130 mm total length). During the pressurization and depressurization phase, the fish were held in normally saturated water so that bubble re-growth could not occur after depressurization.

A pressurization of 5 minutes to 100 feet of head resulted in a significant reduction in the clinical signs of GBT in the fins, lateral line, and gills. In terms of bubble reabsorption, the quickest loss of clinical signs of gas bubble disease were in the gills followed closely by the lateral line. The rate of bubble loss was significantly less for the fin bubbles. If the reabsorption potential of pressure-time history for salmonids is similar to the 5 minute pressurization treatment, the current smolt monitoring program may be under-estimating the prevalence of GBT in the Snake and Columbia Rivers.

While pressurization to 100 feet for 5 minutes resulted in significant reduction in the clinical signals of GBT, all bubbles in a fish will start to disappear if the fish is below the hydrostatic compensation depth. Therefore, there are an infinite number of depths and times that would result in the complete disappearance of bubbles. While this work does not prove that bubble reabsorption is actually occurring in the smolt monitoring program, it does indicate that it may occur.

Task 9.1
Inspection of the 1995 Gas Bubble Biological Monitoring and Research on the Columbia and Snake Rivers.

Compared to the 1994 gas bubble disease monitoring program, the 1995 program is much improved. There was a high level of protocol compliance at each site visited. Observation techniques and the recording of observations was consistent between the sites and among the various programs. The level and consistency of training of personnel is also improved over 1994. Recommendations were made for the 1996 monitoring program.

Task 9.3b
Comparison Of Clinical Signs Of Gas Bubble Disease In The Gills Of Smolts Using Both Compound And Dissecting Microscopes.

The results show that examination of excised gill filaments can detect evidence of GBD that is not detected using stereoscopic methods of examination of fins, lateral line and intact gill filaments.

Task 9.5
Research Priorities Related to Gas Bubble Monitoring Needs in the Columbia River Basin.

The team stated the objective of the monitoring program as: Information on gas bubble disease to make decisions on spill. The strategy selected to meet this objective was: Monitor anadromous salmonids in the Snake and Columbia rivers for GBD signs that put the fish at risk. Five other strategies were identified, but were not assessed in detail because of limited time.
The study team identified 23 assumptions that are required for the strategy to meet the stated objective. If these assumptions are false, then there is significant probability that the strategy will not work at all. Critical assumptions are those assumptions that are "show stoppers." That is, the region would not even consider this strategy if this assumption is false. Seven of these objective were determined to be critical:

1 Samples are taken from selected locations to represent the entire river (the fish) and include the highest risk reaches.
2 The signs in sampled fish are representative of the fish in the river at this site over the whole day.
3 There is no significant mortality between sample sites.
4 Clinical signs do not change during collection.
5 Sample size is statistically adequate for required confidence limits.
6 All possible signs and their relative significance are known.
7 The relationship between bubbles in the fins, gill, lateral line and smolt/adult mortality are known.
A list of research tasks that could resolve these uncertainties were identified for each assumption.

Annual reports and technical papers
(1) Review of Monitoring Plans for Gas Bubble Disease Signs and Gas Supersaturation Levels on the Columbia and Snake Rivers, July 1994.

(2) Bubble Reabsorption In A Simulated Smolt Bypass System - Concept Assessment, June 1995.

(3) Comparison Of Clinical Signs Of Gas Bubble Disease In The Gills Of Smolts Using Both Compound And Dissecting Microscopes, August 1995.

(4) Inspection of the 1995 Gas Bubble Biological Monitoring and Research on the Columbia and Snake Rivers, September 1995, submitted to the NMFS/EPA Gas Bubble Disease Technical Work Group.

(5) Research Priorities Related to Gas Bubble Monitoring Needs in the Columbia River Basin, September, 1995, submitted to the NMFS/EPA Gas Bubble Disease Technical Work Group.

(6) Allowable Gas Supersaturation For Fish Passing Hydroelectric Dams (in draft)

(7) A Review of Historic Levels of Dissolved Gas Supersaturation in the Columbia and Snake Rivers and Its Effect on The Survival of Juvenile and Adult Anadromous Salmonids (completion date: June 30, 1996).

Management implications

Specific measureable objectives

Testable hypothesis

Underlying assumptions or critical constraints

Methods

Brief schedule of activities

Biological need

Critical uncertainties

Summary of expected outcome

Dependencies/opportunities for cooperation

Risks

Monitoring activity

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 3 - do not fund