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
Improving the Effectiveness of the Gas Bubble Disease Monitoring Program on the Columbia and Snake Rivers

BPA project number   5501200

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

Sponsor type   WA-Consultant

Proposal contact person or principal investigator

BPA technical contact   , EWI

Biological opinion ID   

NWPPC Program number   

Short description
Improve the effectiveness of the gas bubble disease monitoring program on the Columbia and Snake Rivers. Develop standardized protocols and non-lethal techniques for the examination of fish. Asses the use of physiological parameters to detect exposure to elevated total gas pressures and estimate risk. Provide additional research and support services relative to this issue.

Project start year   1997    End year   2001

Start of operation and/or maintenance   

Project development phase   Planning

Section 2. Narrative

Related projects
New Project

Project history
New project

Biological results achieved
New Project

Annual reports and technical papers
New Project

Management implications
New Project

Specific measureable objectives
This proposal consists of the following six major tasks:

Task Description


1 Development of standardized protocols for the examination of fish for clinical signs of gas bubble disease

2 Development of non-lethal techniques for the examination of fish for clinical signs of gas bubble disease

3 Assessment of the use of physiological parameters to detect exposure to elevated total gas pressures and estimate risk

4 Provide clinical, histological, and evaluation support during the 1996 peak downstream migration period in the Columbia and Snake Rivers

5 Investigate the kinetics of bubble growth and reabsorption in juvenile pacific salmon smolts exposed to gas supersaturation

6 Assess the state-of-the-art for the development of an implantable ĘP tag with radio transmission capability

Testable hypothesis
(1) Can gill bubbles be estimated in live, intact, anesthetized fish? With further development, non-lethal gas bubble enumeration methods may be useful for the Smolt Monitoring Program.

(2) Can physiological parameters be used to detect exposure to elevated total gas pressures and estimate risk?

(3) Are all the important clinical signs of gas bubble disease being observed?

(4) Is the Smolt Monitoring Program under-estimating the incidence of gas bubble disease? The monitoring of smolts in the Columbia and Snake Rivers for signs of gas bubble disease is essentially limited to fish collected from the smolt collection systems. Preliminary experimental work has shown that significant bubble reabsorption may occurs in the smolt bypass systems. Potentially, reabsorption of bubbles could significantly bias the current smolt monitoring program and provide inaccurate data on the incidence of gas bubble trauma for downstream migrants in the Columbia and Snake rivers.
(5) Can an implantable DP tag with radio transmission capability be developed? This tag would directly measure the actual risk to a smolt from gas supersaturation.

Underlying assumptions or critical constraints
For this project to be effective, access to hatchery fingerlings and migrating hatchery fish is needed. Hatchery fish collected for other purposes may be acceptable for some of the clinical examinations needed in Task 4.

Methods
This proposal consists of the following six major tasks:

Task Description


1 Development of standardized protocols for the examination of fish for clinical signs of gas bubble disease

2 Development of non-lethal techniques for the examination of fish for clinical signs of gas bubble disease

3 Assessment of the use of physiological parameters to detect exposure to elevated total gas pressures and estimate risk

4 Provide clinical, histological, and evaluation support during the 1996 peak downstream migration period in the Columbia and Snake Rivers

5 Investigate the kinetics of bubble growth and reabsorption in juvenile pacific salmon smolts exposed to gas supersaturation

6 Assess the state-of-the-art for the development of an implantable ĘP tag with radio transmission capability

Detailed information is provided on each task in the following section.

Task 1

Development of Standardized Protocols For The Examination Of Fish For Clinical Signs Of Gas Bubble Disease


Problem

The currently used protocols for the examination of clinical signs of gas bubble disease in the Smolt Monitoring Program were developed in-house by the National Biological Service (NBS). The supporting documentation for the protocols have never been published nor have the protocols received a formal outside peer-review. Changes in protocols between 1994 and 1995 may have significantly reduced the detection limits (Montgomery Watson, 1995). The precision and accuracy of the protocols are not defined. Because of these deficiencies, the results of the smolt monitoring program have been questioned.

Better written documentation on the protocols (Montgomery Watson, 1994) and a comprehensive peer-review are needed. To assure a wide acceptance of these protocols, the draft protocols will be submitted to the Fish Health Section, American Fisheries Society for potential addition to the "Blue Book".

Approach

Task 1a Kinetics of Bubble Decay or Growth in Excised Tissues

The purpose of this task is to characterize the decay or growth of bubbles in lateral line, gills, and fins. Based on this task, maximum holding times and holding procedures will be recommended.

Fish will be exposed to gas supersaturation for a period of time sufficient to develop internal and external clinical signs of gas bubble disease. These fish will be euthanized with buffered MS-222. Single fish with observed clinical signs will be examined periodically to track the decay or growth of bubbles. Photographic and video techniques will be used to document this work.

Task 1b Development of Statistically Valid Sampling Protocols for Gill Tissues

The purpose of this task is to examine the variability of bubbles in tissue from fish exposed to gas supersaturation. While the examination of gill bubbles is more difficult than examination for lateral line or external bubbles, bubbles in the gills are the first to develop. The currently used protocol is based on examination of the 1st leftside arch only. The statistical validity of this procedure is unknown at this time. The basic question to be addressed is what type of sampling and counting protocols are needed to obtain a valid measure of the number of bubbles in the gills of fish exposed to gas supersaturation. Based on this task, sampling and counting protocols will be recommended.

Fish will be exposed to gas supersaturation, euthanized and gill tissues excised. The variability of bubbles within a gill arch and between different arches will be determined. Single arches will be counted by several observers to estimate observer variance. Photographic or video techniques will be used to document the work.

Task 1c Comparison of Precision and Accuracy of Different Magnifications and Microscopes for the Detection of Gill Bubbles

The accuracy and precision of gill bubble detection depends both on the type of microscope, lighting, and magnification. The purpose of this task to document the relative detection capabilities of common microscope types and the impact of magnification on bubble detection.

Fish will be exposed to gas supersaturation, euthanized and gill tissues excised. Bubble number and size will be estimated using a number of different microscopes and magnifications. The order of observation will be randomized. Photographic or video techniques will be used to document the work and reduce observation time.

Task 1d Development of Statistically Valid Sampling Protocols for the Fins and Lateral Line

The purpose of this task is develop protocols for the examination of bubbles in the lateral line or fins. Because of operational constraints, it is desirable to reduce the observation to a minimum. Different types of sampling and scoring systems will be tested and compared to a reference protocol. The reference protocol will be based on computer analysis of bubble coverage in the lateral line and fins and computation of area and percent coverage.

Fish will be exposed to gas supersaturation to allow bubbles to form in the lateral line and fins. The fish will be euthanized and photographed. Bubble size, area, percent coverage in the lateral line and fins will be computed from the photographs. Other types of sampling and scoring systems will be used to qualitatively assess bubble coverage. The different techniques will be compared using standard statistical analyses. Based on this task, sampling and counting protocols will be recommended.



Task 1e Development of Standard Methods for The Examination for Bubbles in Aquatic Animals

Based on the information developed in Tasks 1a-1d, draft standard methods would be prepared for review by agencies, tribes, and interested individuals. These draft standard methods would include the full documentation of the results obtained in Task 1a-1d. A half day discussion workshop would be held in the Portland area to gather comments and input from interested parties.

Based on the comments received in writing and from the workshop, the draft standard methods would be revised. These revised draft standard methods would be submitted to the Fish Health Section, American Fisheries Society for potential addition into the "Blue Book".

Statistical Analysis:

The appropriate statistical tests will be defined by our statistical team member in consultation with fish health and gas supersaturation team members.

Type and Number of Fish to be Used:

Rainbow trout: 5,000

Hatchery chinook: 500

The rainbow trout may be obtained from state or federal fisheries agencies or purchased from commercial sources.

Task 2

Development Of Non-Lethal Techniques For The Examination Of Fish For Clinical Signs Of Gas Bubble Disease


Problem

Gill bubbles are probably the first clinical signs of gas bubble disease to form in fish (Montgomery Watson, 1994). The currently used techniques for examination of smolts for the presence of gill bubbles are lethal to the fish. The operculum is excised and the gill arch is observed intact or the gill arch is excised and examined with a stereo- or compound-microscope. Preliminary work has shown that gills bubbles can be estimated in live, intact, anesthetized fish (Montgomery Watson, 1994). With further development, this non-lethal gas bubble enumeration method may be useful for the Smolt Monitoring Program.

Approach

Task 2a Development of Examination Procedures and Protocols for Non-lethal Examination For Gill Bubbles

In previous work, the fish were lightly anesthetized and the operculum was gently lifted to exposed the gills. The gills could then be examined using a stereo-microscope. The lifting of the operculum was done manually using a smooth flat surface. For routine work, a better technique needs to be developed.

An alternative approach to the above technique is the use of a fiber optics system that can be inserted through the fish's mouth. Using this approach, it would not be necessary to remove the lightly anesthetized from the water. This technique may be more accurate than the previously used technique as the gill arches would not collapse on one another.

Task 2b Comparison of Non-lethal Protocols With Conventional Techniques for Examination For Gill Bubbles

The most promising non-lethal gill examination techniques would be compared to the conventional protocols developed in Tasks 1b and 1c.

Task 2c Assessment of the Long-term Impact of Non-lethal Examination for Gill Bubbles on Smolts

The purpose of this task is assess the long-term impact of the non-lethal gill examination on smolts. This task will expose a large number of fingerlings to dissolved gas supersaturation and examination for gill bubbles using the non-lethal techniques. Two controls will be used: (1) un-examined, gas supersaturated fish and (2) un-examined, non-supersaturated fish. The three groups of fish would held in separate rearing containers and examined for mortalities at 1, 4, 10, 20, and 30 days.

Statistical Analysis:

The appropriate statistical tests will be defined by our statistical team member in consultation with fish health and gas supersaturation team members.

Type and Number of Fish to be Used:

Rainbow trout: 2,000

Hatchery chinook: 500

The rainbow trout may be obtained from state or federal fisheries agencies or purchased from commercial sources.

Task 3

Assessment Of The Use Of Physiological Parameters To Detect Exposure To Elevated Total Gas Pressures And Estimate Risk

Problem

The present gas bubble disease monitoring program in the Columbia and Snake Rivers is based on the examination of fish for bubbles (commonly in the gills, fins, or lateral line). Preliminary research has shown (Bonneville Power Administration, 1995) that bubble reabsorption in a simulated by-pass system is rapid. 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. This preliminary work indicates that the presence of bubbles at a given point in time may not be good measure of a fish's potential exposure to elevated dissolved gas supersaturation.

Intravascular gas emboli can result in vascular occlusions in branchial vessels. These emboli initiate vascular damage, clotting, and inflammatory cascades. Local effects of gas emboli are linked to adherence of platelets and leukocytes to the vascular endothelium. Damage to this endothelium is related to the emigration of leukocytes in the proximity of bubble formation resulting in edema and inflammation. Additionally, intravascular gas bubbles may inhibit blood flow leading to anoxic injury and tissue death, especially in the fins.

The pressurization of fish results in a significant reabsorption of bubbles. With limited pressurization, the remaining bubbles were characteristically loose in the tissues. With more extensive pressurization, the area previously occupied by bubbles showed signs of cellular and fluid infiltration that persisted for at least several hour (Bonneville Power Administration, 1995). This observation shows that fish which had a potentially lethal exposure to gas supersaturation followed by bubble reabsorption can be recognized. These observations need to be verified systematically.

Uni- or bilateral exopthalmus is a classic, although not uniformly occurring, sign of gas bubble disease. It is preceded by gas bubbles in the choroid retae which may diffuse into all chambers of the eye. In the eyes, gas emboli can displace the retina and choroid anteriorly into the vitreous cavity. Subacute changes may also include retrobulbar gas bubbles, lenticular cataracts, hydropic degeneration of lens epithelium and attenuation of the optic nerve.

Alternative physiological parameters may offer more stable predictors of past exposure to elevated dissolved gas levels and potential risk from elevated dissolved gas levels. Parameters of interest may include:

(1) Blood chemistry parameters (clotting and inflammatory cascades, fibrin degradation products, and disseminated intravascular coagulation).

(2) Bubble formation in retinal capillary bed.

(3) Presence of inflammatory lesions due to bubble formation and reabsorption (see Bonneville Power Administration, 1995 for a description).

(4) Fin tissue destruction or fungus problems.

(5) Histological verification and characterization of lesions where needed to validate clinical observations

Approach

Task 3a Bubble Formation In Retinal Capillary Bed

This task would consist of exposure of fingerling salmonids to elevated gas levels, anesthetization, and examination of the choroid retae of the eye with an ophthalmoscope.

Task 3b Correlation of Incidence of Conventional Bubbles and Blood Parameters.

This task would consist of exposure of fingerling salmonids to elevated gas levels, estimation of the percentage coverage of bubbles in the gills, fins, and lateral line, and determination of blood chemistry parameters. Statistical relationships between bubble coverage (gills, fins, and lateral line) and clinical chemistry parameters would be determined. It is anticipated that both bubble coverage and clinical chemistry parameters can be estimated for individual fish.

Task 3c Detection Of Residual Lesions and Clinical Chemistry Parameters Following Exposure to Elevated Gas Levels (Single Exposure)

This task would consist of exposure of groups of fingerling salmonids to elevated gas levels, reduction of the gas levels, reabsorption of the bubble, and examination of the fish at various times for residual lesions and clinical chemistry. It is anticipated that separate groups of fish will have to be used for each time period. A separate un-exposed control would be used for each time period.

Task 3d Detection Of Residual Lesions and Clinical Chemistry Parameters Following Exposure to Elevated Gas Levels (Multiple Exposures)

This task would be similar to Task 3c, except that a single group of fish would be cycled through the supersaturated/non-supersaturated exposure a number of times. It is anticipated the number of exposure cycles will be 1, 2, 4, and 8.

Task 3e Impact of Multiple Gas Exposure on Fins, Gills, and Mortality

This task would be similar to Task 3d, except that a fixed number of cycles would be used. At the end of the exposure period, the fish would be transferred to holding tanks for 10, 20, and 30-day post-exposure examination of fins and gills. Mortality would be checked on a daily basis.

Statistical Analysis:

The appropriate statistical tests will be defined by our statistical team member in consultation with fish health and gas supersaturation team members.

Type and Number of Fish to be Used:

Rainbow trout: 5,000

Hatchery chinook: 2,000

The rainbow trout may be obtained from state or federal fisheries agencies or purchased from commercial sources.

Task 4

Provide Clinical, Histological, And Evaluation Support During The 1996 Peak Downstream Migration Period In The Columbia And Snake Rivers


Problem

During the downstream migration of smolts, the Smolt Monitoring Program (SMP) conducts routine monitoring for clinical signs of gas bubble disease at many of the Columbia and Snake River Dams. Standardized protocols are used. The SMP personnel have received brief training on the examination for bubbles, but none are fish health or fish pathology professionals. While the SMP personnel training and background may be adequate for routine monitoring, better trained individuals may be able to better detect other potential clinical impacts of exposure to elevated gas levels.

Montgomery Watson was requested to assist in the evaluation of gas portions of the Smolt Monitoring Program during both 1994 and 1995 spill periods (Montgomery Watson, 1994; Biological Monitoring Inspection Team, 1995). Because of the relatively short duration of the spill period, the contracting for these monitoring assistance efforts have required emergency procedures and major readjustment of work schedules for the personnel involved. If it is anticipated that evaluation work will be needed during the 1996 spill periods, it may be useful to setup these tasks prior to the start of the spill period.

Approach

Task 4a Provide Clinical and Histological Support To Evaluate Gas Bubble Disease During The 1996 Peak Downstream Migration Period

This task would provide a highly trained fish pathologist and equipment for a four week period during the peak downstream smolt migration. This individual could be stationed at a single dam, move between several dams, or move to areas of interest as directed. The primary objective of this task would be to document the clinical signs of gas bubble disease in fish in the Columbia and Snake Rivers.

Task 4b Provide Evaluation Support During The 1996 Peak Downstream Migration Period

This task would provide personnel experienced in the area of gas supersaturation, gas bubble disease, and program evaluation for a period of four weeks during the 1996 smolt migration period.




Statistical Analysis:

The appropriate statistical tests will be defined by our statistical team member in consultation with fish health and gas supersaturation team members.

Type and Number of Fish to be Used:

Hatchery steelhead: 2,000*

* Some of these fish may have been collected for other purposes.
Task 5

Investigate The Kinetics Of Bubble Growth And Reabsorption In Juvenile Pacific Salmon Smolts Exposed To Gas Supersaturation


Problem

The monitoring of smolts in the Columbia and Snake Rivers for signs of gas bubble disease is essentially limited to fish collected from the smolt collection systems. Preliminary experimental work has shown that significant bubble reabsorption may occurs in the smolt bypass systems (BPA, 1995). Potentially, reabsorption of bubbles could significantly bias the current smolt monitoring program and provide inaccurate data on the incidence of gas bubble trauma for downstream migrants in the Columbia and Snake rivers.

Reabsorption of bubbles could also occur in the reservoirs and depends on the depth at which the smolts are traveling. The tendency of these bubbles to reform once the fish have passed through the smolt bypass systems depends on a number of factors, some of which may favor bubble growth and others that do not favor bubble growth. If this reabsorption occurs, it could offer some level of protection from gas supersaturation to smolts passing through the bypass systems and turbines.

Because of the speed at which the reabsorption may occur, special care will have to be taken to ensure that delays in examination of the fish do not bias the results. This may require the exposure of small numbers of fish or even individual fish.

The overall purpose of this task is to define the kinetics of bubble growth and reabsorption that may occur in smolts traveling down the Columbia and Snake rivers. The results of this work will have important implications for the current smolt monitoring program.

Approach

Task 5a Develop Pressure Exposure Equipment For The Tests

Three alternative types of pressure exposure equipment can be developed depending on budget and scope of the experimental work. These systems include: (a) bypass passage system, (b) turbine passage system, and (c) the design and the construction of a separate system for this work. Each of the system alternatives are discussed below:

(1) Bypass Passage System
The current bypass passage system can be operated in a flow-through mode. Some modifications would be needed to operate at the pressures needed for the by-pass passage simulation. This system has the advantage that it is possible to exercise the fish during the exposure, but the control of the pressure and changes in pressure will not be as accurate as in the turbine passage system. The addition of proportional valves, pressure transducers, and a computer would be needed for accurate control of the pressure and pressure changes.

(2) Turbine Passage System
The current turbine passage system can produce the required hydrostatic pressure profiles, but it is operated as a closed system during the pressure phase. To allow its use for exposures in the range of hours to days, it would be necessary to modify the system to operate in a flow-through mode while pressurized. Modifications would include a pump, proportional discharge valve, and active control of the discharge valve. It is probably not feasible to modify this system to force the fish to swim at any significant speed.

(3) Deep Tank System
A deep tank system (separate treatment and control units) could be constructed from PVC pipe. The system could be mounted on the side of a two or three story building or mounted in large drilled sump. The water would be supersaturated to a desired level by adjustment of the level of a diffuser in the sidearm. The fish would be placed in a cage and lowered or raised to simulate the required test hydrostatic pressures. This system has the advantage that multiple batches of fish could be exposed at the same time. It is not feasible to modify this system to force the fish to swim.

Task 5b Develop Optical Systems To Observe Single Bubbles In Intact Fish

Previous work on bubble reabsorption has shown that the inherent variability in bubble formation between fish significantly increased the number of observations needed to detect differences. To reduce the number of fish needed and observation time, optical systems will be developed to facilitate the observation of single bubbles in intact fish during pressurization and depressurization. For the observation of fin and lateral line bubbles, an optical flat holding chamber will be developed. This chamber will allow pressurization of fish and real-time optical monitoring of bubbles. A commercially available fiber optics systems will be tested to monitor the change in size of gill bubbles. The output of both systems will be record on video tape.

This equipment is not intended to detect bubbles under routine operational conditions. Because this task will require development and construction of new equipment, the primary objectives of Task 5 will be based on the techniques used in previous work (see BPA, 1995). Experimental work on bubble reabsorption and growth would be greatly improved when this technique is available.

Task 5c Kinetics of Bubble Absorption in a Simulated Smolt By-Pass System

The purpose of this task is to determine characteristics of bubble absorption under simulated by-pass conditions. Fish would be loaded with gas and then subjected to a series of time-pressure exposures. Pressurization and depressurization would be conducted over a constant period of 2.5 minutes. For each exposure time, one group of fish would examined for clinical signs (lateral line bubbles, gill bubbles, and bubbles in the fins) at time zero and another group at the end of a exposure time. The exposures would be conducted for gas loading conditions of (a) 130 % for 2 hours and (b) 115% for 4 days. It is assumed that 3 replicates will be needed.

Run # Loading Pressurization
1-3 130 % for 2 hours 0.5 minute at 100 ' of head
4-6 130 % for 2 hours 1 minute at 100 ' of head
7-9 130 % for 2 hours 2 minute at 100 ' of head
10-12 130 % for 2 hours 5 minute at 100 ' of head
13-15 115% for 4 days 0.5 minute at 100 ' of head
16-18 115% for 4 days 1 minute at 100 ' of head
19-21 115% for 4 days 2 minute at 100 ' of head
22-24 115% for 4 days 5 minute at 100 ' of head

Task 5d Bubble Re-growth After Simulated By-Pass Passage

The purpose of this task is to determine if bubble re-growth occurs after exposure to simulated by-pass passage. Based on Task 5c, a single gas loading condition and pressurization period will be selected. For each exposure, one group of fish would examined for clinical signs (lateral line bubbles, gill bubbles, and bubbles in the fins) at time zero and another group at the end of an exposure period.

Preliminary Experimental Runs
Run # Re-Growth Period(days) Reservoir TGP(%)
1 4 110
2 4 115
3 4 120
4 4 125

Experimental Runs

Based on the results from the four preliminary experimental runs, a single loading and reservoir TGP will be selected and 4 experimental treatments will be selected. It is assumed that 3 replicates will be needed.

Run # Re-Growth Period(days) Reservoir TGP(%)
5-7 to be determined to be determined
8-10 to be determined to be determined
11-13 to be determined to be determined
14-16 to be determined to be determined


Task 5e Development of Model for Bubble Reabsorption and Growth

Using the optical equipment developed in Task 5b, the reabsorption of single bubbles will be followed as a function of pressure. This information will be used to develop a model of the reabsorption process for the different tissues.

Task 5f Documentation of Dissolved Gas Levels in the Smolt Collection and By-Pass Systems

The purpose of this task is to document the total gas levels in smolt collection and by-pass systems during the high TGP periods. Detailed documentation on total gas levels in collection and by-pass systems is not available at this time. Five dams would be monitored three time during the spring spill period.

Task 5g Bubble Decay and Growth in Smolt Collection Systems

The purpose of this task is to determine if bubble decay or growth occurs in the smolt collection and holding systems at the collector dams. At these dams, 12 or 24 hour samples of downstream migrants are collected.

To assess the potential for changes in clinical signs during holding, hatchery fish would be loaded with dissolved gas until bubbles are visible in the fins and then placed in the smolt collection system. For each exposure time, one group of fish would be examined for clinical signs (lateral line bubbles, gill bubbles, and bubbles in the fins) at time zero and another group at the end of an exposure time.

If it is not possible to conduct these experiments at a Columbia or Snake River dam, a simulated bypass system will be used at Pacific Northwest Laboratory in Richland.

Task 5h Kinetics of Bubble Growth in the Turbine System

The purpose of this task is to determine if bubble growth occurs under simulated turbine conditions. Fish would be loaded with gas, pressurized, and then subjected to a number of simulated turbine transients. For each exposure, one group of fish would examined for clinical signs (lateral line bubbles, gill bubbles, and bubbles in the fins) at time zero and another group at the end of an exposure time. Based on previous work, a single loading scenario will be selected. It is assumed that 3 replicates will be needed.

Experimental Runs
A single loading TGP and 4 experimental treatments will be selected. It is assumed that 3 replicates will be needed.

Run # Number of Transients Loading TGP(%)
1-3 1 to be determined
4-6 2 to be determined
7-9 4 to be determined
10-12 10 to be determined


Statistical Analysis:

The appropriate statistical tests will be defined by our statistical team member in consultation with fish health and gas supersaturation team members.

Type and Number of Fish to be Used:

Rainbow trout: 5,000

Hatchery chinook: 2,000

The rainbow trout may be obtained from state or federal fisheries agencies or purchased from commercial sources.

Task 6

Assess The State-Of-The-Art For The Development Of An Implantable ĘP Tag With Radio Transmission Capability


Problem

Information of the ĘP exposures of migrants in the Columbia and Snake Rivers is complicated by swimming depth. The effective ĘP (ĘPuncomp) that a fish is exposed to depend on both the ĘP and the fish's position in the water column and is equal to:

ĘPuncomp = ĘP - rgZ

where

ĘPuncomp = uncompensated ĘP (mm Hg)

ĘP = measured ĘP (mm Hg)

rg = specific weight of water; equal to 73.5. mm Hg/m of water depth

Z = depth in water column (m)

The fish's depth can be estimated by trawling, hydroacoustics, or depth sensitive radio-tags. Even with this information, it is necessary to know or measure the local ĘP.

The purpose of this task to assess the state-of-the-art for the development of an implantable ĘP radio tag. This tag would measure the ĘPuncomp surrounding the fish and transmit this information on a radio signal.

Approach

Task 6a Documentation of Characteristics of Existing Radio Tags

The characteristics of existing radio tags would be defined. Important characteristics include: size, battery life, and transmission distance.

Task 6b Documentation of Characteristics of Membrane-Diffusion Units for Application to a Radio Tag

The characters of existing membrane-diffusion units would be defined. The size and power requirements would be estimated for existing units, modification of existing units, and custom fabrication of a new unit.
Task 6c Definition of the Potential Characteristics of a ĘPuncomp radio tag for adult salmon and 8-10 inch hatchery steelhead

The operating characteristics and limitations of a potential ĘPuncomp radio tag for adult salmon and 8-10 inch hatchery steelhead would be defined.

Statistical Analysis: Does not Apply


Type and Number of Fish to be Used: None
References

Biological Monitoring Inspection Team. 1995. Inspection of the 1995 Gas Bubble Biological Monitoring and Research on the Columbia and Snake Rivers. A report to the National Marine Fisheries Service/Environmental Protection Agency Gas Bubble Disease Technical Work Group.

Bonneville Power Administration. 1995. Allowable Gas Supersaturation for Fish Passing Hydroelectric Dams. Task 8 - Bubble Reabsorption in a Simulated Smolt Bypass System - Concept Assessment. Prepared by Montgomery Watson, Bellevue, Washington.

Montgomery Watson. 1994. Allowable Gas Supersaturation for Fish Passing Hydroelectric Dams. Task 5 - Review of Monitoring Plans for Gas Bubble Disease Signs and Gas Supersaturation Levels on the Columbia and Snake Rivers Prepared for Bonneville Power Administration.

Montgomery Watson. 1995. Allowable Gas Supersaturation for Fish Passing Hydroelectric Dams. Task 9b - Comparison of Clinical Signs of Gas Bubble Disease in the Gill of Smolts Using Both Compound and Dissection Microscopes. Prepared for Bonneville Power Administration.

Brief schedule of activities
Task Number Start Completion

1 1997 1998

2 1997 1999

3 1997 2000

4 1997 2001

5 1997 2001

6 1997 1997

Biological need
State and Federal fisheries agencies favor the use of spill to increase the number of smolts that pass over the spillways on the Columbia and Snake Rivers. Spill releases at these dams result in total gas pressures (TGP) above the current criteria of 110 % TGP. The states of Oregon and Washington have granted a variance in the water quality standards for total gas pressure during this spill period. To protect the anadromous and resident fishes, a monitoring program has been implemented to detect clinical signs of gas bubble disease. The first year of this program was during the 1994 spill period. Due to the speed with which the program was implemented, there were a number of problems in the protocols used, training, and reporting (Montgomery Watson, 1994).

The monitoring program for the 1995 spill period has changed significantly from the 1994 spill program. An independent QA/QC review of the 1995 monitoring program for gas bubble trauma was conducted (Biological Monitoring Inspection Team. 1995). This team made recommendations (a) to improve data quality, data uniformity, and protocol compliance for the 1995 biological monitoring program, (b) to guide future monitoring programs, and (c) to identify long-term research needs of the gas bubble trauma monitoring program.

Based on our involvement with the 1994 and 1995 monitoring programs and on-going gas supersaturation research, Montgomery Watson has prepared a six task proposal for improving the effectiveness of the gas bubble disease monitoring program on the Columbia and Snake Rivers. The work identified in this proposal will greatly improve the effectiveness of the gas bubble disease monitoring program as well as increasing our basic knowledge of the impacts of elevated gas levels on smolts and adult salmonids.

Critical uncertainties
Access to hatchery chinook and migrating hatchery steelhead.

Summary of expected outcome
The work identified in this proposal will greatly improve the effectiveness of the gas bubble disease monitoring program as well as increasing our basic knowledge of the impacts of elevated gas levels on smolts and adult salmonids. Detailed information on the expected results for the six tasks are presented below:

Task 1 Development of standardized protocols for the examination of fish for clinical signs of gas bubble disease

The standardized protocols developed in this task will greatly increase the acceptance of the results of the gas bubble disease monitoring on the Columbia and Snake Rivers.

Task 2 Development of non-lethal techniques for the examination of fish for clinical signs of gas bubble disease

The results of this task would allow non-lethal examination of smolts for the presence of gill bubbles. This may allow early assessment of increased risk from elevated dissolved gas levels.

Task 3 Assessment of the use of physiological parameters to detect exposure to elevated total gas pressures and estimate risk

The work proposed in this task is exploratory in nature. There is reason to believe that some of these measurements will increase our ability to assess prior exposure to elevated gas levels and predict which fish are at-risk.

Task 4 Provide clinical, histological, and evaluation support during the 1996 peak downstream migration period in the Columbia and Snake Rivers

These two tasks will greatly improve the documentation of the full range of clinical signs of gas bubble disease in downstream migrants in the Columbia and Snake Rivers.

Task 5 Investigate the kinetics of bubble growth and reabsorption in juvenile pacific salmon smolts exposed to gas supersaturation

The results of this task will greatly increase our understanding of the kinetics of bubble reabsorption and growth under river conditions. This information can be used to assess the risk from gas bubble disease at a given level of gas supersaturation. This information will also be used to guide and direct on-going river sampling programs and improve the effectiveness of the dam-based smolt monitoring program.

Task 6 Assess the state-of-the-art for the development of an implantable ĘP tag with radio transmission capability

The results of this task would be an assessment of the potential capacity and characteristics of a ĘPuncomp radio tag. After the completion of this task, it will be possible to assess whether additional development effort should be expended.

Dependencies/opportunities for cooperation
This research will 4,000-5,000 hatchery fingerlings for laboratory work. Task 3 and 4 will require lethal examination of 1,000-2,000 migrating hatchery smolts . Some of this work may be done on fish collected for other purposes.

This research would be coordinated with on-going research being conducted by the National Biological Service and the National Marine Fisheries Service.

Risks
The primary risk to the resource may occur if the current monitoring program is not improved.

Monitoring activity
The results of each task will be documented by a project report. It is anticipated that selected results will be submitted for publication to fisheries or fish health journals.

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   System Policy

Recommendation    Tier 3 - do not fund