BPA Fish and Wildlife FY 1997 Proposal
Section 1. Administrative
Section 2. Narrative
Section 3. Budget
see CBFWA and BPA funding recommendations
Title of project
Symptoms of Gas Bubble Trauma Induced in Salmon by Total Dissolved Gas Pressure Supersaturation in the Snake and Columbia Rivers
BPA project number 9300802
Business name of agency, institution or organization requesting funding
Columbia River Inter-Tribal Fish Commission
Sponsor type CRITFC
Proposal contact person or principal investigator
|Name||Dr. Tom Backman|
|Mailing address||Columbia River Inter-Tribal Fish Commission 729 NE Oregon Portland, OR 97232|
BPA technical contact Bill Maslen, EWI 503/230-5549
Biological opinion ID NMFS BO RPA Sec. 16 + waivers
NWPPC Program number 5.6E.1
Spill is provided to expedite the migration of juvenile salmon past hydroelectric dams in the Columbia River basin. However, mortality may occur during spill operations due to supersaturation of dissolved gases. Project will determine the relationships between supersaturation levels, flow rates, fish movements, fish distribution, and symptoms. Phase I (1996) activities in the field will focus on three objectives: 1) Inspecting adult salmonids for signs of symptoms at Bonneville and an up-river dam (Objective A1); 2) sampling in-river migrating juvenile salmonids at McNary Dam to compare with by-pass sampled fish (Objective J1); and 3) developing sampling techniques, logistics, schedules, and collecting preliminary data for use in design of future experiments to determine occurrence of symptoms among out migrating smolts (Objective J2). Preliminary developmental work for Objective J2 will be conducted in McNary Reservoir, with secondary sites in the lower Columbia River (John Day to Bonneville Dam tailrace area). Analysis of preliminary results during Phase I activities will focus on the feasibility of integrating data on gas levels, fish distributions, and the incidence of symptoms. Based on analysis of the first yearís data we will determine the level of effort and methods required for future field experiments. In Phase II (1997-1998) we will implement the recommendations for design and sampling developed in Phase I and expand the scope of sampling to additional reservoirs.Spill is provided to expedite the migration of juvenile salmon past hydroelectric dams in the Columbia River basin. Under spill conditions, juvenile salmon are expected to experience less direct mortality due to injury than if they pass through the turbines, or screened bypass and collector systems (bypass). However, additional indirect mortality may occur during spill operations due elevated levels of total dissolved gas pressure supersaturation (supersaturation). Two key unknowns are the potential exposure to supersaturation and the portion of fish with gas bubble trauma symptoms (symptoms). The ultimate goal of this study is to determine the relationships between supersaturation levels, flow rates, fish movements, fish distribution, and symptoms. Phase I (1996) activities in the field will focus on three objectives: 1) Inspecting adult salmonids for signs of symptoms at Bonneville and an up-river dam (Objective A1); 2) sampling in-river migrating juvenile salmonids at McNary Dam to compare with by-pass sampled fish (Objective J1); and 3) developing sampling techniques, logistics, schedules, and collecting preliminary data for use in design of future experiments to determine occurrence of symptoms among out migrating smolts (Objective J2). Preliminary developmental work for Objective J2 will be conducted in McNary Reservoir, with secondary sites in the lower Columbia River (John Day to Bonneville Dam tailrace area). Analysis of preliminary results during Phase I activities will focus on the feasibility of integrating data on gas levels, fish distributions, and the incidence of symptoms. Based on analysis of the first yearís data we will determine the level of effort and methods required for future field experiments. In Phase II (1997-1998) we will implement the recommendations for design and sampling developed in Phase I and expand the scope of sampling to additional reservoirs.
Project start year 1995 End year 1999
Start of operation and/or maintenance 0
Project development phase Implementation
The NBS performs hydroacoustic work. The NMFS performs gas transect work. The FPC performs smolt monitoring at bypass facilities, and the USACOE performs gas monitoring at dams.
This project was initiated in May of 1995. During the 1995 spill program, in-river juvenile fish were sampled with purse seines and trawls in six areas to record the frequency and severity of symptoms. Adults were examined at Bonneville and Priest Rapids dams.
Biological results achieved
In 1995 fish were examined for presence and severity of symptoms, and scored according to a protocol developed by a multiagency committee. After an evaluation was made of the protocol in the field, minor changes were recommended. Sub-samples of resident species and salmon stocks not listed under the Endangered Species Act were examined for internal symptoms in their gill lamellae. The differences in presence and severity of symptoms in fish collected in-river and at the bypass were not statistically significant in 1995. Ten of 907 in-river sampled juvenile had minor signs of gas bubble trauma.
Annual reports and technical papers
Data summaries will continue to be provided to BPA, NMFS, and the Fish Passage Center. Quarterly reports have been submitted. An annual report will be published. A final report will be published, and a paper will be published in a refereed journal.
Data from the monitoring of levels of in-river gas bubble trauma in salmon may be used in an adaptive management process. They are used in the present spill management decision making process. If further results of in-river studies differ from those of the smolt-monitoring program, the monitoring program may need to be adapted. Changes may be necessary in GBT reporting to correct for bias, and in-river sampling results may become part of the monitoring program. The results of this investigation may guide the development of future monitoring activities.
Specific measureable objectives
PHASE I OBJECTIVES (and sub-objectives)
Number and Title Description/Notes
A1 Measurements of the frequency and severity of GBT symptoms in adult salmonids (natural and hatchery production) at Bonneville and Priest Rapids dams.
J1 Measurements of the frequency and severity of GBT symptoms in-river juvenile salmonids (natural and hatchery production) near SMP monitoring points. These data will help determine the representativeness of GBT symptom data collected in smolt bypass facilities.
J2 Developed sampling and analytical methods for defining the relationship between gas supersaturation levels (and other physical factors) and the frequency and severity of GBT symptoms in in-river juvenile salmonids. In Phase II, these methods will be used to collect and analyze standard data.
J2.1 Developed sampling methods. Separate tasks address the methods required to collect physical (e.g., gas levels, velocity) data and biological (e.g., fish distribution, capture, and condition) data.
J2.2 Collected physical and biological samples in suspected hot spots. Managers have requested physical and biological sampling in suspected hot spots (e.g., The Dalles tailrace during times of high spill). These data may also be useful for validating data collected during standard sampling.
J2.3 Developed analytical methods. Preliminary data collected in Phase I will be used to help develop the experimental design for Phase II and evaluate potential multi-factor models for describing the relationships between physical conditions and GBTS symptoms.
Ho: There are no differences in prevalence and severity in gas bubble trauma symptoms between in-river and bypass sampled fish.
Ho: The prevalence and severity in gas bubble trauma symptoms in in-river sampled juvenile salmon are below the acceptable management criteria during controlled spill.
Underlying assumptions or critical constraints
Adequate spill and flows will be provided for migratory juvenile salmonids. Sufficient juvenile salmonids will be available for capture in-river. Sample sizes will be large enough for statistical validity. Adequate funding will be received in a timely manner, so that project prepartion time will be sufficient.
To measure the frequency and severity of symptoms in adult salmonids at Bonneville Dam and Priest Rapid Dam.
Sockeye (Oncorhynchus nerka), chinook salmon (O. tshawytscha), and steelhead (O. mykiss) will be trapped at existing fish traps and examined. Sampling at Bonneville Dam will be conducted three days (generally Monday, Wednesday, and Friday) per week between 13 May and 28 June, 1996, for 6-8 hours per day. At Priest Rapids Dam the same species (sockeye, chinook salmon, and steelhead) will be sampled at the exit ladder fish trap and examined. Sampling will be conducted every Tuesday and every-other Thursday between 30 May 1995 and 10 August 1995 for 0-12 hours per day. Sampling will be discontinued when spill does not occur. We expect to sample 3% to 6% of the adult salmonids passing both Bonneville and Priest Rapids dams during the period in which monitoring is conducted
Adult examination procedures: Each fish will be placed in a sampling tank, anesthetized, and carefully examined for external symptoms by using a headband binocular magnifier. External signs of gas bubble trauma included in the examination will be the presence of distended eyes, vesicles in the mouth, on the operculum, and between fin rays. Particular attention will be paid to the head, the operculum plates, and the insertion point of each fin ray. After examination, fish will be allowed to recover in fresh water and released.
To capture in-river fish at selected sites to compare the symptoms of by-pass examined and in-river examined fish.
Purse seine and trawl methods (as described below) will be used to collect samples above the boat restricted zone in the forebay of McNary Dam. We have selected McNary Dam because this dam had a high percentage symptoms (13%) compared to other dams during the 1995 spill season. McNary is the first dam on the Columbia River to sample a mixture of both mid-Columbia and Snake river outmigrating fish. Specific sampling locations above McNary Dam and times depend upon fish movement and presence. Sampling will likely occur during the more proven fishing periods prior to dusk and just after dawn. When fish were present in 1995, we found that a purse seine could obtain samples of 20 to 100 fish per set. Trawls will provide additional fish when fish are deep or less abundant.
Purse seine collection method: A 100 m X 5 m deep, 2.5 cm stretch mesh purse seine will be set with two boats. On retrieval the portion of net containing the trapped fish will be allowed to stay in-river, until the captured fish are transferred with a sanctuary dip-net and placed in live box filled with flowing river water. The captured fish will either be examined on board or at a shore-based station nearby.
Trawl net method: Rectangular and square trawl nets will be utilized to collect fish from the surface, and from depths of up to 50 ft. We have modified the opening and closing trawl developed by Enzenhofer and Hume (1989). This prototype rectangular net (2 m deep X 6 m wide) will capture fish from known 2 m depth strata. Its advantage over conventional nets is its ability to descend to depth, open and begin fishing, and then to close prior to retrieval. This gear will ensure that the fish collected are only from a selected and known depth. Depth of the trawl net will be recorded with a Mk5 time-depth recorder. During the testing and modification of the prototype trawl, hydroacoustic and/or underwater cameras will document the netís depth and attitude in the water.
Juvenile fish examination procedures: Fish will be examined using a variable magnification (10X to 40X) dissecting scope. The body, fins, eyes, opercula, and lateral line on the left side will be examined for symptoms. Up to 100 individuals of each species and stock (i.e., hatchery-origin fish) not listed under the Endangered Species Act will be sub-sampled for internal examination of the gill lamellae. For fish longer than 120 mm, the operculum will be lifted and the gills observed directly. For smaller fish, a section of the operculum will be removed so gill lamellae can be observed. All bubbles will be recorded. A percentage of the lateral line occluded by bubbles will be determined and rank assigned. Additional information will be recorded for each fish including species, fork length, origin (fin clips, or other man made marks), presence of disease or injury, and descaling information. Once normal swimming behavior is observed, the non-sacrificed fish will be returned to the river. All biological staff will be trained in symptom examination techniques developed for field crews by the National Biological Survey (NBS) and the Smolt Monitoring Program.
METHODS: Statistical analysis of sample size. Several related but different approaches have been used to estimate the sample size required to determine the percentage of symptoms in the population.
Estimating the sample size for a given power required to test null hypotheses that there are no significant differences between bypass examined fish and in-river examined fish was determined by the methods of Snedecor and Cochran (1980). The formula:
Where ZĶ and Zb are the normal deviates corresponding to the significance level to be used in the test. We assumed the cost of type I and type II errors are equal. Setting a=b = 0.10 we obtained a value of 6.6 for ZĶ and Zb one-sided test. The p values were based on management criteria.
We have set an upper conservative goal of 100 fish, at which point we will discontinue sampling. If, however, fish are difficult to obtain and/or £ 1 in 50 fish have symptoms, sampling will be discontinued for the day. Each experiment or trial will comprise a reservoir site sampled for up to 12 hours. Actual time depends primarily on hydropower operating conditions and environmental factors affecting fish behavior.
Hydroacoustic methods to determine juvenile salmonid distribution follow. The hydroacoustic system used by NBS was designed to conduct mobile surveys and consists of a down-looking dual-beam transducer and a side-looking single-beam transducer mounted on a towed body deployed one meter below the surface. The down-looking transducer samples an area from two meters below the surface to the bottom. The side-looking transducer samples strata from one to five meters deep. The multiplexing capability of the echo sounder allows both transducers to operate simultaneously. Data will be analyzed by echo counting techniques (Thorne 1983). This procedure consists of a count of the echoes returned from individual fish. Density of fish estimates are determined by dividing the echo count by the volume of water sampled by the hydroacoustic system (Thorne et al. 1992). Improvements in measuring near-surface distribution of fish will be a primary activity of this yearís development work.
NBS will examine different transducer deployment methods. These methods include towed bodies (Enzenhofer and Hume 1992), heavy towed bodies, side-looking split beam, quick-set stationary up-looking, and multiple transducer arrays. The transducer also may be deployed in the up-looking position by an underwater remotely operated vehicle.
Testing buoys to determine feasibility of identifying and tracking water masses with elevated TDGS levels.
High TDGS levels have been associated with water mass spilled at selected mainstem dams, and migrating juvenile salmon may migrate along with such water masses. If we could repeatedly sample fish from the same water mass, we may be able to infer something about their gas exposure history prior to capture. We propose to use instrumented buoys to track a water mass with high or low supersaturation levels. The buoys may contain one or more of the following equipment: safety light, a recording supersaturation meter, a radio transmitter, and a recording global.positioning system (GPS). Deploying buoys as proposed above will provide a record of supersaturation levels, and a time-sequence record of locations.
To determine the distribution of juvenile salmonids with hydroacoustics in the areas between the confluence of the Snake River and Columbia River and McNary Dam and other sites where and when gas supersaturation are >120%:
Transects will be sampled using the hydroacoustic survey system developed under task J2.1.1. Instruments include a GPS to determine location, and an acoustic doppler current profiler to determine water velocities in the study area. Concurrent with the hydroacoustic surveys, fish will be collected with purse seine and trawls and examined as described under task J1.1.
Develop analytical methods.
The analysis will include an evaluation of the symptom procedures, dispersion and central tendency of the data, the power of statistical test, and the ability to conduct a multi-factor field investigation. Based on the analysis, the feasibility of a multi-factor experimental design will be presented.
Brief schedule of activities
Phase I. Spring-Summer 1996
Phase II. 1997-1998.
This is a mainstem, in-river project and our results are applicable to all up-river priority stocks. The results from experiments in reservoirs will provide information to several user groups interested in gas abatement, water management, and smolt survival. The field experiments will be used to validate the fishery agency and tribal Smolt Monitoring Programís (SMP) results and to interpret results from experiments conducted by other investigators in controlled laboratory environments. In addition, field investigations will provide researchers with in-river supersaturation and symptom conditions to direct future study using controlled experiments to determine dose-response relations of fish. The results will aid in developing simulation models by providing quantitative parameter values for the factors measured and by generating empirical data to test new models. These data will provide managers with a better picture of actual physiological and ecological conditions fish experience. Furthermore, if the findings indicate a monitoring program for symptoms in smolts in reservoirs is necessary, then results will provide a basis for managers to design such a program.
1) The effects of spill on production needs to be understood. It is assumed that juvenile salmonids sampled at Smolt Monitoring sites are representative of in-river juvenile salmonids.
In past years the highest levels of supersaturation occurred in areas not sampled by the Smolt Monitoring Program. For example, downstream from Ice Harbor Dam in 1995, Total Dissolved Gas Supersaturation were sufficiently high (up to 138% of saturation) to cause signs in shallow water. Few signs were observed by the Smolt Monitoring Program. Sampling in this reach was not conducted except for an exploratory trial as part of this study. The effects of passing through the bypass system are uncertain and may inter bias into the data.
2) The migrating adult salmonids are un-affected by spill for juvenile salmonids.
The effect of supersaturation on adults is unknown without observations, thus requiring a monitoring during periods of spill.
Summary of expected outcome
The results from experiments in reservoirs will provide information to several user groups interested in gas abatement, water management, and smolt survival. The field experiments will be used to validate the fishery agency and tribal Smolt Monitoring Programís (SMP) results and to interpret results from experiments conducted by other investigators in controlled laboratory environments. In addition, field investigations will provide researchers with in-river supersaturation and symptom conditions to direct future study using controlled experiments to determine dose-response relations of fish. The results will aid in developing simulation models by providing quantitative parameter values for the factors measured and by generating empirical data to test new models. These data will provide managers with a better picture of actual physiological and ecological conditions fish experience. Furthermore, if the findings indicate a monitoring program for symptoms in smolts in reservoirs is necessary, then results will provide a basis for managers to design such a program.
Dependencies/opportunities for cooperation
The USACE has primary responsibility for the enumeration of gas plumes in the study areas. Close coordination between the USACE and the NBS, NMFS, the Fish Passage Center and CRITFC will be important in achieving this projectís objectives. Dennis W. Rondorf (NBS) will have primary responsibility for collecting and analyzing hydroacoustic data and TDGS levels. Alec G. Maule (NBS) will have primary responsibility for Gas Bubble Trauma symptom protocols and quality assurance. Dr. Tom Backman (CRITIC) will have responsibility for coordinating activities of the adult and in-river juvenile sampling. Coordination of funding by USACE and BPA will be required. The funding for the NBS involvement (hydroacoustic, training and quality assurance under tasks J1.2, J2.1.1, J2.1.3, J2.1.2 and J2.2 ) has been requested of the USACE. The staff and contractors of this project cooperated in the development on an educational exibit at the Childrens Museum in 1995.
Field work in-river has associated dangers. All boats will have safety equipment, crews will be trained in boat handling, rules of the road, and first aid.
The NBS will provide training and quality assurance on Smolt Monitoring Protocols under task J1.2. The measurable results of this project will be in-river data on the incidence of gas bubble trauma collected during times of spill.
|Historic costs||FY 1996 budget data*||Current and future funding needs|
||New project - no FY96 data available||1997: 900,000|
* 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.
CBFWA funding review group Mainstem
Recommendation Tier 1 - fund
Recommended funding level $900,000
BPA 1997 authorized budget (approved start-of-year budget) $675,000