Albert E. Giorgi

Susceptibility of Chinook salmon smolts to bypass systems at hydroelectric dams

Abstract Several hydroelectric dams in the Snake-Columbia river system are equipped with submersible traveling screens that project into the turbine intakes. The screens are designed to divert juvenile migrant Pacific salmon Oncorhynchus spp. and steelhead Salmo gairdneri from the intake upward into gatewells and the ajoining central bypass system. Assays ofgill Na+,K+-ATPase were performed on yearling chinook salmon O. tshawytscha collected during several routine fish guidance efficiency tests in 1985 and 1986. On three of the four sampling dates, gill Na+,K+-ATPase levels were significantly higher in fish guided into the gatewell than in those not guided. These data suggest there is a relationship between the physiological status of smolting yearling chinook salmon and their susceptibility to guidance by traveling screens. Assessments of salmonid out-migrations may be biased if they are based on samples from traveling-screen guidance systems.

Effects of Jet Entry at High Flow Outfalls on Juvenile Pacific Salmon

Abstract We conducted field studies and laboratory experiments to explore the relationship between direct injury and mortality rates of juvenile Pacific salmon Oncorhyncus spp. and the jet entry velocities characteristic of high-flow (>28.3 m3/s) outfalls at hydroelectric facilities. During field tests, the range of calculated mean entry velocities was 9.3–13.7 m/s for low (28.3 m3/s) and high (68.0–70.2 m3/s) outfall discharge rates and two receiving water elevations. Mortality and injury rates of balloon-tagged hatchery juvenile spring chinook salmon O. tshawytscha in the field tests were less than 1%. At a high-velocity flume in a laboratory, small (87–100 mm fork length (FL)) and large (135–150 mm FL) hatchery fall chinook salmon were exposed to velocities of 0.0–24.4 m/s in a fast-fish-to-slow-water scenario. Jet entry velocities up to 15.2 m/s provided benign passage conditions for the sizes and physiological states of juvenile salmonids tested under the particular environmental conditions present d...

Evaluating Surrogacy of Hatchery Releases for the Performance of Wild Yearling Chinook Salmon from the Snake River Basin

Abstract The combined juvenile and adult detections of Snake River yearling Chinook salmon Oncorhynchus tshawytscha implanted with passive integrated transponder tags migrating through the hydroelectric facilities in the Federal Columbia River Power System were analyzed using the ROSTER statistical release–recapture model. This model was used to estimate the downriver survival of smolts, ocean survival, adult passage success, and smolt-to-adult ratios (SARs) for wild and hatchery-reared Chinook salmon released as yearlings in the Snake River basin from 1996 through 2004. Estimates from wild and hatchery release groups were compared to assess the extent to which hatchery stocks may be used as surrogates for endangered wild stocks. Wild release groups included both spring and summer Chinook salmon runs, while hatchery release groups were separated by run (spring versus summer). Overall, there was a significant difference between estimates from wild release groups and hatchery spring-run release groups for a...

Estimating the Daily Passage of Juvenile Salmonids at McNary Dam on the Columbia River

Abstract The U.S. National Marine Fisheries Service, under contract to the U.S. Army Corps of Engineers, monitored the seaward migration of juvenile salmonids through the Snake-Columbia river system from 1973 to 1983. We developed a procedure for estimating the numbers of steelhead Salmo gairdneri and yearling chinook salmon Oncorhynchus tshawytscha smolts passing McNary Dam each day in 1982-1983. The method utilized the fingerling collection and bypass system contained within the powerhouse. Freeze-branded groups of smolts released upstream from the dam were used to calibrate the efficiency with which migrants were collected over a range of powerhouse discharge levels. Application of collection efficiency calibration curves enables researchers and fisheries managers to generate daily estimates of smolt passage as a function of the amount of water discharged through the powerhouse and the number of fish collected in the bypass system.

Lower Granite Pool and Turbine Survival Study, 1987.

Survival of yearling spring chinook salmon was estimated as they traversed Lower Granite Reservoir and passed through a turbine at Lower Granite Dam. Fish were PIT tagged at Rapid River Hatchery and transported to release sites near Asotin, Washington, and at Lower Granite Dam. Recovery ratios of treatment and control groups were used to estimate survival. Estimates were based on tags intercepted at both Lower Granite and Little Goose dams. Turbine survival was estimated to be 83.1% (95% CI = 74.1 to 92.2%). A qualified estimate of survival from Asotin to Lower Granite Dam for a single release group was calculated as 71.9%. Uncertainties associated with satisfying certain key mark and recapture statistical assumptions are examined. As a result of these uncertainties, an alternate study design and analytical procedure are recommended for future investigations. 14 refs., 7 figs., 5 tabs.

Synthesis of Biological Reports on Juvenile Fish Passage and Survival at Bonneville Dam through 2005

This report describes a review of available literature on juvenile salmonid passage at Bonneville Dam from 1939 through 2005. Studies of interest included project-wide fish-passage efficiency (FPE) studies by radio telemetry and fixed-aspect hydroacoustics, fish survival studies (direct and indirect), FGE studies, powerhouse and unit (by netting, hydroacoustics, and radio telemetry), predation studies in the forebay and tailrace, behavioral studies on forebay approach and egress, and surface-bypass studies. The FPE effort will include a review of available distribution data (horizontal, diel, and vertical) for juvenile salmon. This study does not repeat the results of previous review and synthesis studies but cites them. Where no previous review exists for a subject area, all reports were reviewed and synthesized. The report includes an annotated bibliography summarizing each of the documents reviewed and a DVD disk containing all of the original papers and reports along with an HTML index to the documents.

Design and Analysis of Salmonid Tagging Studies in the Columbia Basin, Volume XI; Recommendations on the Design and Analysis of Radiotelemetry Studies of Salmonid Smolts to Estimate Survival and Passage Efficiencies, 1991-1998 Technical Report.

The purpose of this investigation was to determine the feasibility of extracting detailed survival and passage efficiency estimates from a properly designed smolt radiotelemetry study.

Management Briefs: An Anchor System for Periodic Retrieval of Current Meters from Fixed Locations

Abstract An inexpensive anchor system was designed and used at numerous sites in the forebay of John Day Dam for the purpose of charting river currents during outmigration of juvenile salmonids. This system allowed for the removal of a current meter from the water for periodic maintenance and data retrieval while the anchor remained in a stationary position on the bottom. The anchor system functioned satisfactorily during the 2-year study.