C. Scott Abernethy

Assessment of Barotrauma from Rapid Decompression of Depth-Acclimated Juvenile Chinook Salmon Bearing Radiotelemetry Transmitters

Abstract This study investigated the mortality of and injury to juvenile Chinook salmon Oncorhynchus tshawytscha exposed to simulated pressure changes associated with passage through a large Kaplan hydropower turbine. Mortality and injury varied depending on whether a fish was carrying a transmitter, the method of transmitter implantation, the depth of acclimation, and the size of the fish. Juvenile Chinook salmon implanted with radio transmitters were more likely than those without to die or sustain injuries during simulated turbine passage. Gastric transmitter implantation resulted in higher rates of injury and mortality than surgical implantation. Mortality and injury increased with increasing pressure of acclimation. Injuries were more common in subyearling fish than in yearling fish. Gas emboli in the gills and internal hemorrhaging were the major causes of mortality. Rupture of the swim bladder and emphysema in the fins were also common. This research makes clear that the exposure of juvenile Chinoo...

The Use of Electromyogram Telemetry to Estimate Energy Expenditure of Adult Fall Chinook Salmon

Abstract Excess energy expenditure during the upstream migration of adult fall chinook salmon Oncorhynchus tshawytscha may reduce spawning success or lead to increased prespawning mortality. Recent advances in biotelemetry make it possible to assess the energetic costs of upstream migration. Our objectives were to evaluate the use of physiological telemetry to estimate the energy expended by adult fall chinook salmon at different swimming velocities and to compare these data to those associated with other species of salmonids. An electromyogram (EMG) telemetry system was used to obtain, transmit, and record an integrated EMG pulse signal that represented the time between muscle contractions. The EMG telemetry system provides a means to evaluate the effects of structural or operational changes in the hydropower system on energy expenditure and reproductive success of upstream migrant adult salmon. Seven adult salmon (71.5 to 106 cm fork length [FL]) were tagged and exercised in a respirometer at 15 and 20°...

Effects of Dewatering on Chinook Salmon Redds: Tolerance of Four Development Phases to One-Time Dewatering

Abstract Four intergravel development phases of chinook salmon Oncorhynchus tshawytscha were experimentally dewatered in artificial redds. The redds consisted of aquaria filled with a gravel mix and supplied with 4 liters of water per minute at 10 C. Cleavage eggs and embryos (the egg phases) and eleutheroembryos and pre-emergent alevins (the alevin phases) were each dewatered once for a continuous period. Egg phases were considerably more tolerant than alevin phases. Cleavage eggs tolerated one-time dewaterings up to 12 consecutive days (98% survival), the maximum exposure period. Embryos had similar tolerance when dewatered 12 consecutive days (92% survival), but survival declined to 64% and 53% when embryos were dewatered 16 and 20 consecutive days, respectively. Loss of embryos after the longer dewaterings was associated with premature hatch. In contrast, eleutheroembryos tolerated only a 6-hour dewatering period (96% survival) and underwent high mortality when dewatered 48 consecutive hours. Pre-emer...

Movement and Injury Rates for Three Life Stages of Spring Chinook Salmon Oncorhynchus Tshawytscha : A Comparison of Submerged Orifices and an Overflow Weir for Fish Bypass in a Modular Rotary Drum Fish Screen : Annual Report 1995.

The Pacific Northwest National Laboratory (PNNL) evaluated the effectiveness of 6-in. and 2-in. submerged orifices, and an overflow weir for fish bypass at a rotary drum fish screening facility. A modular drum screen built by the Washington Department of Fish and Wildlife (WDFW) was installed at PNNL`s Aquatic Ecology research laboratory in Richland, Washington. Fry, subyearlings, and smolts of spring chinook salmon (Oncorhynchus tshawyacha) were introduced into the test system, and their movement and injury rates were monitored. A total of 33 tests (100 fish per test) that lasted from 24 to 48 hr were completed from 1994 through 1995. Passage rate depended on both fish size and bypass configuration. For fry/fingerling spring chinook salmon, there was no difference in passage rate through the three bypass configurations (2-in. orifice, 6-in. orifice, or overflow weir). Subyearlings moved sooner when the 6-in. orifice was used, with more than 50% exiting through the fish bypass in the first 8 hr. Smolts exited quickly and preferred the 6-in. orifice, with over 90% of the smolts exiting through the bypass in less than 2 hr. Passage was slightly slower when a weir was used, with 90% of the smolts exiting in about 4 hr. When the 2-in. orifice was used in the bypass, 90% of the smolts did not exit until after 8 hr. In addition, about 7% of the smolts failed to migrate from the forebay within 24 hr, indicating that smolts were significantly delayed when the 2-in. orifice was used. Few significant injuries were detected for any of the life stages. However, light descaling occurred on about 15% of chinook salmon smolts passing through the 2-in. orifice. Although a single passage through the orifice did not appear to cause significant scale loss or other damage, passing through several screening facilities with 2-in. orifices could cause cumulative injuries.

A Fisheries Evaluation of the Dryden Fish Screening Facility : Annual Report 1994.

Effectivness was evaluated of the Dryden Fish Screening Facility in the Wenatchee Reclamation District Canal near Dryden in north central Washington State. In situ tests were conducted by releasing groups of hatchery reared salmonids of different ages and sizes. Spring chinook salmon smolts (110-165 mm) were not injured or descaled in passing through the canal forebay. Smolts were not delayed as they migrated in the canal. Most fish released at the canal headworks exited the screening facility in 99% of the test fish captured in the fish bypass in <24 h. Steelhead subyearlings 65-125 mm were not injured or descaled in traveling through the bypass flume and fish return pipe. Average time for steelhead subyearlings to travel through thebypass structure was 70 seconds. Small rainbow trout fry 23-27mm could pass through the 0.125-in. profile bar screen openings and were entrained in the irrigation canal; about 38% was lost to the canal within 48 h of release. Some fry stayed in the forebay and did not migrate during the tests. Wild chinook fry 36-42mm were also entrained. Estimated 34% of emergent wild chinook salmon fry passed through the profile bar screens and were entrained in the canal. Approach velocity at the Dryden screens was {ge}0.4 ft/s; low velocities through the first two screen panels indicated that vertical louvers installed behind each screen panel to balance flow were not totally effective.

Velocity Measurements at Three Fish Screening Facilities in the Yakima Basin, Washington : Summer 1989 Annual Report.

The Pacific Northwest Laboratory (PNL) measured the velocity conditions at three fish screening facilities in the Yakima River Basin: Wapato, Chandler, and Easton Screens. The measurement objectives were different at the three screens. At Wapato, approach and sweep velocities were measured to evaluate the effect of rearing pens in the screen forebay. A complete survey was performed at the Chandler Screens. At Easton, velocity was measured behind the screens to provide information for the installation of porosity boards to balance flow through the screens. Salmon-rearing pens used at the Wapato Canal had a minimal effect on the magnitude of approach and sweep velocities at the face of the drum screens, although the pens caused increased turbulence and variability in water velocities. The net pens did not appear to affect flows through the three fish bypasses. 8 refs., 17 figs., 5 tabs.

Velocity Measurements at Six Fish Screening Facilities in the Yakima River Basin, Washington, Summer 1988 : Annual Report.

The Bonneville Power Administration (BPA), the United States Bureau of Reclamation (USSR), and the Washington State Department of Ecology (WDOE) are funding the construction and evaluation of fish passage facilities and fish protection facilities at irrigation and hydroelectric diversions in the Yakima River Basin, Washington State. The program provides offsite enhancement to compensate for fish and wildlife losses caused by hydroelectric development throughout the Columbia River Basin, and addresses natural propagation of salmon to help mitigate the impact of irrigation in the Yakima River Basin. This report evaluates the flow characteristics of the screening facilities. Studies consisted of velocity measurements taken in front of the rotary drum screens and within the fish bypass systems during peak flows. Measurements of approach velocity and sweep velocity were emphasized in these studies; however, vertical velocity was also measured. 5 refs., 18 figs., 15 tabs.

A Fisheries Evaluation of the Richland and Toppenish/Satus Canal Fish Screening Facilities, Spring 1986 Annual Report.

The fisheries evaluation phase of diversion screen effectiveness summarizes the results of work at the Richland and Toppenish/Satus Fish screening facilities (Richland Screens and Toppenish/Satus Screens) during 1986. More than 10,000 steelhead, Salmo gairdneri, and chinook salmon, Oncorhynchus tshawytscha, were released at the screen diversions. At the Richland Screens, 61% of the released steelhead were recovered and 1.1% were descaled; 93% of the spring chinook salmon were recovered and less than 1% were descaled. At the Toppenish/Satus Screens, only steelhead were evaluated for descaling; 88.9% were recovered and 23.9% were descaled. Only steelhead were evaluated because the Yakima River fisheries managers did not expect any other smolts to occur in Toppenish Creek. Because of the acclimation conditions and the amount of time the fish had to be held before testing, some of the test population were descaled during holding and transportation. The 23.9% descaling for the test fish was compared to 26.4% for the controls.