Duane A. Neitzel

Survival Estimates for Juvenile Fish Subjected to a Laboratory-Generated Shear Environment

Abstract Juvenile rainbow trout Oncorhynchus mykiss and steelhead (anadromous rainbow trout), fall (age-0 and age-1) and spring Chinook salmon O. tshawytscha, and American shad Alosa sapidissima were exposed to shear environments in the laboratory to establish injury–mortality thresholds based on estimates of strain rate. Fish were exposed to a submerged jet having exit velocities of 0 to 21.3 m/s, providing estimated exposure strain rates up to 1,185/s. Turbulence intensity in the area of the jet where fish were subjected to shear was minimal, varying from 3% to 6% of the estimated exposure strain rate. Injuries and mortalities increased for all species of fish at strain rates greater than 495/s. American shad were the most susceptible to injury after being subjected headfirst to a shear environment, while steelhead and rainbow trout were the most resistant. There was no apparent size-related trend in susceptibility to high shear except that age-0 fall Chinook salmon were more resistant to shear environm...

Effects of Dewatering on Chinook Salmon Redds: Tolerance of Four Developmental Phases to Daily Dewaterings

Abstract Four intergravel developmental phases of chinook salmon Oncorhynchus tshawytscha were dewatered experimentally in artificial redds. The redds consisted of aquaria containing 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 dewatered 20 consecutive times in 22-day tests. The egg phases were considerably more tolerant than the alevins. Some cleavage eggs were killed by 12- and 16-hour daily dewaterings, but embryos survived up to 22-hour daily dewaterings. Embryos also tolerated extended, multiple dewaterings (over 60% survival for four consecutive 118-hour periods) and one-time, continuous dewatering for up to 12 consecutive days (over 80% survival). In contrast, about half the eleutheroembryos were killed by 4-hour daily dewaterings, and nearly all pre-emergent alevins were killed by 1-hour daily dewaterings. Intergravel temperatures were affected by insolation an...

Comparing Fish Screen Performance to Physical Design Criteria

Abstract Fish screens associated with irrigation diversion structures perform a vital function by protecting rearing and migrating fishes. Irrigation diversions in the western United States were developed in the late 1800s and early 1900s with little regard to how they might affect fish populations. Fish screens were installed on some diversions beginning in the 1930s but were often ineffective. Beginning in the 1980s a “modern-era” fish screening program was initiated in the Yakima River basin in Washington State. A systematic phased approach was employed, with federal funding, to replace antiquated screens and to install screens where there had not previously been fish protection devices. Also during this time, the federal and state agencies responsible for protecting the fish resources developed regional criteria to guide design of these facilities. These criteria, developed by the National Marine Fisheries Service and used by the Washington Department of Fish and Wildlife, dictated physical metrics su...

Laboratory Studies on the Effects of Shear on Fish

The overall objective of our studies was to specify an index describing the hydraulic force that fish experience when subjected to a shear environment. Fluid shear is a phenomenon that is important to fish. However, elevated levels of shear may result in strain rates that injure or kill fish. At hydroelectric generating facilities, concerns have been expressed that strain rates associated with passage through turbines, spillways, and fish bypass systems may adversely affect migrating fish. Development of fish friendly hydroelectric turbines requires knowledge of the physical forces (injury mechanisms) that impact entrained fish and the fishs tolerance to these forces. It requires up-front, pre-design specifications for the environmental conditions that occur within the turbine system, in other words, determining or assuming that those conditions known to injure fish will provide the descriptions of conditions that engineers must consider in the design of a turbine system. These biological specifications must be carefully and thoroughly documented throughout the design of a fish friendly turbine. To address the development of biological specifications, we designed and built a test facility where juvenile fish could be subjected to a range of shear environments and quantified their biological response.

Tolerance of eggs, embryos, and alevins of chinook salmon to temperature changes and reduced humidity in dewatered redds

Abstract Changes in temperature and relative humidity can occur in gravel during dewatering of salmonid redds. Four intergravel development phases of chinook salmon Oncorhynchus tshawytscha were exposed to increased or decreased temperatures, and one phase was subjected to reduced relative humidity to define tolerance limits. Abrupt increases in temperature from 10°C to above 22°C for 1–8 h reduced survival of cleavage eggs. Embryos survived 8-h exposures to 25°C and 2-h exposures to 26.5°C. Eleutheroembryo and pre-emergent alevins tolerated 4-h exposures to 23.5°C and 1-h exposures to 25.0°C. Decreases in temperatures from 10.0°C to near freezing (about 0.0°C) did not reduce survival of eggs, embryos, or alevins. Reduced relative humidity adversely affected survival of embryos. Ninety-eight percent of dewatered embryos exposed to 100% relative humidity for up to 24 hours survived. Embryo survival at 90% relative humidity was 0%, 55%, and 100% for exposure periods of 24, 8, and 4 h, respectively. Control ...

Assessment of intergravel conditions influencing egg and alevin survival during salmonid redd dewatering

SynopsisExtensive water use may alter stream flows so that areas used by salmonids for spawning are dewatered, thus exposing intergravel developmental phases to suddenly changed physical and chemical conditions. Environmental alteration may result in considerable mortality, particularly of the more vulnerable post-hatch phases. Five documented case histories of redd dewatering are reviewed. The primary conditions in the gravel that influence survival during dewatering are residual flow, moisture retention, temperature, gravel composition, dissolved oxygen, alevin behavior, and species characteristics. These factors are discussed and their complex relationships are evaluated. Considerable variation in intergravel conditions can be expected during dewatering at different locations. Onsite studies are needed to obtain data for assessment of potential impacts in other dewatering situations, and for development of effective mitigation procedures.

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...

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...

Washington Phase II Fish Diversion Screen Evaluations in the Yakima River Basin, 1999.

Pacific Northwest National Laboratory (PNNL) evaluated 20 Phase II screen sites in the Yakima River Basin as part of a multi-year study for the Bonneville Power Administration (BPA) on the effectiveness of fish screening devices. The sites were examined to determine if they were being effectively operated and maintained to provide fish a safe, efficient return to the Yakima River. Data were collected to determine if velocities in front of the screens and in the bypass met current National Marine Fisheries Service (NMFS) criteria to promote safe and timely fish bypass and whether bypass outfall conditions allowed fish to safely return to the river. In general, water velocity conditions at the screen sites met fish passage criteria set forth by the NMFS. Although velocities often fluctuated from one sampling location to the next, average sweep velocities typically exceeded approach velocities and increased toward the bypass. Mean approach velocities were below the NMFS criteria of < 0.4 feet per second (fps) at most sites (Table 1). Based on our observations in 1999, we believe that most facilities were efficiently protecting juvenile fish from entrainment, impingement, or migration delay. Most screens were properly sealed to prevent fish entrainment and injury, although potential problems were identified at several screen sites. Six sites (one fewer than the seven sites identified in 1998) had loose or damaged seals that might have allowed fish to be entrained (Table 1). Other sites still had spaces larger than 3/32 in. where small fish could possibly pass into the irrigation canal.

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.