Salmonid Passage Research Articles

Evaluation of passage and sorting of adult Pacific salmonids through a novel fish passage technology

Throughout their life cycle, salmonids migrate between different habitats. During their journey, they often encounter barriers, such as hydropower dams, which may impede their migration and therefore decrease habitat connectivity. Fish passage systems have been developed to enable the migration of fish around barriers but their design is rarely adaptable to a wide range of species and hydraulic conditions. The Whooshh Fish Transport System (WFTS) is a fish passage technology that was designed to move fish around barriers through a flexible tube using differential air pressure. In this study, we evaluated the combination of the WFTS with the Whooshh Ellips Scanning Sorting system (WESS). This combined system allows autonomous and volitional entry, and subsequent selective upstream passage for fish of different sizes. The sorting by size and the passage efficiency of Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) through the WESS-WFTS was assessed. We found that the WESS-WFTS was able to sort the fish by size, few fish had external injuries, and few unexpected events (e.g. backward transport, discontinuous transport) occurred. Our results support the use of the WESS-WFTS as an effective transport system for adult salmonids when used in conjunction with a volitional fishway entrance.

Nonsalmonid versus Salmonid Passage at Nature‐Like and Pool‐and‐Weir Fishways in Atlantic Canada, with Special Attention to Rainbow Smelt

AbstractIn recent years, fish passage efforts have begun shifting away from targeting salmonids and instead toward passing entire fish communities, including nonsalmonids. The objectives of this study were to evaluate the performance of a nature‐like fishway and a pool‐and‐weir fishway at passing Rainbow SmeltOsmerus mordax(2014 and 2016) and Brook TroutSalvelinus fontinalis(2015 and 2016). Both fishways are located at the same dam on the Glenfinnan River, Prince Edward Island, Canada. Fish werePIT‐tagged, and their movements were tracked using stationaryPITantennas. Results indicated that passage efficiency at the pool‐and‐weir fishway was 0% for Rainbow Smelt in both years. In contrast, 100% and 99.2% of Brook Trout passed the pool‐and‐weir fishway in 2015 and 2016, respectively. At the nature‐like fishway, the highest passage efficiency measured for Rainbow Smelt was 28.6% (2016) and was not significantly different between years. In comparison, 100% and 91.7% of Brook Trout passed the nature‐like fishway in 2015 and 2016, respectively. Additionally, attempts to improve attraction efficiency at the nature‐like fishway by directing more water toward the fishway's entrance and removing instream debris were made in 2015, but attraction efficiency did not differ between 2014 and 2016. Finally, Rainbow Smelt were also observed spawning throughout the nature‐like fishway. This study adds to the growing evidence that fishways designed specifically for salmonids can be inappropriate for nonsalmonids. Data indicate that although some passage of Rainbow Smelt was noted at the nature‐like fishway relative to the pool‐and‐weir fishway, overall passage was low. Future efforts directed at improving passage should focus on adjusting the entrance location of the nature‐like fishway. Despite low overall passage for Rainbow Smelt, the presence of spawning adults within the nature‐like fishway suggests that the fishway itself provides suitable spawning habitat and that fishway performance evaluation should take this into consideration.

Effectiveness of a Fishway for Restoring Passage of Colorado River Cutthroat Trout

AbstractLittle is known about the effectiveness of fishways for restoring passage to inland (nonanadromous) salmonids. We used PIT telemetry to evaluate the biological effectiveness of a vertical‐slot fishway constructed to restore passage of adult Colorado River Cutthroat Trout Oncorhynchus clarkii pleuriticus (CRCT) in a small Rocky Mountain stream. Our objectives were to assess (1) fishway efficacy (whether or not the fishway restored fish passage), (2) approach efficiency (the probability that a tagged fish encountered the fishway; an index of population use), (3) attraction efficiency (the probability that a fish near the fishway located its entrance), and (4) passage efficiency (the probability that a fish entering the fishway navigated successfully through it). To account for antenna detection probabilities and avoid biases that can result from simple, proportion‐based calculations, we used a variation of the Cormack–Jolly–Seber model to derive efficiency estimates. The fishway restored passage of adult CRCT to long‐vacant habitats. Approach efficiency was 4%; attraction and passage efficiencies were 100%. We conclude that fishways can effectively restore passage of inland salmonids, and we recommend that additional fishway monitoring studies be conducted to inform decision‐making and elucidate which designs and conditions will best facilitate passage.Received April 19, 2017; accepted September 26, 2017Published online November 6, 2017

Upstream Movement of Juvenile Coho Salmon in Relation to Environmental Conditions in a Culvert Test Bed

AbstractWe measured the upstream passage success of juvenile coho salmon Oncorhynchus kisutch in relation to select experimental factors in a culvert test bed at a salmon rearing facility on the Skookumchuk River in western Washington State. Passage success, the term used for the response variable, was defined as the number of fish in the headwater tank at the end of the test divided by the number of fish released in the tailwater pool at the beginning of the test (2‐ to 17‐h test periods). Passage success was higher for large (139 mm fork length [FL]) than small (55 mm FL) fish, was higher at night than during the day, was not affected by shading, decreased as tailwater pool depth increased (22.9–53.3 cm), and did not differ significantly among the fish densities tested in the tailwater pool (35–141 fish/m3). There was a clear, negative exponential trend in the response relationship between transformed (arcsine of the square root) passage success and culvert discharge (0.028–0.099 m3/s; mean velocities, 0.59–0.98 m/s). The horizontal distribution of fish moving upstream that successfully exited the culvert into the headwater tank was skewed to the right side of the inlet where the reduced‐velocity zone (RVZ) was located. This observation supported the RVZ hypothesis about upstream movement of juvenile salmon in a culvert—fish accomplish upstream movements in roughened culverts via pathways in the low‐velocity, low‐turbulence boundary layer. To facilitate salmonid passage at road crossings, the preferred resource management alternatives are bridges or stream simulation, but in situations where these approaches are constrained by cost or logistics, the hydraulic design of culverts may be appropriate. The findings from these experiments in the culvert test bed are applicable to hydraulic designs of culverts where upstream passage of juvenile salmon is a concern.

Passage of American Shad: Paradigms and Realities

AbstractDespite more than 250 years of development, the passage of American shad Alosa sapidissima at dams and other barriers frequently remains problematic. Few improvements in design based on knowledge of the swimming, schooling, and migratory behaviors of American shad have been incorporated into passage structures. Large‐scale technical fishways designed for the passage of adult salmonids on the Columbia River have been presumed to have good performance for American shad but have never been rigorously evaluated for this species. Similar but smaller fishway designs on the East Coast frequently have poor performance. Provision of effective downstream passage for both juvenile and postspawning adult American shad has been given little consideration in most passage projects. Ways to attract and guide American shad to both fishway entrances and downstream bypasses remain marginally understood. The historical development of passage structures for American shad has resulted in assumptions and paradigms about American shad behavior and passage that are frequently unsubstantiated by supporting data or appropriate experimentation. We propose that many of these assumptions and paradigms are either unfounded or invalid and that significant improvements to American shad upstream and downstream passage can be made via a sequential program of behavioral experimentation, application of experimental results to the physical and hydraulic design of new structures, and controlled tests of large‐scale prototype structures in the laboratory and field.Received March 22, 2011; accepted August 24, 2011

Water Velocity Measurements on a Vertical Barrier Screen at the Bonneville Dam Second Powerhouse

Fish screens at hydroelectric dams help to protect rearing and migrating fish by preventing them from passing through the turbines and directing them towards the bypass channels by means of a sweeping flow parallel to the screen. However, fish screens may actually be harmful to fish if the fish become impinged on the surface of the screen or become disoriented due to poor flow conditions near the screen. Recent modifications to the vertical barrier screens (VBS) in the gate wells at the Bonneville Dam second powerhouse (B2) were intended to increase the guidance of juvenile salmonids into the juvenile bypass system but have resulted in higher mortality and descaling rates of hatchery subyearling Chinook salmon during the 2008 juvenile salmonid passage season. To investigate the potential cause of the high mortality and descaling rates, an in situ water velocity measurement study was conducted using acoustic Doppler velocimeters in the gate well slots at turbine units 12A and 14A of B2. From the measurements collected, the average approach velocity, sweep velocity, and the root mean square value of the velocity fluctuations were calculated. The approach velocities measured across the face of the VBS were variable and typically less than 0.3 m/s, but fewer than 50% were less than or equal to 0.12 m/s. There was also large variance in sweep velocities across the face of the VBS with most measurements recorded at less than 1.5 m/s. Results of this study revealed that the approach velocities in the gate wells exceeded criteria intended to improve fish passage conditions that were recommended by National Marine Fisheries Service and the Washington State Department of Fish and Wildlife. The turbulence measured in the gate well may also result in suboptimal fish passage conditions but no established guidelines to contrast those results have been published.

Effectiveness of a Redesigned Water Diversion Using Rock Vortex Weirs to Enhance Longitudinal Connectivity for Small Salmonids

AbstractFor nearly 100 years, water diversions have affected fish passage in Beaver Creek, a tributary of the lower Methow River in north‐central Washington State. From 2000 to 2004, four dam‐style water diversions were replaced with a series of rock vortex weirs (RVWs). The weirs were designed to allow fish passage while maintaining the ability to divert water into irrigation canals. We observed the new appearance of three species (juvenile Chinook salmon Oncorhynchus tshawytscha, juvenile coho salmon O. kisutch, and mountain whitefish Prosopium williamsoni) upstream of the RVWs, indicating successful restoration of longitudinal connectivity. We used passive integrated transponder (PIT) tags and instream PIT tag interrogation systems during 2004–2007 to evaluate upstream passage of small salmonids (<240 mm fork length) through one series of RVWs. We documented 109 upstream passage events by small salmonids through the series of RVWs; most of the events (81%) involved passage of rainbow trout O. mykiss or juvenile steelhead (anadromous rainbow trout). Small rainbow trout or steelhead ranging from 86 to 238 mm (adjusted fork length) were able to pass upstream through the RVWs, although a delay in fish passage at discharges below 0.32 m3/s was detected in comparison with nearby control sections.

Experimental evaluation of fishway modifications on the passage behaviour of adult Chinook salmon and steelhead at Lower Granite Dam, Snake River, USA

AbstractPrevious studies of Pacific salmonid passage over Snake River dams indicated slowed passage at transition pools, the transition area between the fishway entrance and the fish ladder. In 2001 and 2002, we conducted an experiment to determine if modified weirs affected adult salmon and steelhead passage times and route selection through the Lower Granite Dam transition pool. Fish attraction flows through the lower ladder weirs were experimentally increased using removable panels. During the experiment we monitored radio‐tagged adult Chinook salmon and steelhead to determine passage routes and times through the transition pool. The weir treatment increased the number of spring–summer Chinook salmon passing straight through the transition pool compared to those exiting the transition pool to the collection channel or tailrace. Mean passage times through the transition pool differed among routes and were significantly lower during treatment periods for the exit‐to‐collection channel route in spring‐summer Chinook salmon, but not for other routes. Passage times among routes differed in steelhead, but there was no evidence of treatment effects on route use or passage time. Fall Chinook exhibited similar trends in route use and passage time to spring–summer Chinook, but differences were not significant, perhaps because of relatively small sample size. Total dam passage times did not differ by treatment or route for any run. Fish depth during passage of the transition pool suggested that most fish passed through submerged orifices and supported the hypothesis that increased water velocity through these orifices caused the increase in straight‐through passage in spring–summer Chinook. Collectively, the results suggested the weir modifications provided improvement to passage through the transition pool for spring–summer Chinook and no evidence of negative effects on other runs. The results from this study were used to develop new design criteria and modifications of the Lower Granite Dam fishway. Copyright © 2006 John Wiley & Sons, Ltd.

Defining Flow Windows for Upstream Passage of Adult Anadromous Salmonids at Cascades and Falls

AbstractVariations in streamflow at falls and cascades can create transitory barriers to upstream passage of adult anadromous salmonids. In this study, we evaluated the ability of six anadromous salmonids (coho salmon Oncorhynchus kisutch, pink salmon O. gorbuscha, chum salmon O. keta, sockeye salmon O. nerka, Chinook salmon O. tshawytscha, and steelhead O. mykiss) to pass five sets of falls or cascades within Ward Creek, Alaska, a stream regulated by Connell Dam. The study focused on determining suitable instream flow releases to afford passage. Each set of falls was surveyed under three flow conditions (about 0.91, 1.34, and 3.0 m3/s), and access portals were identified. Using computed stage—discharge relationships and published swimming and jumping criteria, we evaluated the falls barrier potential over a range (0.23–11.33 m3/s) of flows. Analysis indicated pink salmon and chum salmon would be relegated to the area below the lower two falls. Flows affording passage over all five falls for the other species (excluding Chinook salmon) were defined as “flow windows” and ranged from 0.66 to 3.01 m3/s. Flow windows varied by species; the narrowest range of acceptable passage flows was found for sockeye salmon, the widest was found for steelhead, and the range for coho salmon was intermediate. Escapement surveys generally confirmed our analysis; pink salmon and chum salmon were only found below the lowermost falls. The flow windows for passage were compatible with a set of instream flow recommendations derived via a PHABSIM‐based study but were incompatible with the highest flow recommendation based on the method of Tennant (1976). Care must be taken when evaluating instream flow needs to ensure that all flow‐sensitive factors are considered.

Migration Depths of Juvenile Chinook Salmon and Steelhead Relative to Total Dissolved Gas Supersaturation in a Columbia River Reservoir

AbstractThe in situ depths of juvenile salmonids Oncorhynchus spp. were studied to determine whether hydrostatic compensation was sufficient to protect them from gas bubble disease (GBD) during exposure to total dissolved gas (TDG) supersaturation from a regional program of spill at dams meant to improve salmonid passage survival. Yearling Chinook salmon O. tshawytscha and juvenile steelhead O. mykiss implanted with pressure‐sensing radio transmitters were monitored from boats while they were migrating between the tailrace of Ice Harbor Dam on the Snake River and the forebay of McNary Dam on the Columbia River during 1997–1999. The TDG generally decreased with distance from the tailrace of the dam and was within levels known to cause GBD signs and mortality in laboratory bioassays. Results of repeated‐measures analysis of variance indicated that the mean depths of juvenile steelhead were similar throughout the study area, ranging from 2.0 m in the Snake River to 2.3 m near the McNary Dam forebay. The mean depths of yearling Chinook salmon generally increased with distance from Ice Harbor Dam, ranging from 1.5 m in the Snake River to 3.2 m near the forebay. Juvenile steelhead were deeper at night than during the day, and yearling Chinook salmon were deeper during the day than at night. The TDG level was a significant covariate in models of the migration depth and rates of each species, but no effect of fish size was detected. Hydrostatic compensation, along with short exposure times in the area of greatest TDG, reduced the effects of TDG exposure below those generally shown to elicit GBD signs or mortality. Based on these factors, our results indicate that the TDG limits of the regional spill program were safe for these juvenile salmonids.

Forecasting Survival and Passage of Migratory Juvenile Salmonids

Abstract We developed methods to forecast survival and cumulative percent passage for subyearling chinook salmon Oncorhynchus tshawytscha at a dam to help managers effectively time the release of reservoir water to mitigate for passage delays and reduced survival. We tagged Snake River subyearling chinook salmon upstream of a dam from 1993 to 1998 and determined when a subsample of the tagged fish passed the dam. We randomly selected data (1993, 1994, 1996, and 1998) to develop a quadratic discriminant function for predicting which fish would survive to the dam and to develop a multiple-regression equation to predict the date survivors would pass the dam. We used the predicted passage dates within a year to calculate a daily cumulative percent passage forecast and then calculated a 90% forecast interval that varied by year, depending on the number of predicted survivors. We validated the forecast method using data for 1995 and 1997. The 1995 forecasted passage curve differed from the observed passage curv...

Anadromous Salmonid Passage and Video Image Quality under Infrared and Visible Light at Prosser Dam, Yakima River, Washington

Abstract The effect of infrared (>880 nm) and visible (400–700nm) illumination was compared to determine delay rates (percent of population) and delay times (min) of migratory chinook salmon Onchorhynchus tshawytscha, coho salmon O. kisutch, and steelhead (anadromous rainbow trout O. mykiss) in the fish ladder viewing chamber at Prosser Dam during the fall 1996 spawning season. Overall, a significantly (P < 0.05) greater proportion of migratory fish were delayed under visible (41%) than infrared illumination (28%). Species-specific comparisons indicated that significantly (P < 0.05) greater numbers of chinook and coho salmon were delayed under visible (57% and 33%, respectively) than infrared (25% and 12%, respectively) lighting. No significant difference was detected in the proportion of steelhead delayed under visible (35%) and infrared (25%). Passage rates for chinook salmon under infrared light were significantly (P < 0.001, chi square = 10.12) greater at night (70%) than day (30%), whereas under visi...

Index of Predation on Juvenile Salmonids by Northern Pikeminnow in the Lower Columbia River Basin, 1994–1996

We estimated relative abundance of northern pikeminnow Ptychocheilus oregonensis and relative consumption of juvenile salmonids Oncorhynchus spp. by northern pikeminnow at standardized sites in the lower Columbia and lower Snake rivers from 1994 to 1996. Indexes of abundance and consumption were compared with indexes measured from 1990 to 1993 to evaluate changes in predation concurrent with a predator control program in the lower Columbia basin. Reductions in indexes of northern pikeminnow abundance, consumption, or both resulted in mean 1994–1996 predation index values that were 44–91% lower than mean 1990–1993 values throughout the lower Columbia basin. Consumption of juvenile salmonids by surviving northern pikeminnow has not increased in response to predator control efforts. Spatial patterns were consistent among years, being greatest downstream from Bonneville Dam, intermediate in lower Columbia River reservoirs, and lowest at Snake River sites. Reductions in relative predation were consistent with changes in northern pikeminnow population structure associated with harvest, although annual variation in river flow, dam spill, and juvenile salmonid passage may have magnified reductions in predation.

An Air-Lift Pump for Sampling Juvenile Salmonids at John Day Dam

An air-lift pump system was designed and constructed to sample juvenile salmonid accumulations in the turbine-intake gatewells of John Day Dam on the Columbia River. A funnel concentrated fish into a 30.5-cm-diameter thin-walled pipe into which compressed air was delivered. Fish were lifted from water depths of 14–25 m to heights of 1–7.3 m above the water surface. With a 14-m Submergence and 1-m head, the Sampling system operated continuously, dependably, and economically, providing hourly estimates of salmonid passage with little or no injury to fish.