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1
Gilja, Gordon, Eva Ocvirk e Robert Fliszar. "Experimental Investigation of the Reynolds Shear Stress Exceedance Rate for the Injury and Disorientation Biocriteria Boundary in the Pool-Orifice and Vertical Slot Type Fishways". Applied Sciences 11, n. 16 (21 agosto 2021): 7708. http://dx.doi.org/10.3390/app11167708.
Testo completoAbstract (sommario):
Fragmentation of rivers has a negative impact on river’s ecological status which can be improved by the construction of fishways next to obstacles in rivers that prevent a free migration. Flow field characteristics are key factors in the design process of hydraulically efficient fishways—flow and turbulence patterns in a functional fishway allow fish to enter, progress through and exit with minimum time/energy expenditure. The aim of this paper is an experimental study of the flow field characteristics measured in the physical fishway model with the goal of providing information on the Reynold’s shear stress distribution that would facilitate their design in accordance with the environmental requirements. The focus of the research was on the nominally hydraulically efficient con-figuration pool-type fishways—pool-orifice and vertical slot. Fishway geometry was varied for bottom slope (7.5%, 10% and 12.5%), pool length (45 cm, 60 cm and 90 cm) and orifice size (8 × 8 cm, 10 × 10 cm and 12 × 12 cm) in a model scaled 1:3 to the prototype. Since Reynold’s shear stress has been identified as the main turbulent parameter affecting fish swimming performance and behavior, it is used as the basis for the analyses. The velocity data were collected with Vectrino ADV and processed in all three planes—streamwise, horizontal and vertical. Reynold’s shear stress data were analyzed according to the injury (>50 N/m2) and disorientation (>30 N/m2) biocriteria boundaries defined in the literature. The percentage of the flow field exceeding the boundaries were analyzed depending on the fishway geometry. The results obtained in this research suggest that the critical design parameter is the orifice size for the pool-orifice fishways and the pool length for the VS fishway. The Reynold’s shear stress is generally the highest in the bottom layer for pool-orifice fishways and the surface layer for vertical slot fishways.
2
Yu, Fei, Jia Yuan Wang e Li Quan Xie. "Hydrodynamic Characteristics in Ecological Arc-Shaped Baffle Fishway". Applied Mechanics and Materials 212-213 (ottobre 2012): 1119–22. http://dx.doi.org/10.4028/www.scientific.net/amm.212-213.1119.
Testo completoAbstract (sommario):
Fishways are hydraulic structures allowing fishes upstream migration through engineering constructions in the rivers. The Denil type has a wide application and the main components are flat baffles. In this paper, we present a new type of baffle (arc-shaped baffle) to ameliorate the hydrodynamic characteristics in the fishway. The main improvement of arc-shaped baffle fishway is the alteration that the flat baffles are replaced by arc-baffles. In order to investigate the influence of water flow on migratory fish in the arc-baffle fishway, model tests were conducted. Based on the experimental results, the conclusion can be reached that hydrodynamic characteristics in arc-shaped baffle fishways are steadier than that in traditional Denil fishways, which makes fishes ascend easily.
3
Schwalme, Karl, William C. Mackay e Dieter Lindner. "Suitability of Vertical Slot and Denil Fishways for Passing North-Temperate, Nonsalmonid Fish". Canadian Journal of Fisheries and Aquatic Sciences 42, n. 11 (1 novembre 1985): 1815–22. http://dx.doi.org/10.1139/f85-227.
Testo completoAbstract (sommario):
A vertical slot fishway and two Denil fishways (of 10 and 20% slope) built into a weir on the Lesser Slave River (55°18′N, 115°45′W) were studied from May 12 to June 25, 1984, to determine how effectively these designs pass north-temperate, nonsalmonid fishes. Thousands of spottail shiner (Notropis hudsonius), substantial numbers (> 100) of northern pike (Esox lucius), longnose sucker (Catostomus catostomus), white sucker (Catostomus commersoni), immature yellow perch (Perca flavescens), and lesser numbers of burbot (Lota lota), adult yellow perch, lake whitefish (Coregonus clupeaformis), and trout-perch (Percopsis omiscomaycus) ascended the fishways. Walleye (Stizostedion vitreum) and goldeye (Hiodon alosoides), although probably moving extensively through the river, did not use the fishways. Although high water levels allowed most fish to surmount the weir, of those that chose the fishway, pike strongly preferred to ascend the Denil fishways and the two sucker species preferred to ascend the vertical slot. Therefore, a combination of several different fishways may be required for the most efficient passage of a wide variety of species. Plasma glucose and lactate measurements on pike revealed that ascending the Denil fishways was only moderately stressful for these fish.
4
Baumgartner, Lee J., Craig A. Boys, Ivor G. Stuart e Brenton P. Zampatti. "Evaluating migratory fish behaviour and fishway performance: testing a combined assessment methodology". Australian Journal of Zoology 58, n. 3 (2010): 154. http://dx.doi.org/10.1071/zo10035.
Testo completoAbstract (sommario):
To provide passage for migratory native fish, a series of 14 vertical-slot and lock fishways are being constructed on the Murray River in south-eastern Australia. Three of these vertical-slot fishways, at Locks 7, 9 and 10, have a conservative slope (1V : 32H) and are designed with internal hydraulics suitable for the passage of a broad size range of fish (30–1000 mm long). An assessment of these fishways was performed using a combined trapping survey and passive integrated transponder (PIT) approach to determine fishway effectiveness at passing an entire fish community. Fish were trapped within the three fishways between 2004 and 2006, where a total of 13 626 individuals comprising 13 species were collected from 48 sample days (24 h each). Trapping data revealed that the three fishways successfully passed fish within the target size range, though significantly greater numbers of individuals smaller (10–29 mm long) than the target size range could not ascend. PIT tagging revealed important information on fishway ascent times, descent times, seasonality and diel behaviour of medium and large fish. Although each method alone had advantages and disadvantages, the dual assessment approach was useful as it permitted an assessment of fishway success and also provided insights into migratory fish behaviour.
5
Rajaratnam, N., C. Katopodis e A. Mainali. "Pool-orifice and pool-orifice-weir fishways". Canadian Journal of Civil Engineering 16, n. 5 (1 ottobre 1989): 774–77. http://dx.doi.org/10.1139/l89-112.
Testo completoAbstract (sommario):
This technical note presents a method of analyzing the flow in pool-orifice fishways by dividing it into vertical slot and submerged orifice flow regimes. For a pool-orifice-weir fishway, with flow through the orifice as well as over the weir, a method has been suggested for predicting the total flow rate in the fishway. Experimental observations are presented in support of these methods. Key words: open-channel flow, hydraulics, fishways, turbulent flow.
6
Zheng, Tiegang, Zhipan Niu, Shuangke Sun, Jiayue Shi, Haitao Liu e Guangning Li. "Comparative Study on the Hydraulic Characteristics of Nature-Like Fishways". Water 12, n. 4 (27 marzo 2020): 955. http://dx.doi.org/10.3390/w12040955.
Testo completoAbstract (sommario):
Due to the complex structure and the multiformity of boulder arrangements, there is currently no perfect design criterion for nature-like fishways. This paper proposes four types of nature-like fishways arranged with an impermeable partition wall (IPW), a semi-permeable partition wall (SPPW) or a fully permeable partition wall (FPPW). The hydraulic characteristics of these fishways were investigated experimentally. The results show that the discharge of the fishway arranged with a FPPW was almost twice that of an IPW fishway, and the discharge of a SPPW fishway was between the two extremes. The mean flow velocity of the FPPW fishway was larger than that of the other schemes. For the fishway arranged with an IPW, the flow information was basically consistent with that of the engineered technical fishway. In the FPPW or SPPW fishway, there was more abundant flow information and no obvious recirculation zones in the fishway pool, and these conditions are suitable for migratory fish moving up- and downstream. Notably, for the fishway arranged with two fish passages, two mainstreams were formed in the pool, which divided the flow pattern of the pool into three flow regions. A weak recirculation area was formed in the low-velocity region, which facilitates swimming for migratory fish. According to this comprehensive comparative study, the SPPW fishway with two fish passages had low discharge, abundant flow information and favorable fish migration characteristics; thus, it is the optimal fishway scheme among those studied in this paper.
7
Bravo-Córdoba, Francisco Javier, Juan Francisco Fuentes-Pérez, Jorge Valbuena-Castro, Andrés Martínez de Azagra-Paredes e Francisco Javier Sanz-Ronda. "Turning Pools in Stepped Fishways: Biological Assessment via Fish Response and CFD Models". Water 13, n. 9 (25 aprile 2021): 1186. http://dx.doi.org/10.3390/w13091186.
Testo completoAbstract (sommario):
With the aim of building more compact fishways and adapting them to field conditions to improve their location by fish, it is common to use turning pools, reducing the longitudinal development of the construction. However, depending on their design, turning pools may affect the hydraulic performance of the fishway and consequently the fish passage. To study these phenomena, turning pools in a vertical slot and in different configurations of submerged notches with bottom orifice fishway types were assessed. Both types of fishways were studied using numerical 3D models via OpenFOAM, a computational fluid dynamics software, in combination with fish responses, assessed with PIT (Passive Integrated Transponder) tag telemetry for three different species of potamodromous cyprinids in several fishways. Results show differences between the hydrodynamics of straight and turning pools, with lower values in the hydrodynamic variables in turning pools. Regarding fish behavior, the ascent was slower in turning pools but with no effect on passage success and without being a problem for fish migration. This information validates the use of turning pools as a key design component for fishways for studied species.
8
Castro-Santos, Theodore, Xiaotao Shi e Alex Haro. "Migratory behavior of adult sea lamprey and cumulative passage performance through four fishways". Canadian Journal of Fisheries and Aquatic Sciences 74, n. 5 (maggio 2017): 790–800. http://dx.doi.org/10.1139/cjfas-2016-0089.
Testo completoAbstract (sommario):
This article describes a study of PIT-tagged sea lamprey (Petromyzon marinus) ascending four fishways comprising three designs at two dams on the Connecticut River, USA. Migration between dams was rapid (median migration rate = 23 km·day−1). Movement through the fishways was much slower, however (median = 0.02–0.33 km·day−1). Overall delay at dams was substantial (median = 13.6–14.6 days); many fish failed to pass (percent passage ranged from 29% to 55%, depending on fishway), and repeated passage attempts compounded delay for both passers and failers. Cox regression revealed that fishway entry rates were influenced by flow, temperature, and diel cycle, with most lampreys entering at night and at elevated flows, but with no apparent effect of sex or length. Overall delay was influenced by slow movement through the fishways, but repeated failures were the primary factor determining delay. These data suggest that although some lamprey were able to pass fishways, they did so with difficulty, and delays incurred as they attempted to pass may act to limit their distribution within their native range.
9
Masumoto, Taku, Masahiko Nakai, Takashi Asaeda e Mizanur Rahman. "Effectiveness of New Rock-Ramp Fishway at Miyanaka Intake Dam Compared with Existing Large and Small Stair-Type Fishways". Water 14, n. 13 (21 giugno 2022): 1991. http://dx.doi.org/10.3390/w14131991.
Testo completoAbstract (sommario):
The migration of fish is influenced by the unique environmental characteristics of the destination and migratory habitat preferences. There are three fishways in Miyanaka Intake Dam. The rock-ramp fishway was newly established in 2012, creating an environment with different flow velocities and water depths. The purpose of this study was to investigate the effectiveness of the new rock-ramp fishway for native fish through two surveys. In the first survey, traps were installed during the survey period in all three fishways and all fish were caught. The run-up environment was quantified by measuring the flow velocity. In the second survey, fish were caught by spectrum methods upstream and downstream from the dam. It was found that bottom-dwelling fish and swimming fish not bound to the bottom with low migration abilities used the rock-ramp fishway for migration and as a habitat. After the new rock-ramp fishway was built, catches increased upstream from the dam. Further, the rock-ramp fishway is a potential habitat for certain species, such as Cottus pollux. As this is the first study to demonstrate the effectiveness of rock-ramp fishways, the research results are expected to be valuable to fishery managers and those planning river engineering projects.
10
Stuart, Ivor G., Brenton P. Zampatti e Lee J. Baumgartner. "Can a low-gradient vertical-slot fishway provide passage for a lowland river fish community?" Marine and Freshwater Research 59, n. 4 (2008): 332. http://dx.doi.org/10.1071/mf07141.
Testo completoAbstract (sommario):
Fishways are commonly used to restore native fish movements in regulated rivers. In the Murray-Darling Basin, Australia, 14 fishways are to be built by 2011 to improve passage along 2225 km of the river. The first of these fishways, constructed in 2003, is a vertical-slot design with low water velocities (0.98–1.4 m s–1) and turbulence (average 42 W m–3). This design was selected to provide passage for individuals between 20 and 1000 mm long. To determine passage success, trapping and a remote automated passive integrated transponder (PIT) tag reading system was used from October 2003 to February 2006. In 57 24-h samples at the exit (upstream end) and entrance (downstream end), 13 species and 30 409 fish were collected at a maximum rate of 4415 fish per day. Fish between 31 and 1030 mm successfully ascended the fishway. However, significantly smaller (<31 mm) fish and small-bodied (<50 mm) carp gudgeons (Hypseleotris spp.), a species previously considered non-migratory, were sampled downstream from the entrance of the fishway. The remote PIT tag reading system revealed that 81% of native golden perch (Macquaria ambigua) and 87% of non-native common carp (Cyprinus carpio) successfully ascended the fishway. These data will help maximise the efficiency of future fishways against a series of pre-determined performance criteria.
11
Sanz-Ronda, Francisco Javier, Juan Francisco Fuentes-Pérez, Ana García-Vega e Francisco Javier Bravo-Córdoba. "Fishways as Downstream Routes in Small Hydropower Plants: Experiences with a Potamodromous Cyprinid". Water 13, n. 8 (10 aprile 2021): 1041. http://dx.doi.org/10.3390/w13081041.
Testo completoAbstract (sommario):
Fish need to move upstream and downstream through rivers to complete their life cycles. Despite the fact that fishways are the most commonly applied solution to recover longitudinal connectivity, they are not considered viable for downstream migration. Therefore, alternative facilities are recommended to facilitate downstream migration. However, a few recent studies have disagreed with this general assumption, showing the potential for bidirectional movements. This study advances our understanding of the potential of fishways for downstream migration by studying their efficiency in a run-of-the-river hydropower plant in the Duero River (Spain). To achieve this, downstream movements of the Iberian barbel (n = 299) were monitored in a stepped fishway for two years with passive integrated transponder (PIT)-tag technology, considering the effect of fish origin and release zone. The results showed that 24.9% of barbels descended through the fishway, with the origin and release zone affecting the fishway location. In addition, downstream movements were observed throughout the whole year, except in winter. The study concludes that, under specific scenarios, fishways could act as safe alternative routes for downstream migration.
12
Rajaratnam, N., e C. Katopodis. "Hydraulics of steeppass fishways". Canadian Journal of Civil Engineering 18, n. 6 (1 dicembre 1991): 1024–32. http://dx.doi.org/10.1139/l91-125.
Testo completoAbstract (sommario):
This paper presents the results of an experimental study on the hydraulics of steeppass fishways. Using theoretical considerations and experimental observations, an expression has been developed that relates the flow rate, slope of the fishway, and depth of flow. It was also found that the characteristic (similarity) velocity profile found earlier, for smaller values of depth to width ratio,y0/b, with the maximum velocity near the bottom, changes to a rather symmetrical profile with the maximum velocity occurring somewhere near the mid-depth for larger values of y0/b. A correlation has also been found for the maximum velocity. This paper also includes some observations on the M-type backwater curves that would appear in the fishway when the tailwater depths exceed uniform flow depths. Key words: fishways, hydraulics, turbulent flow, open-channel flow, hydraulic design.
13
Fuentes-Pérez, Juan Francisco, Ana García-Vega, Francisco Javier Bravo-Córdoba e Francisco Javier Sanz-Ronda. "A Step to Smart Fishways: An Autonomous Obstruction Detection System Using Hydraulic Modeling and Sensor Networks". Sensors 21, n. 20 (18 ottobre 2021): 6909. http://dx.doi.org/10.3390/s21206909.
Testo completoAbstract (sommario):
Stepped fishways are structures that allow the free movement of fish in transversal obstacles in rivers. However, the lack of or incorrect maintenance may deviate them from this objective. To handle this problem, this research work presents a novel low-cost sensor network that combines fishway hydraulics with neural networks programmed in Python (Keras + TensorFlow), generating the first autonomous obstruction/malfunction detection system for stepped fishways. The system is based on a network of custom-made ultrasonic water level nodes that transmit data and alarms remotely and in real-time. Its performance was assessed in a field study case as well as offline, considering the influence of the number of sensing nodes and obstruction dimensions. Results show that the proposed system can detect malfunctions and that allows monitoring of the hydraulic performance of the fishway. Consequently, it optimizes the timing of maintenance on fishways and, thus, has the potential of automatizing and reducing the cost of these operations as well as augmenting the service of these structures. Therefore, this novel tool is a step forward to achieve smart fishway management and to increase their operability.
14
Branco, Paulo, Ana Margarida Mascarenhas, Gonçalo Duarte, Filipe Romão, Ana Quaresma, Susana Dias Amaral, Maria Teresa Ferreira, António N. Pinheiro e José Maria Santos. "Vertical Slot Fishways: Incremental Knowledge to Define the Best Solution". Biology 12, n. 11 (15 novembre 2023): 1431. http://dx.doi.org/10.3390/biology12111431.
Testo completoAbstract (sommario):
River artificial fragmentation is arguably the most imperilling threat for freshwater-dependent fish species. Fish need to be able to freely move along river networks as not only spawning grounds but also refuge and feeding areas may be spatially and temporally separated. This incapacity of free displacement may result in genetic depletion of some populations, density reduction and even community changes, which may in turn affect how meta-community balances are regulated, potentially resulting in functional resilience reduction and ecosystem processes’ malfunction. Fishways are the most common and widely used method to improve connectivity for fish species. These structures allow fish to negotiate full barriers, thus reducing their connectivity impairment. Among all technical fishway types, vertical slot fishways (VSF) are considered to be the best solution, as they remain operational even with fluctuating water discharges and allow fish to negotiate each cross-wall at their desired depth. In the present study, we collected both published and original data on fish experiments within VSF, to address two questions, (1) What variables affect fish passage during experimental fishway studies? and (2) What is the best VSF configuration? We used Bayesian Generalized Mixed Models accounting for random effects of non-controlled factors, limiting inherent data dependencies, that may influence the model outcome. Results highlight that fish size, regardless of the species, is a good predictor of fishway negotiation success. Generally, multiple slot fishways with one orifice proved to be the best solution. Future work should be focused on small-sized fish to further improve the design of holistic fishways.
15
Cooper, Bethany, Lin Crase e Lee J. Baumgartner. "Estimating benefits and costs: a case of fish passages in Lao PDR and the development of the Lower Mekong Fishway Support Tool". Marine and Freshwater Research 70, n. 9 (2019): 1284. http://dx.doi.org/10.1071/mf19156.
Testo completoAbstract (sommario):
Fishways are often presented as a parsimonious way of assisting water infrastructure development in developing countries while preserving some ecosystem values. More specifically, fishways help preserve migratory freshwater fish species, which are often a main source of protein and other nutrients for many rural communities. To date, much of the literature regarding fishway development focuses on increasing understanding of the interaction between the fish populations and engineering interventions. Accordingly, there is limited analysis that considers fishway construction relative to the specific benefits and costs that subsequently accrue to humans. In this study we outline the development of a decision support tool designed to assist officials in the Lower Mekong evaluate the merits of constructing fishways to address barriers to fish passage. Arguably, the tool can also be modified to assess the avoided cost of building additional barriers that constrain fish migration. The Lower Mekong Fishway Support Tool (LMFST) is underpinned by economic notions and populated with input from experts involved in fishway construction. The LMFST is intended to provide indicative monetary estimates and does not replace comprehensive engineering and social analysis; rather, it guides users in assessing those locations and structures that are more likely to deliver a positive outcome for local communities. The LMFST is buttressed in benefit–cost analysis and encourages decision making to be more transparent and this is one of the major contributions of this work.
16
Aoki, Muneyuki, Masayuki Nitta, Tomoaki Funakoshi e Taisei Sato. "A Novel Roughness and Flow Pattern for Steep Stream-Type Fishways: Preliminary Insights". Water 14, n. 16 (18 agosto 2022): 2540. http://dx.doi.org/10.3390/w14162540.
Testo completoAbstract (sommario):
The purpose of this study was to allow fish to move upstream past barriers or difficult sections of passage, even on steep stream-type fishways. Therefore, the authors devised a roughness arrangement to raise the water depth in the fishway and reduce its flow velocity. Roughness was used as a group in the arrangement so as to expect afflux effects. Water depth was raised and the flow velocity was reduced around the roughness groups, which allowed fish to hold position and move upstream. Although rapid flow was locally formed in some spots in the fishway, its area was small, enabling the fish to move upstream sufficiently. The experimental results obtained in this study will be applied as a removable stream-type fishway to small channels, head constructions, and so on where fishways cannot be installed due to management.
17
Pennock, Casey A., David Bender, Jordan Hofmeier, Jessica A. Mounts, Ryan Waters, Vaughn D. Weaver e Keith B. Gido. "Can fishways mitigate fragmentation effects on Great Plains fish communities?" Canadian Journal of Fisheries and Aquatic Sciences 75, n. 1 (gennaio 2018): 121–30. http://dx.doi.org/10.1139/cjfas-2016-0466.
Testo completoAbstract (sommario):
Fishways are a common tool for mitigating the effects of habitat fragmentation on fish, but their utility in low-gradient, sand-bed rivers of the Great Plains is not well studied. The Lincoln Street Fishway on the Arkansas River became operational in 2015 and was built specifically to pass small-bodied threatened fishes. We compared current and historical surveys up- and downstream of the barrier to test the effect of the fishway on community structure and conducted tagging experiments to test the ability of fishes to move into and through the fishway. Differences in community structure and species richness between communities up- and downstream of the dam were reduced following construction of the fishway. Surveys within the fishway revealed that 74% of species from the sampled community were using the fishway. Fishes marked with visible implant elastomer downstream of the dam were recaptured in the fishway, qualitatively showing that small-bodied fishes could move into and upstream within the fishway. We further quantified upstream movement for three species of small-bodied minnow tagged with passive integrated transponder tags during manipulations of flows through the fishway. Our results illustrate the potential for fishways to mitigate the effects of habitat fragmentation on fishes in sand-bed rivers.
18
Silva, Ana T., María Bermúdez, José M. Santos, Juan R. Rabuñal e Jerónimo Puertas. "Pool-Type Fishway Design for a Potamodromous Cyprinid in the Iberian Peninsula: The Iberian Barbel—Synthesis and Future Directions". Sustainability 12, n. 8 (21 aprile 2020): 3387. http://dx.doi.org/10.3390/su12083387.
Testo completoAbstract (sommario):
The Iberian barbel (Luciobarbus bocagei) is one of the most common cyprinids in the Iberian Peninsula, whose migratory routes are often hampered by anthropogenic barriers. Fishways might be an effective mitigation measure if they integrate designed operational characteristics that account for the biomechanical requirements of this species. Understanding the flow conditions inside the fishway, and how barbel responds to the hydrodynamics of the flow is imperative to improve free migratory routes with minimum energetic cost associated. Herein, we analyze and synthesize the main findings of research on pool-type fishways for upstream passage of the Iberian barbel and derive recommendations of design criteria for pool-type fishways for this species and others of similar biomechanics capacities. Ultimately, we identify research needs to improve upstream passage of this species.
19
Sanz-Ronda, Bravo-Córdoba, Sánchez-Pérez, García-Vega, Valbuena-Castro, Fernandes-Celestino, Torralva e Oliva-Paterna. "Passage Performance of Technical Pool-Type Fishways for Potamodromous Cyprinids: Novel Experiences in Semiarid Environments". Water 11, n. 11 (11 novembre 2019): 2362. http://dx.doi.org/10.3390/w11112362.
Testo completoAbstract (sommario):
Endemic freshwater fish from semiarid environments are among the most threated species in the world due to water overexploitation and habitat fragmentation problems. Stepped or pool-type fishways are used worldwide to reestablish longitudinal connectivity and mitigate fish migration problems. Many of them are being installed or planned in rivers of semiarid environments, however, very few studies about fish passage performance through pool-type fishways has been carried out to date on these regions. The present work focuses on the passage performance of two potamodromous cyprinids endemic of these regions, with different ecological and swimming behavior: southern Iberian barbel (Luciobarbus sclateri) and Iberian straight-mouth nase (Pseudochondrostoma polylepis). These are assessed in two of the most common types of stepped fishways: vertical slot and submerged notch with bottom orifice fishways. Experiments were carried out during the spawning season in the Segura River (southeastern Spain), using a passive integrated transponder (PIT) tag and antenna system. Ascent success was greater than 80%, with a median transit time lower than 17 minutes per meter of height in all trials, and for both species and fishway types. Results show that both types of fishways, if correctly designed and constructed, provide interesting alternatives for the restoration of fish migration pathways in these regions.
20
Mallen-Cooper, M. "Swimming ability of juvenile Australian bass, Macquaria novemaculeata (Steindachner), and juvenile barramundi, LAtes calcarifer (Bloch), in an experimental vertical-slot fishway". Marine and Freshwater Research 43, n. 4 (1992): 823. http://dx.doi.org/10.1071/mf9920823.
Testo completoAbstract (sommario):
Australian bass, Macquaria novemaculeata, and barramundi, Lates calcarlfer, are catadromous fish that spawn in estuaries and the juveniles migrate upstream into fresh water. Lowland fishways in the range of these species therefore need to accommodate these juvenile fish. The swimming abilities of three size classes (fork length (LCF) + s.d.: 40 * 3 mm, 64 + 5 mm and 93 + 8 mm) of juvenile Australian bass and one size class (43 4 mm total length) of juvenile barramundi were tested in an experimental vertical-slot fishway. Water velocity was calculated from the head loss in water level between adjacent pools in the fishway, using a coefficient of discharge (Cd) of 1.0. Both species readily negotiated the fishway at low water velocities, indicating that the fish were in a migratory mode and that these fish could use the vertical-slot design of the fishway. The sigmoidal decrease in this ability with increasing water velocity was described by a probit regression. The NV95 value (maximum negotiable water velocity for 95% of the sample) is suggested as the suitable maximum-velocity criterion for vertical-slot fishways for these fishes. The NV95 values were 0.66 m s-1 for 43-mm barramundi, 1.02 m s-1 for 40-mm bass, 1.40 m s-1 for 64-mm bass and 1.84 m s-1 for 93-mm bass. The NV95 for barramundi is probably an underestimate of their swimming ability in the wild because the water temperature was low for this species. Up to 20% of the 93-mm bass died at test velocities greater than 2.0 m s-1, but there were no mortalities of other fish during or immediately following a trial. The results indicate that water velocity in fishways for juvenile bass and barramundi should not exceed 1.4 m s-1 in a cell size of 1.5 m length and 1.0 m width. The relative swimming speeds (body lengths per second) of bass in the fishway are higher than other estimates of burst swimming speeds of juvenile fish obtained from studies in flumes. This indicates that data from the latter type of study should not be used to determine water velocities for fishways.
21
Maeda, Shigeya, Yuri Yoshida, Kanuka Yoshinari e Naoki Takahashi. "Effective Placement Strategies for Portable Fishways in Agricultural Drainage Canals: A Numerical Investigation". Sustainability 15, n. 23 (24 novembre 2023): 16283. http://dx.doi.org/10.3390/su152316283.
Testo completoAbstract (sommario):
Agricultural drainage canals that connect upstream fish spawning areas to downstream rivers and lakes serve as crucial habitats for migrating fish. However, disconnections, such as drops and chutes, have been constructed in these canals due to agricultural modernization and flood control measures, hindering the movement of fish that find it difficult to ascend in fast-flowing currents. Portable fishways offer a promising solution to reconnect waterbodies in agricultural canals, as they can be easily removed during high water discharges to avoid impeding the canals’ drainage function. In addition to experimental assessments of fishway functionality, employing a hydrodynamic model to explore effective placement strategies for portable fishways is essential to maximize their effectiveness. This study presents a method for determining the best horizontal location of a portable fishway in an agricultural drainage canal using two-dimensional hydrodynamic simulations within the specified cases. The applicability of this method is demonstrated by addressing the positioning challenge of a portable fishway on a chute in an agricultural drainage canal in Japan. The results indicate that the proposed method allows for the selection of a suitable location, considering preferable hydraulic conditions both within the portable fishway and around its entrance.
22
Keefer, Matthew L., Christopher C. Caudill, Tami S. Clabough, Michael A. Jepson, Eric L. Johnson, Christopher A. Peery, Megan D. Higgs e Mary L. Moser. "Fishway passage bottleneck identification and prioritization: a case study of Pacific lamprey at Bonneville Dam". Canadian Journal of Fisheries and Aquatic Sciences 70, n. 10 (ottobre 2013): 1551–65. http://dx.doi.org/10.1139/cjfas-2013-0164.
Testo completoAbstract (sommario):
Fishways designed for salmonids often restrict passage by non-salmonids, and effective tools are needed both to identify passage problems for nontarget species and to inform remediation planning. In this case study, we used migration histories from 2170 radio-tagged adult Pacific lamprey (Entosphenus tridentatus) to identify locations of poor passage (bottlenecks) at a large, multifishway dam. Over 10 years, 49% of tagged lamprey that entered fishways failed to pass the dam. Models accounting for repeated attempts by individual lamprey indicated successful passage strongly depended on attempted passage route. Success also varied with time of fishway entry, water temperature, and lamprey body size. Most failed passage attempts terminated in lower fishway segments, but extensive seasonal shifts in bottleneck locations were detected. Ranking metrics helped prioritize bottlenecks and identified sites where structural or operational modifications should improve lamprey passage. Our integration of spatially intensive monitoring with novel analytical techniques was critical to understanding the complex relationships among fishway features, environmental variation, and lamprey behavior. The prioritization framework can be applied to a wide range of fish passage assessments.
23
Zeng, Guorui, Maosen Xu, Jiegang Mou, Keke Wang e Yun Ren. "Research on the Hydraulic Characteristics of Island Fishways by Experimental and Numerical Methods". Water 15, n. 14 (16 luglio 2023): 2592. http://dx.doi.org/10.3390/w15142592.
Testo completoAbstract (sommario):
With the development of hydraulic structures, rivers are becoming fragmented, and their connectivity is greatly affected. Important migratory routes through which fish complete their life processes are hindered. In severe cases, it may lead to the extinction of fish species. As facilities commonly used to assist fish upstreaming, fishways are significant for environmental remediation and have received attention from different scholars. This article proposed a new type of fishway, inspired by Tesla valves with obstructing reverse flow characteristics and classic fishway structures. Due to its characteristic of introducing a water-blocking island structure, it was denominated as an island-style fishway. This work studied an island fishway through a combination of physical models and numerical simulations. The results show that this fishway could achieve various flow patterns suitable for fish migration, and the flow rate control was stable. This study also explored the impact of island spacing arrangement on the turbulent structure of the pool chamber. It was found that when the island distance is set at 1.5d, indicators such as flow velocity and turbulent kinetic energy could achieve significant control effects. However, inappropriate d values might cause adverse effects. This research could provide reference ideas for the design of new fishways.
24
Rodríguez, Álvaro, María Bermúdez, Juan R. Rabuñal e Jerónimo Puertas. "Fish tracking in vertical slot fishways using computer vision techniques". Journal of Hydroinformatics 17, n. 2 (5 novembre 2014): 275–92. http://dx.doi.org/10.2166/hydro.2014.034.
Testo completoAbstract (sommario):
Vertical slot fishways are hydraulic structures which allow the upstream migration of fish through obstructions in rivers. The appropriate design of these devices should take into account the behavior and biological requirements of the target fish species. However, little is known at the present time about fish behavior in these artificial conditions, which hinders the development of more effective fishway design criteria. In this work, an efficient technique to study fish trajectories and behavior in vertical slot fishways is proposed. It uses computer vision techniques to analyze images collected from a camera system and effectively track fish inside the fishway. Edge and region analysis algorithms are employed to detect fish in extreme image conditions and Kalman filtering is used to track fish along time. The proposed solution has been extensively validated through several experiments, obtaining promising results which may help to improve the design of fish passage devices.
25
Peake, S., F. WH Beamish, R. S. McKinley, D. A. Scruton e C. Katopodis. "Relating swimming performance of lake sturgeon, Acipenser fulvescens, to fishway design". Canadian Journal of Fisheries and Aquatic Sciences 54, n. 6 (1 giugno 1997): 1361–66. http://dx.doi.org/10.1139/f97-039.
Testo completoAbstract (sommario):
Fishways have traditionally been designed to provide safe passage for jumping fish and only recently have nonjumping species been considered. Concern over dwindling populations of lake sturgeon, Acipenser fulvescens, has focused attention on fishway designs that accommodate its swimming abilities. The objective of this study was to derive a model that relates swimming endurance of lake sturgeon to length and flow characteristics of fishways. Endurance at sustained and prolonged swimming speeds (those maintainable for more than 20 s) increased with water temperature but was independent of temperature at higher burst speeds. Endurance increased with total length at all swimming velocities. Swimming performance of lake sturgeon, relative to body length, is inferior to that of most salmonids, particularly at burst speeds. Fishway designers need to consider swimming ability, space requirements, and behavior of lake sturgeon to ensure that they can ascend potential migratory obstacles safely.
26
Qi, Shengzhe, Chenghua Fu e Meiling Xie. "Analysis of Two-Dimensional Hydraulic Characteristics of Vertical-Slot, Double-Pool Fishway Based on Fluent". Water 16, n. 12 (14 giugno 2024): 1695. http://dx.doi.org/10.3390/w16121695.
Testo completoAbstract (sommario):
Research shows that the novel vertical-slot, double-pool fishway can reduce the flow velocity at the vertical slots of the fishway, enhance the efficiency of the water flow in the chambers, and increase the fish passage area and migratory corridor for fish. Utilizing Fluent, two-dimensional and three-dimensional models of the novel fishway were established, and numerical simulation analysis was conducted on their hydraulic characteristics. The results indicate that the flow velocity at the cross-section of the middle vertical slot in the fishway pool decreases horizontally from left to right and increases vertically from top to bottom, with similar water flow distribution patterns on different vertical lines. The flow conditions and hydraulic characteristics of the surface, middle, and bottom layers in the pool are similar, mainly characterized by planar, two-dimensional flow. The error between the trajectory of the water flow in the main flow area and the maximum velocity value is within 10%. The novel vertical-slot, double-pool fishway retains the planar binary characteristics of traditional vertical-slot fishways. The results of the two-dimensional numerical simulation can be analogized to the vertical uniformization of the three-dimensional numerical simulation, providing support for the study of its two-dimensional numerical simulation of hydraulic characteristics and presenting a theoretical basis for the structural design and construction of fishways.
27
Puzdrowska, Marta, e Tomasz Heese. "Turbulent Kinetic Energy in Bolt Fishway". AgriEngineering 1, n. 2 (3 giugno 2019): 265–82. http://dx.doi.org/10.3390/agriengineering1020020.
Testo completoAbstract (sommario):
The paper presents an analysis the spatial distribution of turbulent kinetic energy (TKE) for bolt fishways, including the impact of additional spillway slots and fixed channel development. The research was done for two models, each containing a different arrangement of slots. The presented results of research for bolt fishways were obtained as an effect of laboratory tests. The measurements were done for three components of instant flow velocity magnitude (speed). Analysis of the results was done for a 3D flow structure using Matlab software. In the case of bolt fishways, significant differences were noted for the method of velocity and TKE distribution, in reference to research comprising channels with biological development. It was stated that a reason for this is the flexible development of the channel. The occurrence of extreme TKE values in the chamber (pool) is strictly associated with the characteristics of interaction zones between various flow structures. It was also stated that the lower the parapet of the slot’s spillway shelf is in the fishway’s partition, the higher TKE could be expected just downstream of the section. These establishments may be important for the designing process in the case of fish passes of various types of construction.
28
Romão, Filipe, Ana L. Quaresma, José M. Santos, Susana D. Amaral, Paulo Branco e António N. Pinheiro. "Multislot Fishway Improves Entrance Performance and Fish Transit Time over Vertical Slots". Water 13, n. 3 (24 gennaio 2021): 275. http://dx.doi.org/10.3390/w13030275.
Testo completoAbstract (sommario):
Pool-type fishways have been increasingly tested to improve fish passage performance and minimize migration delays. Designing cost-effective fishways is essential for a trade-off between water uses and successful longitudinal connectivity restoration. The multislot fishway (MSF) concept, which operates with 30–50% lower discharge than a vertical slot fishway (VSF), was recently developed. This study assessed and compared the entrance performance (entrance time; entry efficiency) and transit times of two cyprinids for VSFs and MSFs. Four configurations, with the same structural characteristics (slope; water depth; head drop; pool width and depth), operating with different discharges (Q), were tested (VSF 1: Q = 112 L·s−1; VSF 2: Q = 80 L·s−1; MSF 1: Q = 58 L·s−1; MSF 2: Q = 37 L·s−1). Hydrodynamics characterization was performed using a numerical model. Results showed that entry efficiency was higher in MSFs than in VSFs, while entrance time and transit time were overall lower. Numerical modelling revealed that velocities were around 30% lower in MSFs, and turbulence could reach a difference of around 70% in Reynolds shear stress and 50% in turbulent kinetic energy. Overall, MSFs can be considered as a cost-effective fishway solution that can balance the trade-offs between divergent interests in water uses.
29
Keefer, Matthew L., Michael A. Jepson, Tami S. Clabough e Christopher C. Caudill. "Technical fishway passage structures provide high passage efficiency and effective passage for adult Pacific salmonids at eight large dams". PLOS ONE 16, n. 9 (2 settembre 2021): e0256805. http://dx.doi.org/10.1371/journal.pone.0256805.
Testo completoAbstract (sommario):
Fishways have been widely used for upstream passage around human-built structures, but ‘success’ has varied dramatically. Evaluation of fishway success has typically been conducted at local scales using metrics such as fish passage efficiency and passage time, but evaluations are increasingly used in broader assessments of whether passage facilities meet population-specific conservation and management objectives. Over 15 years, we monitored passage effectiveness at eight dams on the Columbia and Snake rivers for 26,886 radio-tagged spring-summer and fall Chinook Salmon O. tshwaytscha, Sockeye Salmon O. nerka, and summer steelhead O. mykiss during their migrations to spawning sites. Almost all fish that entered dam tailraces eventually approached and entered fishways. Tailrace-to-forebay passage efficiency estimates at individual dams were consistently high, averaging 0.966 (SD = 0.035) across 245 run×year×dam combinations. These estimates are among the highest recorded for any migratory species, which we attribute to the scale of evaluation, salmonid life history traits (e.g., philopatry), and a sustained adaptive management approach to fishway design, maintenance, and improvement. Full-dam fish passage times were considerably more variable, with run×year×dam medians ranging from 5–65 h. Evaluation at larger scales provided evidence that fishways were biologically effective, e.g., we observed rapid migration rates (medians = 28–40 km/d) through river reaches with multiple dams and estimated fisheries-adjusted upstream migration survival of 67–69%. However, there were substantive uncertainties regarding effectiveness. Uncertainty about natal origins confounded estimation of population-specific survival and interpretation of apparent dam passage ‘failure’, while lack of post-migration reproductive data precluded analyses of delayed or cumulative effects of passing the impounded system on fish fitness. Although the technical fishways are effective for salmonids in the Columbia-Snake River system, other co-migrating species have lower passage rates, highlighting the need for species-specific design and evaluation wherever passage facilities impact fish management and conservation goals.
30
Zhang, Di, Chunming Liu, Xiaotao Shi, Yakun Liu e Yingmin Qu. "A novel H-shape fishway with excellent hydraulic characteristics". Journal of Hydrology and Hydromechanics 71, n. 1 (4 febbraio 2023): 64–79. http://dx.doi.org/10.2478/johh-2022-0026.
Testo completoAbstract (sommario):
Abstract Fishway design not only takes into account the swimming abilities of target fishes, but also considers the hydrodynamic characteristics within the fishway. In this study, the flow fields of one vertical-slot fishway (i.e. VSF), five T-shape fishways (i.e. TSF-1~TSF-5) and two H-shape fishways (i.e. HSF-1 and HSF-2) are numerically simulated by solving the three-dimensional Reynolds-averaged Navier-Stokes equations and the K-Omega-SST turbulence model. The numerical results clearly indicate that the hydrodynamic properties of HSF-2 are overall superior to the remaining seven cases, in terms of the time-averaged flow pattern, the time-averaged velocity magnitude, the depth-mean time-averaged velocity magnitude along the vertical-slot section, the volume percentages of the time-averaged velocity magnitude less than some critical values, and the distribution of the time-averaged turbulent kinetic energy. Therefore, HSF-2 is more friendly for fishes with relatively smaller sizes and weaker swimming capacities to transfer upstream. The novel HSF-2 is firstly proposed in this paper, and it is naturally designed during the process of improving the flow regime. Furthermore, the generalizability of the superiority of HSF-2 over VSF and the original T-shape fishway (i.e. TSF-1) has been exhibited with the aid of the numerical results of four operating conditions (i.e. Q = 400 L/s, 600 L/s, 800 L/s and 1000 L/s).
31
Rajaratnam, N., C. Katopodis e S. Lodewyk. "Hydraulics of offset baffle culvert fishways". Canadian Journal of Civil Engineering 15, n. 6 (1 dicembre 1988): 1043–51. http://dx.doi.org/10.1139/l88-137.
Testo completoAbstract (sommario):
This paper presents the results of an experimental study on the hydraulics of culverts with offset baffles to pass fish. Using analytical considerations and experimental observations, a flow equation has been developed between the discharge, diameter, depth, and slope for a culvert fish way with the standard offset baffle system. The velocity field at the slot has also been evaluated. Some further experiments were performed to assess the effect of baffle spacing and height on the hydraulics of the culvert fishway. Key words: culverts, fishways, baffles, hydraulics, open-channel flow, turbulent flow.
32
Quaresma, Ana, e António Pinheiro. "Modelling of Pool-Type Fishways Flows: Efficiency and Scale Effects Assessment". Water 13, n. 6 (20 marzo 2021): 851. http://dx.doi.org/10.3390/w13060851.
Testo completoAbstract (sommario):
In this study, the 3D numerical modelling of flow in a pool-type fishway with bottom orifices was performed using computational fluid dynamics (CFD) software (FLOW-3D®). Numerical results were compared with experimental data obtained from acoustic Doppler velocimetry (ADV) and particle image velocimetry (PIV) measurements. Several hydrodynamic variables that influence fishways efficiencies, such as flow depths, flow patterns, water velocity, turbulent kinetic energy, Reynolds normal stresses, and Reynolds shear stress parallel to the bottom component, were qualitatively and quantitatively compared. The numerical model accurately reproduced the complex flow field, showing an overall good agreement between the numerical model predictions and the experimental data for the analysed variables. The importance of performing a numerical model validation for all the parameters under analyses was highlighted. Additionally, scaling effects were analysed by running an upscaled numerical model of the prototype fishway. The model performed with similar accuracy for both physical model and prototype dimensions with no evidence of scale effects. The present study concludes that CFD models (namely FLOW-3D®) may be used as an adequate and efficient design and analysis tool for new pool-type fishways geometries, reducing and complementing physical model testing.
33
Shen, Chunying, Ruiguo Yang, Mingming Wang, Shihua He e Shan Qing. "Application of Vortex Identification Methods in Vertical Slit Fishways". Water 15, n. 11 (29 maggio 2023): 2053. http://dx.doi.org/10.3390/w15112053.
Testo completoAbstract (sommario):
The reproduction and survival of fish are often negatively affected by the construction of dams and other hydroelectric projects, which cut off their migratory routes. Building effective fish passage facilities that allow fish to pass through dams smoothly alleviates the negative impact of hydroelectric projects on the ecological environment, thus protecting the diversity of aquatic species and preventing the extinction of indigenous fish. Vertical slit fishways are highly effective, but turbulence inside the fishway pools directly affects fish passage. In this study, the large-eddy simulation framework is used to capture the vortex characteristics in the interior of vertical slit fishway pools, and the volume of fluid method is applied to simulate the free surface. The independence of the grid is assessed by the large-eddy simulation quality index, and the simulation results are compared with experimental acoustic Doppler velocimetry data. This work characterizes the vortex flow field inside the vertical slit fishway using the Q-criterion, Omega method, and Liutex vortex identification method. The results show that the vortex structure inside the fishway pool has obvious three-dimensional characteristics and vortex structure varies within the different fishway pool chambers. The analysis and comparison of the three different vortex identification methods show that the vortex structure captured by the Liutex method is more consistent with the actual motion pattern of the fishway water flow.
34
Duarte, Bernardo Alan de Freitas, Isabella Cristina Resende Ramos e Hersília de Andrade e. Santos. "Reynolds shear-stress and velocity: positive biological response of neotropical fishes to hydraulic parameters in a vertical slot fishway". Neotropical Ichthyology 10, n. 4 (ottobre 2012): 813–19. http://dx.doi.org/10.1590/s1679-62252012000400014.
Testo completoAbstract (sommario):
The barriers created by dams can cause negative impacts to aquatic communities, and migratory fish species are directly affected. Fishways have been developed to allow the upstream passage of fishes through dams. In Brazil, after the implementation of environmental laws, these structures have been built based on European and American fishway designs. Studies have shown selectivity for different neotropical fishes in some Brazilian fishways, and the main challenge has been to promote upstream passage of a large number of diverse fish species. The patterns of flow circulation within the fish ladder may explain fish selectivity although few studies detail the fish response to hydraulic characteristics of fish ladder flow. This paper presents a laboratory study, where a vertical slot fishway was built in a hydraulic flume and the behavior of two neotropical fish species (Leporinus reinhardti and Pimelodus maculatus) were analyzed. The structure of flow was expressed in terms of mean velocity, Reynolds shear-stress and velocity fluctuation fields. The individuals of Leporinus reinhardti had higher passage success than Pimelodus maculatus in the laboratory flume. Both species preferred areas of low to zero Reynolds shear-stress values. In addition, different preferences were observed for these species concerning the horizontal components of velocity fluctuation.
35
Zhang, Jian, Tianpeng Ruan e Tingxin Xu. "Simulation study on hydraulic characteristics of Changzhou fishway based on FLUENT". Journal of Physics: Conference Series 2756, n. 1 (1 maggio 2024): 012024. http://dx.doi.org/10.1088/1742-6596/2756/1/012024.
Testo completoAbstract (sommario):
Abstract Guangxi Changzhou Fishway is the first significant water conservancy project above the mouth of the Pearl River and also the first large fishway independently designed in China. It is the primary migration channel for six kinds of state-level protected fish, such as Chinese sturgeon and a typical vertical slit fishway. This paper takes the Changzhou fishway as the research object, based on the theory of fluid mechanics, and adopts the method of combining theoretical analysis, experimental research, and numerical simulation to study the flow field of different water depths in the pond. The analysis results show that the upper water flow has a larger resting area than the lower water flow, and the fishway has a rich flow field distribution and can produce “S” shaped meandering flow characteristics. The research results provide some reference for the design of vertical fishways.
36
G. Doupé, Robert, David L. Morgan e Howard S. Gill. "Prospects for a restorative fishery enhancement of Lake Kununurra: a high-level tropical impoundment on the Ord River, Western Australia". Pacific Conservation Biology 11, n. 2 (2005): 136. http://dx.doi.org/10.1071/pc050136.
Testo completoAbstract (sommario):
The high-level irrigation water supply dams of the Ord River in tropical Western Australia impede the movement of Barramundi Lates cafcarifer and other tropical fish species. A recreational Barramundi fishery enhancement of Lake Kununurra using a fishway has been widely promoted as advancing fishery conservation and the reformation of land and water management practices within the greater Ord River region. Of the fishways considered here, none have been found to admit Barramundi in the numbers and size classes necessary to establish or maintain the recreational fishery. Reasons for this include an inadequate understanding of fish behaviour and/or fishway deSign faults. The seemingly reluctant use of fishways by Barramundi might also be confounded by some observations being made on rivers where Barramundi populations are either comparatively small or non-existent. The alternative to a fishway is hatchery stocking. This option, like a dedicated Barramundi fishway, represents a single-species approach to fishery enhancement and is the least legitimate attempt to restore the ecological integrity of the fish communities of either Lake Kununurra or the Ord River. We argue that progress toward the restoration of the lake should continue, though a fishery enhancement programme that incorporates the broader fish community and not just a single species, would better rebuild the presently degraded Ord River system. Of the available options, we recommend testing an experimental model that incorporates aspects of the vertical-slot and bypass fishway designs, with the objectives being to learn migratory fish behaviour, abundance, and patterns and cues for fish movement. This approach can incorporate Barramundi as the target species to better understand entrance design constraints, minimum slot widths for larger fish, and operation under low flows during peak irrigation water demands, but still accommodate the movement of tropical fishes during these periods.
37
Schemmel, Avery, David L. Smith, Marcela Politano, Damian Walter e Jeremy Crossland. "Assessing Zebra Mussels’ Impact on Fishway Efficiency: McNary Lock and Dam Case Study". Water 16, n. 12 (12 giugno 2024): 1671. http://dx.doi.org/10.3390/w16121671.
Testo completoAbstract (sommario):
The Columbia River Basin faces a threat from the potential invasion of zebra mussels (Dreissena polymorpha), notorious for their ability to attach to various substrates, including concrete, which is common in fishway construction. Extensive mussel colonization within fishways may affect fish passage by altering flow patterns or creating physical barriers, leading to increased travel times, or potentially preventing passage altogether. Many factors affect mussel habitat suitability including vectors of dispersal, water parameters, and various hydrodynamic quantities, such as water depth, velocity, and turbulence. The objective of this study is to assess the potential for zebra mussels to attach to fishway surfaces and form colonies in the McNary Lock and Dam Oregon-shore fishway and evaluate the potential impact of this infestation on the fishway’s efficiency. A computational fluid dynamics (CFD) model of the McNary Oregon-shore fishway was developed using the open-source code OpenFOAM, with the two-phase solver interFoam. Mesh quality is critical to obtain a reliable solution, so the numerical mesh was refined near the free surface and all solid surfaces to properly capture the complex flow patterns and free surface location. The simulation results for the 6-year average flow rate showed good agreement with the measured water column depth over each weir. Regions susceptible to mussel infestation were identified, and an analysis was performed to determine the mussel’s preference to colonize as a function of the depth-averaged velocity, water depth, and wall shear stress. Habitat suitability criteria were applied to the output of the hydraulic variables from the CFD solution and provided insight into the potential impact on the fishway efficiency. Details on the mesh construction, model setup, and numerical results are presented and discussed.
38
Sanagiotto, Daniela, Júlia Rossi e Juan Bravo. "Applications of Computational Fluid Dynamics in The Design and Rehabilitation of Nonstandard Vertical Slot Fishways". Water 11, n. 2 (24 gennaio 2019): 199. http://dx.doi.org/10.3390/w11020199.
Testo completoAbstract (sommario):
Vertical slot fishways are increasingly common structures for the passage of a wide variety of migratory fish and contribute to the maintenance of fish diversity in fragmented rivers. These structures are designed with several geometric arrangements and, consequently, flow patterns through them can be shaped to present suitable characteristics for the fish species. To aid in the design of vertical slot fishways, a three-dimensional numerical model was used to simulate the flow for different geometric configurations. An existing vertical slot fishway with nonstandard dimensions was initially modeled and validated. This geometry was used as a reference design. Modifications to the reference design, such as the insertion of cylinders, changes in the baffle shape and position of the vertical slots, as possible rehabilitation measures, were proposed and tested. In summary, five different designs were evaluated with several slopes, totaling 17 geometries. Hydraulic parameters, flow patterns, maximum velocities, velocity fields and turbulence kinetic energy in the pools were analyzed. The results indicate that the maximum velocity values were between 9% and 68% higher than those obtained by the theoretical equation. This indicates that maximum velocities can be underestimated for nonstandard vertical slot fishways if a simplified evaluation is conducted. The insertion of cylinders in the region close to the slot reduces the maximum velocity up to 8.2%. The positioning of the vertical slots on alternating sides increases the maximum values of turbulence kinetic energy and the regions subjected to higher values. However, this configuration provided greater energy dissipation and reduction of velocities by up to 27%. Thus, modifications in nonstandard vertical slot fishways can be useful in future design or rehabilitation of existing structures in order to provide velocities and turbulence more friendly for a higher number of fish species.
39
Chen, Chang Chun, La Chun Wang, Jie Song e Xue Zhang Cao. "The Development and Ecological Responses of Fishways under the Legislative Trend of Environmental Flows in China". Applied Mechanics and Materials 361-363 (agosto 2013): 949–53. http://dx.doi.org/10.4028/www.scientific.net/amm.361-363.949.
Testo completoAbstract (sommario):
Fishways play an important role in the mitigation of negative influence of hydraulic projects on fish, and can help maintain river connectivity and fish migration in river ecological systems. Based on the current situation of fishways construction in China, this paper demonstrated the legislative prospect of environmental flows, and analyzed the historical reason of depression of fishways. Focusing on adaptable measures of fishways development to legislative and ecological water requirements, four proposals were provided, which included strengthening the supervision, promoting the ecological integration, exploring the behavior of fish, and investigating the ecohydraulics of fishways.
40
Heneka, Patrick, Markus Zinkhahn, Cornelia Schütz e Roman B. Weichert. "A Parametric Approach for Determining Fishway Attraction Flow at Hydropower Dams". Water 13, n. 5 (9 marzo 2021): 743. http://dx.doi.org/10.3390/w13050743.
Testo completoAbstract (sommario):
High discharges at hydropower plants (HPP) may mask fishway attraction flows and, thereby, prevent fishes from locating and using fishways critical for their access to upstream spawning and rearing habitats. Existing methods for determining attraction flows are either based on simple guidelines (e.g., a proportion of HPP discharge) that cannot address the spatial and temporal complexity of tailrace flow patterns or complicated studies (e.g., combinations of detailed hydraulic and biological investigations) that are expensive and time-consuming. To bridge this gap, we present a new, intermediate approach to reliably determine attraction flows for technical fishways at small to medium-sized waterways (mean annual flow up to 400 m3/s). Fundamental to our approach is a design criterion that the attraction flow should maintain its integrity as it propagates downstream from the fishway entrance to beyond the highly turbulent zone characteristic of HPP tailraces to create a discernable migration corridor connecting the fishway entrance to the downstream river. To implement this criterion, we describe a set of equations to calculate the width of the entrance and the corresponding attraction discharge. Input data are usually easy to obtain and include geometrical and hydraulic parameters describing the target HPP and its tailrace. To confirm our approach, we compare model results to four sites at German waterways where the design of attraction flow was obtained by detailed experimental and numerical methods. The comparison shows good agreement supporting our approach as a useful, intermediate alternative for determining attraction flows that bridges the gap between simple guidelines and detailed hydraulic and biological investigations.
41
LARINIER, M. "BAFFLE FISHWAYS". Bulletin Français de la Pêche et de la Pisciculture, n. 364 supplément (2002): 83–101. http://dx.doi.org/10.1051/kmae/2002109.
Testo completo
42
Rajaratnam, N., C. Katopodis e R. Paccagnan. "Field studies of fishways in Alberta". Canadian Journal of Civil Engineering 19, n. 4 (1 agosto 1992): 627–38. http://dx.doi.org/10.1139/l92-072.
Testo completoAbstract (sommario):
This paper presents a detailed account of field studies performed on one pool-weir and several Denil and vertical slot fishways in the province of Alberta. The pictures show the broad features of the flow. The velocity profiles obtained in the field studies have confirmed the measurements made in the laboratory on scale models and have enhanced the general picture, particularly for the vertical slot fishways. This paper provides hydraulic engineers with information for understanding the primary hydraulic characteristics of fishways. Key words: fishways, field studies, hydraulics, open-channel flow, turbulent flow.
43
Nakai, Masahiko, Taku Masumoto, Takashi Asaeda e Mizanur Rahman. "Improving the efficiency of adaptive management methods in multiple fishways using environmental DNA". PLOS ONE 19, n. 4 (1 aprile 2024): e0301197. http://dx.doi.org/10.1371/journal.pone.0301197.
Testo completoAbstract (sommario):
Dams and weirs impede the continuity of rivers and transit of migratory fish. To overcome this obstacle, fishways are installed worldwide; however, management after installation is important. The Miyanaka Intake Dam has three fish ladders with different flow velocities and discharges and has been under adaptive management since 2012. Fish catch surveys, conducted as an adaptive management strategy, place a heavy burden on fish. Furthermore, a large number of investigators must be mobilized during the 30-day investigation period. Thus, a monitoring method using environmental DNA that exerts no burden on fish and requires only a few surveyors (to obtain water samples) and an in-house analyst was devised; however, its implementation in a fishway away from the point of analysis and with limited flow space and its effective water sampling frequency have not been reported. Therefore, in 2019, we started a trial aiming to evaluate the methods and application conditions of environmental DNA surveys for the continuous and long-term monitoring of various fish fauna upstream and downstream of the Miyanaka Intake Dam. To evaluate the fish fauna, the results of an environmental DNA survey (metabarcoding method) for 2019 to 2022 were compared to those of a catch survey in the fishway from 2012 to 2022. The results confirmed the use of environmental DNA surveys in evaluating the contribution of fishways to biodiversity under certain conditions and introduced a novel method for sample collection.
44
Rajaratnam, N., C. Katopodis e N. McQuitty. "Hydraulics of culvert fishways II: slotted-weir culvert fishways". Canadian Journal of Civil Engineering 16, n. 3 (1 giugno 1989): 375–83. http://dx.doi.org/10.1139/l89-061.
Testo completoAbstract (sommario):
This paper presents the results of an experimental study on the hydraulics of culvert fishways with a slotted-weir baffle system. Six designs with two baffle heights and three spacings were tested. A flow equation has been developed to predict the flow depth for any given discharge, diameter, and slope. The barrier velocity that would exist at the slot in the baffles has also been predicted in a general manner. This relatively simple slotted-weir baffle system has been found to match the performance of the more complicated but frequently used offset baffle system of similar dimensions. Key words: culverts, fishways, baffles, hydraulics, turbulent flow, open-channel flow.
45
Rajaratnam, N., e C. Katopodis. "Hydraulics of culvert fishways III: weir baffle culvert fishways". Canadian Journal of Civil Engineering 17, n. 4 (1 agosto 1990): 558–68. http://dx.doi.org/10.1139/l90-064.
Testo completoAbstract (sommario):
This paper presents the results of a laboratory study of culvert fishways with weir-type baffles. Baffles with heights equal to 0.15 and 0.1 times the diameter (D) of the culvert were studied with longitudinal spacings of 0.6D and 1.2D. Equations have been developed to describe the relation between the discharge, slope, diameter, and the depth of flow. It has been possible to predict the barrier velocity that would exist at the baffles. The performance of the weir baffles has been found to be as good as that of the slotted-weir baffles. Key words: culverts, fishways, hydraulics, turbulent flow, open-channel flow.
46
Rajaratnam, N., C. Katopodis e S. Lodewyk. "Hydraulics of culvert fishways IV: spoiler baffle culvert fishways". Canadian Journal of Civil Engineering 18, n. 1 (1 febbraio 1991): 76–82. http://dx.doi.org/10.1139/l91-010.
Testo completoAbstract (sommario):
This paper presents the results of an experimental study on the hydraulics of culvert fishways with spoiler baffles. Four designs were studied with the heights of the baffles equal to 0.09D and 0.15D and longitudinal spacings of 0.53D and 1.06D, where D is the diameter of the culvert. Design equations have been developed relating the flow depth to the flow rate, the diameter and the slope of the culvert for each baffle design. Expressions have also been found for the barrier velocity. Key words: culverts, fishways, hydraulics, turbulent flow, open-channel flow.
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Masumoto, Taku, Masahiko Nakai, Takashi Aoki, Takashi Asaeda e Mizanur Rahman. "Quantifying Vegetation on a Rock-Ramp Fishway for Fish Run-Up and Habitat Enhancement: The Case of the Miyanaka Intake Dam in Japan". Water 15, n. 12 (10 giugno 2023): 2188. http://dx.doi.org/10.3390/w15122188.
Testo completoAbstract (sommario):
The Miyanaka Intake Dam fishway underwent improvements in 2012, and we established a new rock-ramp fishway called the Seseragi Fishway, cognizant of its utility as a passage and a habitat for bottom-dwelling and small fish with weak swimming ability. However, the fishway is occasionally submerged by floods, causing sediment accumulation that leads to changes in the vegetation composition. In addition, the arrival and inflow of seeds from upstream and the surrounding areas result in vegetation changes. In this study, the inside and outside of the rock-ramp fishway were divided into eight areas, and the vegetation succession after 2012 was determined. A correlation was observed between the results of fish catch surveys during the same period and the vegetation. Based on these results, we reported on the process of steadily operating the rock-ramp fishway while devising and improving specific management methods. Changes in vegetation, such as an increase in upright vegetation and a decrease in flow-obstructing vegetation, contributed to an increase in the population of bottom-dwellers, weak swimmers, and juvenile fish. The existence and management of appropriate vegetation are important for maintaining fishways inhabited by a variety of fish species.
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Makrakis, Sergio, Ana P. S. Bertão, Jhony F. M. Silva, Maristela C. Makrakis, Fco Javier Sanz-Ronda e Leandro F. Celestino. "Hydropower Development and Fishways: A Need for Connectivity in Rivers of the Upper Paraná Basin". Sustainability 11, n. 13 (9 luglio 2019): 3749. http://dx.doi.org/10.3390/su11133749.
Testo completoAbstract (sommario):
South American rivers have become intensely affected by the construction of hydroelectric dams that block the river’s connectivity for migratory fish species. In order to mitigate the problems caused by dams and to reestablish connections between habitats, fishways are implemented. Fishways are structures that aid fish in overcoming obstacles and help preserve migratory, reproductive, and feeding routes. This study performed an inventory of all hydropower plants—present and future—in the Upper Paraná River, with the objective of identifying fishways unknown to scientific literature, as well as the task of mapping them. By doing so, the current situation of structural connectivity via fishways in the Upper Paraná River Basin was described. Overall, 389 dams along 209 rivers were identified; of these, only 9% (35 dams) have fishways. In addition, an alarming explosion of future medium-sized hydropower plants was observed, with an expectation of an almost 500% increase in relation to those existing. This data reveals a trend of reduction of free-flowing river stretches, which are crucial habitats for Neotropical potamodromous species, and point to a deficiency in the structural connectivity of existing hydropower dams. Furthermore, if the implementations of these expected constructions are associated with limited connectivity as a result of the absence of fishways, the management of fisheries and their resources in the Upper Paraná River may become unsustainable.
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Seidl, Georg, e Josef Schneider. "Comparative Biotic Monitoring of a Modified Denil Fishway and a Pool and Weir Fishway on a Small Tributary in the Upper Trout Region". Water 15, n. 13 (21 giugno 2023): 2322. http://dx.doi.org/10.3390/w15132322.
Testo completoAbstract (sommario):
Modified Denil fishways have a centred gabion containing gravel and are intended to enable the free passage of riverbed-oriented species and invertebrates. An experimental plant was built at a small hydropower station which provided a newly arranged Denil fishway and a pool and weir fishway parallel to one another. It was possible to alternately operate the systems for monitoring purposes owing to the parallel design, allowing an appropriate comparison and analysis of the results to be carried out. The primary objective of this study is to qualitatively and quantitatively compare the size selectivity and ascent numbers between the new development and the conventional construction type. An important component of this study is the test to prove the passage of bullheads in the modified Denil fishway using an experimental set-up. The results of this study depict a similar size distribution of ascended fish in both construction types and thus provide no evidence of selectivity for small fish sizes. Likewise, no deficit of the modified Denil fishway compared with the pool and weir fishway could be proven within the scope of a monitoring. The successful passage of bullheads could be demonstrated in the experiment as well as during monitoring.
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PORCHER, J. P. "FISHWAYS FOR EELS". Bulletin Français de la Pêche et de la Pisciculture, n. 364 supplément (2002): 147–55. http://dx.doi.org/10.1051/kmae/2002099.
Testo completo