C. Katopodis

Turbulent flows are investigated upstream of a bar rack system that is recommended as optimum in recent literature from tests with several fish species of different morphology, swimming ability, and behavior. Both two‐dimensional two‐component and two‐dimensional three‐component state‐of‐the‐art particle image velocimetry were used to quantify and...

Multiple anthropogenic forces have pushed river ecosystems into undesirable states with no clear understanding of how they should be best managed. The advancement of riverine fish habitat models intended to provide management insights has slowed. Investigations into theoretical and empirical gaps to define habitat more comprehensively across differ...

Computational fluid dynamics (CFD) is increasingly applied in the study of fishways. Applications and methodologies, however, vary substantially among scientific studies and no overview is currently available in the primary literature. Here we review published papers on CFD use in upstream fish passage solutions to identify and describe related spa...

Lateral intakes are very important for diverting a portion of the river flow and providing the proper flow depth. In cases where small dams are used to operate and control the river's water level for the intake and to meet downstream water needs, the opening and closing of the dam gates before the construction of the intake and during its operation...

Turbulent flows are investigated in the bypass of a bar rack system to understand the effects of weirs placed at the bypass entrance on hydraulic conditions used to guide fish moving downstream. Three test cases were studied: (a) no weir (reference case), (b) arc-shaped weir and (c) triangular weir. A stereo particle image velocimetry system was em...

Dams and other flow control structures constitute obstacles to upstream and downstream aquatic habitats, reducing life‐cycle success and even eliminating diadromous and potamodromous fish species from river basins. Providing effective passage past hydroelectric dams is critical for restoring habitat connectivity and sustaining populations of fish s...

Fishways are used to allow fish to migrate around water infrastructure, whether movements are in the upstream or downstream direction. Hydrodynamic conditions within various fishways, including turbulence levels, are important for successful fish passage. A numerical hydrodynamic study was conducted for V-weir fishways, which assist species migrati...

Boulder placement is a common method to restore degraded instream habitats by enhancing habitat complexity. This experimental study is the foremost attempt to systematically investigate the influence of rock-ramp boulder placement with varying boulder concentration and flow rate on habitat hydraulic complexity metrics, including the kinetic energy...

The development of a hydropower facility has, in nearly all cases, some impact on natural river flows and the wider environment. This impact often includes the effect on fish, most notably curtailment of migration routes and changes to their natural habitat and ecosystem services fish is dependent on. The general relationship between fish and hydro...

Anthropogenic obstructions such as dams with Spillways have adverse impacts on the aquatic habitats and affect the downstream migration of fish. During the migratory cycle of fish, water levels encountered at spillway entrances vary significantly. It is therefore important to understand how changing the water depth over spillways influences hydrody...

Spillways are anthropogenic obstructions that significantly impact the downstream migration of fish to their spawning grounds. Hence, it is important to understand the influence of spillway geometry on flow hydraulics and fish behavioral responses. The hydraulic environment generated by the commonly used 90° standard spillway designs may provide li...

Setting e-flows (instream, environmental or ecological flow regimes) for existing or new hydroelectric and other projects is a key worldwide consideration. A Canadian perspective and experience in arriving at e-flow regimes for ice-free or ice-covered rivers, with emphasis on small and large hydroelectric projects, is presented through general conc...

Experiments were performed in a novel pool & weir fishway to study the relationship between hydrodynamic and physiological parameters using rainbow trout (Oncorhynchus mykiss; mean TL = 15 cm). Fish were tested randomly using three fishway slopes (4, 7 and 10%) and three spacing ratios of W shaped weirs. Effect on fish hematology, immunology and st...

The migration corridors in regulated rivers lead downstream fish migrants, particularly juveniles to pass through water infrastructure. Accelerating flow, experienced by fish, might trigger avoidance behaviour and then influence the downstream migration efficacy. It is essential to understand the causes of avoidance behaviour exhibited by downstrea...

The addition of substrates to small instream obstacles, like low-head ramped weirs, has been considered a useful management solution to retrofit those structures and enhance fish passage. Substrate dimensions and spatial arrangement, together with discharge, and consequently water depths, appear as important factors for the creation of hydrodynamic...

Low-head ramped weirs are one of the most common small engineered structures present in Iberian rivers. Fish passability of these obstacles, where water passes over but does not generate a waterfall, is primarily related to ramp length and slope. However, the relative contribution of these factors has seldom been investigated. This study aims to as...

The objective of this research was to determine the effects of diel cycle and flow velocity on rheotaxis, measure the swimming performance of Perch-barbel (Percocypris pingi, Tchang, 1930) and use the results to recommend an appropriate fishway entrance velocity and fish lift operating schedule. PIT tagging was used to monitor fish rheotaxis for 48...

Vertical slot fishways (VSFs) are the most efficient and least selective typology of technical fish passage, due to their ability to remain effective even when significant upstream and/or downstream water level fluctuations occur. Fishway construction costs can be reduced by increasing its bed slope, but this affects the flow field inside the pools...

The rapid decline in sturgeon populations is largely a result of human activities, especially the proliferation of hydraulic structures and lack of fish passage systems effective for sturgeon. This review highlights: (1) the importance of sturgeon conservation; (2) the need for data on swimming performance, including capability, metabolism and kine...

Low-head ramped weirs are a common instream obstacle to fish movements. Fish passability of these structures, where water passes over but does not generate a waterfall, is primarily related to ramp length and slope, but their relative contribution has seldom been considered. This study aims to assess the passage performance of a potamodromous cypri...

Ecohydraulics research is just beginning to have all the tools needed to examine the 2-dimensional velocity preference of fish in flow fields. We developed an experimental system with a gradient flow field in a test channel to observe flow-field preference of juvenile silver carp, Hypophthalmichthys molitris. We used automatic methods, which acquir...

A dam will be built in the upper reaches of the Mekong River, obstructing fish migration and gene exchange, and a fish lift will be constructed to mitigate these impacts. Target species for the lift were selected based on five criteria: (1) passage demand, (2) passage utility, (3, 4) protection worthiness (protection class and economic value) and (...

The presence of small weirs, far more numerous than dams, have altered the river systems and negatively affected fish communities, mainly by disturbing fish movements. However, contrarily to the vast literature on dams, much less is known about the effects of small weirs on fish movements. This study aims to evaluate the upstream passage performanc...

Most fishway studies are conducted during the reproductive period, yet uncertainty remains on whether results may be biased if the same studies were performed outside of the migration season. The present study assessed fish passage performance of a potamodromous cyprinid, the Iberian barbel (Luciobarbus bocagei), in an experimental full-scale verti...

The cover image, by S.D. Amaral et al., is based on the Research Article To swim or to jump? Passage behaviour of a potamodromous cyprinid over an experimental broad-crested weir, DOI 10.1002/rra.3232.

Much effort has been devoted to developing, constructing and refining fish passage facilities to enable target species to pass barriers on fluvial systems, and yet, fishway science, engineering and practice remain imperfect. In this review, 17 experts from different fish passage research fields (i.e., biology, ecology, physiology, ecohydraulics, en...

Physical stressors, such as man-made obstacles, are considered one of the main causes that negatively affect freshwater fish. Even small weirs may impact fish populations, including potamodromous cyprinids, by partially or totally blocking upstream migratory movements. Some studies have addressed the effect of key hydraulic parameters on upstream m...

Fishways are hydraulic structures that allow passage of fish across obstructions in rivers. Vertical slot fishways—VSFs—are considered the most efficient and least selective type of technical fishway solutions, especially due to their ability to remain effective even when significant upstream and/or downstream water level fluctuations occur. The sc...

The impact of varying computational mesh discretization on the accuracy of simulating velocities and water-surface elevations was investigated using the River2D model and data from 10 study reaches in three low-slope (<0.2%) Canadian rivers. A wide range of computational aspects were examined, including node spacing (1.35 to 60 m), number of mesh n...

Poster presented in the 10 Symposium for European Freshwater Sciences. Olomouc (Czech Republic), 2 – 7 July.

Adequately designed vertical slot fishways (VSF) mitigate the impact of anthropogenic obstructions onfish migrations. Until now, most studies on VSF were conducted focusing on high priority species, partic-ularly salmonids, while other species, such as cyprinids, have received less attention. In Mediterraneanrivers, where water availability is a pr...

Flow regime is a fundamental driver in fluvial ecosystems, shaping habitat structure and biodiversity, and sustaining ecological integrity. Fish respond to flow fluctuations but whether aspects of flow variability represent organism-level stressors is poorly understood. To find existing evidence of fluvial fish organism-level responses to flow vari...

The presence of small weirs, far more numerous than dams, has increased habitat fragmentation on rivers worldwide. This study aims to evaluate the upstream passage performance of a potamodromous cyprinid, the Iberian barbel (Luciobarbus bocagei), over an experimental broad-crested weir by varying key-hydraulic parameters. Fish passage success was s...

- Vertical slot fishways are hydraulic structures that allow fish to pass over an obstacle. Several experimental tests have been performed, but fewer numerical simulations have been explored. - The standard design of a vertical slot fishway and a modified version were investigated using CFD simulations, in order to simulate the turbulent flow field...

- Vertical slot fishways are hydraulic structures that allow fish to pass over an obstacle. Several experimental tests have been performed, but fewer numerical simulations have been explored. - The standard design of a vertical slot fishway and a modified version were investigated using CFD simulations, in order to simulate the turbulent flow field...

O projeto FISHMOVE – Desenvolvimento de Medidas de Mitigação para Pequenas Barreiras à Migração de Peixes Dulçaquícola em Rios Portugueses, teve como principais objetivos avaliar os efeitos de pequenos obstáculos fluviais nos movimentos migratórios de espécies ciprinícolas nativas, em particular a sua capacidade de transposição através de açudes de...

The presence of small man-made barriers like small weirs, far more numerous than dams, alters the river system and negatively affects fish communities, mainly by disturbing fish movements and hindering access to spawning, feeding and refuge locations. However, in contrast to the vast literature on dams, much less is known about the effects of small...

At the heart of the inter-and trans-disciplinary science of Ecohydraulics is the study trilogy of habitat and ecosystem restoration (including dam removal and wetland rehabilitation), e-flows (ecological, environmental or instream flow regimes), and passage systems for migrations of fish and other aquatic organisms. These ecohydraulic science theme...

Around the world, many fishways have been constructed to provide a route for upstream migrating fish to pass dams. Most were designed for salmon, but other species have also been targeted. While sometimes successful, often these fishways are not, because they were constructed with insufficient hydraulic and biological knowledge about the target spe...

The placement of artificial substrates at the bottom of conventional fishways has been of increasing interest, as a means to improve passage for several fish species. The aim of this work is to study the behaviour and performance of the Iberian barbel (Luciobarbus bocagei), a benthic potamodromous fish, in a full-scale experimental pool-type fishwa...

Size matters even for the ubiquitous fish speed metric of BL/s Christos Katopodis1 and Richard Gervais2 1Katopodis Ecohydraulics Ltd., Winnipeg, Canada 2Fisheries and Oceans Canada, Winnipeg, Canada The use of BL/s, i.e. body lengths per second (dimensions of s-1), to express relative swim speeds for fish is very common. The physiological literat...

Flow characteristics associated with spillways are important to restore ecological connectivity because spillways can either constrain or offer safe routes for downstream passage of fish. We studied the hydrodynamics of flow and downstream movement behaviour of the catadromous European eel (Anguilla anguilla) and the potamodromous Iberian barbel (L...

Fishways have been developed to restore longitudinal connectivity in rivers. Despite their potential for aiding fish passage, fishways may represent a source of significant energetic expenditure for fish as they are highly turbulent environments. Nonetheless, our understanding of the physiological mechanisms underpinning fishway passage of fish is...

The paper reports on an experimental study of turbulent open-channel flow near small-scale and large-scale bar rack models. The experiments were conducted for a wide range of bar depth, bar shape, bar spacing and bar inclination to the approach flow. The contours of the mean velocity near the small-scale models revealed that bar inclination produce...

Effective culvert fish passage depends, among other factors, on the fish swimming abilities and behaviour of the different sizes of migratory species. This is particularly important for hydraulic conditions within the culvert barrel, as well as, the outlet and inlet over the hydrological range which corresponds to periods of upstream fish movements...

Fish passage through culverts has been addressed through various strategies, ranging from empirical approximations to ecohydraulic studies, which integrate ecological, biological and habitat needs, as well as fish abilities and behaviour with hydraulics, hydrology and morphodynamics. Maximum scour, appropriate culvert invert placement or tailwater...

Developments to protect juvenile fish at industrial water intakes, such as those for oilsands projects on the Athabasca River in northern Alberta, provide practical design guidance. Scale models demonstrate the importance of water intake geometry, flow guidance devices, and pump arrangements to achieve appropriate velocity magnitudes and distributi...

Establishing e-flow regimes (i.e. environmental, in-stream, or ecological flow regimes), is a key consideration in sustainable water resources development. The most sophisticated e-flow methods to date are those based on hydrodynamic and habitat modeling. Ecohydraulic relationships between water depths, velocities, substrates and habitat suitabilit...

Effective culvert fish passage depends, among other factors, on the fish swimming abilities and behaviour of the different sizes of migratory species. This is particularly important for hydraulic conditions within the culvert barrel, as well as the outlet and inlet over the hydrological range which corresponds to periods of upstream fish movements....

The goal of this study was to assess the performance of two boulder density designs combined with two fishway discharges, in assisting upstream passage of a potamodromous cyprinid species, the Iberian barbel (Luciobarbus bocagei), in an experimental full-scale pool-type fishway. Four different configurations were tested by changing the flow (Q), ma...

Efforts to restore river connectivity have been made in an attempt to improve the sustainability of fish stocks in rivers impacted by in-stream structures. Of particular concern is the development of efficient downstream passage systems, which minimize the risk of injury and mortality associated with turbines in hydropower stations (HPS). Spillways...

Both water managers and researchers have the same goal when it comes to fish conservation, namely, to sustain, to improve or to restore aquatic habitat. To this aim, two-dimensional (2D) hydrodynamic models have been widely used in aquatic habitat studies because they simulate flow with high accuracy and can predict habitat dynamics. The River2D mo...

Dams and weirs strongly affect or inter-rupt the longitudinal connectivity of rivers, by limiting the movements of several fish species while altering and fragmenting habitats. Fishways, especially pool-type fishways, are used to diminish this impact by enabling fish to negotiate barriers. The aim of this work is to study the behaviour of a small-s...

ABSTRACTA shift from target species to ecosystem restoration has generated interest in developing fishways that are capable of passing entire fish communities. Although a number of multispecies fishways now exist in North America, evaluations of these fishways are lacking. We used a passive integrated transponder antenna array to quantify passage s...

Literature related to pool-type fishways has seen a recent upsurge of interest in the placement of instream structures for improving fish passage. However, there is still no information on how different flow regimes created by boulder placement have an influence on upstream fish movements. The main goal of this study was to assess the performance o...

Fish are particularly sensitive to connectivity loss as their ability to reach spawning grounds is seriously affected. The most common way to circumvent a barrier to longitudinal connectivity, and to mitigate its impacts, is to implement a fish passage device. However, these structures are often non-effective for species with different morphologica...

Flow characteristics near and over spillways are important for ecological, as well as design, aspects. Spillways may either interfere with fish movements or offer a safe route for downstream passage. Hydrodynamics and movement behaviour of the European eel and Iberian barbel are investigated for standard WES ogee spillways with upstream face inclin...