Entity

Time filter

Source Type

Winnipeg, Canada

Katopodis C.,Katopodis Ecohydraulics Ltd | Williams J.G.,National Oceanic and Atmospheric Administration | Williams J.G.,University of Washington
Ecological Engineering | Year: 2012

For centuries, humankind has constructed dams on rivers to control flooding, provide for irrigation and utilize potential energy for power, but generally dams had no or little provision for fish passage. Thus, they often blocked or impeded fish migrations. Empirical observations and "trial and error" approaches that characterized historical efforts to develop passage systems for upstream migrating fish often did not work. The first concerted efforts to develop scientifically based fishways for upstream migrant fish began in the early 1900s in Europe with field and laboratory testing of different fishway designs. These were followed by extensive efforts beginning in the 1940s in North America. Scientifically based testing of configurations for fishways for downstream migrant fish began in the 1950s. Nearly all early efforts were directed at salmonid species, with smaller efforts on shad. Recent species at risk legislation in the U.S.A., Canada, and Europe places renewed emphasis on fish passage for all migratory species, and efforts have also begun to develop successful passage strategies for migratory species in other countries worldwide. This has led to renewed efforts to develop effective passage systems and to try creative solutions using natural materials in addition to concrete or metal used in standard technical fishways. Regardless of the type of structures built, history has shown that the most effective means to develop successful installations has occurred when engineers and biologists worked together systematically to design passage structures based on the ability and willingness of fish to seek and accept the hydraulic conditions presented to them. © 2011 Elsevier B.V. Source


Williams J.G.,National Oceanic and Atmospheric Administration | Williams J.G.,University of Washington | Armstrong G.,UK Environment Agency | Katopodis C.,Katopodis Ecohydraulics Ltd | And 2 more authors.
River Research and Applications | Year: 2012

Worldwide, obstructions on watercourses have interfered with migratory pathways of fish species, reducing life-cycle success and often eliminating diadromous fish species altogether from river basins. Over the last century, efforts to mitigate these effects were initially directed at developing fishways for upstream, high-value migrant adult salmon. In more recent years, efforts have turned to developing fishways for other species. Results of past research suggest that the development of effective fishways requires biological knowledge of fish behaviour when encountering variable flows, velocity and turbulence, combined with hydraulic and civil engineering knowledge and expertise to develop facilities that provide appropriate hydraulic conditions that fish will exploit. Further, it often requires substantial financial resources for biological and hydraulic testing as well as engineering design, particularly where prior knowledge of the behaviour of target fish species does not exist. Where biological or engineering knowledge (or both) is absent, development of effective passage facilities must take on a trial and error approach that will almost certainly require years to attain success. Evaluations of existing adult and juvenile fish passage facilities, where they have been carried out, suggest that migrant fish reject areas with hydraulic conditions they determine unsuitable. Even well designed fish ladders or nature-like bypass channels for upstream migrants, even those with good attraction flows, will fail if incorrectly sited. Although progress has been made, developing successful installations for downstream migrants remains much more difficult, probably because downstream fish move with the flow and have less time to assess cues at entrances to any bypasses that they encounter. © 2011 John Wiley & Sons, Ltd. Source


Boavida I.,University of Lisbon | Santos J.M.,University of Lisbon | Katopodis C.,Katopodis Ecohydraulics Ltd | Ferreira M.T.,University of Lisbon | Pinheiro A.,University of Lisbon
River Research and Applications | Year: 2013

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 model is able to integrate the habitat suitability curves for fish life stages with the simulated depth and velocity fields and the riverbed characteristics of substrate and cover, thereby estimating the corresponding weighted usable area, and thus predicting the potential distribution of fish species in the river. However, little is known about the in situ variability associated with such predictions both for hydraulic and biological data, whereas ecological responses are known to be driven by variability. Moreover, when calculating habitat availability, differences can be found by considering in the weighted usable area formulation substrate or cover or even both. To test the level of predictive accuracy of hydraulic and biological simulations, we modelled the habitat use by two fish species, the Iberian barbel Luciobarbus bocagei and the Iberian straight-mouth nase Pseudochondrostoma polylepis, according to their requirements for depth, velocity, substrate and cover and then compared measured and simulated hydraulic and biological outcomes using the River2D model. Results indicate that 2D simulation depends on data collection, especially the density and location of bed topography points. Substantial differences were found in the biological responses. Results may differ when choosing different habitat availability variables. Similarly, habitat use may also be influenced by other biotic and abiotic interactions occurring in ecosystems, and restoration planning should be aware of such variability. © 2012 John Wiley & Sons, Ltd. Source


Thiem J.D.,Carleton University | Binder T.R.,Carleton University | Dumont P.,Ministere des Ressources Naturelles et de la Faune | Hatin D.,Ministere des Ressources Naturelles et de la Faune | And 4 more authors.
River Research and Applications | Year: 2013

A 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 success and passage duration of fish using a vertical slot fishway (85m in length, 2.65m elevation rise, 12 regular pools and 2 turning basins) at a low head dam on the Richelieu River in Quebec, Canada. Fourteen of the 18 tagged species re-ascended the fishway, and passage efficiency was highly variable among species (range 25%-100%); however, it was >50% for five of the species well represented in this study (n>10) (Atlantic salmon, channel catfish, smallmouth bass, walleye and white sucker). Passage duration was likewise highly variable both among and within species (e.g. 1.0-452.9h for smallmouth bass, 2.4-237.5h for shorthead redhorse). Although this fishway design was not uniformly successful in passing fish of all species, this study does reveal the species that have problems with ascent and provides an estimate on the time spent in the fishway that is an important component of passage delay. Such information could be used to inform future design refinements to facilitate passage of the entire assemblage with minimal delay. © 2012 John Wiley & Sons, Ltd. Source


Santos J.M.,University of Lisbon | Branco P.,University of Lisbon | Katopodis C.,Katopodis Ecohydraulics Ltd | Ferreira T.,University of Lisbon | Pinheiro A.,University of Lisbon
Ecological Engineering | Year: 2014

Retrofitting, or the addition of features to existing fishways to make them more suitable for upstream fish passage, is an issue of increasing interest in fishway science. Despite its potential for aiding fish passage, few studies are available on retrofitting of pool-and-weir fishways by adding boulders at the bottom of each pool of these facilities. The aim of this study was to assess the performance of a full-scale retrofitted pool-and-weir fishway model with boulders placed at the bottom of each pool, to enhance passage of a cyprinid species, the Iberian barbel (Luciobarbus bocagei), which was considered as a representative of medium-sized benthic potamodromous cyprinids in Iberia and Western Europe. Particular attention was given to testing the effects of boulder density and fishway discharge on passage success and fish transit time, both of which affect fish passage efficiency. Although no significant difference in passage success was detected between boulder spacings (mean proportion for high density: 35% success; mean proportion for low density: 40% success), increased flows (62.7 l/s) induced a higher mean proportion (P< 0.05) of successful negotiations (50%), relative to low flows (38.5 l/s, 25%). With regard to fish transit time, under higher flows, fish took significantly less time (P< 0.05) to ascend the fishway with the higher (5.3 ± 4.2 min) vs the lower boulder density (12.1 ± 6.5 min). This study showed that fish passage success was discharge-related and independent of boulder density. However, a high density boulder configuration combined with higher fishway discharge can be beneficial as it reduced fish transit time. Such information could be used to retrofit ill-functioning fishways in order to improve fish passage efficiency and negotiation of fishways for benthic potamodromous cyprinids. © 2014 Elsevier B.V. Source

Discover hidden collaborations