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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.
Ana Quaresma; António Pinheiro. Modelling of Pool-Type Fishways Flows: Efficiency and Scale Effects Assessment. Water 2021, 13, 851 .
AMA StyleAna Quaresma, António Pinheiro. Modelling of Pool-Type Fishways Flows: Efficiency and Scale Effects Assessment. Water. 2021; 13 (6):851.
Chicago/Turabian StyleAna Quaresma; António Pinheiro. 2021. "Modelling of Pool-Type Fishways Flows: Efficiency and Scale Effects Assessment." Water 13, no. 6: 851.
Requalification of low-head ramped weirs through the addition of substrates (retrofitting) has attracted attention in recent years. However, few studies are available on how this measure affects the negotiation of ramped weirs by fish. This study aimed to assess the performance of an experimental ramped weir (3.00 m long with 10% slope; 0.30 m head-drop) to enhance the passage of a potamodromous cyprinid species, the Iberian barbel (Luciobarbus bocagei). Attention was given to testing the effects of the addition of a substrate, in this case cobbles, to the ramp (Nature) vs. a smooth bottom (Control), and discharge (Q; 55 L·s−1 and 110 L·s−1 (or specific discharge per unit width, q = 92 L·s−1·m−1 and 183 L·s−1·m−1)) on fish passage performance. Fish physiological responses to stress and fatigue, measured by glucose and lactate concentrations in blood samples, were also analysed. Results showed that the Nature design generally increased fish movements and successful upstream passages, and enhanced fish passage performance by enabling faster negotiations. Fish movements were also affected by increasing discharge, registering reductions with 110 L·s−1. Results of the physiological parameters indicate that both glucose and lactate concentrations were also influenced by discharge. The outcomes from this study present important information about fish passage performance across low-head ramped weirs and could provide data needed to help biologists and engineers to develop more effective structures to alleviate small instream obstacles.
Susana Amaral; Paulo Branco; Filipe Romão; Maria Ferreira; António Pinheiro; José Santos. Evaluation of Low-Head Ramped Weirs for a Potamodromous Cyprinid: Effects of Substrate Addition and Discharge on Fish Passage Performance, Stress and Fatigue. Water 2021, 13, 765 .
AMA StyleSusana Amaral, Paulo Branco, Filipe Romão, Maria Ferreira, António Pinheiro, José Santos. Evaluation of Low-Head Ramped Weirs for a Potamodromous Cyprinid: Effects of Substrate Addition and Discharge on Fish Passage Performance, Stress and Fatigue. Water. 2021; 13 (6):765.
Chicago/Turabian StyleSusana Amaral; Paulo Branco; Filipe Romão; Maria Ferreira; António Pinheiro; José Santos. 2021. "Evaluation of Low-Head Ramped Weirs for a Potamodromous Cyprinid: Effects of Substrate Addition and Discharge on Fish Passage Performance, Stress and Fatigue." Water 13, no. 6: 765.
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.
Filipe Romão; Ana L. Quaresma; José M. Santos; Susana D. Amaral; Paulo Branco; António N. Pinheiro. Multislot Fishway Improves Entrance Performance and Fish Transit Time over Vertical Slots. Water 2021, 13, 275 .
AMA StyleFilipe Romão, Ana L. Quaresma, José M. Santos, Susana D. Amaral, Paulo Branco, António N. Pinheiro. Multislot Fishway Improves Entrance Performance and Fish Transit Time over Vertical Slots. Water. 2021; 13 (3):275.
Chicago/Turabian StyleFilipe Romão; Ana L. Quaresma; José M. Santos; Susana D. Amaral; Paulo Branco; António N. Pinheiro. 2021. "Multislot Fishway Improves Entrance Performance and Fish Transit Time over Vertical Slots." Water 13, no. 3: 275.
Downstream of small-scale hydropower plants (SHPs), the intensity, frequency and persistence of hydropeaking events often cause an intolerable stress on fish of all life stages. Rapid increases in flow velocity result in fish avoiding unstable habitats and seeking refuge to reduce energy expenditure. To understand fish movements and the habitat use of native Iberian cyprinids in a high-gradient peaking river, 77 individuals were PIT tagged downstream of Bragado SHP in the North of Portugal. Tagged fish species included Pseudochondrostoma duriense and Squalius carolitertii. Fish positions were recorded manually on two different occasions: during hydropeaking events (HP) and without hydropeaking events (NHP). From the 77 tagged fish, we were able to record habitat use for 33 individuals (20 P. duriense and 13 S. carolitertii) in a total of 125 relocations. Fish species were distributed along the river reach with high density in the upstream area in the vicinity of the SHP tailrace, in particular during HP. Fish locations were associated with velocity for P. duriense and S. carolitertii. The latter tended to use faster flowing waters than P. duriense. Our findings on the habitat use in peaking rivers are a valuable tool to help in the selection and design of mitigation measures.
Isabel Boavida; Filipa Ambrósio; Maria João Costa; Ana Quaresma; Maria Manuela Portela; António Pinheiro; Francisco Godinho. Habitat Use by Pseudochondrostoma duriense and Squalius carolitertii Downstream of a Small-Scale Hydropower Plant. Water 2020, 12, 2522 .
AMA StyleIsabel Boavida, Filipa Ambrósio, Maria João Costa, Ana Quaresma, Maria Manuela Portela, António Pinheiro, Francisco Godinho. Habitat Use by Pseudochondrostoma duriense and Squalius carolitertii Downstream of a Small-Scale Hydropower Plant. Water. 2020; 12 (9):2522.
Chicago/Turabian StyleIsabel Boavida; Filipa Ambrósio; Maria João Costa; Ana Quaresma; Maria Manuela Portela; António Pinheiro; Francisco Godinho. 2020. "Habitat Use by Pseudochondrostoma duriense and Squalius carolitertii Downstream of a Small-Scale Hydropower Plant." Water 12, no. 9: 2522.
The use of stepped spillways with nappe flow has been more closely related to the use of gabion spillways, where maximum flow velocities must be respected in order to guarantee the integrity of gabions. The increasing interest in stepped spillways built with different construction materials, either founded on the downstream slope of embankment dams, with usual slopes comprised within 1:2 to 1:3, or on mild slope chute spillways, with even lower inclination, showed the necessity to improve the knowledge on nappe flows. An experimental facility developed at the Hydraulics and Water Resources Laboratory of the Instituto Superior Técnico (IST), allowing to change the steps slope from 1:5 up to 1:2, is described. A bibliographic review on nappe flow occurrence and energy dissipation is presented. Results concerning the two previous aspects are presented and compared with published data and criteria.
António Pinheiro; Cristina S. Fael. Nappe flow in stepped channels – Occurrence and energy dissipation. Hydraulics of Stepped Spillways 2020, 119 -126.
AMA StyleAntónio Pinheiro, Cristina S. Fael. Nappe flow in stepped channels – Occurrence and energy dissipation. Hydraulics of Stepped Spillways. 2020; ():119-126.
Chicago/Turabian StyleAntónio Pinheiro; Cristina S. Fael. 2020. "Nappe flow in stepped channels – Occurrence and energy dissipation." Hydraulics of Stepped Spillways , no. : 119-126.
Many embankment dams have been considered unsafe due to inadequate spillway capacity and predicted overtopping during extreme flood events. In recent years hydraulic research has greatly advanced the concept of embankment protection systems. Based on the available experimental data gathered on laboratory and near-prototype flumes, the authors address the design of stepped overlays for embankment dams. Results show that properly designed stepped overlays are inherently stable, critical for embankment dam. Also, a considerable amount of energy is dissipated by flow over the steps formed by the block surface. Topics discussed include block shape, stability, air entrainment and flow resistance in skimming flow on stepped spillways. Remarks on the hydraulic design are included with the projected cost-effectiveness of a tapered concrete block system over embankment dams.
Kathleen H. Frizell; Jorge Matos; António Pinheiro. Design of concrete stepped overlay protection for embankment dams. Hydraulics of Stepped Spillways 2020, 179 -186.
AMA StyleKathleen H. Frizell, Jorge Matos, António Pinheiro. Design of concrete stepped overlay protection for embankment dams. Hydraulics of Stepped Spillways. 2020; ():179-186.
Chicago/Turabian StyleKathleen H. Frizell; Jorge Matos; António Pinheiro. 2020. "Design of concrete stepped overlay protection for embankment dams." Hydraulics of Stepped Spillways , no. : 179-186.
A large share of future European hydropower projects will be run-of-the-river schemes. To understand the potential for RoR hydropower development and modernization of the technology as an opportunity for sustainable decentralization, we use the Q-methodology to compare public values about RoR hydropower in German, Portuguese and Swedish case studies. Four perspectives on the importance of RoR hydropower emerged from our analysis: (i) maintain regional control, (ii) fight climate change, (iii) promote citizen well-being and (iv) protect natural ecosystems. Strong preferences for regional control imply RoR should be managed as distributed generation rather than viewed as part of a centralized, national system like traditional large-scale reservoir hydropower. Based on the importance of citizen well-being and ecological measures, operators could adopt strategies such as river widening and the reconstruction of secondary channels, which help control floods, create recreational opportunities as well as enhance ecological habilitation and biodiversity. Additionally, policymakers could support rigorous monitoring programs to assess the ecological impact of RoR.
Terese E. Venus; Mandy Hinzmann; Tor Haakon Bakken; Holger Gerdes; Francisco Nunes Godinho; Bendik Hansen; António Pinheiro; Johannes Sauer. The public's perception of run-of-the-river hydropower across Europe. Energy Policy 2020, 140, 111422 .
AMA StyleTerese E. Venus, Mandy Hinzmann, Tor Haakon Bakken, Holger Gerdes, Francisco Nunes Godinho, Bendik Hansen, António Pinheiro, Johannes Sauer. The public's perception of run-of-the-river hydropower across Europe. Energy Policy. 2020; 140 ():111422.
Chicago/Turabian StyleTerese E. Venus; Mandy Hinzmann; Tor Haakon Bakken; Holger Gerdes; Francisco Nunes Godinho; Bendik Hansen; António Pinheiro; Johannes Sauer. 2020. "The public's perception of run-of-the-river hydropower across Europe." Energy Policy 140, no. : 111422.
The rapid river flow variations due to hydropower production during peak demand periods, known as hydropeaking, causes several ecological impacts. In this study, we assessed the potential of an overhead cover and velocity-refuge structure in an indoor flume as an indirect hydropeaking mitigation measure for the cyprinid species Iberian barbel (Luciobarbus bocagei). We designed a lab-scale LUNKERS-type structure using two different materials which were used separately: Wood (opaque) and acrylic (transparent), tested under hydropeaking and base-flow events. Physiological (glucose and lactate) and behavioral (structure use) responses were quantified. The structure use (inside and in the vicinity) and the individual and schooling behavior was assessed. Although there was no evidence that the hydropeaking event triggered a physiological response, the wood structure use was significantly higher than the acrylic one, where the metrics of use increased in the hydropeaking event. Differences between individual and group behavior were only higher for the entrances in the wood structure. The higher frequency of wood structure use under hydropeaking conditions suggests that the visual stimulus conferred by this shaded refuge enables fish to easily find it. The results suggest that the use of overhead and velocity-refuge structures may act as an effective hydropeaking flow-refuge mitigation measure.
Miguel Moreira; Maria João Costa; Jorge Valbuena-Castro; António N. Pinheiro; Isabel Boavida. Cover or Velocity: What Triggers Iberian Barbel (Luciobarbus Bocagei) Refuge Selection under Experimental Hydropeaking Conditions? Water 2020, 12, 317 .
AMA StyleMiguel Moreira, Maria João Costa, Jorge Valbuena-Castro, António N. Pinheiro, Isabel Boavida. Cover or Velocity: What Triggers Iberian Barbel (Luciobarbus Bocagei) Refuge Selection under Experimental Hydropeaking Conditions? Water. 2020; 12 (2):317.
Chicago/Turabian StyleMiguel Moreira; Maria João Costa; Jorge Valbuena-Castro; António N. Pinheiro; Isabel Boavida. 2020. "Cover or Velocity: What Triggers Iberian Barbel (Luciobarbus Bocagei) Refuge Selection under Experimental Hydropeaking Conditions?" Water 12, no. 2: 317.
Due to peak electricity demand, hydropeaking introduces rapid and artificial flow fluctuations in the receiving river, which alters the river hydromorphology, while affecting the downstream ecological integrity. The impacts of hydropeaking have been addressed in flumes and in rivers. However, few studies propose mitigation solutions based on fish responses. The objective of this communication was to assemble the methods and outputs of flume research focused on Iberian cyprinids and to present recommendations to be used by freshwater scientists and hydropower producers. Emphasis was given to the critical role of integrating ecology and hydraulics to find the causal pathway between a flow change and a measurable fish response. The use of diverse behaviour quantification methods, flow sensing technologies, and statistical tools were decisive to strengthen the validity of the findings and to identify fish-fluid relationships, according to flow events. This communication encourages further research to identify flow thresholds for key life-cycle stages and complementary river studies to design and assess mitigation solutions for hydropeaking. Although the research focused on an Iberian cyprinid, the methods suggested have the potential to be extended to other fish species affected by hydropeaking.
Maria João Costa; António N. Pinheiro; Isabel Boavida. Habitat Enhancement Solutions for Iberian Cyprinids Affected by Hydropeaking: Insights from Flume Research. Sustainability 2019, 11, 6998 .
AMA StyleMaria João Costa, António N. Pinheiro, Isabel Boavida. Habitat Enhancement Solutions for Iberian Cyprinids Affected by Hydropeaking: Insights from Flume Research. Sustainability. 2019; 11 (24):6998.
Chicago/Turabian StyleMaria João Costa; António N. Pinheiro; Isabel Boavida. 2019. "Habitat Enhancement Solutions for Iberian Cyprinids Affected by Hydropeaking: Insights from Flume Research." Sustainability 11, no. 24: 6998.
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 conditions that may facilitate the successful passage of fish, though related studies are scarce to support decision-making. This study assessed the influence of discharge (Q) and different retrofitting designs (RD) on the upstream passage performance of a potamodromous cyprinid, the Iberian barbel (Luciobarbus bocagei). Different substrates (small boulders, large boulders, cobbles) and spatial arrangements (aligned, offset) were tested. Numerical modelling was performed to characterize the hydrodynamics. Results indicate that Q and RD influenced the upstream negotiation of ramped weirs. Cobbles randomly distributed along the ramp (Nature design) was the most successful configuration, recording the highest number of upstream passages. Low velocities along the ramp, and low turbulence downstream, were registered in this configuration, indicating that the use of natural substrate may help to increase the permeability of ramped weirs to fish movements. The outcomes from this work can help engineers and biologists to design more appropriate passage structures for low-head instream obstacles.
Susana D. Amaral; Ana L. Quaresma; Paulo Branco; Filipe Romão; Christos Katopodis; Maria T. Ferreira; António N. Pinheiro; José M. Santos. Assessment of Retrofitted Ramped Weirs to Improve Passage of Potamodromous Fish. Water 2019, 11, 2441 .
AMA StyleSusana D. Amaral, Ana L. Quaresma, Paulo Branco, Filipe Romão, Christos Katopodis, Maria T. Ferreira, António N. Pinheiro, José M. Santos. Assessment of Retrofitted Ramped Weirs to Improve Passage of Potamodromous Fish. Water. 2019; 11 (12):2441.
Chicago/Turabian StyleSusana D. Amaral; Ana L. Quaresma; Paulo Branco; Filipe Romão; Christos Katopodis; Maria T. Ferreira; António N. Pinheiro; José M. Santos. 2019. "Assessment of Retrofitted Ramped Weirs to Improve Passage of Potamodromous Fish." Water 11, no. 12: 2441.
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 cyprinid, the Iberian barbel (Luciobarbus bocagei), negotiating an experimental ramped weir with varying ramp length (L) and slope (S). Four configurations were tested, with a constant discharge of 110 L∙s−1. Results suggest that both factors influenced passage performance of fish. Attraction efficiency (AE) increased with increasing L and S, whereas the number of successes (N) and passage efficiency (PE) decreased upon increasing L. For S, it was found that both N and PE peaked at the intermediate level (20%). These results suggest that configurations with the lowest slopes may not necessarily be the best option because they may be less attractive for the fish and their demand for space is higher. Higher slopes (but not excessive) could be more attractive to fish, less space-demanding, and therefore, more cost-effective. Future studies should investigate how discharge and boulder placement influence fish passage across ramped weirs, to improve habitat connectivity.
Susana Amaral; Paulo Branco; Christos Katopodis; Maria Ferreira; António Pinheiro; José Santos. Passage Performance of Potamodromous Cyprinids over an Experimental Low-Head Ramped Weir: The Effect of Ramp Length and Slope. Sustainability 2019, 11, 1456 .
AMA StyleSusana Amaral, Paulo Branco, Christos Katopodis, Maria Ferreira, António Pinheiro, José Santos. Passage Performance of Potamodromous Cyprinids over an Experimental Low-Head Ramped Weir: The Effect of Ramp Length and Slope. Sustainability. 2019; 11 (5):1456.
Chicago/Turabian StyleSusana Amaral; Paulo Branco; Christos Katopodis; Maria Ferreira; António Pinheiro; José Santos. 2019. "Passage Performance of Potamodromous Cyprinids over an Experimental Low-Head Ramped Weir: The Effect of Ramp Length and Slope." Sustainability 11, no. 5: 1456.
Hydropeaking is the rapid change in the water flow downstream of a hydropower plant, driven by changes in daily electricity demand. These fluctuations may produce negative effects in freshwater fish. To minimize these impacts, previous studies have proposed habitat enhancement structures as potential mitigation measures for salmonids. However, the recommendation of these mitigation measures for cyprinids remains scarce and their effects unknown. In this study, the effects of potential habitat mitigation structures under simulated hydropeaking and base-flow conditions are examined for Iberian barbel (Luciobarbus bocagei) in an indoor flume. Solid triangular pyramids and v-shaped structures were evaluated as potential flow-refuging areas and compared with a configuration without structures. A novel, interdisciplinary approach is applied to investigate individual and group responses to rapidly changing flows, by assessing physiological (glucose and lactate), movement behaviour (structure use, sprints and drifts) and the pressure distribution using a fish-inspired artificial lateral line flow sensor. The major findings of this study are four-fold: 1) Under hydropeaking conditions, the v-shaped structures triggered a lactate response and stimulated individual structure use, whereas solid structures did not elicit physiological adjustments and favoured individual and group structure use. Overall, both solid structures and their absence stimulated sprints and drifts. 2) The hydrodynamic conditions created in hydropeaking did not always reflect increased physiological responses or swimming activity. 3) Each event-structure combination resulted in unique hydrodynamic conditions which were reflected in the different fish responses. 4) The most relevant flow variable measured was the pressure asymmetry, which is caused by the vortex size and shedding frequency of the structures. Considering the non-uniform nature of hydropeaking events, and the observation that the fish responded differently to specific flow event-structure combinations, a diverse set of instream structures should be considered for habitat-based hydropeaking mitigation measures for Iberian barbel.
M. J. Costa; Juan Francisco Fuentes-Pérez; I. Boavida; J. A. Tuhtan; António Pinheiro. Fish under pressure: Examining behavioural responses of Iberian barbel under simulated hydropeaking with instream structures. PLoS ONE 2019, 14, e0211115 .
AMA StyleM. J. Costa, Juan Francisco Fuentes-Pérez, I. Boavida, J. A. Tuhtan, António Pinheiro. Fish under pressure: Examining behavioural responses of Iberian barbel under simulated hydropeaking with instream structures. PLoS ONE. 2019; 14 (1):e0211115.
Chicago/Turabian StyleM. J. Costa; Juan Francisco Fuentes-Pérez; I. Boavida; J. A. Tuhtan; António Pinheiro. 2019. "Fish under pressure: Examining behavioural responses of Iberian barbel under simulated hydropeaking with instream structures." PLoS ONE 14, no. 1: e0211115.
New engineering solutions are required to minimise the effects of an increasing number of anthropogenic barriers on watercourses. Longitudinal connectivity must be provided through fishways to allow free passage for the whole fish community. Recently, a multislot fishway (MSF) was developed, with two consecutive vertical slots that divide the overall head drop by two, thus reducing the flow velocity, the magnitude of turbulence and operational discharge compared with a standard vertical slot fishway (VSF) with similar pool and slot dimensions. The present study assessed the effectiveness of a MSF design for two cyprinid species with different ecological traits, under laboratory conditions, namely the Iberian barbel (Luciobarbus bocagei), a large-bodied potamodromous benthic fish, and the southern Iberian chub (Squalius pyrenaicus), a small-bodied water column fish. Experiments were conducted in a full-scale experimental fishway, in spring and autumn. Results showed differences in passage performance between seasons and species. During spring, chub had a higher entry efficiency and shorter transit time to fully negotiate the fishway, whereas no seasonal differences were found for the barbel. Overall, the MSF could be considered a cost-effective design for cyprinids with different ecological traits because it offers lower operational costs than a standard VSF. However, concerns about the entrance and attraction conditions should be addressed. In addition, because of the lower operational discharge, the propensity for obstruction with woody debris and sediments should not be disregarded.
Filipe Romão; Ana L. Quaresma; José Maria Santos; Paulo Branco; António Pinheiro. Cyprinid passage performance in an experimental multislot fishway across distinct seasons. Marine and Freshwater Research 2019, 70, 881 .
AMA StyleFilipe Romão, Ana L. Quaresma, José Maria Santos, Paulo Branco, António Pinheiro. Cyprinid passage performance in an experimental multislot fishway across distinct seasons. Marine and Freshwater Research. 2019; 70 (6):881.
Chicago/Turabian StyleFilipe Romão; Ana L. Quaresma; José Maria Santos; Paulo Branco; António Pinheiro. 2019. "Cyprinid passage performance in an experimental multislot fishway across distinct seasons." Marine and Freshwater Research 70, no. 6: 881.
Hydroelectric power plants managed in response to sub-daily changes of the electricity market undergo rapid variations of turbine discharge, entailing quickly fluctuating water levels downstream. This operation regime, called hydropeaking, causes numerous adverse impacts on river ecosystems. The hydrological alterations which affect hydropeaking rivers can be described by five parameters that change over space and time (magnitude, rate of change, frequency, duration, and timing), where each parameter may be correlated with distinct environmental impacts and therefore may be used to define flow thresholds and set targets for operational mitigation strategies. Thus, this study aims to present an extensive review on the so far established hydropeaking targets and thresholds regarding the outputs from the scientific community as well as from national regulations. We found that only few European countries (Switzerland and Austria) have legal regulations regarding hydropeaking flow thresholds. Other countries, such as Canada and the USA, present environmental legislation that can force hydropeaking mitigation measures. Most mitigation thresholds and management recommendations in literature deal with the effect of downramping on the stranding of salmonids, as well as with minimum flows between peak-flows to avoid spawning ground desiccation. Regarding other fish species and parameters, information on mitigation targets or thresholds is scarcer or non-existent, as well as on hydropeaking mitigation case-studies, resulting in a lack of knowledge and guidelines for its implementation or regulation. Nevertheless, the available literature indicates that multiple aspects must be considered when assessing such values. Thus, to aid in that process, we propose that mitigation targets and thresholds must be based on key species, including particular features regarding season, life-stage and time of day, which must be combined with site-specific morphological characteristics. The presented approach may benefit impacted organism groups in hydropeaking reaches through the establishment of ecologically-based relevant mitigation thresholds and/or targets.
Miguel Moreira; Daniel Hayes; Isabel Boavida; Martin Schletterer; Stefan Schmutz; António Pinheiro. Ecologically-based criteria for hydropeaking mitigation: A review. Science of The Total Environment 2018, 657, 1508 -1522.
AMA StyleMiguel Moreira, Daniel Hayes, Isabel Boavida, Martin Schletterer, Stefan Schmutz, António Pinheiro. Ecologically-based criteria for hydropeaking mitigation: A review. Science of The Total Environment. 2018; 657 ():1508-1522.
Chicago/Turabian StyleMiguel Moreira; Daniel Hayes; Isabel Boavida; Martin Schletterer; Stefan Schmutz; António Pinheiro. 2018. "Ecologically-based criteria for hydropeaking mitigation: A review." Science of The Total Environment 657, no. : 1508-1522.
Fish responses to hydropeaking may range from sub-organismal adjustments to key life-event changes. It is currently difficult to quantify these responses and to assess the potential of artificial refuges accordingly. To address this problem, two experimental trials were conducted in an indoor flume. In the first, two hydropeaking events were tested in the presence of deflectors as flow refuges. In the second, the presence and absence of deflectors was tested for the same hydropeaking event. A multidisciplinary approach combined physiological and movement behaviour responses of Iberian barbel (Luciobarbus bocagei) with hydrodynamic models. These were used as a complementary tool to explain the fish responses. In the first experiment, no evident physiological adjustments occurred. However, individual refuge use and swimming activity were higher in the single-step event where velocities above 0.6 m.s−1 were observed. In the second experiment, the levels of glucose were the highest in the repeated single-step event with deflectors, whereas in their absence no visible changes were observed. The sequence of discharges affected the frequency of individual sprints and group drifts, particularly evident with deflectors. Additionally, the deflector use increased in the first peak in opposition to the second. Overall, the fish responses were indicative that the low velocity areas (<0.1 m.s−1) existing behind the deflectors were favourable under hydropeaking conditions. However, the flow complexity resulting from the presence of deflectors impaired their ability to successfully find them. The integrated approach used in this study provided novel insight considering the responses of cyprinids to hydropeaking in the presence and absence of deflectors as a mitigation measure. This study emphasized the importance of characterizing the hydrodynamic conditions due to hydropeaking, particularly after including the artificial refuges.
Maria João Costa; Maria Teresa Ferreira; António N. Pinheiro; Isabel Boavida. The potential of lateral refuges for Iberian barbel under simulated hydropeaking conditions. Ecological Engineering 2018, 127, 567 -578.
AMA StyleMaria João Costa, Maria Teresa Ferreira, António N. Pinheiro, Isabel Boavida. The potential of lateral refuges for Iberian barbel under simulated hydropeaking conditions. Ecological Engineering. 2018; 127 ():567-578.
Chicago/Turabian StyleMaria João Costa; Maria Teresa Ferreira; António N. Pinheiro; Isabel Boavida. 2018. "The potential of lateral refuges for Iberian barbel under simulated hydropeaking conditions." Ecological Engineering 127, no. : 567-578.
Adequately designed fishways mitigate the negative effects of barriers in rivers, restoring longitudinal connectivity. To do so, they must present suitable hydraulic conditions, with velocity and turbulence fields adequate for multiple fish species. In the present study, numerical modelling was used to compare the hydrodynamics of two widely used vertical slot fishways (VSF) configurations and three multi slot fishway (MSF) configurations. The MSF configuration needs a lower discharge to operate than the VSF, while keeping similar flow depths, which is vital in regions where water availability is limited, such as most Mediterranean regions. By reducing the discharge, the velocity, turbulent kinetic energy, and Reynolds shear stress values in the studied MSF configurations are much lower than the values for VSF configurations. Thus, besides requiring smaller discharges than similar VSF geometries, the MSF additionally could be less selective for fish species, particularly smaller-sized individuals, and individuals with weaker swimming capacities, and a better option for a multiple-species fishway.
Ana L. Quaresma; Filipe Romão; Paulo Branco; Maria Teresa Ferreira; António N. Pinheiro. Multi slot versus single slot pool-type fishways: A modelling approach to compare hydrodynamics. Ecological Engineering 2018, 122, 197 -206.
AMA StyleAna L. Quaresma, Filipe Romão, Paulo Branco, Maria Teresa Ferreira, António N. Pinheiro. Multi slot versus single slot pool-type fishways: A modelling approach to compare hydrodynamics. Ecological Engineering. 2018; 122 ():197-206.
Chicago/Turabian StyleAna L. Quaresma; Filipe Romão; Paulo Branco; Maria Teresa Ferreira; António N. Pinheiro. 2018. "Multi slot versus single slot pool-type fishways: A modelling approach to compare hydrodynamics." Ecological Engineering 122, no. : 197-206.
The rapid flow fluctuations experienced downstream of hydropeaking facilities can alter the river hydromorphology. Given the dependence of riverine fish on physical habitat, those alterations have the potential to change the physiology and behaviour of fish. We assessed whether artificial velocity refuges mitigated the physiological and behavioural consequences of hydropeaking for the Iberian barbel (Luciobarbus bocagei). Hydropeaking trials were conducted in an indoor flume equipped with deflectors that created low flow velocity areas to serve as refuges. The FLOW‐3D® was used to obtain detailed characterizations of the different velocity fields, which facilitated the interpretation of fish responses. Changes in flow magnitude and duration triggered stress responses, demonstrated by the increased blood glucose levels in the single up‐ramping event for 60 l.s‐1 and in the step up‐ramping event. Fish tended to seek out velocity refuges to avoid higher flow velocities and harsh hydraulic conditions at peak‐flows, and during the longer events. The movement behaviour frequency increased when fish were subjected to the highest peak‐flow (60 l.s‐1), particularly the individual sprints, and the drifts. For the base‐flow (7 l.s‐1) and the lowest peak‐flow (20 l.s‐1) conditions, fish swam freely in the flume, whereas in the harshest hydraulic conditions they showed more difficulty in finding velocity refuges. This research presents a novel approach by combining physiology and behavioural observations with hydraulic modelling to assess the extent to which artificial flow refuges mitigate the consequences of hydropeaking. Our work serves as a model approach for future mitigation studies for fish in hydropeaking rivers.
M.J. Costa; I. Boavida; V. Almeida; S.J. Cooke; A.N. Pinheiro. Do artificial velocity refuges mitigate the physiological and behavioural consequences of hydropeaking on a freshwater Iberian cyprinid? Ecohydrology 2018, 11, e1983 .
AMA StyleM.J. Costa, I. Boavida, V. Almeida, S.J. Cooke, A.N. Pinheiro. Do artificial velocity refuges mitigate the physiological and behavioural consequences of hydropeaking on a freshwater Iberian cyprinid? Ecohydrology. 2018; 11 (7):e1983.
Chicago/Turabian StyleM.J. Costa; I. Boavida; V. Almeida; S.J. Cooke; A.N. Pinheiro. 2018. "Do artificial velocity refuges mitigate the physiological and behavioural consequences of hydropeaking on a freshwater Iberian cyprinid?" Ecohydrology 11, no. 7: e1983.
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 vertical slot fishway during spring (reproductive season) and early-autumn (non-reproductive season). Results revealed that no significant differences were detected on passage performance metrics, except for entry efficiency. However, differences between seasons were noted in the plasma lactate concentration (higher in early-autumn), used as a proxy for muscular fatigue after the fishway navigation. This suggests that, for potamodromous cyprinids, the evaluation of passage performance in fishways does not need to be restricted to the reproductive season and can be extended to early-autumn, when movements associated with shifts in home range may occur. The increased effort during the non-reproductive period suggests that adapting the operational regime of fishways, at biologically meaningful seasons in a year, should be assessed by considering the physiological state of the target species.
Filipe Romão; José M. Santos; Christos Katopodis; António N. Pinheiro; Paulo Branco. How Does Season Affect Passage Performance and Fatigue of Potamodromous Cyprinids? An Experimental Approach in a Vertical Slot Fishway. Water 2018, 10, 395 .
AMA StyleFilipe Romão, José M. Santos, Christos Katopodis, António N. Pinheiro, Paulo Branco. How Does Season Affect Passage Performance and Fatigue of Potamodromous Cyprinids? An Experimental Approach in a Vertical Slot Fishway. Water. 2018; 10 (4):395.
Chicago/Turabian StyleFilipe Romão; José M. Santos; Christos Katopodis; António N. Pinheiro; Paulo Branco. 2018. "How Does Season Affect Passage Performance and Fatigue of Potamodromous Cyprinids? An Experimental Approach in a Vertical Slot Fishway." Water 10, no. 4: 395.
Developing and testing new fishway designs is important to improve these facilities. Discharge-efficient passage systems are required in Mediterranean regions and other areas with dry climates. The present study compares the passage performance of the Iberian barbel, Luciobarbus bocagei (Steindachner, 1864), a potamodromous cyprinid, negotiating two different types of vertical slot fishways (VSF): a standard VSF and a multi-slot VSF (MSF). Results show that differences exist between configurations in the number of fish movements through the first slot. The I. barbel performed a significantly higher number of movements in the MSF. However, no differences were found in the entrance time and entry efficiency. The performance was similar between configurations in terms of successes, suggesting that both fishways could be used to restore longitudinal connectivity. Nevertheless, the MSF is a more discharge-efficient configuration, since it requires 31% less water to operate for the same water depth in the pools. Consequently, the velocity and turbulence have lower magnitudes which generally favour the negotiation by smaller individuals. Since it is a more discharge-efficient and cost-efficient configuration, future studies should focus on the passage performance of smaller species to determine if MSF is a useful solution for the whole fish community.
Filipe Romão; Paulo Branco; Ana L. Quaresma; Susana D. Amaral; António N. Pinheiro. Effectiveness of a multi-slot vertical slot fishway versus a standard vertical slot fishway for potamodromous cyprinids. Hydrobiologia 2018, 816, 153 -163.
AMA StyleFilipe Romão, Paulo Branco, Ana L. Quaresma, Susana D. Amaral, António N. Pinheiro. Effectiveness of a multi-slot vertical slot fishway versus a standard vertical slot fishway for potamodromous cyprinids. Hydrobiologia. 2018; 816 (1):153-163.
Chicago/Turabian StyleFilipe Romão; Paulo Branco; Ana L. Quaresma; Susana D. Amaral; António N. Pinheiro. 2018. "Effectiveness of a multi-slot vertical slot fishway versus a standard vertical slot fishway for potamodromous cyprinids." Hydrobiologia 816, no. 1: 153-163.
Contrary 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 and downstream passage of the Iberian barbel (Luciobarbus bocagei), when facing a small broad-crested experimental weir with varying widths of the weir crest (W) and discharges (Q). Nine configurations (W×Q) were tested. Fish were released downstream of the weir and upstream and downstream passages were monitored. Hydrodynamics were characterised with a flow probe and a three-dimensional acoustic Doppler velocimeter (ADV). Fish negotiated all configurations, registering a total of 273 upstream passages and 192 downstream passages. The number of fish that approached, attempted and successfully ascended and descended the weir varied among configurations, emphasising the complex influence of factors on passage performance. Discharge was preponderant on both passages, proving that fish movements may be hampered by increasing discharges. However, the width of the weir crest only significantly influenced downstream passages, showing that strong velocity gradients experienced on narrower widths of the weir crest may discourage downstream movements. Results from the present study are expected to be useful to identify potential migration obstacles and may be applicable to other cyprinid species.
Susana D. Amaral; Paulo Branco; Filipe Romão; Teresa Viseu; Maria T. Ferreira; António N. Pinheiro; José M. Santos. The effect of weir crest width and discharge on passage performance of a potamodromous cyprinid. Marine and Freshwater Research 2018, 69, 1795 .
AMA StyleSusana D. Amaral, Paulo Branco, Filipe Romão, Teresa Viseu, Maria T. Ferreira, António N. Pinheiro, José M. Santos. The effect of weir crest width and discharge on passage performance of a potamodromous cyprinid. Marine and Freshwater Research. 2018; 69 (12):1795.
Chicago/Turabian StyleSusana D. Amaral; Paulo Branco; Filipe Romão; Teresa Viseu; Maria T. Ferreira; António N. Pinheiro; José M. Santos. 2018. "The effect of weir crest width and discharge on passage performance of a potamodromous cyprinid." Marine and Freshwater Research 69, no. 12: 1795.