RT info:eu-repo/semantics/article
T1 Debating the rules: an experimental approach to assess cyprinid passage performance thresholds in vertical slot fishways
A1 Romão, Filipe
A1 Quaresma, Ana L.
A1 Simão, Joana
A1 Bravo Córdoba, Francisco Javier
A1 Viseu, Teresa
A1 Santos, José María
A1 Sanz Ronda, Francisco Javier
A1 Pinheiro, António
K1 Fishways
K1 Peces - Hábitat
K1 Carp
K1 Carpas - Cría y explotación
K1 Freshwater fishes
K1 Peces de agua dulce
K1 Fish culture
K1 Turbulence
K1 Fish monitoring devices
K1 Computational fluid dynamics
K1 Dinámica de fluidos computacional
K1 Fluid dynamics
K1 Dinámica de fluidos
K1 Hydraulics
K1 Hidráulica fluvial
K1 River engineering
K1 3105.02 Piscicultura
K1 3305.15 Ingeniería Hidráulica
AB Throughout the world, emerging barriers in river systems block longitudinal connectivity for migrating fish, causing significant impacts by precluding them from carrying out vital life cycle activities. Fishways are still the main mitigation solution implemented, where barrier removal is not feasible. Within the multiple technical fish passage devices, the vertical slot fishway (VSF) is considered the most reliable. Early design guidelines, established for cyprinids, indicate that the volumetric dissipation power (Pv) in the pools should be Pv < 150 Wm−3, while most frequent slope values range from 10 to 12%. In this study, an experimental approach was conducted to question and debate the validity of these recommendations. For this, the Iberian barbel (Luciobarbus bocagei, Steindachner, 1864) passage performance was assessed in a full-scale fishway that exceeded Pv design guidelines, under different configurations. These varied in discharge (Q) and mean pool water depth (hm): VSF1 (Q = 81 Ls−1; hm = 0.55 m); VSF2 (Q = 110 Ls−1; hm = 0.80 m); and the same design was equipped with a deep notch: DN1 (Q = 71 Ls−1; hm = 0.55 m); DN2 (Q = 99 Ls−1; hm = 0.80 m). The slope was set to 15.2% while the head drop per pool was Δh = 0.28 m, which generated a Pv that ranged from 222 in VSF1 to 187 Wm−3 in DN2. Passage behaviour was assessed using PIT telemetry and time-to-event analysis to evaluate the barbel upstream passage using standardized metrics: (i) motivation (ii) ascend success, and (iii) transit time. The hydrodynamic scenarios experienced by fish were characterized through a numerical model using computational fluid dynamics (CFD). The results, contrary to what was expected, showed a higher performance in VSF1 confirmed by the ascent analysis and transit time. Although no differences were found in fish motivation, the results indicate that larger fish displayed lower times to perform the first passage attempt. The CFD results show that, although maximum velocities and turbulence (turbulent kinetic energy (TKE) and Reynolds shear stress (RSS)) do not change significantly between configurations, their distribution in the pools is quite different. Regarding TKE, larger volumes with magnitudes higher than 0.05 m2s−2 were notorious in both DN1 and DN2 configurations compared to VSF1, influencing passage efficiency which is in line with the ascent and transit time metrics results. Overall, the present research undeniably debates the literature design guidelines and reinforces the need to jointly assess species-specific fish passage criteria and fishway hydrodynamics, whereas precaution should be taken when using very general recommendations.
PB MDPI
SN 2073-4441
YR 2024
FD 2024
LK https://uvadoc.uva.es/handle/10324/69798
UL https://uvadoc.uva.es/handle/10324/69798
LA eng
NO Water, 2024, Vol. 16, Nº. 3, 439
NO Producción Científica
DS UVaDOC
RD 24-nov-2024