Effects of Water Velocity and Trash Rack Architecture on Juvenile Fish Passage and Interactions: A Simulation

2007 ◽  
Vol 136 (5) ◽  
pp. 1177-1186 ◽  
Author(s):  
Emily Y. Floyd ◽  
Roger Churchwell ◽  
Joseph J. Cech
2018 ◽  
Author(s):  
Jabin R. Watson ◽  
Harriet R. Goodrich ◽  
Rebecca L. Cramp ◽  
Matthew A. Gordos ◽  
Craig E. Franklin

SignificanceHabitat fragmentation is a significant contributor to the worldwide decline of freshwater ecosystem health, the most pervasive cause of which is culverts. Culverts act as a barrier to fish movement, impacting feeding, predator avoidance, spawning, and community structures. Here we show that a common remediation strategy that involves baffles, is detrimental to the successful passage of small bodied and juvenile fish at high velocities. To remedy this widespread problem, we present a novel remediation design that benefits a range of small-bodied species and juvenile fish at the same high velocities, regardless of morphology or ecological niche. The application of this remediation design may be expanded to any smooth surfaced anthropogenic structure, to improve fish passage and restore ecosystem functionality.AbstractCulverts are a major cause of habitat fragmentation in freshwater ecosystems, are a barrier to fish movement, and are regarded as a significant contributor in the decline of freshwater fish populations globally. To try to address this, various culvert remediation designs have been implemented, including the installation of vertical baffles and the provision of naturalistic (rock) substrates. While remediation strategies generally aim to reduce the velocity of water flowing through the structure, there is often resistance to their use because the resultant reduction in culvert discharge can negatively impact upstream flooding while also resulting in debris clogging and increased culvert maintenance costs. In addition, baffles markedly increase water turbulence that may be detrimental to passage by some fish species or size classes. Here we present some novel remediation designs that exploit the reduced water velocity in boundary layers along the culvert wall to enhance fish passage without significantly compromising discharge capacity. These longitudinal designs produce an expanded reduced velocity zone along the culvert margins that generate minimal turbulence. We show that these novel designs are significantly advantageous to the swimming endurance and traversability for six small-bodied Australian fish species. We also provide data on how and why some culvert baffle designs may impede small-bodied fish passage. This data scales with increasing water velocity, encompassing inter-specific differences in swimming capacity. These results have broad implications for fish community structure and the requirement of juvenile cohort of large-bodied commercially important species where baffles have been implemented to facilitate fish passage.


2006 ◽  
Vol 8 (4) ◽  
pp. 271-295 ◽  
Author(s):  
L. J. Weber ◽  
R. A. Goodwin ◽  
S. Li ◽  
J. M. Nestler ◽  
J. J. Anderson

The Eulerian–Lagrangian–Agent method (ELAM) couples three modelling approaches into a single, integrated simulation environment: (i) Eulerian descriptions, (ii) Lagrangian formulations, and (iii) agent reference frameworks. ELAMS are particularly effective at decoding and simulating the motion dynamics of individual aquatic organisms, using the output of high fidelity computational fluid dynamics (CFD) models to represent complex flow fields. Here we describe the application of an ELAM to design a juvenile fish passage facility at Wanapum Dam on the Columbia River in the United States. This application is composed of three parts: (1) an agent-based model, that simulates the movement decisions made by individual fish, (2) an Eulerian CFD model that solves the 3D Reynolds-averaged Navier–Stokes (RANS) equations with a standard k–ɛ turbulence model with wall functions using a multi-block structured mesh, and (3) a Lagrangian particle-tracker used to interpolate information from the Eulerian mesh to point locations needed by the agent model and to track the trajectory of each virtual fish in three dimensions. We discuss aspects of the computational mesh topology and other CFD modeling topics important to this and future applications of the ELAM model for juvenille salmon, the Numerical Fish Surrogate. The good match between forecasted (virtual) and measured (observed) fish passage proportions demonstrates the value-added benefit of using agent-based models (i.e. the Numerical Fish Surrogate model) as part of common engineering practice for fish passage design and, more fundamentally, to simulate complex ecological processes.


Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2131 ◽  
Author(s):  
Mu ◽  
Cao ◽  
Gong ◽  
Baiyin ◽  
Li

In fishway design, the combination of fish swimming behaviors and suitable fishway hydraulic characteristics increases the fish passage efficiency. In this study, the most representative grass carp among the “four major Chinese carps” was selected. Under conditions similar to the time period for feeding migration, juvenile grass carps were targeted to study the swimming characteristic indicators (i.e., critical and burst swimming speeds) and swimming behaviors that were closely associated with fishway hydraulic design using the incremental water velocity method in a homemade test water tank. (1) The study results reveal that both the absolute critical (Ucrit) and burst (Uburst) swimming speeds increased linearly with increasing body length and both the relative critical (U’crit) and burst (U′burst) swimming speeds decreased linearly with increasing body length. There existed a quantitative relationship between Uburst and Ucrit, which could facilitate the fishway hydraulic design. (2) This study analyzed the effects of water velocity changes on fish swimming behaviors and proposed a classification method for four fish swimming behaviors—swimming freely, staying, dashing at a long distance, and dashing at a short distance—of tested fish during the process of adapting to water velocity changes interspersed with one another. The entire swimming process under the incremental water velocity was divided into four stages. (3) This study suggests that the maximum water velocity of the mainstream in a fishway using grass carp as the major passage fish should not exceed 52–60% Uburst at stage 1. For the high-water velocity areas of a fishway, such as vertical slots and orifices, the optimal water velocity should not be higher than 76–79% Uburst at stage 2 and should absolutely not exceed 90–96% Uburst at stage 3.


2011 ◽  
Vol 62 (1) ◽  
pp. 38 ◽  
Author(s):  
Katharina Doehring ◽  
Roger G. Young ◽  
Angus R. McIntosh

Alteration of urban streams by culverts is common throughout the world and is known to impede freshwater fish movement. The main objectives were therefore to investigate how different culvert characteristics (e.g. height, length, angle, perched v. non-perched) and habitat variables (e.g. water velocity, riverbed gradient) affect the passage success of juvenile inanga (Galaxias maculatus), a weak-swimming migratory fish. We determined whether passage of juvenile G. maculatus could be improved by installing a ramp at thirteen replicate in situ culverts in Nelson City, New Zealand. As expected, none of the 400 fish tested were able to pass undercut (i.e. perched) culverts before ramp installation (0% passage), compared with the 250 fish (65% passage) that were able to pass non-perched culverts. Significantly more fish (44% passage) reached perched culvert outlets when aided by the ramp. Passage success with the ramp depended on its length and angle, with fewer fish passing longer or steeper ramps. To provide upstream passage for weak-swimming species such as juvenile (fork length < 60 mm) G. maculatus, ramp length and angle should not exceed three metres and 20 degrees, respectively. With passage requirements known and mitigation processes in place, urban fish populations might be able to be sustained.


1992 ◽  
Vol 43 (4) ◽  
pp. 823 ◽  
Author(s):  
M Mallen-Cooper

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.


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