Passage efficiency of offset and straight orifices for upstream movements of Iberian barbel in a pool‐type fishway

Abstract

Although coarse fish species are frequently the predominant taxa found in rivers, they are often neglected in fish passage studies. Detailed knowledge on the impact of hydraulics on the movements and swimming performance of these species is very limited. In this study, offset and straight orifices in a pool‐type fishway prototype were tested in terms of their suitability for Iberian barbel's (Luciobarbus bocagei) upstream movements. The effects of water velocity and turbulence descriptors on fish swimming performance were herein also analysed. Overall, the offset configuration was found to have a significantly higher rate of fish passage success (68%) than the straight arrangement (28%). The time taken to successfully negotiate the fishway was also significantly lower when it featured an offset configuration, particularly for small adults. Of all analysed hydraulic parameters, Reynolds shear stress (RSS) seemed to be the one that most strongly influenced the movements of Iberian barbel within the fishway. The findings provide evidence that the barbel's swimming performance and capacity to successfully migrate upstream through a fishway strongly depend on the arrangement of orifices and turbulence, in particular RSS, within a fish pass. More detailed research focusing on other ‘weak’ swimmers is recommended to improve future designs of pool‐type fishways suitable for other coarse species. Copyright © 2010 John Wiley & Sons, Ltd.

Swimming performance and ecomorphology of the Iberian barbel Luciobarbus bocagei (Steindachner, 1864) on permanent and temporary rivers

“…With the increase in flow and in more turbulent and well-defined vortical structures, which happens more intensely and frequently in permanent and high flowing environments than in temporary low flow rivers, pectoral fin activity is induced to aid fish maintaining a benthic station holding in turbulent areas (Arnold & Weihs 1978;Webb 1989). In studies evaluating the performance of L. bocagei in an experimental fishway, fish showed exactly this behaviour, often using pectoral fins to maintain position and rest, especially before moving upstream through the passage orifices (e.g., Silva et al 2011Silva et al , 2012Alexandre et al 2013). Longer pectoral fins can be useful to improve this behaviour, resulting in longer endurance time and higher persistence probability (McLaughlin & Noakes 1998), thus explaining the different fin sizes observed in the two studied barbel populations.…”

“…Barbels from the permanent river exhibited longer pectoral and higher dorsal fins when compared with the smaller pectoral and lengthier but shorter dorsal fins found in the population inhabiting the temporary system. In studies evaluating the performance of L. bocagei in an experimental fishway, fish showed exactly this behaviour, often using pectoral fins to maintain position and rest, especially before moving upstream through the passage orifices (e.g., Silva et al 2011Silva et al , 2012Alexandre et al 2013). With the increase in flow and in more turbulent and well-defined vortical structures, which happens more intensely and frequently in permanent and high flowing environments than in temporary low flow rivers, pectoral fin activity is induced to aid fish maintaining a benthic station holding in turbulent areas (Arnold & Weihs 1978;Webb 1989).…”

“…During spring, this species migrates upstream to spawn in gravel or sandy riverbed areas with fast water flow, thus being considered a reophilic species (Rodr õguez-Ruiz & Granado-Lorencio 1992). This species has received some attention in recent years through studies on its aerobic swimming capacity (Mateus et al 2008) and behaviour (e.g., Silva et al 2011Silva et al , 2012. However, the majority of these studies are focused on fish from a single specific area.…”

Behavior of western blacknose dace in a turbulence modified flow field

“…This is because fish often encounter insurmountable jumping barriers such as dams (Zheng et al, 2009, Price et al, 2010, while other structures present hydraulic and behavioral deterrents that are encountered once the fish enter the structure, such as excessive velocities or highly turbulent conditions (Bunt et al, 1999;Haro et al, 2004;Silva et al, 2010). These deterrents can present significant navigational impediments to fish, reducing crossing movement rates in some culverts by as much as an order of magnitude (Norman et al, 2009).…”

Pool-Type Fishway Design for a Potamodromous Cyprinid in the Iberian Peninsula: The Iberian Barbel—Synthesis and Future Directions

“…In the past years, studies focusing on barbel have grown due to the aforementioned awareness of the need for allowing permanent free movement of the complete fish community in passage facilities [34]. Studies on the swimming performance conducted in respirometers or swim tunnels (e.g., [35]), ecomorphology [32,36,37], and fish biomechanical and physiological response to hydraulics in fishway physical models (e.g., [15,34,[38][39][40][41]) have been conducted. Although these studies have increased our knowledge of the behavior and hydraulic requirements of the barbel when ascending a fishway, practical guidance into how to develop fishway designs targeting this species is still lacking.…”