Swimming Performance and Fishway Model Passage Success of Rio Grande Silvery Minnow

Abstract

We used a swim chamber, flume, and large-scale fishway models to assess the swimming performance, behavior, and passage success of endangered Rio Grande silvery minnow Hybognathus amarus. Field-captured silvery minnow (53-88 mm total length) swam 114-118 cm/s (i.e., up to 20.9 body lengths/s) in a swim chamber in water temperatures of 15, 19, and 238C. The relationship between time to fatigue and water velocity showed that endurance declined sharply at velocities above 60 cm/s, a threshold that is consistent with critical swimming speed estimates and may represent a transition from aerobic to anaerobic metabolism. Water temperature and fish length were positively correlated with swimming performance. At water velocities of 60 cm/s and less, silvery minnow routinely swam the equivalent of 50 km (125 km maximum) in a swim chamber in less than 72 h. The proportions of silvery minnow that successfully ascended a flume over sand, gravel, or cobble substrate declined as water velocity increased to 53 cm/s. Passage times increased at higher water velocities and at a faster rate over sand substrate because fish were stationary for longer periods over the lower-velocity boundary layers created by gravel and cobble at all velocities. Dualvertical-slot fishway passage was 52% in a less turbulent flow of 78 cm/s; passage was 8% at a faster, more turbulent flow of 87 cm/s. Conversely, 75% of silvery minnow ascended a rock channel fishway with a holding pool present and a 1% hydraulic gradient in low (58-cm/s) and high (83-cm/s) mean flow velocities. Differences in willingness to swim, longer test duration, and the mosaic of water velocities created by the bed roughness elements may explain the higher silvery minnow passage success in the rock channel. Predictive swimming fatigue relationships, together with fish length and water temperature, may guide decisions regarding fishway lengths and velocities so as to permit passage of Rio Grande silvery minnow.

Movement patterns and dispersal potential of Pecos bluntnose shiner (Notropis simus pecosensis) revealed using otolith microchemistry

“…In comparison, Pecos bluntnose shiner exhibited higher swimming capacity (U crit, 52.5 cm·s −1 ) at 90 days posthatch. Bestgen et al (2010) reported upper critical swimming speeds of 51.5 cm·s −1 (53-75 mm TL) for Rio Grande silvery minnow, noting that swimming ability increased with fish size. Although Pecos bluntnose shiner demonstrated strong swimming ability and upriver movement, downriver dispersal of propagules has potentially tripled to distances up to 142 km from predam-prechannelization of the river (Dudley and Platania 2007).…”

Behavior of western blacknose dace in a turbulence modified flow field

“…These problems are commonly associated with private and public infrastructure such as dams, culverts, water diversions, and grade control structures (Castro-Santos et al, 2009;Dermisis and Papanicolaou, 2009;Norman et al, 2009;Castro-Santos and Haro, 2010;Martens and Connolly, 2010;Hall et al, 2011). Often this infrastructure disrupts or prohibits natural fish movement patterns, fragments fish habitat, degrades populations, and influences overall biotic structure of aquatic systems (Pratt et al, 2009;Bestgen et al, 2010;Bouska and Paukert, 2010;Castro-Santos and Haro, 2010;Hall et al, 2011). The restricted ability to access needed habitats has even led to the demise of some fish populations (Zheng et al, 2009;Castro-Santos and Haro, 2010;Hall et al, 2011).…”

Evaluation of swimming performance for fish passage of longnose dace Rhinichthys cataractae using an experimental flume

“…Laboratory studies allow precise control of experimental conditions and examination of the effects of variables such as fish length and morphology, temperature and water velocity on swimming performance. The majority of laboratory studies have been conducted in small enclosed swim chambers and have examined the time to fatigue at a set velocity (Billman & Pyron, ; Bestgen et al , ; Ficke et al , ) or the maximum aerobic swimming speed using an incremental velocity test ( U crit test) in which the velocity is incrementally increased and time to failure at the maximum velocity is measured (Nelson et al , ; Holthe et al , ; Leavy & Bonner, ). Recent studies, however, have suggested that space constraints in swim chambers may restrict volitional behaviour and the ability of fishes to utilize different muscle groups, thereby resulting in an underestimation of swimming abilities (Tudorache et al ., , ; Castro‐Santos et al , ; Sanz‐Ronda et al , ).…”