Upstream Swimming Performance of Adult White Sturgeon: Effects of Partial Baffles and a Ramp

Abstract

The upstream passage of sturgeon (family Acipenseridae) past barriers such as dams has become a concern of fisheries managers in California. Knowledge about the swimming abilities of adult sturgeon species, particularly with relationship to fish ladders, is limited. Wild adult white sturgeon Acipenser transmontanus (n = 25; total length, 135–198 cm) captured in the San Francisco Estuary and Yolo Bypass toe drain were swum in a variable‐speed aluminum flume (24.4 m long × 2.1 m wide × 1.4 m deep) to evaluate swimming behavior around simulated fish‐ladder‐type partial baffles. Four baffle types (one horizontal ramp and three different vertical slot designs) set in two configurations were tested at three velocity regimes (velocity range around baffles, 0.28–2.52 m/s). In general, faster velocities (0.76–1.07 m/s) cued fish to swim upstream sooner (≤100 s). Among the baffle types, the percentage of successful passage was variable, and no statistically significant pattern was detected. The tail‐beat frequency of fish significantly increased in the high‐velocity (to 2.52 m/s) regions of the flume adjacent to the energy‐dissipating baffles, where sturgeon were able to pass by swimming in bursts, followed by a resting and recovery period in slower water. Successful white sturgeon passage structures should incorporate rapid‐velocity (e.g., 0.84–2.52‐m/s) sections between somewhat slower (e.g., 0.51–0.68‐m/s) sections for rest and recovery.

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

“…Few comparative studies have been completed on passage success in technical structures, particularly for small-bodied fishes (Schwalme et al 1985;Katopodis et al 1991;Katopodis 1992;Webber et al 2007). The dual-vertical-slot fishway facilitated moderate passage success of Rio Grande silvery minnow at the relatively low 78 cm/s water velocity.…”

“…Moderate passage success at the lower velocity was probably due to the absence of large eddies and high-velocity turbulent flows that were present in higher velocity Denil and single-vertical-slot fishways (Bestgen et al 2003), and the dual-verticalslot fishway at the high velocity, where passage success was negligible. High turbulence has been demonstrated to reduce passage success even in relatively large-bodied white sturgeon Acipenser transmontanus (Webber et al 2007), so the negative effect of turbulence on small-bodied Rio Grande silvery minnow was not surprising.…”

Swimming activity and energetic costs of adult lake sturgeon during fishway passage

“…It is worth noting that the methods to determine distance travelled likely result in underestimates as they represent the minimum distance between two locations, and thus COT estimates may be artificially inflated, although path selection and the subsequent distance travelled by individuals through basins remains unknown. Previous studies have identified that the presence of turning basins increases passage failure and delays passage (Bunt et al, 2000;Silva et al, 2015;White et al, 2011), including for this species (Thiem et al, 2011). Webber et al (2007 recommended the inclusion of lower-velocity areas between higher-velocity passage areas for white sturgeon.…”

“…In terms of a time optimisation strategy, the absence of turning basins would be beneficial as the addition of large low-velocity regions appears to delay passage, presumably because of the absence of high velocity cues (Marriner et al, 2014). Indeed, the low-velocity range (0.51-0.68 m s −1 ) recommended by Webber et al (2007) exceeded that determined to be the threshold (0.45 m s −1 ) attraction velocity to initiate upstream swimming in white sturgeon.…”

“…Sturgeon have a relatively limited capacity for high-speed swimming, resulting from high profile drag (Webb, 1986) and poor aerobic capacity (Peake et al, 1997). Considerable attention has been devoted to facilitating upstream passage of sturgeon at fishways via laboratory-derived swimming models (Peake et al, 1997), observations of captive sturgeon ascending experimental fishways (Cheong et al, 2006;Cocherell et al, 2011;Kynard et al, 2011;Webber et al, 2007) and field observations of passage behaviour including quantification of fishway efficiency (Parsley et al, 2007;Thiem et al, 2011). Given their poor aerobic swimming ability, it is possible that fishways impose a particularly high energetic cost to migrating sturgeon, and that energetic expenditure may explain differences in passage success.…”