Estimating Differences in Growth and Metabolism in Two Spatially Segregated Groups of Columbia River White Sturgeon Using a Field-Based Bioenergetics Model

Abstract

Recovery of white sturgeon in the Upper Columbia River continues to be limited by our understanding of the species' biology, including factors which influence growth, habitat selection and their interaction. Sampling challenges in large rivers coupled with limitations to invasive research on endangered species also create specific challenges to the detailed understanding of growth and metabolism. A new bioenergetics modelling approach which estimates basic parameters from field data, specifically length-increment and length-at-age data was therefore applied in order to provide novel insights into white sturgeon growth and metabolism. A large existing capture database was used to examine two groups of white sturgeon which preferentially occupy habitats in the transboundary section of the Upper Columbia River downstream of Keenleyside Dam (HLK group) or further downstream near Waneta (WAN group). Successful application of the model showed differences in both growth and metabolism. Mean annual food intake appears similar for the two groups; however growth was more rapid for the HLK group. This resulted from a higher metabolic rate for the WAN group coupled with contrasts in seasonal food intake. Growth differences between groups lead to slower growth and later maturity for the WAN group. In aggregate, results suggest that the WAN group may be food limited and ultimately may have lower lifetime fecundity due its apparently later maturity and the possibility that lower energy intake might increase the interspawning interval. Finally, the functional structure of the model leads to concerns that both groups are approaching the thermal maxima for consumption, which may lead to reductions in body growth if increases in water temperature continue. Overall, application of this bioenergetics model identified new avenues for study which should assist conservation efforts in this species.

Run-of-River hydropower and salmonids: potential effects and perspective on future research

“…Although evidence in the peer-reviewed literature specific to RoR hydropower is more limited (n = 31), it suggests that water quality, habitat quantity, and geomorphology can also be affected by RoR hydropower operations (Kubečka et al 1997;Baker et al 2011;Nislow and Armstrong 2012;Bilotta et al 2016). Changes to NFR following diversion of flow can affect water quality mainly through changes to temperature regimes, pH, and dissolved oxygen (Valero 2012). Changes to NFR also alter channel hydraulic, sediment transport, and geomorphology downstream of low-head dams.…”

“…The factors influencing stream temperatures are a complex mix of external drivers and internal stream dynamics (Poole and Berman 2001), and reducing flow in a river reach has the potential to lead to warmer and more variable stream temperature regimes. Studies conducted in bypassed reaches of rivers with RoR hydropower dams reported slight increases in water temperature in Spain (Valero 2012 Zhou et al 2008Zhou et al , 2009Wu et al 2010aWu et al , 2012 but no significant differences between bypassed and upstream reaches in Portugal (Jesus et al 2004). Low flows during dry and hot seasons, however, triggered markedly warmer temperatures in bypassed reaches (ϳ1-3°C) compared to upstream reaches in Costa Rica (Anderson et al 2006) and the Czech Republic (Kubečka et al 1997) and compared to water temperature immediately downstream in China (ϳ5-6°C) (Wu et al 2010b).…”

“…Despite such empirical evidence of changes to water quality parameters in bypassed reaches of RoR hydropower, neither the factors influencing these changes nor the consequences for fish have been clearly identified in the studies reviewed. For example, of all the studies reporting on changes to water temperatures, pH, or conductivity, only three (Kubečka et al 1997;Anderson et al 2006;Valero 2012), reported on the size of the rivers (small to medium), the length of bypassed reaches (0.05-4 km), or the amount of flow diverted (59%-100%) ( Table 1). Details about designs and river characteristics are equally sparse in the studies reporting changes to Fig.…”

“…Below the thermal optimum, increases in growth with temperature are only possible when food or other resources are not limiting (Bryant 2009;Taylor and Walters 2010). If food consumption decreases while water temperatures increase, fish experience higher metabolic costs that may lead to slower growth and later maturation (e.g., Van Poorten and McAdam 2010) or declines in total biomass (Beakes et al 2014). The most important characteristic of RoR hydropower for temperature regimes in bypassed reaches may be the seasonality of flow diversion and its consequence for water temperature and, ultimately, salmonids.…”

Population Dynamics and Evaluation of Management Scenarios for White Sturgeon in the Sacramento–San Joaquin River Basin

“…Beamesderfer et al. () and Van Poorten and McAdam () reported that alterations in hydrology due to dam construction (e.g., limited food resources and habitat availability) may explain differences in White Sturgeon growth. In northern systems like the Kootenai River, reduced growth of White Sturgeon is likely due to limited food availability and long distances from estuarine and marine resources (Ireland et al.…”