A traits-based approach for prioritizing species for monitoring and surrogacy selection

Abstract

The bar for justifying the use of vertebrate animals for study is being increasingly raised, thus requiring increased rigor for species selection and study design. Although we have power analyses to provide quantitative backing for the numbers of organisms used, quantitative backing for selection of study species is not frequently employed. This can be especially important when measuring the impacts of ecosystem alteration, when study species must be chosen that are both sensitive to the alteration and of sufficient abundance for study. Just as important is providing justification for designation of surrogate species for study, especially when the species of interest is rare or of conservation concern and selection of an appropriate surrogate can have legal implications. In this study, we use a combination of GIS, a fish traits database and multivariate statistical analyses to quantitatively prioritize species for study and to determine potential study surrogate species. We provide two case studies to illustrate our quantitative, traits-based approach for designating study species and surrogate species. In the first case study, we select broadly representative fish species to understand the effects of turbine passage on adult fishes based on traits that suggest sensitivity to turbine passage. In our second case study, we present a framework for selecting a surrogate species for an endangered species. We suggest that our traits-based framework can provide quantitative backing and added justification to selection of study species while expanding the inference space of study results.

Turbine entrainment and passage of potadromous fish through hydropower dams: Developing conceptual frameworks and metrics for moving beyond turbine passage mortality

“…Indeed, it seems likely that exploratory, mobile types, with large home ranges or dispersive tendencies, likely also carry greater risk of forebay entry (Harrison et al., ). Forebay use may also be influenced by ecological traits, such as littoral, benthic, pelagic habitat specializations, with risk of use dependent on the distribution of available habitats within and outside the forebay (Pracheil, McManamay, et al., ). Thus, individual, phenotypic, inter‐specific and life‐history variation in these behavioural and ecological traits, along with diel, seasonal and climatic variation, all have the potential to influence two‐dimensional (2D) location in the reservoir (Gido & Matthews, ) and thus potentially influence forebay entry probability.…”

“…It is generally assumed that higher velocities promote avoidance responses in fish species that are not actively migrating (Coutant & Whitney, ). Consequently, traits related to swimming ability, and traits such as body size which determine swimming speed, are thought to be important for predictions of involuntary FEZentry p (Pracheil, McManamay, et al., ). Thus, species with lower swimming speeds and endurance are thought to have increased vulnerability (Pracheil, McManamay, et al., ).…”

“…In addition, the areas of elevated velocity surrounding FEZ, which while not exceeding swimming capabilities, may also play a role in the involuntary entrainment process (Johnson et al, 2004). It is generally assumed that higher velocities promote avoidance responses in fish species that are not actively migrating (Coutant & Whitney, 2000 (Pracheil, McManamay, et al, 2016). Thus, species with lower swimming speeds and endurance are thought to have increased vulnerability (Pracheil, McManamay, et al, 2016).…”

“…Turbine passage mortality, that is, the proportion of individuals that do not survive the passage past turbines, can lower or eliminate downstream movement, and is an important metric for understanding dam impacts (Colotelo et al., ). Indeed, turbine passage mortality and the traits which predict mortality have been extensively reviewed (Cada, ; Čada & Schweizer, ; Pracheil, McManamay, Bevelhimer, DeRolph, & Čada, ). This focus on turbine passage mortality may have occurred due to regulatory interest in high‐value anadromous fish and an engineering focus on turbine design to reduce injury and mortality.…”

“…Turbine passage mortality, that is, the proportion of individuals that do not survive the passage past turbines, can lower or eliminate downstream movement, and is an important metric for understanding dam impacts (Colotelo et al, 2017). Indeed, turbine passage mortality and the traits which predict mortality have been extensively reviewed (Cada, 1990;Čada & Schweizer, 2012;Pracheil, McManamay, Bevelhimer, DeRolph, & Čada, 2016 and enable the quantification of the impacts of these processes on upstream and downstream fish populations. To illustrate the applicability of these two frameworks, we consider two case-studies.…”