Concurrent Sessions B: Fish Physiology and Fishway Passage Success - Comparative Physiology and Relative Swimming Performance of Three Redhorse (Moxostoma Spp.) Species: Associations with Fishways

Fishways have been constructed to maintain longitudinal connectivity for fish in fluvial systems impacted by barriers but there are relatively few studies of their biological effectiveness. Trend analysis of the CanFishPass fishway database showed that only 9% of Canadian fishways have been studied using methods that enable proper evaluation of biological effectiveness. A biological evaluation of the Vianney-Legendre fishway in Quebec for the passage of three redhorse species (Moxostoma anisurum, M. carinatum, M. macrolepidotum; silver, river and shorthead redhorse respectively) showed attraction efficiencies of 51%, 12%, 50%, respectively, and passage efficiencies of 88%, 50% and 69% respectively. For all species, failures in the fishway were likely to occur beforethe second turning basin in the fishway (84% of failures). Shorthead redhorse had higher maximum metabolic rates and were faster swimmers than silver and river redhorse. River redhorse recovered their lactate and glucose concentrations more quickly than silver and shorthead redhorse, and river redhorse were second in terms of metabolic recovery and swim speed. Fish sampled from the top of the fishway had nearly identical lactate, glucose and pH values compared to control fish. Additional research is required to understand how organismal performance, environmental conditions, and other factors interact with fishway designs to dictate which fish are successful and to inform research of future fishways. Our research suggests that there may be an opportunity for a rapid assessment approach where manual chasing and sampling of fish from the top of the fishway are used to determine which species (or sizes of fish) are exceeding their physiological capacity during passage

What are the impacts of flow regime changes on fish productivity in temperate regions? A systematic map protocol

Background: Ecosystem changes from altered flows can have multiple impacts on fish, including changes to physical habitat, habitat access, food supplies, behaviour, community composition, energy expenditure, and population dynamics. There is growing evidence of the potential negative consequences of altered flow regimes on fluvial ecosystems and the fisheries they support. As such, the scientific and policy communities have acknowledged the need for maintaining or restoring natural flow variability in order to sustain ecological health of fluvial ecosystems. However, for resource managers, making decisions on the potential effects of flow alterations on fish productivity has been problematic because there are still uncertainties regarding flow-fish productivity relationships. Therefore, to ensure the maintenance of healthy and productive aquatic ecosystems and the sustainability of riverine fisheries, a better understanding of the impacts of flow alteration on fish productivity is needed. Due to the wide scope of this review, and the diversity of fish productivity outcomes used to evaluate flow alteration impacts, the set of studies will be quite heterogeneous. Therefore, prior to undertaking a comprehensive and quantitative synthesis, we propose to begin with a systematic map to provide an overview of the available evidence on the impacts of flow regime changes on fish productivity. We will also use this systematic map to identify subtopics that are sufficiently covered by existing studies to allow full systematic reviewing. Methods: This systematic map will compile evidence on the impacts of flow regime changes on fish productivity. All studies that evaluate the effects of flow regime change on direct outcomes of fish productivity, will be included in the review. We will use a broad definition of fish productivity to include any measurement related to: biomass, abundance, density, yield, diversity, growth, survival, individual performance, migration, reproduction, recruitment, or surrogate thereof. Relevant causes of a change in/modification to flow regime can include: (1) anthropogenic causes: dams, reservoirs (impoundments), hydroelectric facilities, locks, levees, water withdrawal (abstraction), water diversion, land-use changes, and road culverts; or (2) natural causes: climate change (possible indirect anthropogenic cause as well), floods, droughts, seasonal changes. Any freshwater or estuarine fish species or species groups in temperate regions will be considered. The review will include a wide range of sources including primary and grey literature and use public databases, search engines and specialist websites. A searchable database containing extracted meta-data from relevant included studies will be developed and provided as a supplementary file to the map report. The final narrative will describe the quantity and key characteristics of the available evidence, identify knowledge gaps for future research and identify subtopics that are sufficiently covered by existing studies to allow full systematic reviewing

The effectiveness of spawning habitat creation or enhancement for substrate spawning temperate fish: a systematic review protocol

Background: Habitat is the foundation for healthy and productive fisheries. For substrate spawning fish, lack of appropriate spawning substrate is inherently limiting and a lack of access to suitable spawning habitat will lead to population collapse. When specific properties of a habitat (e.g., temperature, depth, vegetation composition) are matched to the species’ ecological niche, a spawning habitat can be created or enhanced as a means of mitigating or offsetting the harmful effects of human development. Given the acceleration of habitat degradation in aquatic systems as a result of human activity and resultant loss of biodiversity, it is becoming ever more important to consider the effectiveness of the techniques being used to enhance or create habitat, to ensure management resources are being allocated wisely. The primary aim of this systematic review will be to assess the effectiveness of techniques currently being used to create or enhance spawning habitat for substrate spawning fish in temperate climate regions. Methods: This review will examine studies on the effectiveness of habitat creation or enhancement for substrate spawning fish. We will consider studies in either the North or South temperate climate regions, and include freshwater, estuarine, coastal, or marine environments. Relevant outcomes will include a range of measures used by authors to define effectiveness, including but not limited to the presence of eggs, successful emergence, or improved recruitment. This review will obtain relevant studies from online publication databases, specialist websites, and grey literature using a range of search engines and networking tools. Additional searches will be conducted using the bibliographies of relevant review publications. Study data will be extracted and appraised for quality, including study design, confounding factors, and statistical analysis. A narrative synthesis will be compiled and a meta-analysis will be completed should the data availability and quality allow for it

An optimistic outlook on the use of evidence syntheses to inform environmental decision-making

Practitioners and policymakers working in environmental arenas make decisions that can have large impacts on ecosystems. Basing such decisions on high‐quality evidence about the effectiveness of different interventions can often maximize the success of policy and management. Accordingly, it is vital to understand how environmental professionals working at the science‐policy interface view and use different types of evidence, including evidence syntheses that collate and summarize available knowledge on a specific topic to save time for decision‐makers. We interviewed 84 senior environmental professionals in Canada working at the science‐policy interface to explore their confidence in, and use of, evidence syntheses within their organizations. Interviewees value evidence syntheses because they increase confidence in decision‐making, particularly for high‐profile or risky decisions. Despite this enthusiasm, the apparent lack of available syntheses for many environmental issues means that use can be limited and tends to be opportunistic. Our research suggests that if relevant, high quality evidence syntheses exist, they are likely to be used and embraced in decision‐making spheres. Therefore, efforts to increase capacity for conducting evidence syntheses within government agencies and/or funding such activities by external bodies have the potential to enable evidence‐based decision‐making.Additional co-authors: Karen E. Smokorowski, Steven M. Alexander, Steven J. Cook