Charles Hatry

Behaviour and Locomotor Activity of a Migratory Catostomid during Fishway Passage

Fishways have been developed to restore longitudinal connectivity in rivers. Despite their potential for aiding fish passage, fishways may represent a source of significant energetic expenditure for fish as they are highly turbulent environments. Nonetheless, our understanding of the physiological mechanisms underpinning fishway passage of fish is still limited. We examined swimming behaviour and activity of silver redhorse (Moxostoma anisurum) during its upriver spawning migration in a vertical slot fishway. We used an accelerometer-derived instantaneous activity metric (overall dynamic body acceleration) to estimate location-specific swimming activity. Silver redhorse demonstrated progressive increases in activity during upstream fishway passage. Moreover, location-specific passage duration decreased with an increasing number of passage attempts. Turning basins and the most upstream basin were found to delay fish passage. No relationship was found between basin-specific passage duration and activity and the respective values from previous basins. The results demonstrate that successful fishway passage requires periods of high activity. The resultant energetic expenditure may affect fitness, foraging behaviour and increase susceptibility to predation, compromising population sustainability. This study highlights the need to understand the physiological mechanisms underpinning fishway passage to improve future designs and interpretation of biological evaluations.

Comparative Physiology and Relative Swimming Performance of Three Redhorse (Moxostoma spp.) Species: Associations with Fishway Passage Success*

Our understanding of biological criteria to inform fish passage design is limited, partially due to the lack of understanding of biological motivators, cues, and constraints, as well as a lack of biological performance evaluations of structures once they are built. The Vianney-Legendre vertical slot fishway on the Richelieu River, Quebec, Canada, passes large numbers of migrating redhorse (Moxostoma spp.) upriver to spawning grounds each year. We evaluated the physiological capacity and relative swimming ability of three redhorse species (Moxostoma anisurum, Moxostoma carinatum, Moxostoma macrolepidotum; silver, river, and shorthead redhorse, respectively) to determine how these biotic factors relate to variation in fishway passage success and duration. Shorthead redhorse had higher maximum metabolic rates and were faster swimmers than silver and river redhorse at their species-specific peak migration temperatures. Blood lactate and glucose concentrations recovered more quickly for river redhorse than for silver and shorthead redhorse, and river redhorse placed second in terms of metabolic recovery and swim speed. Interestingly, fish sampled from the top of the fishway had nearly identical lactate, glucose, and pH values compared to control fish. Using passive integrated transponders in 2010 and 2012, we observed that passage success and duration were highly variable among redhorse species and were not consistent among years, suggesting that other factors such as water temperature and river flows may modulate passage success. Clearly, additional research is needed to understand how organismal performance, environmental conditions, and other factors (including abundance of conspecifics and other comigrants) interact with fishway features to dictate which fish will be successful and to inform research of future fishways. Our research suggests that there may be an opportunity for a rapid assessment approach where fish chased to exhaustion to determine maximal values of physiological disturbance are compared to fish sampled from the top of the fishway, which could reveal which species (or sizes of fish) are approaching or exceeding their physiological capacity during passage.

Development of a National Fish Passage Database for Canada (CanFishPass): Rationale, Approach, Utility, and Potential Applicability to Other Regions

Barriers resulting from anthropogenic activities (e.g., hydropower development, irrigation, flood control, low flow augmentation) can prevent the upstream migration of fish, reducing the connectivity of river systems. As a result, great efforts have been devoted to the design and installation of engineered fishways to enable the movement of fishes across barriers. However, the literature is generally devoid of scientific papers dealing with fishway design and effectiveness, making it difficult for those developing such facilities to determine which fishway designs are most appropriate for a given system and target species. One approach for providing information to support future fishway development is through the creation of databases that contain detailed accounts of existing facilities. Described here is the development of an engineered fishway database in Canada (called CanFishPass) intended to serve as a repository for information that has previously been difficult to find. The database includes detailed geo-referenced information such as engineering details, hydraulic characteristics, and biological effectiveness of one general class of fish passage facility (i.e., engineered fishways), as well as photographs and design drawings where available. The database is searchable by species, fishway type, and ecozone, and includes a reference section comprised of both peer-reviewed and grey literature. It is anticipated that the database will serve as an important resource for future fishway development projects enabling quantitative analyses, while also serving as the first inventory of engineered fishways in Canada. Although our efforts to date have been focused on Canada, the expansion to a global inventory of fishways would enable opportunities to learn directly from facility operations in other regions.