The determination if fish movement of potadromous species is impeded in a river system is often difficult, particularly when timing and extent of movements are unknown. Furthermore, evaluating river connectivity poses additional challenges. Here, we used large-scale, long-term fish movement to study and identify anthropogenic barriers to movements in the Lake Winnipeg basin including the Red, Winnipeg, and Assiniboine rivers. In the frame of the project, 80 Bigmouth Buffalo (Ictiobus cyprinellus) and 161 Channel Catfish (Ictalurus punctatus) were tagged with acoustic transmitters. Individual fish were detected with an acoustic telemetry network. Movements were subsequently analyzed using a continuous-time Markov model (CTMM). The study demonstrated large home ranges in the Lake Winnipeg basin and evidence of frequent transborder movements between Canada and the United States. The study also highlighted successful downstream fish passage at some barriers, whereas some barriers limited or completely blocked upstream movement. This biological knowledge on fish movements in the Lake Winnipeg basin highlights the need for fish passage solutions at different obstructions.

To determine the temperature preference for juvenile Westslope Cutthroat Trout, we conducted an experiment using an automated shuttlebox design (Loligo® Systems), whereby fish regulated ambient temperature by freely moving between cooling and warming chambers. The duration of the acclimation and experimental periods and effect of photoperiod were also evaluated, guiding future thermal preference experiments.

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BackgroundHabitat that is necessary for the survival and recovery of a species listed as threatened, endangered, or extirpated (i.e., Critical Habitat) is protected in Canada. For aquatic species, Critical Habitat may include riparian habitat, however it is unclear how much of this riparian habitat needs to be protected to support the survival and recovery of a listed species (primary question). To provide quantitative evidence to support the delineation of riparian Critical Habitat, the systematic review will be used to determine the relationships between aquatic and riparian attributes and the dependence of these relationships on the quantity of riparian habitat (secondary questions). MethodsWe will search for primary research articles in bibliographic databases for primary literature, theses, and preprints and for grey literature including reports published on relevant organizational using a search string consisting of substrings for riparian habitat, and for riparian processes (i.e., erosion, filtration, infiltration, shading, and subsidization) or aquatic attributes. The results will be screened at title and abstract, and full text levels against predefined inclusion criteria and consistency checking will be performed on a subset of 100 records to ensure the inclusion criteria are consistent across multiple reviewers. Quantitative data on the riparian and aquatic habitats will be extracted and synthesized to perform dose response meta-analyses. First, the riparian habitat attributes will be combined using probabilistic principal component analysis to develop appropriate dependent variables that describe riparian habitat types. The principal component axes will then be used in a multiple regression analysis along with a measure of the riparian habitat size, and study specific identifiers and modifiers to determine the shape of the relationship and the magnitude of the effect of on the aquatic habitat. These analyses will be used to determine the extent of riparian habitat required to maintain natural levels of riparian process to protect aquatic Critical Habitat. The findings of the systematic review will support the delineation of riparian Critical Habitat for aquatic species at risk in Canada.

Standard metabolic rates (SMR) were measured empirically for carmine shiner Notropis percobromus and common shiner Luxilus cornutus to develop SMR models that predict metabolic responses of each species under thermal conditions observed in the wild. SMR increased significantly with body mass and rising water temperature, ranging from 0.05 mg O 2 h −1 at 10 C to 0.89 mg O 2 h −1 at 20 C for N. percobromus weighing 0.6-2.5 g and from 0.11 mg O 2 h −1 at 10 C to 0.98 mg O 2 h −1 at 20 C for L. cornutus weighing 0.8-6.6 g. SMR models significantly differed between sympatric species on account of differences in model intercepts (RA) and temperature coefficients (RQ), however, the allometric relationships between mass and SMR did not significantly differ between species. Known distribution of N. percobromus and L. cornutus includes the Birch River located in Manitoba, Canada, where N. percobromus is listed as Endangered. Little is known about the physiology of N. percobromus or the species' ability to acclimate or adapt to different environmental conditions. While size differences between species contributed, in part, to differences in SMR predictions for Birch River populations, SMR trends (< 2 mg O 2 h −1 ) for individuals weighing 1 g were similar for both species across daily temperatures. Respirometry experiments contributed to developing species-specific SMR models and inform on the effect of natural and anthropogenic stressors, namely water temperature, on the conservation of N. percobromus in this ecosystem. K E Y W O R D Scarmine shiner, common shiner, conservation physiology, SMR, species at risk, water temperature