Background: In the subarctic Dehcho region of the Northwest Territories, many remote communities rely on traditional foods, including fish, to supplement more expensive store-bought options. Fish are an excellent source of omega-3 and omega-6 polyunsaturated fatty acids (n-3 and n-6 PUFAs, respectively), essential compounds that can only be obtained through the diet. Long-chain n-3 PUFAs, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are especially important for human health. As the health benefits derived from consuming fish can be diminished by the risk imposed by exposure to contaminants, such as mercury, researchers and communities in the Dehcho region began a collaborative project in 2012 to quantify both fatty acid and mercury concentrations in fish. In the course of this work, it was found that concentrations of fatty acids in fish differed significantly among lakes in the Dehcho region. In freshwater ecosystems, fatty acids are produced by algae and bacteria and transferred up the food chain through consumption. The type and quality of fatty acids produced varies among primary producer taxa, meaning that fatty acid profiles in fish may vary among lakes due to variation in the composition of algal and bacterial communities, which in turn vary in response to abiotic conditions in lakes. Objectives: As some fish samples were stored for multiple years before processing, the first objective of this study was to determine if there was a relationship between concentrations of fatty acids and storage time at -20 degrees C. After determining which fatty acids were affected by storage time and how they were affected by storage time, the second objective was to update existing fish fatty acid profiles (analysed from samples collected 2013-2015) for the study lakes. The third objective was to determine whether there were differences in concentrations among lakes for several fatty acid groups of interest, including total fatty acids (TFA), n-3 and n-6 PUFAs, DHA, and EPA, and whether observed differences in fish fatty acid profiles could be explained by water chemistry and/or watershed characteristics among lakes. Methods: A total of 433 fish, including Burbot (Lota lota), Cisco (Coregonus artedi), Lake Trout (Salvelinus namaycush), Longnose Sucker (Catastomus catastomus), Lake Whitefish (Coregonus clupeaformis), Northern Pike (Esox lucius), Walleye (Sander vitreus), and White Sucker (Catastomus commersoni) were captured in 10 important subsistence lakes within the Dehcho region between the years of 2013 and 2018. Sampled lakes were located in three different eco-zones, the Hay River Lowlands, the Horn Plateau, and the Northern Alberta Uplands. Fish muscle tissue was frozen on-site and transported back to the University of Waterloo for laboratory analysis of both fatty acid and mercury concentrations. Water samples were collected at each lake to characterise lake chemistry (e.g. major nutrients, ions, dissolved organic carbon, etc.), and these data were compared to an existing dataset on watershed characteristics (e.g. lake area, watershed area, etc.). Results: In every fish species, DHA concentrations decreased exponentially with increasing storage time, while C:24:0, a saturated fatty acid, increased significantly with increasing storage time. Updated fish fatty acid profiles and mercury concentrations confirmed results found by Reyes et al (2017) and Laird et al (2018); Cisco, Lake Whitefish, Longnose Sucker, and White Sucker are the fish species with the highest fatty acid concentrations and lowest mercury concentrations. Concentrations of all fatty acid groups examined in Northern Pike were statistically different among lakes (TFA, n-3 and n-6 PUFAs, EPA, and DHA), while only some fatty acid groups in Lake Whitefish (TFA, n-6 PUFAs, and DHA) and Walleye (n-3 and n-6 PUFAs) varied significantly among lakes. Significant predictors of concentrations of fish fatty acids included both water chemistry and watershed characteristics, and fell into 3 distinct groups of variables: lake productivity (total phosphorus), indicators of carbon quality (UV254, specific UV absorbance, dissolved organic carbon, and total nitrogen), and catchment influence (chloride concentrations, calcium concentrations, and the ratio of lake perimeter to watershed area). Understanding factors that lead to variation in concentrations of fish fatty acids, both among lakes and because of storage practices, can inform predictions of the nutritional value of fish in other lakes, provide a baseline for assessing ongoing effects of climate-induced change, and allow community members to make informed choices about the fish that they are eating.

Lake Erie’s commercial and recreational walleye fishery is the largest of the Great Lakes, requiring effective management to maintain a sustainable and complex fishery. Lake Erie’s walleye fishery is composed of multiple spawning populations, which presents a management challenge. The movement patterns and recruitment of distinct walleye populations that make up the fishery must be considered by managers to avoid overexploitation and to maintain population diversity. The Grand River walleye population in Lake Erie’s eastern basin is considered a priority for rehabilitation due to blocked access to spawning habitat by a low-head dam and degraded habitat quality. The objectives of this study were to: i) investigate movement patterns of spawning walleye in the Grand River using acoustic telemetry; and, ii) investigate movement and habitat use of young-of-the-year (YOY) walleye in relation to the Dunnville Dam and surrounding habitat segments using stable isotope analysis. Between 2015 and 2018, 267 mature walleye were tracked in the Grand River using acoustic telemetry, and in fall of 2018 144 YOY walleye were sampled from the river via boat-mounted electrofishing. Both male and female mature walleye that were moved upstream of the Dunnville dam were found to actively migrate ~20-40 km up-river to areas with suspected suitable spawning substrate during the spring spawning season. Residence time of walleye above the Dunnville Dam and timing of return migrations suggest that the dam may be acting as an impediment to downstream movement. Of all the walleye tagged, 43% returned to the Grand River during at least one year subsequent to the initial spawning season during which they were tagged, and those that returned were detected at spawning habitat below the Dunnville Dam during March and April. Although differences in YOY walleye stable isotope signatures (carbon and nitrogen) were evident across sampling locations in the Grand River in fall of 2018, YOY walleye were not successfully sampled in 2019 and a description of the trophic baseline was needed to infer YOY walleye movements. Condition of YOY walleye sampled during the fall of 2018 was highest at the river mouth, which may indicate relatively favourable health conditions for YOY walleye at this location. The results of the biotelemetry study suggest that the removal of the Dunnville Dam or the construction of a functional fishway would increase access to potential additional spawning habitat, which may lead to an increase in successful spawning activity for the Grand River walleye population. Future research on YOY walleye in the southern Grand River will be necessary to enhance the understanding of how recruitment and year-class strength is impacted by movement barriers (i.e., Dunnville Dam) and variation in spawning and nursery habitat quality (i.e., abiotic and biotic stressors). Furthermore, additional analyses on mature walleye apparent annual survival and spawning site fidelity probabilities would further inform our understanding of Grand River walleye movement and support walleye management in Lake Erie’s eastern basin.

As wetlands around the world are being lost, policies are implemented to help protect further destruction and loss of valuable services that wetlands provide. In Alberta, wetland policy has been put in place with the goals of protecting the most valuable wetlands and replacing necessary loss of wetlands to maintain functional value. To help the policy meet its objectives, the Alberta Wetland Rapid Evaluation Tool-Actual (ABWRET-A) was developed and implemented in Alberta’s settled area in 2015 as a standardized way to give a value score via functional assessment to any wetland in the province, with the hopes that the most valuable wetlands will be conserved. These assessment tools are in constant need of review and improvement to make sure they are helping meet policy goals. I assess biases made in the selection for ABWRET-A calibration wetlands and determine how these biases affect ABWRET-A scoring to determine if subsequent scores provided by this tool are over or under estimating wetland value. I also assess the wetlands that underwent ABWRET-A evaluation and were drained or filled in under a permit in the 1.5 yr after ABWRET-A implementation in Alberta’s settled region to determine whether they mirror the calibration wetlands. I found that the calibration dataset comprised larger, more permanently ponded wetlands distributed closer to roads than the general wetland population. I also found that the calibration dataset included fewer bogs and more fens. I found that larger wetlands and wetlands classified as fens received higher ABWRET-A scores, whereas wetlands close to roads received lower scores. Consequently, I surmise that the scores being given out since ABWRET-A’s implementation are likely underestimates. This is corroborated by a lower distribution of scores in the wetlands permitted for drainage than policy recommends. The wetlands being targeted for permitted loss were also smaller, more road-proximate, and concentrated around major cities, implying permanent regional loss of those wetlands and their functions. Based on these findings, I make suggestions for improving ABWRET-A, including adding calibration sites to better capture the natural variability of wetlands in the area to improve ABWRET-A’s accuracy in estimating relative wetland value.