Open Access Journals University of Manitoba
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Mycological diversity on Jack Pine and Black Spruce bark by Payuk Lake, Manitoba.
Get PDFFungi provide an essential role to the ecosystem they inhabit by decomposing dead organic material; however they have been little studied in Northern Manitoba. Payuk Lake is located within a chain of lakes that make up the headwaters of the Grass River. This region is currently under consideration for conservation. The objectives of this study were to investigate the mycological diversity of Payuk Lake, MB, and to examine the difference in mycological diversity between Jack Pine (Pinus banksiana) and Black Spruce (Picea mariana) and the heights on each tree trunk. Bark samples were collected from three heights on Jack Pine and Black Spruce trees along the ridges of Payuk Lake. The bark samples were dried and placed in moist chambers for three weeks and described using the dissecting and compound light microscopes. A total of 18 organisms were cultured from the bark samples, nine of which were classified as myxomycetes. Two-way cluster analysis showed that the most common organisms were zygomycetes, and the uncommon were myxomycetes. Cluster analysis also showed distinct clustering between tree species and heights. Shannon’s diversity index was not significant between Jack Pine and Black Spruce, but trends were evident. The diversity of fungi, and other organisms, could be large and should be further investigated to better understand the importance of the Payuk Lake region and to help conserve the headwaters of the Grass River
The response of Scenedesmus quadricauda and Selenastrum capricornutum to glyphosate toxicity (Roundup® formulation) with cellular growth and chlorophyll-a synthesis as endpoints
Get PDFGlyphosate is a commonly-used agricultural herbicide which enters freshwater sources and risks affecting non-target aquatic organisms, including algae. In this study, lab cultures of Scenedesmus quadricauda and Selenastrum capricornutum were inoculated with glyphosate (Roundup® formulation) to determine its impact on cellular growth and chlorophyll-a (Ch-a) synthesis. A concentration of 10 mg/L of glyphosate significantly inhibited growth and Ch-a synthesis in S. quadricauda and S. capricornutum. Concentrations ranging from 0 to 3 mg/L of glyphosate did not affect cellular growth or Ch-a synthesis in either species. A concentration of 6 mg/L of glyphosate did initially reduce the growth of S. quadricauda, but growth recovered and Ch-a concentrations were high. For S. capricornutum, growth and Ch-a synthesis were low, and pheophytin concentrations were significantly elevated relative to the control at 6 mg/L of glyphosate. Based these results, S. capricornutum was more sensitive to glyphosate than S. quadricauda, which was likely due to differences in the surface area to volume ratios between the species. In the future, algal toxicity should be studied in greater detail by conducting mesocosm studies within the natural aquatic environment
Microplastics Flowing into Lake Winnipeg: Densities, Sources, Flux, and Fish Exposures
Get PDFMicroplastics (plastic particles < 5.0 mm in diameter) have been detected in freshwater ecosystems worldwide. Recently, surface concentrations of microplastics in Lake Winnipeg, Manitoba were shown to be comparable to those observed in Lake Erie, Ontario, despite large differences between the lakes in terms of population density and industrial activity. To better understand potential sources of microplastics into Lake Winnipeg, two inflowing tributaries (the Red and Assiniboine rivers) and the lake outflow (the Nelson River) were sampled for microplastics. To determine the role of wastewater treatment plants in contributing to microplastic pollution, microplastic densities upstream and downstream of wastewater treatment plants in the city of Winnipeg were compared. Finally, to determine the bioavailability of microplastics to fishes, we evaluated the presence of microplastics in the gastrointestinal tracts of two fish species, common carp (Cyprinus carpio)Â and sauger (Sander canadensis) collected from the Red River. Microplastics in the Red and Assiniboine rivers were comparable to those from Great Lake tributaries, but were elevated four to six times relative to concentrations observed in the Nelson River, suggesting significant losses to settling in Lake Winnipeg. On average, densities of microplastics downstream of wastewater treatment plants were elevated, and a significant correlation was observed between standardized daily effluent discharge from Winnipeg and river flux of microplastics/m2/s. On average, sauger were found to contain one microplastic particle and carp were found to contain seven microplastics within their gastrointestinal tracts. The number of particles ingested did not appear to affect body condition of fish collected in this study.Â
Cryogenic Hibernation: A Review of Overwintering Mechanisms in the North American Wood Frog (Rana sylvatica)
Get PDFThe North American wood frog, Rana sylvatica, can inhabit extremely cold climates utilizing a variety of adaptions. The purpose of this review was to identify the driving mechanisms behind the overwintering response of R. sylvatica. The major response factors that were found to be instrumental to survival include environmental and behavioral adaptations, internal freezing point depression by increasing blood and tissue concentration of glucose and urea, and reduced metabolic activity by increasing blood and tissue concentration of urea. These factors were contrasted between the Alaskan and Ohioan variants to explore and explain the relationships between their overwintering response factors and their geographical positioning
Proceedings of the University of Manitoba Undergraduate Research Poster Competition
Get PDFAbstracts and titles of students interested in publishing their abstracts or poster titles of the 2018 University of Manitoba Undergraduate Research Poster Competition