Quantifying Human and Ecological Dimensions to Advance Holistic Understanding of Prairie Lake Ecosystems

Abstract

Successfully managing the impacts of changing environmental conditions on complex socio-ecological systems (SES) requires identifying, quantifying, and understanding the multitude of threats facing such systems. Research that transcends disciplinary boundaries is the best means of accomplishing this task. Therefore, in this study, I combined multiple methods from the social sciences and natural sciences to quantify the human and ecological dimensions of prairie lakes in Saskatchewan, Canada. Firstly, to advance understanding of lake-use patterns and users’ perceptions of these systems, I designed and distributed a stakeholder survey. Results indicate primary lakeuses in this region are recreational, particularly fishing. Walleye (Sander vitreus) are targeted more than native fishes such as northern pike (Esox lucius) or yellow perch (Perca flavscens). Overall, respondents expressed concerns about pollution and urbanization, but invasive species and climate change were of minimal concern. Next, I quantified the current status and potential resilience of the aforementioned game fish species to changing environmental conditions using three parameters. I used Bayesian mixing models (MixSIAR) to evaluate resource-use, while body condition was expressed as relative weight indices (Wr), and parasite loads were enumerated via gut analyses. Based on the results, stocked walleye appear to be less resilient to environmental variability compared to naturally occurring species. This suggests that walleye will need to be continuously stocked in the future, particularly under climate change scenarios. Finally, because invasive species are expected to significantly impact game fish populations in temperate regions, and humans being key vectors in the spread and ii establishment of invasive species, I examined stakeholder knowledge about aquatic invasive species (AIS). Results from a survey questionnaire indicated low education and communication success, as respondents exhibited substantial knowledge gaps regarding non-native mussels and key preventative behaviours. Furthermore, I identified correlates of AIS knowledge and recommend exploitation of these predictors to improve effectiveness of education, outreach, and communication efforts. Based on the collated results from this interdisciplinary study, I recommend development of management strategies that focus on ensuring the long-term sustainability of recreational angling, improving AIS knowledge through re-structured education campaigns, and enhancing efforts for detecting AIS transfer. Overall, utilizing an interdisciplinary approach to examine the human and ecosystem dimensions of prairie lakes advanced comprehensive understanding of these complex SES.