The Effects of Land-Use Change on the Abundance and Diversity of Benthic Functional Feeding Groups: A Case Study from Lake Simcoe, Canada

Over the past decades, human activities have profoundly altered freshwater ecosystems, primarily through urbanization and agricultural activities. Such transformations of land carry significant implications for aquatic biodiversity and water quality. The increasing human population has propelled rapid urban and agricultural expansions, notably within the Lake Simcoe basin, resulting in a surge in nutrient loading attributed to these land-use changes. A comprehensive land-use analysis has been undertaken to gauge the magnitude of these transformations. Bioindicators (i.e., macroinvertebrate functional feeding groups) have also been utilized to draw insights from pre-settlement and post-settlement in Lake Simcoe to better understand the impacts it has had on aquatic ecosystems and water quality. The first comprehensive Lake Simcoe study of this nature by Rawson (1928) provides a foundational reference point, complemented by recent investigations by Conway (2011). This comparative approach allows for the identification of potential changes in community composition and functional diversity among feeding groups over time, shedding light on the cumulative impacts of land-use change on macroinvertebrate assemblages. Through this analysis, I highlight the impacts of anthropogenic activities on nutrient dynamics, particularly phosphorus and chloride, and their subsequent effects on the lake’s ecosystem, including changes in functional feeding group structure. Notably, gatherer-collectors exhibited resilience in polluted environments, while filter-feeders decreased in diversity and abundance due to pollution-induced stressors. Despite efforts such as the Lake Simcoe Clean-Up Fund and the Lake Simcoe Protection Plan, challenges persist in mitigating nutrient and other pollution loading. This comprehensive analysis underscores the urgent need for coordinated and sustained efforts to protect Lake Simcoe's ecosystem and ensure its ecological integrity in the face of ongoing environmental changes.