Remote Sensing Monitoring of Phragmites Treatment and Fish Habitat Restoration in Long Point, Lake Erie, Canada

The invasive expansion of Phragmites australis in coastal wetlands, including the Long Point wetland complex in Ontario, has led to significant declines in plant and wildlife diversity, impacting ecosystem functions. Despite ongoing management efforts, the long-term ecological outcomes of Phragmites control remain poorly understood. This study developed a framework to evaluate the long-term efficacy of herbicide treatment by tracking changes in target and non-target plant species and fish habitats in Long Point, Ontario, over an eight-year period (2016–2024). High-resolution satellite imagery from WorldView sensors was classified using a random forest algorithm, achieving over 94% mapping accuracy. Results showed a decrease in Phragmites cover (3–21%) and an increase in fish habitat area (7–58%) within treatment areas. However, some sites also experienced increases in Dead Vegetation (up to 23.6%) and declines in Grass/Herbaceous and Typha (up to 20.5% and 32%, respectively). These findings highlight both the success of Phragmites Best Management Practices and the temporary non-target effects on wetland vegetation.