Geospatial Modeling of Land Use Dynamics and Fishery Sustainability in the Southeast Arm of Lake Malawi and Upper Shire River

Freshwater fish biodiversity faces increasing threats from human activities and environmental changes, prompting the need for comprehensive studies to understand and mitigate these impacts. This study focuses on assessing the effects of land use and land cover changes on fish biodiversity and catches in the Southeast Arm of Lake Malawi, Lake Malombe, and the Upper Shire River. Field data collection encompassed both qualitative observations and quantitative measurements of fish species from various points within the study area. This involved gathering information on fish species, their weight, length, and age, alongside qualitative data such as fish colors and species sex. Satellite imagery from the Landsat series, covering the period from 2000 to 2017, was utilized to analyze land use dynamics, employing supervised classification methods to categorize the land cover into different classes, including cultivation, natural forests, agroforests, grasslands, settlements, and water bodies. The analysis revealed significant changes in land use over the study period, with a notable increase in cultivation and settlements negatively correlating with fish catches, suggesting that agricultural expansion and urbanization driven by population growth contribute to habitat degradation and a decline in fish populations. Conversely, areas with natural forests, agroforests, grasslands, and water bodies positively correlated with fish productivity, highlighting the importance of preserving these areas for maintaining healthy aquatic ecosystems. The study underscores the urgent need for integrated land and water management policies to mitigate the adverse effects of land use changes on aquatic ecosystems. Key recommendations include implementing conservation buffer zones, promoting sustainable agricultural practices, and adopting community-based management strategies. This research provides critical insights into the relationship between land use changes and fish biodiversity, emphasizing the importance of maintaining natural vegetation and sustainable land use practices. Future research should prioritize long-term monitoring and community engagement to ensure effective conservation and management of these vital ecosystems.