The role of GIS in monitoring and mitigating chemical pollution in aquatic ecosystems: A case study of Nigeria and Africa

Chemical contamination of aquatic ecosystems is on the rise across Africa, causing serious problems for human health and the environment that require innovative approaches to monitoring and reducing the impact of this threat. This paper examines the revolutionary potential of GIS technology in combating chemical contamination of water bodies, with a particular focus on Nigeria as a case study within the broader African context. Heavy metals from mining, hydrocarbons from petroleum extraction, fertilisers and pesticides from farms, and recently found compounds like per-and polyfluoroalkyl substances (PFAS) used in food packaging, waterproof materials, and industrial processes all influence the local aquatic ecosystems. This research demonstrates how geographic information system (GIS) methods facilitate predictive modelling of pollution patterns across a variety of aquatic habitats, as well as real-time monitoring and comprehensive spatial analysis. Geographic information systems (GIS) provide the resources needed to assess the environmental impacts on both marine and freshwater ecosystems, trace the spread of contaminants, and identify pollution sources by combining satellite imagery, terrestrial sensor networks, and water quality databases. Although PFAS contamination is less well-known in African contexts compared to industrialised nations, the study demonstrates that it is becoming more of a problem due to the fact that these chemicals are present in drinking water sources, groundwater, rivers, and everywhere else on the continent and do not break down naturally. Sediments at several locations in Nigeria have PFAS concentrations ranging from 1.64 to 10.29 ng/g, while surface water samples had concentrations between 1.71 and 16.19 ng/L. Environmental agencies and research institutions are able to better support evidence-based policymaking, deploy focused mitigation strategies, and optimise resource allocation for corrective activities with the help of GIS-based monitoring systems, according to the results. Applying comprehensive GIS solutions in developing countries presents both opportunities and challenges, as shown in the Nigerian case study, which reveals infrastructure restrictions, poor data quality, and the necessity of capacity building. The study concludes that the strategic implementation of GIS technology, along with international collaboration and continuous investment in technological infrastructure, offers promising avenues for improving chemical pollution management in African aquatic ecosystems.