Monitoring and improving the quality of the coastal and marine environment is essential for most countries in the Gulf of Guinea. In Côte d’Ivoire, topics such as suspended solids (SS) mapping can contribute to the development of management and protection tools for coastal waters, as illustrated in this study. The acquisition and processing of images from the Sentinel-2 satellite’s MSI sensor have enabled us to map the concentration of suspended solids and their inherent optical properties in the Adjin lagoon between 2021 and 2024. Level 2 products, generated using the Case-2 Regional CoastColour (C2RCC) processor integrated with Sentinel Application Platform (SNAP) software, extracted various water constituents, such as total suspended solids and inherent optical properties at 443 nm. The results show that the monthly concentration of Suspended Solids is highest in November and lowest in March. In addition, monthly averages of the diffusion coefficient of marine particles reveal a maximum concentration in May and a minimum in March. Analysis of seasonal variability, from January 2021 to December 2024, reveals a strong correlation between suspended solids concentration and the marine particle diffusion coefficient. During rainy seasons, abundant precipitation leads to a significant increase in suspended solids, while during dry seasons, their concentration decreases due to lower precipitation. This work makes an important contribution to our understanding of the complex biogeochemical processes influencing water quality in Adjin Lagoon. The results obtained offer avenues for better management and protection of aquatic ecosystems, particularly in the face of pollution and eutrophication problems. The study also highlights the effectiveness of remote sensing and the validation of its results for long-term environmental monitoring.