Assessment of Coastal Aquaculture Site Suitability Along Ogun State Coastline

Coastal aquaculture holds significant promise for enhancing food security and livelihoods in Nigeria, yet site selection based on rigorous oceanographic and environmental criteria remains limited in practice. This study assesses the suitability of the Ogun State coastline, South West Nigeria, for coastal aquaculture development, applying a multi-criteria evaluation approach within a geographic information system environment. Evaluation criteria include water quality parameters (salinity, dissolved oxygen, temperature, turbidity, pH), coastal hydrodynamics (current velocity, tidal range, wave exposure), bathymetry, proximity to freshwater sources, distance from pollution sources, seabed substrate type, and land use conflicts. Spatial data layers are sourced from Copernicus Marine Service products, Landsat-8 imagery, topographic maps, and field surveys conducted between March and September 2024. Each criterion layer is reclassified into suitability scores and weighted using the analytical hierarchy process, with expert consultation provided by aquaculture and oceanography professionals. The resultant composite suitability map delineates highly suitable, moderately suitable, marginally suitable, and unsuitable zones along the 60-kilometre coastline from Ilaro to Badagry. Findings identify Ipokia Creek and Yewa River mouth as priority zones for cage culture and pen culture development, respectively. Recommendations are addressed to the Ogun State Ministry of Agriculture and the Nigerian Agricultural Development Authority. Keywords: aquaculture site selection, Ogun State, multi-criteria evaluation, coastal suitability, GIS oceanography