Evaluating the Spatial Extent of Oil Spill Contamination in Ogba/Egbema/Ndoni LGA, Rivers State

Oil spill contamination in Ogba/Egbema/Ndoni Local Government Area (ONELGA) in Rivers State represents a persistent environmental crisis in Nigeria's South South geopolitical zone, with cumulative impacts on farmland, freshwater systems, and fishing livelihoods spanning multiple decades of petroleum extraction activity. This study evaluates the spatial extent and distribution of oil spill contamination in ONELGA using a combination of Sentinel-2 multispectral imagery, total petroleum hydrocarbon (TPH) analysis of soil and water samples, and incident records from the Nigerian National Petroleum Corporation's Joint Investigation Visit database. Spectral indices including the Oil Spill Index and modified NDVI were applied to remote sensing data to delineate contamination footprints across the LGA. Field sampling at 40 stations collected soil cores to 30 centimetres depth and surface water samples from 15 creek transects during the 2023 dry season. Results indicate that at least 12,400 hectares within ONELGA show spectral signatures consistent with active or residual hydrocarbon contamination, of which 68 percent overlap with agricultural and riparian land use categories. TPH concentrations exceed Federal Environmental Protection Agency permissible limits at 73 percent of soil sampling stations. Community household surveys confirm that contaminated creek fisheries are the primary economic casualty, with fishing households reporting income losses averaging 60 percent relative to pre-contamination benchmarks. Urgent remediation through bioremediation and phytoremediation technologies is recommended alongside enhanced spill response protocols. Keywords: oil spill, contamination, ONELGA, Rivers State, South South Nigeria.