Assessment of Oil Spill Impacts on Mangrove Wildlife in Bayelsa State

Mangrove ecosystems in Bayelsa State, within Nigeria's South South geopolitical zone, support exceptionally high biodiversity including fish nurseries, waterbirds, and mammals, yet they are subject to chronic and acute oil spill contamination from pipeline failures and artisanal refining activities. This study assesses the impact of recent oil spill incidents on wildlife populations and habitat quality in mangrove areas of Kolokuma/Opokuma and Southern Ijaw Local Government Areas. Field surveys were conducted at three spill-affected sites and three reference sites to compare wildlife diversity, substrate condition, and vegetation health. Waterbird counts, fish sampling, and benthic invertebrate assessments were conducted at each site. Results indicate a statistically significant reduction in waterbird species richness and abundance at spill-affected sites, with complete absence of several wading bird species previously recorded at these locations. Fish biomass was 62 percent lower at impacted sites, and benthic invertebrate diversity was severely reduced in heavily oiled sediment zones. Vegetation assessments confirm pneumatophore blockage and canopy dieback at the two most severely affected sites. The study recommends the accelerated implementation of bioremediation protocols, community involvement in spill detection and reporting, and independent wildlife impact assessments as a mandatory post-spill regulatory requirement in Bayelsa State. Keywords: oil spill, mangrove, wildlife impact, Bayelsa State, South South Nigeria