Remote Sensing Assessment of Mangrove Degradation in Ondo State Coastline

Mangrove forests along the Ondo State coastline in South West Nigeria perform critical ecological functions including carbon sequestration, coastal protection, and fisheries habitat provision. This study assesses mangrove degradation using Sentinel-2 multispectral imagery and the Mangrove Forest Index computed from near-infrared and short-wave infrared bands. Multi-temporal imagery from 2018 and 2023 is classified to delineate intact mangrove, degraded mangrove, mudflat, and open water. Accuracy assessment using ground-truthed data yields an overall accuracy of 88 percent. Results indicate a 14 percent reduction in intact mangrove cover over the five-year period, concentrated in areas adjacent to artisanal fishing communities and timber extraction sites near the Igbokoda and Apoi Creek zones. Seasonal flooding patterns and proximity to oil infrastructure are identified as compounding stressors. The study recommends integrating mangrove monitoring into the Ondo State Coastal Resources Management Programme and enforcing existing regulations on mangrove harvesting. Findings contribute to Nigeria's national reporting obligations under the Ramsar Convention. Keywords: mangrove, Sentinel-2, coastal degradation, Ondo State, remote sensing