Investigating Coastal Erosion Dynamics Along the Bonny Island Shoreline, Rivers State

Coastal erosion represents one of the most visible consequences of climate variability and human activity along Nigeria's South South coastline, threatening settlements, infrastructure, and ecosystems in the Niger Delta region. This study investigates erosion dynamics along the Bonny Island shoreline in Rivers State, focusing on shoreline change rates, driving factors, and community exposure. Multi-temporal satellite imagery from Google Earth Pro (2010, 2015, 2020, and 2024) was used alongside field measurements to quantify shoreline position changes using the Digital Shoreline Analysis System (DSAS) tool in ArcGIS. Data on wave height, tidal range, vegetation cover, and sediment characteristics were collected during two wet and two dry season field visits. Analysis reveals a net shoreline retreat of 3.2 metres per year along the most vulnerable stretches of the Bonny waterfront, driven primarily by wave action amplified by vessel wake from intensified maritime traffic in the Bonny Channel. Loss of mangrove buffer vegetation due to oil-related deforestation further reduces natural coastal protection. Communities in Finima and Kalaibiama report recurrent property loss, with 14 residential structures abandoned due to erosion between 2018 and 2023. The study recommends reforestation of degraded mangrove belts, installation of geotextile revetments at critical erosion hotspots, and integration of coastal hazard mapping into Rivers State urban planning instruments. Keywords: coastal erosion, shoreline change, Bonny Island, Niger Delta, Rivers State.