Mangrove forests in Nigeria’s Niger Delta are rapidly declining, leaving coastal communities increasingly exposed to flooding, erosion and storm surges, according to new research that uses advanced ecosystem modelling to track the health of these vital forests.
The Niger Delta, home to Africa’s largest mangrove ecosystem and the third-largest mangrove forest in the world, supports fisheries, biodiversity and the livelihoods of thousands of people. In Rivers State alone, mangroves act as a critical natural barrier between coastal settlements and rising waters. However, decades of oil exploration, industrial activity and local resource extraction have severely degraded these ecosystems.
The region is the centre of Nigeria’s oil and gas industry, and its landscape has been reshaped by pipeline construction, dredging, oil spills and gas flaring. At the same time, mangrove wood continues to be harvested by local communities for fuel, construction and income. Together, these pressures have weakened the natural coastal defences that once protected communities from flooding and shoreline erosion.
Mangroves grow in shallow coastal waters and function as biophysical shields. Their dense roots dissipate wave energy, trap sediments and reduce the force of storm surges. When these forests are damaged or cleared, communities lose a crucial line of protection.
The study was conducted by an environmental scientist specialising in coastal zone management and flood risk assessment. Using ecosystem modelling tools, the research examined how changes in mangrove condition influence exposure to flooding and erosion across coastal communities in Rivers State.
The model compared areas with healthy, continuous mangrove cover against areas where mangroves were fragmented or degraded. The results showed that locations with intact mangrove forests consistently scored lower on vulnerability indicators, confirming that mangroves provide significant protection against coastal flooding.
The findings also reflect what many residents in the Niger Delta have observed for years: as mangrove forests disappear, flooding events are becoming more frequent and more severe.
To conduct the analysis, the study applied the InVEST Coastal Vulnerability model developed by the Natural Capital Project. This model assesses shoreline vulnerability using variables such as coastal landforms, wind and wave exposure, and the distribution of populations and infrastructure. The output allows researchers to directly compare flood risks in areas with and without mangrove cover.
One of the key findings is that mangrove protection is not linear. Narrow and fragmented mangrove belts offer limited defence, while wide, dense mangrove forests provide disproportionately stronger protection. These broader belts significantly reduce wave energy and flood inundation, a pattern consistent with similar studies from Southeast Asia and the Caribbean.
Beyond flood protection, mangrove loss has wider socio-ecological consequences. Degradation driven by oil pollution, land conversion, fuelwood harvesting and infrastructure development has reduced biodiversity and fisheries productivity. It has also weakened the resilience of human communities that depend on these ecosystems.
In areas where mangroves have disappeared, residents increasingly rely on artificial measures such as sandbags and embankments. These solutions are costly, temporary and far less effective than natural defences, increasing dependence on engineering interventions instead of sustainable, ecosystem-based approaches.
The study highlights mangrove restoration and protection as a cost-effective solution for reducing disaster risk. Healthy mangrove ecosystems not only lower flood and erosion exposure but also support livelihoods, store carbon and contribute to long-term climate adaptation.
Rivers State, the research suggests, could serve as a model for other vulnerable coastal regions. The modelling framework allows for “with mangroves” and “without mangroves” scenarios, producing maps that identify where mangroves provide the greatest protection. This makes it possible to prioritise areas for restoration and conservation efforts in real time.
The research calls for mangrove conservation to be fully integrated into coastal zone management and spatial planning policies at both state and national levels. Large-scale restoration programmes should focus on degraded and flood-prone areas, with an emphasis on re-establishing wide, dense mangrove belts using native species and community-led approaches.
The study also urges stronger action from government authorities and oil companies to curb pollution, dredging and land-use practices that destroy mangroves. Promoting sustainable livelihoods such as mangrove-friendly fisheries, eco-tourism and responsible aquaculture can help reduce pressure on these forests.
By combining scientific evidence with local knowledge, the research concludes, policymakers and communities can develop effective nature-based solutions that reduce flood risk while strengthening ecological and socio-economic resilience in the Niger Delta.