Southern Nigeria’s vast Niger Delta boasts Africa’s most extensive mangrove forests — and some of the world’s largest fossil fuel reserves. Efforts to extract oil and gas have resulted in numerous oil spills, which have damaged the region’s biodiversity, as well as the livelihoods of coastal communities. Niger Delta mangroves are also affected by logging, farming and urban expansion, and are being replaced by invasive nipa palm. Research suggests Niger Delta’s mangroves could be gone within 50 years at the current rate of loss.

Oil spills affect both animal and plant communities. When released into bodies of water, oil can disperse across a vast area, aided by tides and storms. As oil is less dense than water, it floats on the surface, where it forms a barrier through which oxygen can’t diffuse. Mangrove trees “breathe” through pores called lenticels; but if oil coats their bark, this process is stymied, effectively choking the tree. Exposure to crude oil can also kill mangrove seedlings and seeds.