Assessing the Changes in the Mangrove Ecosystem of Oron and Eastern Obolo Estauries

Abstract

Studies were carried out to assess the impact of nipa palm (Nypa fruticans) population on the sustainability of the mangrove forest of Oron and Eastern Obolo estuaries in Akwa Ibom state for a period of 30 years. Assessment of the land use change of Oron and Eastern obolo mangrove forests revealed a progressive succession of the nipa palms over the mangroves within a period of three decades (1986- 2018). The result showed a significant reduction (P > 0.05) in the population of mangrove, from 7610 in 2000 to 5540 in 2018 and an increase in the population of nipa palm from 3411 to 6229 within the same period. Satellite imageries obtained for both Oron and Eastern Obolo showed a decrease (P > 0.05) in the land area covered by mangroves while there was an increase (P > 0.05) in the area of land covered by nipa palms. These observed changes resulted in the loss of 1.9km2 and 4.8km2 of mangroves in Oron and Eastern Obolo respectively as well as an increase of 2.5km2   and 7.4km2 respectively (P > 0.05) in nipa palms. In summary, the outcome of the research shows a progressive succession of nipa palm over the mangroves. This calls for urgent action to mitigate the impact caused by the alarming succession that is currently on-going in the mangrove forest of Oron and Eastern Obolo, and by extension other mangrove forests across Nigeria and the world at large, if the ecosystem services performed by these mangroves will have to be sustained.