Impact of Disturbances on the Biodiversity of Ijala-Ikeren Wetland Ecosystem in Niger Delta

An assessment of Ijala-Ikeren wetland in the Niger Delta of Nigeria was conducted for 9 months for biodiversity data comprising flora and specific aquatic fauna (amphibians and insects) in order to inventorise the species and ecosystem and to ascertain the effects of anthropogenic and natural disturbances on the wetland ecosystem. Five sites comprising three sites within the mangrove swamp and two ponds at the fringes of the mangrove ecosystem were sampled. Data collection methods include insect and amphibian sampling, and a few abiotic data. Empirical data on fish fauna was also obtained from fishermen. The pH value of the sampled sites in the mangrove ranged between 4.7 and 6.1, while temperature ranged from 28 to 29°C. Red mangrove species (Rhizophora sp.) and few species of white mangrove (Avicennia sp.) were dominant plants. Only three insect species from three families were encountered and thirteen species of amphibians from three families were only encountered in ponds at the fringes of the wetland. Amphibians had the highest value of species richness index (d) (2.75) and diversity index (H´) (2.08). The acidic pH values maybe attributed to the influx of effluent from the Warri refinery about 2.5 km away and the low insect diversity is due to the salinity.