Evaluating the Physico-chemical Characteristics and Plankton Diversity of Nwaniba River, South-South Nigeria

Abstract

The physicochemical characteristics and plankton diversity of Nwaniba River, Uruan, Akwa Ibom, Nigeria were studied between April and September 2013. Surface water samples were collected for physicochemical parameter and plankton analysis according to standard methods. The results of the physicochemical parameters were within recommended limits of the National Environmental Standards and Regulations Enforcement Agencies (NESREA) for aquatic life. Twenty plankton species belonging to five taxa were encountered in the following order of dominance; Bacillariophyceae (69.23%) > Chlorophyceae (18.38%) > Cyanophyceae (11.97%) > Dinophyceae (0.85%) > Rotifera (0.43%). The most abundant phytoplankton was Coscinodiscus radiates, accounting for 47.7%, the least were Peridinium bipes, Pediastrum duplex, Rivularia spp, Gonatozon monalaenum, Navicular peroltelti, Tabelaria spp, Epithemia zebra and accounting for less than 1% respectively, while Lacane bulla was the only species for zooplankton. High Diversity indices values were recorded for Chlorophyceae =1.36 while the least was Cyanophyceae = 1-21. The presence of certain plankton-pollution tolerant species such as Anabaena circularis, Navicula peroltelti, and Peridinium bipes suggests a low level of organic pollution in the river.