Variation in the physico-chemical features and phytoplankton of new Calabar river at Aluu, Rivers State, Nigeria.

Abstract

The physico-chemical features and phytoplankton community of the upper reaches of the New Calabar river at Aluu were studied at high and low water slacks for a period of 12 months. The water was acidic (pH 5.5 – 6.5) with low alkalinity (10 – 20mg CaCO3 L-1 and characteristically soft (total hardness ranging from 10 to 60mg CaCO3L-1). There was obvious seasonal flux in the silica level, with dry season having higher values than wet season. The phytoplankton was predominated by the diatoms, which constituted more than 85% of the total phytoplankton population. The predominant taxa were Melosira sp. Tabellaria spp. Surirella spp. and Navicula spp. The phytoplankton density was significantly higher during the dry season than rainy season (Czekanowski’s Coefficient.Cz = 0.332) but there was no significant difference between the high and low tide values (Cz = 0.66).