Abstract:

Studies on the microalgae of the New Calabar River were conducted in the months of March and April, 2014to ascertain the abundance and distribution of microalgae in the New Calabar River. The experimental approach was: the deployment of an ARC GIStool to select six geo-reference stations; the collection of water samples with 20µm plankton net and a light microscope to provide a quantitative account of microalgae and ahoriba water checker to investigate the physicochemical characteristics of the water body. The result forphysicochemical parameters ranged from 3.70mg/l to 7.08 mg/l (dissolved oxygen); 16.95cm to 78cm (turbidity); 24.0°C to 31.0oC (temperature); 17.20µScm to 2693µScm (conductivity); 10.34ppm to 2446.5ppm (total dissolved solid);4.98 to 7.05 (pH); and 2.20mg/l to 4.14mg/l (BOD). Analysis of Variance showed some level of variability between the physicochemical parameters tested in all stations. The microalgae recovered were a total of three classes, representing twelve genera. Bacillariophyceae had the highest number of genera (9) while Cyanophyceae (2) and Dinophyceae (1). Shannon-Weiner’s and Margalef indices indicated that species diversity was maximum in station 2. Pielou’s index of evenness revealed a more evenly distribution in station 2; while the lowest species evenness occurred in station 6. This study therefore, provided information on the diversity, distribution and abundance of microalgae in the study area. However, the abundance and distribution of microalgae were influenced by physicochemical variables and biogeography of the area. Thus, a regular account of the abundance and distribution of microalgae and physicochemistry is recommended to ascertain the dynamics of microalgae with respect to the increasing anthropogenic activities in the study area.