Bacterial Abundance - Chlorophyll a Concentration Relationships in Cross River Basin, Southeastern Nigeria: An Evaluation of Empirical Bacterial Abundance - Chlorophyll a Models Using a Multivariate Analysis

摘要

The relationship between bacteria and chlorophyll a was investigated for three months from July to September, 2008 during flood and ebb tide periods at two sites in the Cross River basin, southeastern Nigeria, to ascertain the reliance of bacteria on autochthonous organic matter. There was no significant difference between flood water and ebb water samples at both stations for the entire variable measured. Bacterial cell abundance showed a weak positive correlation with chlorophyll a concentration at Station 1 (r~* = 0.132, P > 0.05) and a strong positive correlation at Station 2 (r~* = 0.599, P > 0.5). The micronutrients at both stations showed a weak negative correlation with chlorophyll a concentration. Linear regression analysis together with standardized coefficient value revealed a high bacteria/chlorophyll a relationship at Station 2 and a weak bacteria/chlorophyll α relationship at Station 1. Principal Component Analysis was applied to the measured variable, and a high correlation was observed between bacterial cell abundance and chlorophyll a concentration at Station 2. A strong reliance of bacteria on chlorophyll α was established at Station 2 whereas Station 1 showed a weak correlation indicating the strong dependence of bacteria on allochthonous organic matter. This bacterial abundance could serve as a good source food for protozoans in transferring energy to classic food chain.