EVALUATION OF SEASONAL VARIATION IN THE MICROBIAL AND HEAVY METAL CONCENTRATIONS OF IMO RIVER ESTUARY OF THE NIGER DELTA MANGROVE ECOSYSTEM

Evaluation of seasonal variation in the microbial and heavy metal content in Imo River estuary of the Niger Delta mangrove ecosystem using standard analytical methods was carried out on samples collected. The study was conducted during the wet and dry seasons (August and November). The results obtained showed that the sediment samples had a significantly (P 0.05) in the population of THB in the surface water during the wet and dry seasons (2.23 ± 2.23 × 106 cfuml-1 and 2.39 ±1.63 × 106 cfuml-1) respectively, while there was a significant difference (P < 0.05) in the population of total heterotrophic bacteria (THB) in the sub-surface water during the dry and the wet seasons (2.27 ±2.00 × 106 cfuml-1 and 2.13 ± 1.84 × 106 cfuml-1) respectively. The total fungal (TF) densities in the surface water were 1.17 ± 0.93 x 105 cfuml-1 and 1.38 ± 0.63 x 105 cfuml-1 during the wet and dry seasons respectively, the mean densities of 1.15 ± 0.63 x 105 cfuml-1 and 1.30 ± 0.48 x 105 cfuml-1 were observed in the sub-surface water during the wet and dry seasons respectively, while in the sediments, the mean densities observed were 1.42 ± 1.19 x 106 cfug-1 and 1.60 ± 1.05 x 106 cfug-1 during the wet and dry seasons respectively. The results obtained also indicate that the water and sediment samples show a remarkable variation in the concentrations of heavy metals during the wet and dry seasons.