Iko River Estuary: Anthropogenic impacts and the microbial community alterations

The contamination of the aquatic systems with heavy metals has been on the increase since the last century due to industrial activities and this has contributed greatly to the variations in the microbial community structure and function in the ecosystem. The natural and anthropogenic variations in microbiological and heavy metals analysis in Iko River estuary was analyzed using standard methods. From the result, it was observes that anthropogenic variations influence greatly the microbial proliferation as significantly (p<0.05) higher microbial levels were observed across all microhabitats (tidal water, intertidal water and benthic sediment) as well as stations (upstream – Okoro, midstream – Kampa and downstream – Emeroke). It was observed that the sediment samples produced significantly (p<0.05) higher THB counts than tidal and intertidal water samples. Similar trends were observed for CUB, TF and CUF respectively. There was no significant difference (p>0.05) between the mean values of upstream, midstream and downstream. In all microhabitats and stations, the densities of crude oil-utilizing microorganisms were significantly (p<0.05) low compared to total heterotrophic counts. The total fungal counts were significantly (p<0.05) low compared to total heterotrophic bacteria counts. The result showed relatively higher concentrations of heavy metals in sediment than in tidal and intertidal water samples. The results indicate that the water and sediment samples show a remarkable variation in heavy metals and total petroleum hydrocarbon as a result of the great human activities in the estuary.