Biological Significances of Environmental Pollution in the New Calabar River, Southern Nigeria: a Case Study in Zooplankton Composition

The study was conducted for three months (May to July 2020), focusing on the physicochemical parameters and zooplankton composition in the Ogbogoro region of the New Calabar River in Nigeria. This investigation was carried out at three distinct monitoring stations. The physicochemical parameters were determined using standard ecological analytic procedures. PAST and SPSS were used for the statistical analysis. The temperature ranged between 26.5 to 33 ºC, salinity (1.23 to 1.86 %), pH (7.4 to 9.62), Total Dissolved Solids (2419 to 5,817 mg/L), conductivity (223.83 to 7,328 μS/cm), turbidity (3.415 to 15.05 NTU) and Dissolved Oxygen (3.8 to 6.8 mg/L). The conductivity was observed to be above the recommended values by WHO (2006). Zooplankton are very important in assessing pollution in water bodies by indicating changes in quality. The percentage frequency distribution of zooplankton from May to July were; Protozoa (48 %), Copepoda (29 %), Nematoda (14 %), Rotifera (9 %) and Porifera (0.3 %). A total number of 288 Individuals were recorded during the sample period. Protozoa recorded the highest number of species (10) with a total number of 138 individuals while Porifera recorded the lowest number of species (3) with a total number of 26 individuals. The highest number of taxa (27) was recorded in station 1 while the lowest (24) was observed in station 2 during the sampling periods. The physicochemical parameters showed a polluted hydrological environment with degraded water conditions and the presence of a high impact on the distribution, abundance and diversity of zooplankton at the station adjacent to the dredging site. Hence there is a need to conserve the conditions of the creek because of its uniqueness and significance generally in the life history of many aquatic organisms.