THE HYDROGRAPHIC PROPERTIES AND PLANKTON COMMUNITY OF SOME STRETCHES OF THE CALABAR RIVER, CALABAR, CROSS RIVER STATE, NIGERIA.

This study was intended to measure the Hydrographic Properties and plankton communities of some stretches of the Calabar River, Calabar, Cross River State, Nigeria. It was guided by the following objectives: To ascertain the quality of the Calabar River, Cross River State, by measuring the physicochemical parameters such as; pH, Conductivity, Dissolved Oxygen, turbidity, Nitrate, Nitrite, Alkalinity, Salinity, Temperature, TDS, Tidal range and Speed of flow and to assess the plankton communities at the designated stretches (Station 1 Tinapa, station 2, Adiabor and Station 3; Marina area). Water samples from the three sampling points were collected and analyzed at the Institute of Oceanography, University of Calabar following standard scientific methods. The result of the physicochemical parameters showed some variations, temperature in the study area was slightly higher in Adiabo with a mean value of 30.10±0.20 oC, pH of water from the three sampling points was observed to be higher in Marina area with a mean value of 6.25±0.42 mg/L while the lowest pH values was recorded in Tinapa for the three months to be 5.93±0.83 mg/L. Conductivity values had a mean ranged between 858.33±109.13µm/S in Tinapa and 262.00±104.23µm/S recorded in Adiabor. Dissolved Oxygen was observed to be higher in Tinapa with a mean value of 5.00±0.10 mg/L when compared to Marina station and Adiabo station. Salinity (mg/l) was higher in Adiabo (0.17±0.06 mg/L) in the study. Nitrate concentration was slightly higher in Tinapa with a mean value of 0.55±0.00 mg/L. Nitrite concentration recorded a higher mean value of 0.06±0.01 mg/l at Adiabor and Marina stations respectively. Alkalinity concentration in the study recorded the highest value in Tinapa 0.727±0.04 mg/L. The lowest value was recorded for Adiabor. Turbidity concentration in the study was higher in Tinapa with a mean value of 25.25±14.68mg/L. Total dissolve solute (TDS) concentration in the study ranged between 147.62 ±19.89 mg/L recorded for Marina station and 584.63± 86.46 mg/L recorded for Tinapa. Tidal range of the Calabar River from the three sampling points ranged between 0.2m to 0.97m, speed of flow ranged between 0.72m/s and 1.15ms. Among the phtoplankton species recorded, Bacillariophyceae was more predominant, while among zooplankton species examined, Copepoda was observed to be higher. Station1 had the highest relative abundance of species.The parameters examined were lower than the compliance limit of the Federal Ministry of Environment (FMENV) and World Health Organization (WHO) tolerance limit for domestic uses.