Spatial Variation in Physical and Chemical Parameters and Macro-Invertebrates in the Intertidal Regions of Calabar River, Nigeria

The study of spatial variation in physical and chemical water quality and macro-invertebrates in the intertidal regions of Calabar River was carried out in Adiabo Community for a period of four months (September to December, 2012). The surface water was collected from four different stations along the river. The mean values of triplicate samples of all the water parameters include temperature of 28.69 ± 0.03⁰C, pH of 6.60 ± 0.02, dissolved oxygen (DO₂) of 4.06 ± 0.21 mgO2/L, Total Suspended Solid (TSS) of 535.63 ± 39.8mg/L, Turbidity of 0.020 ± 0.0025mg/L, Conductivity of 8.87 ± 0.26 Sµ/Cm, Chemical Oxygen Demand (COD) of 1.82 ± 0.013mgO₂/L, Biochemical Oxygen Demand (BOD), of 1.23 ± 0.04mg/L, Phosphate of 0.49 ± 0.0025mg/L, Sulphate of 0.022 ± 0.00 mg/L, Nitrate of 0.020 ± 0.0025mg/L, Iron of 0.53 ± 0.0025mg/L, Lead of 0.45 ± 0.0025mg/L, Zinc of 0.48 ± 0.0025mg/L. The analysis of variance (ANOVA) showed significant differences (P<0.05) in the mean values of Biochemical Oxygen Demand (BOD), Total Suspended Solids (TSS), Total Dissolved Solids (TDS) and Turbidity. Ten macro-invertebrate fauna: Uca tangeri, Hemigrapsussp, Penaeus notialis, Macrobranchium vollenhovenii, Machrobranchium felicium,Machromia sp, Pachymelania fusca, Pachymelania byronensis, Pachymelania auritaand Neritina rubricata were recorded. The results showed that Calabar River is moderately polluted. Analysis of metals showed that phosphate, iron, lead and zinc levels are slightly high in the River. Spatial variation showed some stations to be more polluted than others. All the macro-invertebrates recorded were clean water and pollution tolerant species.