Studies on plankton community and physico-chemical parameters of Elechi Creek, Eagle Island, Port Harcourt

Abstract

Studies on the plankton communities and physico-chemical characteristics of Elechi Creek were carried out for six months, from January to June. Fourteen physico-chemical parameters were evaluated, and monthly plankton alteration was investigated. Water quality samples and plankton analyses were obtained simultaneously. Water temperature was in the range of (29.4–35.5⁰C) across the (3) study locations. The results revealed no spatial dissimilarity (P˃0.05) of all physicochemical factors while results of the monthly variations test showed significant elevations (P˂0.05) for some parameters between (April and June), except for Turbidity, Nitrate, pH, Sulphate and Chloride. The mean concentration levels in total hardness (1600 mg/L), chloride (1075.8 mg/L) and sulphate (621.6 mg/L), were found considerably above the acceptable levels. Most plankton showed negative changes subsequent to these elevations. Phytoplankton identified comprised two families, of which Bacillariophyceae (diatoms) were higher followed by Cyanophyceae. Bacillariophyceae, cell density (46 cells L-1) contributed the highest (80.7%) sum phytoplankton cell–density while Cyanophyceae had (11 cells L-1) contributing (19.3%). The zooplankton density was from (17 L-1 - 1190 L-1). Copepoda recorded the utmost percentage population, contributing (91%) zooplankton, followed by Cladocera (4.8%), Crustaceae (2.9%) and most reduced (1.3%) contribution by Rotifera. Monthly variations of Plankton density showed that most families recorded higher density during the wet months (April–June). The occurrence of these factors and conditions in Elechi Creek underscore pollution therefore, aquatic organisms from such water are almost unsafe for food. Hence, standard checking of the creek is advocated to ensure seafood safety.