Heavy Metals and Macroinvertebrate Communities in Bottom Sediment of Ekpan Creek, Warri, Nigeria

The macrobenthic fauna in bottom sediments of Ekpan Creek was studied from January to June 2007. Analyzed heavy metals were Lead, Iron, Zinc, Copper, and Chromium. Variations in chemical parameters showed that station 2 had the highest values recorded in all parameters except for Iron and Zinc, where they were higher at station 1. A total of 1135 individual organisms were recorded. Nineteen (19) macroinvertebrate taxa belonging to four major groups were identified. Mollusca were the most dominant and constituted 92.51% density occurrence, while insecta, crustacean, and polychaeta constituted 1.94, 2.29, and 3.26% respectively. Diversity varied at the study stations, with the highest taxa richness recorded at station 1. Mollusca were positively significantly correlated with lead (P 0.05, r = 0.836), and Zinc (P 0.05, r = 0.96). Sorenson index indicates similarity in species composition between the stations