Journal of Emerging Trends in Engineering and Applied Sciences: Research Areas

Article Title: The Effects of Dredge Spoil on the Zooplankton and Macrobenthic Fauna in the Alakiri Oil Field (Niger Delta Nigeria)
by Asimiea, Aminanyanaba. O.

Abstract:
The zooplankton, sub-tidal benthic fauna and the physicochemical parameters of surface water and soil samples of dredge spoil obtain from Alakiri oil fields in the Niger Delta of Nigeria were investigated. pH values of surface water were slightly alkaline (7.2 to 7.6) while dredge spoils soil were acidic (pH 4.50 to 5.50). Nutrient parameters were generally low (N=0.02-0.06; P=2.08-8.72; K=0.06-2.76) and organic carbon contents of the soils were also low (1.36 to 3.19%). Other Nitrogen related parameters (NH4 = 2.16-15.20; NO2 = 1.54-5.20) suggest a slow rate of nitrogen mineralization in the dredge spoil soil. Copepoda constituted the bulk of the population of zooplankton representing 94.5% to 99.1%. Thirteen subtidal benthic macrofauna species comprising 9 species of Polychaete, 2 of Crustacea, 1 specie of gastropod, and 1 specie of fish were encountered. Three species (Nereis falsa, Nephthys sp and Capitella capitata) were common. Changes observed in the benthic community are the presence of the bivalve, Donax sp which occurred in most stations. Also peculiar was the relatively high density of Capitella capitata in most stations. The occurrence of these species is attributed to dredging activities which have changed the river bottom to be sandy as against its original muddy nature. The relatively high density of Capitella capitata in most stations is attributed to the accumulation of petroleum hydrocarbon in the study environment

Keywords: Zooplankton, macrobenthic fauna, Alakiri Oil-field, Niger-Delta, Nigeria

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