Chemical and biogenophysical impact of four-dimensional (4D) seismic exploration in sub-Saharan Africa, and restoration of dysfunctionalized mangrove forests in the prospect areas
Chemistry and Biodiversity
Petroleum and Environmental Chemistry Research Group, Department of Pure and Industrial Chemistry, University of Port Harcourt, PMB 5323, Choba, Port Harcourt, Nigeria; Department of Soil Science, Rivers State University of Science and Technology, Port Ha
Four-dimensional (4D) seismic exploration, an improved geophysical technique for hydrocarbon-data acquisition, was applied for the first time in the Nembe Creek prospect area of Nigeria. The affected soils were slightly alkaline in situ when wet (pH 7.2), but extremely acidic when dry (pH 3.0). The organic carbon content (4.6-26.8%) and other physicochemical properties of soils and water (N, P, and heavy-metal contents, etc.) were higher than the baseline values obtained in 2001 before seismic profiling. Most values also exceeded the baseline compliance standards of the Department of Petroleum Resources (DPR), the World Health Organization (WHO), and the Federal Environmental Protection Agency (FEPA). Rehabilitation of the affected areas was achieved by stabilizing the mangrove floor by liming and appropriate application of nutrients, followed by replanting the cut seismic lines over a distance of 1,372 km with different mangrove species, including juvenile Rhizophora racemosa, R. mangle, and Avicennia species, which were transferred from nursery points. Quicker post-operational intervention is recommended for future 4D surveys, because the time lag between the end of seismic activity and post-impact investigation is critical in determining the relationship between activity and impact: the longer the intervening period, the more mooted the interaction. © 2007 Verlag Helvetica Chimica Acta AG, Zürich.
heavy metal; hydrocarbon; organic carbon; water; petroleum; article; Avicennia; biogeography; chemical analysis; controlled study; ecosystem regeneration; environmental protection; mangrove; Nigeria; nutrient; petrochemical industry; pH; physical chemistry; Rhizophora mangle; Rhizophora racemosa; soil pollution; water contamination; world health organization; methodology; Rhizophoraceae; soil; tree; Avicennia; Rhizophora racemosa; Conservation of Natural Resources; Hydrocarbons; Metals, Heavy; Nigeria; Petroleum; Rhizophoraceae; Soil; Trees