Microbes in Environmental Changes: Changes in the Chemical and Microbiological Characteristics of Agricultural Soil of Urhonigbe Forest Reserve, Edo State, Nigeria as a Consequence of E&P Activities in OML 4

Abstract

Soils reveal a diverse array of information. Hydrocarbon exploitation effects the environment. This research investigates change in soils in a rural community due to its proximity to an E&P site. 6 soils samples and 3 composite hydrocarbon-impacted drill cutting samples from Oben village and OML 4 respectively were studied. The authors investigated the relationship between changes in microbial diversity, population and soils properties in Oben village due to petroleum prospecting activities in OML 4 (approximately 5 Km away). OML 4 was excised out of the Urhonigbe Forest Reserve in 1974 due to its vast hydrocarbon deposits. Changes were occasioned by introduction of hydrocarbon into the soil during drilling, exploration and exploitation activities. Much is known about changes in an ecosystem due to massive major oil spills; but minute chronic release of hydrocarbon within legally sanctioned limits is disregarded and often overlooked. Although operational discharges may be considered small in volume, they are repetitive and chronic. The prevailing regulatory approach is incapable of capturing fundamental issues involved in contemporary, continuous, routine, release of hydrocarbon or its products into the environment due to mundane procedures. This article documents changes in the soil of Urhonigbe Forest Reserve due to several years of E & P operations in OML 4. Findings were compared to 2008 Environmental Impact Assessment (EIA) report to show effects on Oben village that proximate OML 4. Although, no major oil spill has occurred, the study revealed that area proximate to E & P activities were affected. Microbiological testing revealed reduction in total heterotrophic bacterial isolates count in agricultural soils of the Reserve and OML4's hydrocarbon-impacted soil as 7.0±0.30 x10 cfu/g and 2 8 10 7 8 6 2.23±0.15 x10 cfu/g, respectively as against 1.4 x 10 ± 2.6 x 10 cfu/g soil , 2.5 x 10 ± 2.2 x 10 cfu/g soil during wet season and dry season respectively. Understanding the subtle and pernicious effect of E & P operations on neighbouring rural communities calls for re-examination of environmental laws; without major oil spills, E & P operations change soil in proximate locations.

Publication Info:

Author: Onwuachi-Iheagwara, P.N. ; Iheagwara, B.I. ; Oloro, J. ; 1 3 Iheagwara, P. and Ogofure, G

Volume: 56

Issue: March

Published By: Journal of Mining and Geology, 2024-03-01