This study critically assesses some of the ecological implications of a proposed refinery to be built in Obuanagha Community of Yenagoa Local Government Area in Bayelsa State. It places the analysis in the wider context of oil and gas exploration activities across Nigeria, and especially in the ecologically delicate Niger Delta area, where such operations have long raised serious environmental fears. The paper also explores the introduction and application of Environmental Management Plans (EMPs) within the sector as part of responses to address possible negative environmental externalities. Ecological Impact Assessment (EIA) is defined as a structured process for identifying, predicting, and evaluating the potential environmental effects of projects likely to have significant impacts on ecological integrity. As a multi-stage process that crosses through various disciplines, the EIA process aims to incorporate environmental concerns into the planning and decision-making of projects, as well as promote transparency and stakeholder involvement. However, one has to keep in mind that the EIA process does not automatically prevent or allow projects with regard to their environmental impact; it simply guarantees the disclosure of potential impacts and then allows decision-makers—within certain regulatory boundaries—to proceed with projects even if less environmentally-friendly alternatives are chosen.