Offshore gas in West Africa as a driver of change: an assessment of impacts and redistribution of pressures

Oil and gas are among the most important non-renewable energy sources globally, and recent technological advancements have accelerated offshore exploration, especially in Africa. Countries like Nigeria, Sudan, Algeria, and Egypt are major players, with Algeria, Nigeria, and Egypt among the top ten nations with substantial liquefied natural gas (LNG) capacities. West Africa, once underrepresented in the sector, has gained prominence with the 2016 discovery of the Greater Tortue Ahmeyim (GTA) reserve, located between the maritime borders of Senegal and Mauritania. The emergence of this new sector could significantly alter the region's approach to managing its marine resource. The GTA project unfolds in four stages exploration, construction, exploitation, and decommissioning all of which pose environmental risks. These include habitat destruction, pollution from discharges, noise, species displacement or death, light pollution, and the degradation of nesting, feeding, and breeding grounds. Sessile species are particularly vulnerable. However, there is a less studied dimension of the implications of this new sector. The development of these phases requires the displacement of other activities, particularly fishing, leading to knock-on effects that also warrant consideration. The complexity introduced by this emerging marine sector necessitates a holistic assessment of its implications for the region's present and future development. Integrated Ecosystem Assessment (IEA) are widely used to inform ecosystem-based management (EBM). Using the ODEMM (Options for Delivering Ecosystem-Based Marine Management) approach, the study identifies the interconnections between sectors, environmental pressures, and ecological components. A modification of the ODEMM framework, distinct from previous applications (focusing on a single sector), was made during our analysis to better highlight the effects of the GTA project in our study area. Results showed that this new sector has several impacts on ecological components, increasing certain existing pressures and introducing new ones. Despite these negative impacts, positive effects, such as the use of platforms as artificial coral reefs, were also observed.