Conventionally environmental assessments (EAs) have been carried out to enhance the understanding of the environment and for the purpose of developing appropriate environmental management and protection strategies. There are, however, limitations to the application of traditional EA approaches, particularly in rural communities in the developing world, where livelihood is dependent on common pool resources (CPRs), and baseline data are inadequate or unavailable. Eco-livelihood assessment (EcLA) is an adaptive approach that integrates a people focused sustainable livelihood approach with ecological assessment, as well as exploring traditional eco-livelihood knowledge (TELK). EcLA is identified as a promising EA tool that could help environmental professionals in planning for equitable development. This approach has been used in the Kolo and Otuoke Creeks, Niger Delta, Nigeria to investigate the ecological impact of dredging that may impact on livelihoods in such a rural setting. Ecological and social surveys have been carried out in four communities in the Study Area; two Test communities and two Reference communities (two communities from each study creek). The information collected from the social survey includes TELK, and has been used to build up a baseline scenario of the Study Area. Abundance and diversity of fish are good indicators of the eco-livelihood impacts of inland river dredging. The research shows that livelihood characteristics, river use profile, fish species diversity and abundance are very similar among all four sample communities. In addition, all sample communities have been associated with similar natural and human induced environmental consequences except that the Test communities have had river sections dredged for the purpose of land reclamation representing the baseline scenario. The analysis of the results of the ecological survey shows a difference in fish catch per unit effort, catch per unit hour, and species diversity between the Test and Reference communities, this have been attributed to the impacts of inland river dredging. The study shows that TELK has a place in environmental assessment, and that eco-livelihood assessment is one promising environmental assessment approach that could be used in areas where livelihood is strongly dependent on common pool resources.