 Microbial fuel cells, MFCs, use bacterial metabolism to produce electricity from organic substrates and have shown promise for sustainable energy production from organic wastes. However, practical applications of marine sediment MFCs are limited, and further research is needed to understand the limitations and microbiology of these systems to improve MFC technology and its potential value in waste degradation and toxic chemical removal. This article was authored by Kelly P. Nevin and Ashley E. Franks.