Book excerpt: This book provides an up-to-date overview of the microbiology, biogeochemistry, and ecology of marine hydrocarbon seeps, a globally occurring habitat for specialized microorganisms and invertebrates that depend on natural hydrocarbon seepage as a food and energy source. Prominent examples include the briny hydrocarbon seeps and mud volcanoes on the continental slope of the Gulf of Mexico and in the Mediterranean, the hydrothermally heated hydrocarbon seeps at Guaymas Basin (Mexico), and the oil and gas seeps off the coast of California and in the Gulf of Mexico. Featuring topical chapters by leading researchers in the area, the book describes geological settings, chemical characteristics of hydrocarbon seepage, hydrocarbon-dependent microbial populations, and ecosystem structure and trophic networks at hydrocarbon seeps. Further, it also discusses applied aspects such as bioremediation potential (oil-degrading microorganisms).