MARINE BIOLOGYMarine Biology: Comparative Ecology of Planet Ocean provides a learning tool to those who love the ocean to help them understand and learn about the life that populates it, the extraordinary adaptations of marine organisms to their environment, and the spectacular variety of marine life forms that inhabit the many marine habitats and contribute to the life support system of Planet Ocean. The book introduces marine biology by seeing the ocean through the eyes of its inhabitants, describing the properties of sea water, the surface waters and its currents, and the characteristics of the seabed according to how marine organisms perceive, exploit, and shape them. This book explains to the reader and those who love the ocean not only how to recognize the most common marine organisms and habitats, from the coast to great depths, but it also explains their complex life cycles and the environmental factors controlling their distribution, reproduction, and growth. Finally, the book evaluates the role that living biota play in how different marine ecosystems function in order to understand better their characteristics, peculiarities, and threats. This book offers an up-to-date and comprehensive text on the study of marine biology, presenting insights into the methodologies scientists have adopted for the study of marine ecosystems. It also includes chapters about human impacts on marine biodiversity, from overfishing to climate change, from pollution (including microplastics), to alien-species invasions, from conservation of marine resources to the restoration of degraded marine habitats. The authors developed this text for Bachelor and Masters level students taking classes on marine biology and marine ecology, but it will also interest high-school students and marine enthusiasts (dive masters, tour guides) who wish to deepen their knowledge of marine biology.