At a time when threats to the marine environment have never seemed greater, the importance of marine biological diversity and its conservation have never been more clear. While the traditional measure of biological richness as species diversity has kept terrestrial ecosystems at the forefront of discussions in conservation biology, new perspectives of biodiversity that use higher taxa highlight the great diversity of marine biota. Unique forms of marine life, such as deep-sea hydrothermal vent communities, continue to be discovered in the marine environment. A diversity of marine organisms enhances critical ecosystems functions, such as sequestering atmospheric carbon and protecting coastal areas from storm processes. Although global marine productivity is patchy, productivity rivals that of terrestrial ecosystems in many places with gross productivity in coral reef and estuarine ecosystems reaching 20 g of carbon per square meter per day. The great diversity of marine organisms form the foundation that enables human communities to sustainably utilize marine resources for animal protein (up to 50% of total animal protein intake in some areas), sources of anti viral and anti tumor medicines, and raw materials used in agriculture and other activities.