and inland seas. as of 2023, more than 242,000 marine species have been documented, and perhaps two million marine species are yet to be documented. On average, researches describe about 2,300 new marine species each year. The study of marine life spans into multiple fields, which is primarily marine biology, as well as biological oceanography.

By volume, oceans provide about 90% of the living space on Earth, and served as the cradle of life