Modern Usage Map of the world's oceans. From the 19th century to today, the phrase "Seven Seas" has been used to refer to the world's oceans. In the early modern days, the phrase referred to the four traditional oceans, Atlantic, Arctic, Indian, Pacific Oceans, alongside the Gulf of Mexico, the Mediterranean, and the Caribbean Sea.

Default Background InfoVocabulary The numbers are staggering: There are 5.25 trillion pieces of plasticdebrisin the ocean. Of that mass, 269,000 tons float on the surface, while some four billion plasticmicrofibers per square kilometer litter the deep sea. Scientists call these statistics the "wow factor" of ocean trash.

The majority of life on Earth is based on a food chain which revolves around the Sun, as plants use sunlight to make food via photosynthesis. However, in environments where there is no sunlight and thus no plants, organisms instead rely on primary production through a process called chemosynthesis, which runs on chemical energy.

Our world is made up over 70% of water, and the largest bodies of water we call Oceans. What makes an ocean different from other bodies of water ? How many oceans are there?