Ocean
From Envirowiki
An ocean is, on earth, a large body of salt water. There are a number of oceans on earth (Atlantic, Pacific, Indian, Southern). A small ocean is called a sea.
Oceans hold a huge diversity of life, from cetaceans and fish to molluscs and plankton. However, because humans have until recently had trouble experiencing marine ecosystems, we have had little understanding of those systems, resulting in many anthopogenic problems. Some problems include over fishing, and coral bleaching.
Earth's oceans are extremely polluted, as a result of humans not really living in it, and treating it as a waste dump, with ocean outfalls, and millions of tonnes of plastic ending up in plastic soups.
