The oceans hold approximately 96.5% of all of Earth's water.
71% of Earth is covered by the ocean. Due to the vast size of the ocean it is impossible to know about everting that lives in it. This means that it is impossible to know the exact number of different species that live in the ocean. Every day new species are being found and every day scientists are amazed at the diversity of this habitat.
As well as new species being found, we are losing species all the time. Entire ecosystems are collapsing and many of them we are unaware of.
It is estimated that 91% of marine species are yet to be classified and 95% of the ocean remains unexplored. This may seem as though it is irrational to even attempt studying all the knowledge of the ocean but scientist are determined to learn as much as they possibly can about the world's largest body of water.
Everything is somehow connected to the ocean. The canals and reservoirs in the city will join to a fresh water source, such as a river, and then the river will connect to the sea. No matter where you are in comparison to the sea you are somehow connected. This is why it is vital not to leave waste wherever and whenever. It will always find its way to the ocean.
The global oceans is the interconnected system of the Earth's oceanic waters. The world ocean is made up of 5 oceans. These oceans are (in order of size) : Pacific Ocean, Atlantic Ocean, Indian Ocean, Southern Ocean (the newest world ocean) and Artic Ocean.