This falls as rain and provides us with the fresh water needed for agriculture, industry and human uses. Thus, plant life thrive on land and in the sea, feeding animal life and producing the oxygen needed for all animals to survive. Physically, the seas act as a giant reservoir for heat from the sun. Their movements help moderate the planet's temperatures and shape our climate. And without water circulation, the human and industrial wastes that have for generations been dumped into the seas would gradually build up and poison both land and air.
Oceans are also a major source of food and employment and balance of trade.
In short, the oceans are a highly productive system which continuously recycles the chemicals necessary for living organisms to survive. However, development in many ways is now threatening the oceans and other seas. Although the oceans are vast, they are not infinite in their resources or in what they are able to bear. Change takes place gradually in the open seas and the risks are numerous. The fate of the oceans and the future of our planet are intimately related.