The ocean is the birth place of life on earth. Through a very intricate and complex balance of natural phenomena over several billions of years it has developed into what it is today . The ocean remains home to several hundred thousand different plant and animal species. It is essential to all living beings, both in the water and on land. The oceans provide the most basic needs, such as the oxygen we breathe and much of the food we eat. Ocean ecology is severely threatened by pollution and global warming. Read about the threat to our oceans at Marine Environment.