Oceans and life

Oceans and continents are vital parts of our environment and affect most parts of our lives, even when we do not notice.

Oceans send rain to the continents; this is part of the Earth's water cycle. Without oceans there would be no rainfall, and the Earth would be a desert.

More than half of the world's oxygen is made by the oceans' flora, the algae and seaweeds, which is why the oceans are called 'the planet's lungs'. These sea plants also give food and shelter to fish and other sea animals. So the oceans play a crucial role in keeping the climate steady and supporting life on Earth.

Oceans have shaped people in many other ways. From early times, people have used the seas to migrate to other lands, to trade all kinds of goods, for military campaigns, and as a source of food through fishing.

Oceans have also fed the cultures of coastal people everywhere. Almost all of them have tales and legends about the sea: sea gods and goddesses, sea monsters and treasures, the ocean's dangers and its blessings.

The United Nations has named 8 June as World Oceans Day, to 'remind us all of the major role the ocean plays in everyday life. It serves as the lungs of our planet, a major source of food and medicine and a critical part of the biosphere.'

Scientists have shown how human activity pollutes the oceans. We throw several million tonnes of plastic into the sea every year, choking marine life, and there are other kinds of pollution too. Overfishing (catching too many fish) is another reason sea life is shrinking. It is our shared responsibility to protect the oceans for the future of the planet and of people.