Oceans

Oceans cover 71% of the Earth’s surface and play a vital role in regulating the planet’s climate. They also provide nearly 20% of humanity’s total food supply.

But all is not well in the world’s oceans and seas. Nine of the world’s 17 major fishing grounds are now severely depleted, and productivity is falling in all but four of them. Many formerly plentiful species, such as cod, are in danger of extinction. One major fishery – Grand Banks in Newfoundland – has already collapsed, putting tens of thousands of people out of work.

The main problem arises from over-fishing, which is undertaken with the efficiency of a mining operation. High-tech boats deploy nets kilometres long, which kill almost everything in their path. Pollution is also taking its toll, mainly from the outwash of rivers contaminated with fertiliser, sewage and industrial waste.

Coral reefs are of particular concern, since they contain a quarter of all marine species despite occupying less than 0.2% of the ocean floor. They are being damaged by pollution and over-fishing as well coastal development, rising sea temperatures and storms (made worse by climate change). 70% of the world’s remaining coral reefs could be lost in the next 40 years.

See also Biodiversity, Pollution and waste.

Finding out about the world's oceans

The Australian Department of Environment and Heritage Coasts and Oceans page and the National Oceans Office will give you information on the Australian situation.

People and Planet's Coasts and Oceans page offers an excellent introduction to this topic.

The Intergovernmental Oceanographic Commission is the UNESCO portal to oceanographic issues, such as ocean monitoring, fisheries, ecosystems and marine environmental protection. The site contains a wealth of scientific data.

While American in orientation, the National Oceanographic and Atmospheric Administration site does gives access to lot of useful information. The National Ocean Service page can also be reached from this site.

SeaWeb focuses on ocean conservation, with programs related to the Asia Pacific region, aquaculture and healthy fisheries.

The Worldwide Fund for Nature Marine Conservation page gives an overview of pollution, fisheries management, tourism, oil and gas mining and other maritime issues.

Greenpeace Australia is an activist organisation which works on environmental issues. They are particularly concerned with the oceans and the prevention of whaling and overfishing.

The Coral Reef Alliance seeks to protect the health of coral reefs by integrating ecosystem management, sustainable tourism, and community partnerships. Reef Check also works in this area. For information about Australian reefs, go to the Great Barrier Reef Marine Park Authority site.