The earth's oceans are all connected to one another. The same water is circulated throughout them all. The oceans cover more than seventy percent of the surface of the earth.  Until the year 2000, there were four recognized oceans: The Pacific, Atlantic, Indian, and Arctic. In the spring of 2000, there was a a new ocean delemited, the Southern Ocean. This new ocean surrounds Antarctica. There are also many seas (smaller branches of an ocean). Seas are often partly enclosed by land. The largest seas are the South China Sea, the Caribbean Sea, and the Mediterranean Sea.

Due to polluting and overfishing, many species are in danger of extinction, and our coral reefs, wetlands, and kelp forests are disappearing.

Valuable fish stocks are threatened by overfishing. Two-third of Europe’s fish stocks are estimated to be overexploited, and 24% of the world's total fisheries are already overexploited. Humans are taking far more fish out of the oceans than can be replaced by nature.
Numerous independent scientific studies have shown high concentrations of plastics waste, blocking the guts of as much as 177 marine species. Almost 80% of pollution to this marine environment comes from land-based sources, such as runoff pollution. Runoff pollution includes many small sources, like septic tanks, cars, trucks and boats, plus larger sources such as farms, ranches and forest areas. Some water pollution actually starts as air pollution, which settles into waterways and oceans. Another dangerous pollution to our oceans happens when ships leak oil. Even today there are still up to two dozen oiltanker-disasters happening every year. These are a big threat to plants and animals in the oceans. Acid rain is another threat. Pollution originating from land goes up into the air and then rains back down into the oceans, poisoning marine life.

• Lakes
• Rivers
• Oceans
• Groundwater

The Antarctic Whaling Fleet - Our interactive guide to the Japanese Government whaling fleet in the Antarctic.

Behind the spin: bearing witness in the Southern Ocean - 22 February - In the last week, the difference between what we see and hear, here in the Ross Sea, and what we read in the news could not have been more stark. We are getting conflicting reports from the whaling fleet and from the Institute of Cetacean Research (ICR), Mr Glenn Inwood, who is thousands of miles away on land. Dave and Sara on the Esperanza take a look at the truth and lies of Southern Ocean whaling.

Nisshin Maru ready to go? - The stricken whaling ship Nisshin Maru has ropes and cables attached indicating that the crew is making preparations to depart the Antarctic Treaty Area by towing. It is not yet clear what vessel will tow the ship or when. The Nisshin Maru is currently lashed to the fleet's tanker the Oriental Bluebird, which sails under the Panama flag. Panama is not a signatory to the Antarctic Treaty.