A container ship stuck on a New Zealand reef risks breaking up and releasing more oil into a pristine bay, escalating the nation's worst maritime pollution disaster.
The Liberian-flagged Rena, which hit the Astrolabe Reef 15m off the North Island coast a week ago, has already leaked up to 300 tonnes of heavy fuel into the environmentally sensitive Bay of Plenty.
There are concerns that the Rena, which has developed cracks in its hull, could break up and release all 1,700 tonnes of oil on board.
Here are some of the world's worst oil spills over the past 40 years.
BRITAIN/FRANCE: March, 1967: The Torrey Canyon, a Liberian ship, sinks off Britain's Scilly Isles and spills almost 120,000 tonnes of crude oil into the sea, creating a slick that reaches the coast of France.
FRANCE: March, 1978: The Liberian supertanker Amoco Cadiz sinks off the western tip of Brittany, France, dumping 230,000 tonnes of crude oil and polluting 400km of coastline.
GULF OF MEXICO: June 1979: The spilling of a million tonnes of petrol in the Gulf of Mexico after the explosion of the Ixtoc Uno oil well causes an enormous oil slick.
US: March, 1989: The Exxon Valdez spills 38,000 tonnes of oil into Alaska's Prince William Sound after running aground on a reef, and 1,300km of coast are polluted. According to the University of Alaska only a quarter of marine wildlife survives.
THE GULF - January 1991: Up to 1m tonnes of oil spills during the Gulf war, when Iraqi forces set ablaze Kuwaiti wells before withdrawing in defeat. As a result, more than 500km of the northwest Saudi coast are polluted.
SPAIN - December, 1992: Near the Spanish port La Coruna, the Greek tanker Aegean Sea crashes into the rocks in a storm, breaking in two and leaking 70,000 tonnes of fuel oil. Oil washes up along 200km of Galician coastline.
RUSSIA - August to October 1994: A pipeline leak in Russia's remote northern republic of Komi leads to the spillage of up to 280,000 tonnes of oil, according to the US and Greenpeace. Russian authorities downplay the fall-out, saying between 14,000 and 60,000 tonnes were spilled.
BRITAIN - February, 1996: A Liberian tanker, the Sea Empress, sinks off Wales. The leakage of 147,000 tonnes of crude oil causes a major ecological disaster killing more than 25,000 seafaring birds.
SPAIN - November, 2002: The Liberian-registered tanker Prestige breaks up and sinks off northwestern Spain, spewing out more than 50,000 tonnes of heavy fuel oil into the waters, fouling thousands of kilometres along the Atlantic coast of France, Spain and Portugal.
US - April 2010 (above): The worst maritime oil spill in US history begins when an explosion and fire rip through a BP-licensed rig in the Gulf of Mexico, killing 11 men. The well gushes oil into the Gulf for three months before it is capped.
