INTERNATIONAL: November 12, 2007


A severe storm broke a Russian oil tanker in two between the Azov and Black Seas, stranding 13 crew members and spilling fuel oil into the sea in what a Russian official said was an "environmental disaster".


Here are some key facts about oil spills:

OVERVIEW

Pipelines and fixed facilities are responsible for more than two-thirds of oil spilt onto water or land. Accidental spills from ships account for about 15 percent of the oil entering the ocean every year.

Tankers and barges have spilt nearly six million tonnes of oil into the marine environment since 1970, with large spills (greater than 700 tonnes) responsible for most of the oil spilt into water bodies. In 2005, spillage from tankers and barges was about 17,000 tonnes. Oil spills happen most frequently in the Gulf of Mexico, northeastern United States and the Mediterranean Sea.

CAUSES AND EFFECTS

Oil spills can be caused by accidents, breakdown of equipment, natural disasters such as hurricanes or acts of terrorism and war.

Large oil spills at sea can kill thousands of marine animals and destroy habitats, as well as affect the fishing and the tourist industries. Exposure to hydrocarbons can also harm people's health.

CLEAN UP AND COSTS

The cost of clean up depends on the type of oil -- the more viscous and sticky it is, the higher the cost -- and the size and area of the spill. Refined products such as diesel evaporate and dissipate quickly. Oil spills can be contained through use of equipment such as booms and skimmers. The clean up could involve dispersants, gelling agents and raking and bulldozing on shorelines.

The 1989 Exxon Valdez spill of some 34,000 tonnes (240,000 barrels) of crude oil onto Alaskan shores was the costliest ever. The clean up alone cost around US$2.5 billion while the total cost, including fines and claims settlement, is estimated at US$9.5 billion.

LARGEST EVER SPILLS

- The largest oil spill ever was during the 1991 Gulf war, when about 800,000 tonnes of crude oil was deliberately released by Iraq into the Persian Gulf.

- The biggest oil spill due to an accident at sea occurred in 1979 when the "Atlantic Empress" collided with another vessel and spilt 287,000 tonnes off Tobago.

Sources: Reuters; United Nations Environment Programme (www.unep.org); International Tanker Owners Pollution Federation (www.itopf.com); US Environmental Protection Agency (www.epa.gov)


REUTERS NEWS SERVICE