Oil spills may linger indefinitely -say scientists

 
UK: October 24, 2002
 
LONDON - Oil pockets have been found just below the sea bed off the U.S. coast in Massachusetts, 30 years after a tanker ran ashore there, raising fears that spills could continue to pollute the environment indefinitely.
 

Scientists thought the ecosystem returned to normal over 10 years ago and were surprised to discover the oil concentrations were about the same as in 1976, seven years after the ship, The Florida, ran aground.  The Florida spilled nearly 700,000 litres of oil into the backyard of the Woods Hole Oceanographic Institution.

Christopher Reddy, a chemist at the institute who is conducting the longest study of a major oil spill, said oil levels in sediment 15 centimetres (six inches) deep were so high you could probably smell it.

          He was also amazed bacteria had not broken down the oil. *

"It still looks like run-of-the-mill diesel fuel. We were flabbergasted," he told the New Scientist magazine yesterday.

Reddy and his team have monitored the oil spill's impact on the environment and had thought it had become little more than a distant memory.

Now the new findings have raised concerns that researchers may have underestimated the long-term environmental impact of events like the 1989 grounding of the Exxon Valdez tanker, which spilled 60 times more oil than The Florida.

But Reddy pointed out that the Massachusetts coast is marshy, and other environments like rocky shorelines are more likely to be scrubbed clean by the wind and waves.



REUTERS NEWS SERVICE

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*  Note: 

It is well established that microbial activity (so also biodegradation)

drops significantly from 30 degrees C to 10 degrees C.

At temperatures of 4 degrees C, most microbial activity ceases.

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Not all microbes eat the oil *