In gulf oil spill's long reach, ecological damage could last decades

By Joel Achenbach and David Brown
Washington Post Staff Writer
Sunday, June 6, 2010

Snorkeling along a coral reef near Veracruz, Mexico, in 2002, Texas biologist Wes Tunnell spotted what looked like a ledge of rock covered in sand, shells, algae and hermit crabs. He knew, from years of research at the reef, that it probably wasn't a rock at all. He stabbed it with his diving knife. His blade pulled up gunk.

"Sure enough, it was tar from the Ixtoc spill," Tunnell said.

Twenty-three years earlier, in 1979, an oil well named Ixtoc I had a blowout in 150 feet of water in the southern Gulf of Mexico. The Mexican national oil company Pemex tried to kill the well with drilling mud, and then with steel and lead balls dropped into the wellbore. It tried to contain the oil with a cap nicknamed The Sombrero. Finally, after 290 days, a relief well plugged the hole with cement and the spill came to an end -- but only after polluting the gulf with 138 million gallons of crude.

That remains the worst accidental oil spill in history -- but the Deepwater Horizon blowout off the Louisiana coast is rapidly gaining on it.

(More here.)