Over 140 million gallons makes oil spill the largest ever in the Gulf of Mexico

BP'S massive oil spill became the largest ever in the Gulf of Mexico yesterday, based on the highest of the United States government's estimates.

The oil that has spewed for two and a half months from a blown-out well a mile under the sea hit the 140.6 million gallon mark, eclipsing the record-setting, 140-million-gallon Ixtoc I spill off Mexico's coast from 1979-80.

Even by the lower end of the government's estimates, at least 71.7 million gallons are in the Gulf.

The growing total is crucial because BP is likely to be fined per gallon spilled, said Larry McKinney, director of Texas A&M University at Corpus Christi's Gulf of Mexico research institute. "It's an important number to know because it has an impact on restoration and recovery," Mr McKinney said.

The oil calculation is based on the higher end of the government's range of barrels leaked per day, minus the amount BP says it has collected from the blown-out well using two containment systems. BP collected a smaller amount of oil than usual on Wednesday, about 969,000 gallons.

Measuring the spill helps scientists work out where the missing oil is, hidden below the water surface, with some even stuck to the seafloor. Oil not at the surface damages different parts of the ecosystem.