US Oil spill

The consequences of oil extraction along the US coast have dramatically risen as the oil from a massive spill in the Gulf of Mexico is beginning to wash ashore near the mouth of the Mississippi. The slick is threatening wildlife along Louisiana's islands and barrier marshes, and is potentially catastrophic to the productive ecosystems and fisheries in the region.

Yesterday the coastguard said up to 5,000 barrels a day were flowing into the sea, five times the rate previously estimated after the explosion of the Deepwater Horizon rig last week. President Obama, who said yesterday that BP was "ultimately responsible" for the spill, and the joint chiefs of staff are being briefed regularly on the situation.

Fingers of oil began reaching the Mississippi river delta late last night, lapping the shore in long, thin lines. Thicker oil was expected today. Fears are growing that the oil slick could become the nation's worst environmental disaster in decades, threatening to eclipse the 1989 Exxon Valdez spill. Hundreds of species of fish, birds and other wildlife are in danger along the Gulf Coast – one of the world's richest seafood grounds. For updates see the Guardian environment blog.