It seems the earth’s waters have a powerful capacity to repair themselves:
Scientists said the rapid dissipation of the [Gulf spill] surface oil was probably due to a combination of factors. The gulf has an immense natural capacity to break down oil, which leaks into it at a steady rate from thousands of natural seeps. Though none of the seeps is anywhere near the size of the Deepwater Horizon leak, they do mean that the gulf is swarming with bacteria that can eat oil.
So even the Times admits that oil in the Gulf is an ongoing and naturally-generated problem, and that the body of water seems to contain naturally-occurring ways of dealing with it.