Excellent point ... same one I often bring up. Usually followed by much sputtering and evil looks.
At which point many will say ... that is in the vastness of the Ocean not the Gulf of Mexico.
My answer ... there has been more oil spilled in the gulf then in any ocean and yet the gulf is thriving. Also, there is more oil seeping into the Gulf from the seabed on a daily basis than has ever been spilled by accident. (All corroborated by Government studies).
Crude is a 100% natural substance.