Unfortunately decades of intensive nitrogen-rich fertilizer use has created a zone at the mouth of the Mississippi that is starved of oxygen. This "dead zone," which now measures over 7,900 square miles, was first discovered in 1985 and it now appears to be growing much larger. The increase in corn cultivation as a result of ethanol demand may be partly to blame. The business of growing corn means that more nitrogen runs off from corn fields and into the watersheds. Previous EPA estimates had about 210 million pounds of nitrogen fertilizer going into the Gulf annually, with 2007 figures not yet available. The increase in corn growing and the size of the algae bloom visible from satellite photos points to a big increase.