Chemical fertilizers I'm sure,Cow Manure..who are you kidding?
How about the oil production in the gulf region, drilling, refineries. and how about the shipping sludge from all those boats.
Cow Manure, give me a break.

You must not be from the midwest.
This article lays out the most simplistic aspects of the pollution problem. The key watersheds (wiki that if you dont understand) absorb the large amounts of nitrates from the breakdown of the manure. These watersheds empty into the Mississippi and then flow without filter down to the gulf.
Seriously, you could have googled this for yourself if you do not have the benefit of living in the region, or having studied this exact issue.

cow shlt isnt the only issue here. Obama is a fake. solar flares are at a minimum in 2009 (guess what!? what goes down, must go up!) (2012 will be solar catastrophe). G-20 summit just announced they're pro-new-world-order (just like the bible predicts). There is going to be big change soon, and it isn't the change the new administration in the white house is preaching about. Enjoy your life folks, spend time with your children, take these warnings as an opportunity to finally live your life and be who you want to be. A lot of intense things will happen abruptly, but remember that the good will prevail in the end. email me if you'd like more insight shd191@gmail.com thx for caring.

zone I have been researching the dead for for a long time and every study comes to the same conclusion. The fertilizers, expecially nitrogen and phosphorus and manure are responsible for the increased eutrophication within the dead zone. Fertilizers are the ones that are mostly responsible for pollution in aquatic environments.

Either get your facts together people are do not even bother to comment.

How many city sewer plants filter out the Nitrates and Phosphates out of the treated water returning to the Mississippi? I found it amazing that the technology does not exist or is too expensive to use.

What happens to the Nitrates that we eat from plants and other sources? Since the human body does not use much Nitrates or Nitrogen what does it do with the excess? From what I understand it passes it right down the toilet. What about the excess Phosphorus or vitamin and mineral supplements, does the same thing happen? Aren’t there allot of large cities along the Mississippi? What do they do with their waste water? I know in Portland, OR they dump allot of it down the Columbia.

Here in Oregon I know it is a crime for a farmer to pollute any water leaving their farm, don't they have the same laws in the Midwest? I could not imagine they would not.

Until we properly answer these questions should we be hating farmers and ranchers?