Gentlemen,
Was interesting to read the back and forth on Jon's thread related to the Gulf dead zone and it's tie to the recent oil disaster.
Was watching Minnesota Public Television a few days ago and viewed the documentary linked above, entitled, "Troubled Waters: A Mississippi River Story" which links agricultural activity and urban runoff to an even bigger dead zone in the Gulf of Mexico. The oil spill effects pale in comparison to this.
The gist of it is that fertilizers and other biomass have run into the Gulf causing gigantic algeal blooms, after which the algae die and are consumed by an onslaught of bacteria, which uses up all available oxygen, creating dead zones. Interesting to note, too, and it's covered in the documentary, that it is not only a U.S./Gulf of Mexico phenomenon - there are dozens and dozens of river deltas worldwide where this is occuring.
Did not know this until researching for this thread, but the documentary caused quite a bit of controversy for it's "villifying" of agriculture and, surprisingly, a University of Minnesota "embargo" on showing it.
Shot almost entirely in SE Minnesota, it does villify agriculture, and rightfully so. Plus take the time to view the doc in its enitrety at your leisure. Very informative, eye-opening and revealing. The government has a large role in this, too. They are failing to do anything about it, for fear of upsetting farmers. Note the portion of the video in which an entrepeneur tries to raise alternative crops on land allocated solely for corn or soybeans. His landlord gets fined $9000 for this affront. Shameful.
Anyway, our bountiful food comes at a terrible cost to the environment, yet we do nothing to halt the degradation.
Edit: The word "Minnesota" is Sioux for "cloudy water".
Grew up during the Depression...counted every dime and died with millions. 