For several years, we’ve been hearing about the “dead zone” in the Gulf of Mexico, where a lack of oxygen is driving the life out of a large area off the Louisiana coast. The problem is said to come from high levels of nutrients coming down the Mississippi River, allowing large algal blooms that eventually die and decay. The decay process creates inordinate amounts of bacteria which consume all the oxygen near the ocean floor.
There’s an EPA website devoted to this topic, which is more complicated than I’ve described here. There’s even a map of this year’s dead zone: http://www.noaanews.noaa.gov/stories2008/images/deadzone_gulf.jpg.
I do find myself with a few questions. First, do we know what the normal levels of oxygen are (i.e., what they would be without the nutrients attributable to human sources)? I didn’t think we did.
Second–if the dead zone is caused by nutrients coming down the Mississippi River, why isn’t the dead zone centered on the Mississippi River, and not almost entirely west of the river mouth? It’s not like the river only has one outlet. Maybe there are further reasons; I don’t have enough marine biology to know.
And third–well, I can’t help noticing that the area of the dead zone includes areas where there are likely to be drilling platforms. If part of the problem is getting oxygen down to the ocean floor…I wonder, how much it would cost, and how effective it would be, to equip some of those platforms with giant fishtank aerators? Same principle, surely….