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Posts Tagged ‘dead zone’

What Causes Oxygen to be Used Up In Deep Waters?

by February 26, 2012

ANSWER (CURRENTLY UNDER REVIEW): Bacteria use up the oxygen in the process of breaking down organic matter, like the waste from tiny animals and dead algae. This answer is focused on coastal ocean waters, but generally applies to deep waters in estuaries, ponds, lakes, and slow-moving stretches of rivers.
 

Q001 how oxygen is used up in deep waters v04

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A Billion Dollars Flowing Down the Mississippi Annually

by December 20, 2011

In a recent post, I did a bit of research to update the picture of nutrient flows down the Mississippi due to runoff and other sources in its watershed. There’s been an ongoing debate about the source of the nutrients in the river that are directly linked to low-oxygen conditions in the Gulf of Mexico.

For a taste of the debate, check out the controversy a year ago surrounding the premier of Troubled Waters, A Mississippi River Story (link to view on Twin Cities Public TV). Among other activity, there was a heated back-and-forth on the opinion pages of the Minneapolis Star Tribune (first piece arguing that research for film was dubious, counter piece by producers about the research behind the film). The flare up nearly squelched the premier, although it ultimately took place.

Personally, I experienced how difficult it can be to establish a “consensus view” of how to describe nitrogen flows for the report on ecosystem indicators described in my previous post. There was a constant tension throughout the report process to “tell readers what to do with the information” rather than just “giving them the facts.” I believe we ultimately struck a good balance, however, we nearly had resignations of participants when we unintentionally pushed the line on the indicator dealing with the movement of nitrogen and got too close to pointing fingers. (more…)

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