Vaccare, Jessica, Meselhe, Erab, and John White. 2019. The denitrification potential of eroding wetlands in Barataria Bay, LA, USA: Implications for river reconnection.” Science
Vaccare, Jessica, Meselhe, Erab, and John White. 2019. The denitrification potential of eroding wetlands in Barataria Bay, LA, USA: Implications for river reconnection.” Science of The Total Environment, 686, pp. 529–537., https://doi.org/10.1016/j.scitotenv.2019.05.475
The Problem with Nutrients
The last century has seen a doubling of nitrate in the Mississippi River, a fertilizer which humans use for farming and agriculture. These extra nutrients commonly wash into natural ecosystems and contribute to poor water quality. Eutrophication is one result of nutrient enrichment which can lead to algal blooms and “dead zones”.
“Dead zone” areas have very low oxygen concentrations and cannot support animal life, usually leading to die-offs of important animals that cannot escape the bad conditions. One report found that eutrophication has created a total area of 245,000 square kilometers of “dead-zones” world-wide, about the size of the whole United Kingdom.
Luckily, wetlands have the ability to capture and remove excess nutrients from the system, preventing ecosystem damage from eutrophication. Microbes living in wetland soils can use nitrate as an energy source during denitrification and transform the nitrogen into a less damaging form. Wetland plants also remove nitrogen, taking it up from nitrate enriched water and using it to grow, like plants in a well fertilized garden.
Nitrogen removal is very important in coastal Louisiana where the Gulf of Mexico Dead Zone, the second largest in the world, occurs just offshore and is fed mostly by the nutrient rich Mississippi River. Howeve