Effects of Salinity on Denitrification Rates in Louisiana Coastal Wetlands Soils.

Coastal wetlands areas are becoming more saline with increasing sea level rise and impacts from increased occurrence of more severe hurricanes predicting with accelerated global warming. A few studies have noted a negative effect of salinity on the ability of coastal marshes to remove nitrogen by denitrification. We examine the effect of salinity on the denitrifying enzyme activity and potential denitrification of Louisiana coastal freshwater marsh sediments. Nitrate loaded batch incubations will be inundated with a range of salinity from 0-35 ppt. The effect of salinity on DEA and potential denitrification will allow us to begin to elucidate the mechanisms of salinity-driven depressed denitrification rates. The significance of these findings can also be applied to large surface water diversion projects in the Florida Everglades and Mississippi River Delta, where more saline sediments are exposed to freshwater and nitrate loading.