Nitrogen Cycling and Denitrification in Galveston Bay

Denitrification is a microbial process that converts inorganic nitrogen (nitrate or nitrite) to a biologically unavailable form of nitrogen (nitrogen gas) and regarded as a significant sink for the nitrogen loading in coastal environment. Seasonal pattern of denitrification with the environmental factors potentially important for the process was studied in Galveston Bay, Texas from 1995 to 1998. The denitrification rate measured with direct nitrogen has flux ranged from 0.29 to 6.12 mmole N2/m^2/day. Temperature was the most important variable that explains the variability of denitrification rate in Galveston Bay. The rate was higher in the sediment composed of fine grain size than the coarse sediment. The denitrification rates accounted for 51% of total nitrogen loading into the bay.