Rising water temperatures endanger health of coastal ecosystems, study finds
"Increasing water temperatures are responsible for the accumulation of a chemical called nitrite in marine environments throughout the world, a symptom of broader changes in normal ocean biochemical pathways that could ultimately disrupt ocean food webs, according to new research from the University of Georgia. "
Temperature Decouples Ammonium and Nitrite Oxidation in Coastal Waters
"Nitrification is a two-step process linking the reduced and oxidized sides of the nitrogen cycle. These steps are typically tightly coupled with the primary intermediate, nitrite, rarely accumulating in coastal environments. Nitrite concentrations can exceed 10 μM during summer in estuarine waters adjacent to Sapelo Island, Georgia, U.S.A. Similar peaks at other locations have been attributed to decoupling of the two steps of nitrification by hypoxia; however, the waters around Sapelo Island are aerobic and well-mixed. Experiments examining the response to temperature shifts of a nitrifying assemblage composed of the same organisms found in the field indicate that ammonia- and nitrite-oxidation become uncoupled between 20 and 30 °C, leading to nitrite accumulation. [...]"
Source: Environmental Science & Technology
Authors: Sylvia C. Schaefer, James T. Hollibaugh