Biomarker evidence for anammox in the oxygen minimum zone of the Eastern Tropical North Pacific

Anaerobic oxidation of ammonium (anammox) is an important process in the marine nitrogen cycle. It has been estimated to contribute up to 50% of nitrogen loss from the ocean, and is especially prevalent within oxygen minimum zones (OMZs). Here we studied the presence and distribution of anammox in the extended OMZ of the Eastern Tropical North Pacific (ETNP) using ladderane fatty acids, specific biomarkers for anammox bacteria. The validity of ladderane fatty acids as proxies for anammox bacteria was demonstrated by their excellent correspondence with anammox 16S rRNA functional gene abundance... Mehr ...