Title of article :
The contribution of anaerobic ammonium oxidation to nitrogen loss in two temperate eutrophic estuaries
Author/Authors :
Teixeira، نويسنده , , Catarina and Magalhمes، نويسنده , , Catarina and Joye، نويسنده , , Samantha B. and Bordalo، نويسنده , , Adriano A.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2014
Abstract :
Studies of anaerobic ammonium oxidation (anammox) continue to show the significance of this metabolic pathway for the removal of nitrogen (N) in several natural environments, including estuaries. However, the seasonal dynamics of the anammox process and related environmental controls within estuarine systems remains poorly explored. We evaluated the seasonal anammox activity along a salinity gradient in two temperate Atlantic estuaries, the Ave and the Douro (NW Portugal). Anammox potential rates were measured in anaerobic sediment slurries using 15N-labeled NO 3 − and NH 4 + amendments. Production of 29N2 and 30N2 in the slurries was quantified using membrane inlet mass spectrometry (MIMS). Environmental characteristics of the sediment and water column were also monitored. Anammox potentials in the Ave and Douro estuarine sediments varied between 0.8–8.4, and 0–2.9 nmol cm−3 wet sediment h−1, respectively, with high seasonal and spatial fluctuations. Inorganic nitrogen availability emerged as the primary environmental control of anammox activity, while water temperature appeared to modulate seasonal variations. The contribution of anammox to overall N2 production averaged over 20%, suggesting that the role of anammox in removing fixed N from these two systems cannot be neglected.
Keywords :
Anammox , Nitrogen , sediments , estuary
Journal title :
Estuarine, Coastal and Shelf Science
Journal title :
Estuarine, Coastal and Shelf Science