Nitrification rates, ammonium and nitrate distribution in upper layers of the water column and in sediments of the Indian sector of the Southern Ocean

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• 作者：Bianchi ; Micheline ; Feliatra ; F. ; Tré ; guer ; Paul ; Vincendeau ; Marie-Anne ; Morvan ; Jean
• 刊名：Deep Sea Research Part II: Topical Studies in Oceanography
• 出版年：1997
• 出版时间：1997
• 年：1997
• 卷：44
• 期：5
• 页码：1017-1032
• 全文大小：918 K

文摘

During the ANTARES 1/F-JGOFS cruise (April-May 1993) concentrations of inorganic nitrogen, nitrification rates (ammonium and nitrite oxidation) and ¹⁴C carbonate incorporation by nitrifying bacteria were measured at 0, 50 and 100 m in the water column, and at the water-sediment interface between the polar front (52°S) and the subantarctic and subtropical fronts (42°S) in the Indian Ocean Sector of the Antarctic Ocean. The 0-100 m water layer showed a global increase of NH⁺₄ (from 0.4 to 0.6 μM) and a global decrease of NO⁻₂ + NO⁻₃ (from 25 to 5 μM) along the south-north transect. Anomalies were detected for both ammonium and nitrite + nitrate concentrations in the SubTropical Front (STF) and SubAntarctic Front (SAF). Pelagic nitrifying activities (N oxidation) did not demonstrate any latitudinal gradient in the water column. In terms of integrated rates between 0 and 100 m, the nitrification increased by a factor 1.8-2 in the STF-SAF area. The N oxidation processes mostly depended on the substrate availability. For both ammonium and nitrite oxidizers the C fixation was well correlated (r