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Denitrification In The Hypolimnion Of Permanently Ice-Covered Lake Bonney, Antarctica, B. B. Ward, J. Granger, M. T. Maldonado, K. L. Casciotti, S. Harris, Mark Wells
Denitrification In The Hypolimnion Of Permanently Ice-Covered Lake Bonney, Antarctica, B. B. Ward, J. Granger, M. T. Maldonado, K. L. Casciotti, S. Harris, Mark Wells
Marine Sciences Faculty Scholarship
The distribution of denitrification was investigated in the hypolimnion of the east and west lobes of permanently ice-covered Lake Bonney, Taylor Valley, Antarctica. Anomalously high concentrations of dissolved inorganic nitrogen (DIN; nitrate, nitrite, ammonium and nitrous oxide) in the oxygen-depleted hypolimnion of the east lobe of the Lake implied that denitrification is or was active in the west, but not in the east lobe. While previous investigations reported no detectable denitrification in the east lobe, we measured active denitrification in samples from both the east and west lobes. In the west lobe, measured denitrification rates exhibited a maximum at the …
What Limits Bacterial Production In The Suboxic Region Of Permanently Ice-Covered Lake Bonney, Antarctica?, B. B. Ward, J. Granger, M. T. Maldonado, Mark Wells
What Limits Bacterial Production In The Suboxic Region Of Permanently Ice-Covered Lake Bonney, Antarctica?, B. B. Ward, J. Granger, M. T. Maldonado, Mark Wells
Marine Sciences Faculty Scholarship
Bacterial production assays (thymidine incorporation rates) were used to evaluate the activity of heterotrophic bacteria at the chemocline region in both the East (ELB) and West (WLB) Lobes of permanently ice-covered Lake Bonney, in the Taylor Valley of Antarctica. The magnitude of activity varied dramatically within the depth interval of 1 to 2 m from moderate to very low levels below the chemocline, especially in the East Lobe, where chemical distributions indicate the absence of a normally functioning nitrogen cycle. Several parameters (e.g. addition of nutrients or chelators, dilution) were manipulated in incubation experiments in order to identify factors that …