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Oxygen‐consuming processes at the profundal and littoral sediment‐water interface of a small meso‐eutrophic lake (Lake Vechten, The Netherlands)
Author(s) -
Sweerts JeanPierre R. A.,
BärGilissen MarieJose,
Cornelese Adi A.,
Cappenberg Thomas E.
Publication year - 1991
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1991.36.6.1124
Subject(s) - profundal zone , anoxic waters , littoral zone , eutrophication , hypolimnion , environmental chemistry , sediment , oxygen , chemistry , geology , oceanography , nutrient , geomorphology , organic chemistry
Oxygen consumption in the profundal gyttja and littoral sands of Lake Vechten was determined with pore‐water analyses and core incubations. Methane (58–64%), ammonium (10–13%), iron (2–6%), and sulfide (<12%) oxidation accounted for ∼75% of the oxygen consumed in the profundal sediments. Almost the complete diffusive flux of CH 4 out of the anoxic layer into the oxic surface layer (7.9–9.4 mmol m ‒2 d ‒1 ) was oxidized, while only 27–36% of the NH 4 + flux (5.1–5.2 mmol m ‒2 d ‒1 ) was oxidized in the oxic surface layer and 64–73% diffused into the overlying water. In contrast to the profundal sediments, oxidation of reduced end products of anoxic respiration was of minor importance (<15%) in littoral sandy sediments. Also, sediment oxygen consumption rate was higher in the profundal gyttja (29 mmol m ‒2 d ‒1 at 7°C) during overturn than in the littoral sandy sediments in both winter (8.7 mmol m ‒2 d ‒1 at 7°C) and summer (18.6 mmol m ‒2 d ‒1 at 22°C). Poisoning the sediment cores with formaldehyde stopped bacterial activity, but oxygen profile measurements showed that this treatment does not reveal the bacterial or chemical nature of the oxidative processes.