ABSORPTION OF DISSOLVED OXYGEN BY THE UPPER LAYER OF BOTTOM SEDIMENTS IN A SMALL LAKE DURING LATE WINTER

• Main Authors: Nikolai Palshin, Galina Zdorovennova, Tatyana Efremova, Roman Zdorovennov, Galina Gavrilenko, Sergey Bogdanov, Sergey Volkov, Arkady Terzhevik
• Format: Article
• Language: English
• Published: Karelian Research Centre of the Russian Academy of Sciences 2017-03-01
• Series: Transactions of the Karelian Research Centre of the Russian Academy of Sciences
• Subjects: dissolved oxygen; bottom sediments; absorption of dissolved oxygen; shallow lake; ice-covered period
• Online Access: http://journals.krc.karelia.ru/index.php/limnology/article/view/451

<p>The results of measurements of dissolved oxygen in the vicinity of the water-sediment interface in a small mesotrophic Lake Vendyurskoe (Southern Karelia) at the end of the ice-covered period are reported. The measurements were carried out in April 2008 on 18 slope sites (depths from 2.5 m to 9.3 m), with a predominance of water-saturated silt. The content of dissolved oxygen decreased sharply at the contact with silt. The maximum oxygen gradient reached 9 (mgO₂/l)/cm on the silt surface . The rate of oxygen consumption by the sediment was maximal at a depth of 6-8 m. This rate was 1.5 times lower in shallower and deeper areas. The amount of dissolved oxygen absorption by sediments was estimated based on the lake’s bathymetric curve. A comparison of our estimates with the measured dissolved oxygen content in the water column suggests that over 60 % of oxygen reduction is the result of absorption by silt and less than 40 % is due to the destruction of labile organic matter in the water column at the stage of winter stagnation.</p>