The Chaoborus pump: Migrating phantom midge larvae sustain hypolimnetic oxygen deficiency and nutrient internal loading in lakes

WATER RESEARCH

卷:122

Article

Tang, Kam W.¹  Flury, Sabine^2,3  Grossart, Hans-Peter^4,5  McGinnis, Daniel F.² 

[1] Swansea Univ, Dept Biosci, Swansea SA2 8PP, W Glam, Wales

[2] Univ Geneva, Fac Sci, Sect Earth & Environm Sci, Dept FA Forel Environm & Aquat Sci DEESE, CH-1211 Geneva 4, Switzerland

[3] Ecole Polytech Fed Lausanne, Environm Engn Inst, CH-1015 Lausanne, Switzerland

[4] Leibniz Inst Freshwater Ecol & Inland Fisheries I, D-16775 Stechlin, Germany

[5] Potsdam Univ, Inst Biochem & Biol, D-14476 Potsdam, Germany

关键词: Chaoborus;    Eutrophication;    Oxygen;    Nutrient;    Remediation;   

DOI  :  10.1016/j.watres.2017.05.058

来源: Elsevier

【 摘 要 】

Hypolimnetic oxygen demand in lakes is often assumed to be driven mainly by sediment microbial processes, while the role of Chaoborus larvae, which are prevalent in eutrophic lakes with hypoxic to anoxic bottoms, has been overlooked. We experimentally measured the respiration rates of C flavicans at different temperatures yielding a Q(10) of 1.44-1.71 and a respiratory quotient of 0.84-0.98. Applying the experimental data in a system analytical approach, we showed that migrating Chaoborus larvae can significantly add to the water column and sediment oxygen demand, and contribute to the observed linear relationship between water column respiration and depth. The estimated phosphorus excretion by Chaoborus in sediment is comparable in magnitude to the required phosphorus loading for eutrophication. Migrating Chaoborus larvae thereby essentially trap nutrients between the water column and the sediment, and this continuous internal loading of nutrients would delay lake remediation even when external inputs are stopped. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

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