Unionid shells (Hyriopsis cumingii) record manganese cycling at the sediment-water interface in a shallow eutrophic lake in China (Lake Taihu)
Autor: | Bernd R. Schöne, Regina Mertz-Kraus, Eric Otto Walliser, Liqiang Zhao |
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Rok vydání: | 2017 |
Předmět: |
010504 meteorology & atmospheric sciences
Environmental change Aquatic ecosystem Paleontology Mussel 010501 environmental sciences Oceanography 01 natural sciences Algal bloom Sediment–water interface Water quality Bivalve shell Eutrophication Ecology Evolution Behavior and Systematics Geology 0105 earth and related environmental sciences Earth-Surface Processes |
Zdroj: | Palaeogeography, Palaeoclimatology, Palaeoecology. 484:97-108 |
ISSN: | 0031-0182 |
Popis: | Aquatic eutrophication is becoming a serious environmental problem throughout the world. The utility of bivalves as bio-filters to improve water quality and reduce algal blooms has been widely acknowledged, but the potential usefulness of bivalve shells as retrospective monitors of eutrophication-induced environmental change has received little attention. Here, we present the first multi-year, high-resolution Mn/Ca shell records of the freshwater mussel, Hyriopsis cumingii (Lea, 1852) from a shallow eutrophic lake (Lake Taihu, China). Mn/Ca shell time-series of the two studied shells exhibit a high degree of synchrony after being placed in a precise temporal context by means of growth pattern analysis. There is a large inter-annual variability of Mn/Ca shell records during 2011–2015, with the highest value occurring in 2013. Mn/Ca shell also displays a pronounced intra-annual variability with maxima consistently occurring during late spring/early summer. The high reproducibility of Mn/Ca shell time-series among contemporaneous specimens highlights the existence of strong environmental rather than biological control on the incorporation of Mn into the shells. In particular, the striking feature of late spring/early summertime Mn/Ca shell maxima is synchronous with the occurrence of reducing conditions beneath the sediment-water interface (SWI). The latter results in substantial increases of biologically available Mn 2 + in the sediment pore water and organic particles, the element being rapidly taken up from these sources by the mussels with subsequent incorporation of Mn into their shells. Therefore, Mn/Ca shell can potentially serve as a high-resolution proxy of the mobility of Mn at the SWI. As demonstrated by the present study, documenting and understanding geochemical properties of bivalve shells can help to retrospectively monitor eutrophication-induced environmental change in aquatic ecosystems. |
Databáze: | OpenAIRE |
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