The influence of macrophytes on sediment resuspension and the effect of associated nutrients in a shallow and large lake (Lake Taihu, China)

PLoS One. 2015 Jun 1;10(6):e0127915. doi: 10.1371/journal.pone.0127915. eCollection 2015.

Abstract

A yearlong campaign to examine sediment resuspension was conducted in large, shallow and eutrophic Lake Taihu, China, to investigate the influence of vegetation on sediment resuspension and its nutrient effects. The study was conducted at 6 sites located in both phytoplankton-dominated zone and macrophyte-dominated zone of the lake, lasting for a total of 13 months, with collections made at two-week intervals. Sediment resuspension in Taihu, with a two-week high average rate of 1771 g·m(-2)·d(-1) and a yearly average rate of 377 g·m(-2)·d(-1), is much stronger than in many other lakes worldwide, as Taihu is quite shallow and contains a long fetch. The occurrence of macrophytes, however, provided quite strong abatement of sediment resuspension, which may reduce the sediment resuspension rate up to 29-fold. The contribution of nitrogen and phosphorus to the water column from sediment resuspension was estimated as 0.34 mg·L(-1) and 0.051 mg·L(-1) in the phytoplankton-dominated zone. Sediment resuspension also largely reduced transparency and then stimulated phytoplankton growth. Therefore, sediment resuspension may be one of the most important factors delaying the recovery of eutrophic Lake Taihu, and the influence of sediment resuspension on water quality must also be taken into account by the lake managers when they determine the restoration target.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • China
  • Environmental Monitoring
  • Eutrophication
  • Geologic Sediments / analysis*
  • Lakes*
  • Nitrogen / analysis
  • Phosphorus / analysis

Substances

  • Phosphorus
  • Nitrogen

Grants and funding

This work was funded by the External Cooperation Program of the Chinese Academy of Sciences (GJHZ1214, http://www.cas.cn/, received by GZ), the National Natural Science Foundation of China (grant 41230744, http://www.nsfc.gov.cn/, received by BQ), the Key Program of Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences (NIGLAS2012135002, http://niglas.ac.cn/, received by GZ), and the Finnish Academy of Science (FICCA, No. 256244 and No. 256240, http://www.acadsci.fi/, received by LN and AV). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.