In situ resuspension rate monitoring method in the littoral zone with multi-ecotypes of a shallow wind-disturbed lake

Abstract

Sediment resuspension has been recognized as a crucial internal process in aquatic ecosystems. However, there is still a lack of reliable measuring methods due to the complex hydrodynamic conditions in large shallow eutrophic lakes. In this study, sequential sediment traps (SST) and instantaneous multiple point (IMP) methods were compared at 6 sites located in the littoral zone of Zhushan Bay in Lake Taihu. Results show that the average resuspension rates (RRs) estimated using the IMP method at sites 1 to 6 were 266.39, 272.79, 235.17, 254.95, 392.25, and 483.85 g·m⁻²d⁻¹, respectively. While the RRs estimated using the SST method were 195.16, 236.99, 116.76, 156.23, 389.53, and 509.85 g·m⁻²d⁻¹, respectively. In wind-disturbed areas, both methods were suitable for RR analysis in large and shallow eutrophic lakes and SST provides high-resolution temporal RR estimations. However, in the areas with cyanobacterial blooms and vegetation cover, the IMP method overestimated the RR. Therefore, SST was more suitable across different conditions in large and shallow eutrophic lakes, providing a simple, accurate, and high-resolution temporal estimation of RR, while furthering our understanding of lake evolution processes.

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