Biofiltering function of macrophytes for a potentially toxic elements cycles in aquatic systems

The removal of toxic elements from freshwaters is challenging. Among the crucial agents facilitating water purification, macrophytes stand out as significant contributors. This study examines the Selenga River delta, one of the largest freshwater deltas that serves as a buffer for Lake Baikal from mining and urban activities in the watershed. We conducted summer field campaigns in 2011-2013 and 2017-2019, when water, suspended and bottom sediments, and macrophytes (Phragmites australis, Nuphar pumila, Ceratophyllum demersum) were sampled. Potentially toxic elements (PTEs) concentrations were analyzed in all samples using ICP-MS and ICP-AES methods at “VIMS” Institute (Moscow). Bioconcentration Factors (BCF) indicating the PTEs accumulation in aquatic plants, calculated in relation to the PTEs content in suspended and bottom sediments, and river water revealed that plants exhibit the highest accumulation rates for dissolved PTEs, while BCF values for suspended and bottom sediments were lower. Coastal Phragmites australis and submerged Ceratophyllum demersum had higher BCF levels relative to dissolved PTEs than floating Nuphar pumila. Our study demonstrates the crucial contribution of macrophyte species in accumulation of pollutants originating from upstream sources in the delta region. Combining these findings with the application of remote sensing methods to evaluate the spatial distribution of macrophyte species improves our comprehension of sedimentation patterns and the capacity of macrophytes to intercept PTEs fluxes in the deltaic ecosystems.

Primary Presenter: Galina Shinkareva, Illinois State University (galina1989@yahoo.com)

Authors:

Galina Shinkareva, Illinois State University  (galina.shinkareva@gmail.com)

Tatiana Dubrovskaya, Lomonosov Moscow State University  (dtv97@yandex.ru)

Mikhail Lychagin, Lomonosov Moscow State University  (lychagin2008@gmail.com)

Nikolay Kasimov, Lomonosov Moscow State University  (nskasimov@mail.ru)