1500 / 2024-09-27 19:05:24

Does microplastics found in submarine groundwater discharge in coastal bay ------ case from Quanzhou Bay and Meizhou Bay?

microplastics，submarine groundwater discharge，microplastics flux

    Although microplastics (MPs) are known to be found in global oceans, rivers and atmosphere, their transport and fate in the groundwater largely unknown. Microplastics are retained in the coastal waters, and with the change of hydrodynamic conditions, they are constantly transported between groundwater and near-shore seawater. Submarine groundwater discharge (SGD) has been recognized as an important carrier of water which is a key factor to quantify in evaluating material budgets of any coastal system.

    In this study, Quanzhou Bay and Meizhou Bay, which are typical representatives of the area near the coastal Fujian-Taiwan Strait into the sea runoff, were chosen as the study area. Twenty-four groundwater samples and thirty -four seawater samples were collected in the study area in autumn 2021 and spring 2022 respectively. This study show that the groundwater MPs samples abundance in Quanzhou Bay and Meizhou Bay are 5.40~9.82 n/L (7.53±1.88 n/L) and 4.62~27.17 n/L (17.13 ±10.25n/L), and the seawater MPs samples abundance ranged from 3.51~7.95 n/L (6.12 ±1.51n/L) and 3.29~16.46 n/L (7.81±4.62 n/L) respectively. This study is expected to reveal new sources of coastal microplastics and quantify the net SGD-associated microplastics fluxes, which is important for the understanding of the transport and fate of new pollutants in multi-environmental medium and the development of prevention and controlling strategies.

    This study was supported by the National Natural Science Foundation of China (NSFC) (U2005207、41776088), Key Research and Development Project of Hainan Province (ZDYF2022SHFZ317), Natural Science Key Foundation of Fujian Province, China (2020J01412103). We are grateful to Prof. Guizhi Wang's group about their support and assistance at the College of Ocean and Earth Sciences, Xiamen University.