A comparative study of sediment-bound trace elements and iron-bearing minerals in S. alterniflora and mudflat regions

Elevated sediment-bound trace elements and iron-bearing minerals in intertidal habitats have been drawing more attention, but there is rarely a comparative study assessing these features between halophyte plants habitat and mudflats. In this paper, sediment samples were collected in S. alterniflora and the corresponding mudflat at 7 typical intertidal habitats (Chongming, Xiapu, Yueqing, Yunxiao, Zhanjiang, Beihai, and Zhuhai) from north to south of China, respectively. Trace element concentrations, including arsenic (As), mercury (Hg), cadmium (Cd), antimony (Sb) and scandium (Sc), and magnetic characteristics were determined. Variations in sediment-bound As, Hg, Cd, Sb were associated with S. alterniflora. Accumulations of sediment-bound As, Hg, Sb, Cd and Sc in S. alterniflora in Beihai were much higher than those in the mudflat. Concentration of sediment-bound As, Hg, Sb, Cd and Sc in S. alterniflora and mudflat were comparable in Yueqing, Xiapu, Yunxiao and Zhanjiang, respectively. Variations in low-frequency susceptibility, susceptibility of anhysteretic remanence magnetization, saturation isothermal remanence magnetization and frequency dependent susceptibility can explain the site-dependent accumulation of magnetic minerals in intertidal habitats. S. alterniflora tend to deplete sediment magnetic concentration and enhance sediment-bound As, Hg, and Sb concentration. The results of our study further revealed the coexistence of trace elements and magnetic minerals between the sampling sites and vegetative in intertidal habitats. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study compared the sediment characteristics between halophyte plants habitat and mudflats in intertidal habitats, showing higher concentrations of trace elements in sediment associated with S. alterniflora in Beihai. Variations in magnetic minerals accumulation in different sites explained the differences in sediment-bound As, Hg, Sb, Cd and Sc between S. alterniflora and mudflats.