Spatiotemporal distribution and environmental control factors of halocarbons in the Yangtze River Estuary and its adjacent marine area during autumn and spring

Yawen Zou; Zhen He; Chunying Liu; Gui-Peng Yang

doi:10.1016/j.envpol.2022.119244

Spatiotemporal distribution and environmental control factors of halocarbons in the Yangtze River Estuary and its adjacent marine area during autumn and spring

Environ Pollut. 2022 Jul 1:304:119244. doi: 10.1016/j.envpol.2022.119244. Epub 2022 Apr 1.

Authors

Yawen Zou¹, Zhen He², Chunying Liu², Gui-Peng Yang³

Affiliations

¹ Frontiers Science Center for Deep Ocean Multispheres and Earth System, And Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.
² Frontiers Science Center for Deep Ocean Multispheres and Earth System, And Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Institute of Marine Chemistry, Ocean University of China, Qingdao, 266100, China.
³ Frontiers Science Center for Deep Ocean Multispheres and Earth System, And Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Institute of Marine Chemistry, Ocean University of China, Qingdao, 266100, China. Electronic address: gpyang@mail.ouc.edu.cn.

PMID: 35378200
DOI: 10.1016/j.envpol.2022.119244

Abstract

The oceanic production and release of volatile halocarbons (VHCs) to the atmosphere play a vital role in regulating the global climate. In this study, seasonal and spatial variations in VHCs, including trichlorofluoromethane (CFC-11), methyl iodide (CH₃I), dibromomethane (CH₂Br₂), and bromoform (CHBr₃), and environmental parameters affecting their concentrations were characterized in the atmosphere and seawater of the Yangtze River Estuary and its adjacent marine area during two cruises from October 17 to October 26, 2019 and from May 12 to May 25, 2020. Significant seasonal variations were observed in the atmosphere and seawater because of seasonal differences in the prevalent monsoon, water mass (Yangtze River Diluted Water), and biogenic production. VHCs concentrations were positively correlated with Chl-a concentrations in the surface water during autumn. The average sea-to-air fluxes of CH₃I, CH₂Br_2, and CHBr₃ in autumn were 19.7, 4.0, and 7.6 nmol m^-2 d^-1, respectively, while those in spring were 6.3, 6.4, and -3.6 nmol m^-2 d^-1. In the ship-based incubation experiments, ocean acidification and dust deposition had no significant effects on VHCs concentrations. The concentrations of CH₂Br₂ and CHBr₃ were significantly positively correlated with phytoplankton biomass under lower pH condition (M3: pH 7.9). This result indicated that CH₂Br₂ and CHBr₃ concentrations were mainly related to the biological release.

Keywords: Distribution; Halocarbons; Ship-based incubation experiments; Yangtze river estuary.

MeSH terms

China
Environmental Monitoring
Estuaries*
Hydrocarbons, Halogenated* / analysis
Hydrogen-Ion Concentration
Rivers / chemistry
Seasons
Seawater / chemistry
Water

Substances

Hydrocarbons, Halogenated
Water