The mercury (Hg) cycle in estuaries has been globally discussed, although Holocene deposition in mangrove sediments remains unknown. Herein, a sediment core from a mangrove system in southeastern Brazil was C-dated to evaluate millennial Hg deposition. The highest Hg concentrations (1010-2540 ng g) in surface sediments were explained by emissions from a chlor-alkali industry (1964 CE). However, Hg levels were also high in pre-industrial periods, associated to fine grain-size and algal organic deposition. Less anomalous Hg concentrations in bottom sediments indicate Holocene ages (~1940-3324 cal yr BP), potentially associated to Serra do Mar mountains weathering. This study reveals the capacity of mangrove to retain Hg over millennial time scales, acting as significant and long-term Hg sinks. Therefore, the use of Hg as an Anthropocene marker must be considered cautiously in coastal systems that act as Hg sinks in times when environmental changes were not caused by human activities.
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http://dx.doi.org/10.1016/j.marpolbul.2021.113031 | DOI Listing |
Mar Pollut Bull
January 2025
State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China.
Investigations of the spatial-temporal variations of nutrients within mangrove coastal zones are essential for assessing the environmental status of an aquatic ecosystems. However, major processes controlling nitrate cycle along the submarine groundwater discharge (SGD) pathway from the mangrove areas to adjacent tidal creek remain underexplored. A time series measurement over a 25 h tidal cycle was conducted in Qinglan Bay tidal creek (Hainan Island, China).
View Article and Find Full Text PDFSci Total Environ
January 2025
College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China; Zhongshan Innovation Center of South China Agricultural University, Zhongshan 528400, China. Electronic address:
Mangrove sediments in southern China are a large reservoir for microplastics (MPs). In particular, polyethylene microplastics (PE-MPs) are environmentally toxic and have accumulated in large quantities in these sediments, posing a potential threat to the overall mangrove and the organisms that inhabit it. We screened sediments from 5 mangrove sites and identified a potential source of PE-MP degrading bacteria.
View Article and Find Full Text PDFMar Environ Res
January 2025
Key Laboratory of Marine Geology and Metallogeny, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China; Laboratory for Marine Geology, Qingdao Marine Science and Technology Center, Qingdao, 266237, China. Electronic address:
Mangrove wetlands are strategic locations for mitigating climate changes. In order to address the harm of rapid climate change to mangrove ecosystems, it is necessary to scientifically predict the fate of mangrove ecosystems, which can be achieved by reconstructing the development history of mangrove forests. This study analyzes the contribution of mangrove-derived organic matter (CMOM) from sediment core F in Phang Nga Province, Thailand by using the endmember mixing model based on stable organic carbon isotopes (δC) and C/N (molar) ratio.
View Article and Find Full Text PDFSci Total Environ
January 2025
College of Marine Sciences, South China Agricultural University, Guangzhou 510642, China. Electronic address:
Mangrove ecosystem has attracted global attention as a hotspot for mercury (Hg) methylation. Although numerous biotic and abiotic parameters have been reported to influence methylmercury (MeHg) production in sediments, the key factors determining the elevated MeHg levels in mangrove wetlands have not been well addressed. In this study, Hg levels in the sediments from different habitats (mudflats, mangrove fringe, and mangrove interior) in the Futian mangrove wetland were investigated, aiming to characterize the predominant factors affecting the MeHg production and distinguish the key microbial taxa responsible for Hg methylation.
View Article and Find Full Text PDFEnviron Pollut
January 2025
Center of Advanced Technology for the Environment (CATE), Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, 790-8566, Japan; Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama, 790-8577, Japan. Electronic address:
The first comprehensive analysis of halogenated organic compounds (HOCs), including 209 full congeners of polychlorinated biphenyls (PCBs), 26 organochlorinated pesticides (OCPs), 41 polybrominated diphenyl ethers (PBDEs), and four other brominated flame retardants (BFRs), was performed on surface mangrove sediments from Bintan Island, Province of the Riau Archipelago, Indonesia. Among the measured HOC contaminants, the mean concentration of ∑PCBs (2.3 ± 0.
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