This study examines metal concentrations in sediments under the influence of the oxygen minimum zone of the SE-Pacific and the anthropogenic impact following industrialization in Caldera Bay (27° S), which is one of the main ore-loading ports in operation from 1849. Pb and the CRS dating method were employed to estimate the age in two sediment cores sectioned at 1 cm. Metal concentrations from selected samples suggested clear impacts of industrial activities after ∼1860 on Cu, and moderate impacts on Fe, Pb, and Zn. Further, authigenic enrichment of nutrient type and redox-sensitive elements (Ni, Cd, Mo, and V) in ancient times was observed. This enrichment was related to low oxygen at the bottom and high productivity. As this condition varies over time, it could result in erroneous estimations of preindustrial values. Overall, we highlight the impact of natural processes on metal distribution in marine sediments during environmental assessments and regulations.
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http://dx.doi.org/10.1016/j.marenvres.2022.105619 | DOI Listing |
Environ Int
January 2025
Department of Physics, University of Girona, Campus de Montilivi, Girona 17003 Spain.
Using lock-exchange experiments, this study investigates the transport and sedimentation of microplastics (MPs) via turbidity currents. Two hypotheses were tested: MP sedimentation is influenced by suspended sediment concentration and grain size. Utilizing flows with different sediment concentrations and grain sizes in combination with three different MPs (PET fibers, melamine, and PVC fragments), the experiments revealed distinct sedimentation patterns: higher sediment concentrations enhance MP transport, and turbidity currents with finer sediments transported MPs over greater distances, highlighting the importance of sediment characteristics to predict MP distribution by such flows.
View Article and Find Full Text PDFWater Res
December 2024
Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 211135, China; Sino-Danish Centre for Education and Research, University of Chinese Academy of Sciences, Beijing 100039, China; Poyang Lake Wetland Research Station, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Jiujiang 332899, China. Electronic address:
Flash drought (FD) events induced by climate change may disrupt the normal hydrological regimes of floodplain lakes and affect the plant-microbe mediated dissimilatory nitrate reduction (DNR), i.e., denitrification, anammox and dissimilatory nitrate reduction to ammonium (DNRA), thus having important consequences for nitrous oxide (NO) emissions and nitrogen (N) retention.
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 PDFPLoS One
January 2025
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, China.
Algal decomposition plays an important role in affecting phosphorus (P) release from sediments in eutrophic lakes under global warming. Yet how rising air temperature affect endogenous P release from sediments during the algal decomposition is poorly understood. In this study, effect of increasing air temperature on endogenous P release was investigated.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
January 2025
Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan.
A crude oil aggregation-forming, strictly anaerobic, Gram-stain-positive, spore-forming, rod-shaped, motile and mesophilic bacterium, named strain SH18-2, was isolated from marine sediment near Sado Island in the Sea of Japan. The temperature, salinity and pH ranges of this strain for the growth were 15-40 °C (optimum 35 °C), 0.5-6.
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