We investigate the distributions of the metalloid arsenic (As) and metals iron (Fe) and manganese (Mn) in the sediments of two pristine areas of a biological reserve in the Patos Lagoon Estuary. This area is occupied by Spartina alterniflora and by Neohelice granulata crab colonies and low concentrations of As are expected. The bioturbation/bioirrigation of sediments by crabs and the roots of plants lead to the penetration of oxygen below the oxic/suboxix division and the subsequent precipitation of Fe-Mn hydroxides. Ferruginous incrustations and nodules along roots and crab channels propagate to depths of over 35 cm and sediment contains up to 33 mg kg of As. The metalloid distribution in sediments is strongly correlated with that of Fe but not with Mn. This study revealed that areas with biologically disturbed sediments could demonstrate contamination in As, which is not anthropogenic in origin.
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http://dx.doi.org/10.1007/s00128-016-2024-z | DOI Listing |
Can J Microbiol
January 2025
Sherbrooke Research and Development Centre, Agriculture and Agri-Food Canada, Sherbrooke, Quebec, Canada;
Agricultural practices, specifically the use of antibiotics and other biocides, have repercussions on human, animal and plant health. The aim of this study was to evaluate the levels of Enterobacteriaceae and Enterococcus, as antibiotic resistant marker bacteria, in various matrices across the agro-ecosystem of an antibiotic-free swine farm in Quebec (Canada), namely pig feed, feces, manure, agricultural soil, water and sediment from a crossing stream, and soil from nearby forests. Samples were collected in fall 2022, spring and fall 2023 and spring 2024.
View Article and Find Full Text PDFIntegr Environ Assess Manag
January 2025
Department of Civil, Environmental, and Construction Engineering, Texas Tech University, Lubbock, TX, United States.
This study evaluated a novel ex situ passive sampling biomimetic extraction (BE) method to estimate toxic potency in sediments. Gas chromatography with flame ionization detection (GC-FID) analysis of polydimethylsiloxane fibers equilibrated with field sediments was used to quantify bioavailable polyaromatic hydrocarbons (PAHs) and other unresolved, site-specific contaminant mixtures. This method is biomimetic because contaminants partition to the fiber based on hydrophobicity and abundance, and GC-FID quantification accounts for all constituents absorbed to the fiber that may contribute to toxicity.
View Article and Find Full Text PDFIntegr Environ Assess Manag
January 2025
Department of Environmental Toxicology, College of Agricultural and Environmental Sciences, University of California, Davis, CA, United States.
The herbicide oxyfluorfen [OXY; 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene] recently emerged as a potential solution to combat herbicide resistance in California rice. Proposed as a preemergent applied preflood to soil, products are in development for use with OXY-tolerant rice strains. Currently, OXY is not registered for use with rice and its use in or near aquatic resources is restricted due to its high aquatic toxicity.
View Article and Find Full Text PDFWorld J Microbiol Biotechnol
January 2025
Graduate School of Science and Technology, Shizuoka University, Shizuoka, Japan.
Marine resources are attractive for screening new useful bacteria. From a marine sediment sample, we performed isolation and screening of bacterial strains in search of new bioactive compounds. HPLC and ESI-MS analysis indicated that the new bacterium, Lysinibacillus sp.
View Article and Find Full Text PDFMicrobiol Resour Announc
January 2025
Singapore Centre for Environmental Life Sciences Engineering (SCELSE), National University of Singapore, , Singapore.
Coastal water, sediment, and algae samples were collected from St. John's Island, Singapore, and enriched in either broth or agar. Metagenomic sequencing was carried out on DNA from these enrichments and analyzed.
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