New rock magnetic results (thermal fluctuation tomography, high-resolution first-order reversal curves and low temperature measurements) for samples from the Paleocene-Eocene thermal maximum and carbon isotope excursion in cored sections at Ancora and Wilson Lake on the Atlantic Coastal Plain of New Jersey indicate the presence of predominantly isolated, near-equidimensional single-domain magnetic particles rather than the chain patterns observed in a cultured magnetotactic bacteria sample or magnetofossils in extracts. The various published results can be reconciled with the recognition that chain magnetosomes tend to be preferentially extracted in the magnetic separation process but, as we show, may represent only a small fraction of the overall magnetic assemblage that accounts for the greatly enhanced magnetization of the carbon isotope excursion sediment but whose origin is thus unclear.
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http://dx.doi.org/10.1073/pnas.1205308110 | DOI Listing |
Food web architecture and trophic interactions between organisms can be studied using ratios of naturally occurring stable isotopes of carbon (C/C) and nitrogen (N/N). Most studies, however, focused on free-living organisms, but recently, there has been growing interest in understanding trophic interactions of parasites. The crustacean ectoparasite is a well-studied parasite of freshwater teleost fish, which has low host specificity and a cosmopolitan distribution.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Department of Plankton and Microbial Ecology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Stechlin, Germany; Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany. Electronic address:
Ecological impacts of tire wear particles (TWPs) on microbial communities and biogeochemical cycles in freshwater remain largely unknown. Here, we conducted a microcosm experiment to investigate interactions between the overlying water and sediment without and with TWPs addition in a rural vs. urban lake system.
View Article and Find Full Text PDFSci Total Environ
January 2025
Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada. Electronic address:
Mercury (Hg) and persistent organic pollutant (POP) accumulation among species and biomagnification through food webs is typically assessed using stable isotopes of nitrogen (δN) and carbon (δC) in bulk (whole) tissues. Yet, bulk isotopic approaches have limitations, notably from the potential overlap of isotope values from different dietary sources and from spatial variation in source (baseline) signals. Here, we explore the potential of fatty acid carbon isotopes (FA δC) to (1) evaluate the trophic structure of a marine food web, (2) distinguish feeding patterns among four marine mammal consumers, (3) trace contaminant biomagnification through a food web, and (4) explain interspecific variation in contaminants among high-trophic position predators.
View Article and Find Full Text PDFSci Data
January 2025
Department of Archaeology, Max Planck Institute of Geoanthropology, Jena, 07745, Germany.
Here, we present the North American Repository for Archaeological Isotopes (NARIA), the largest open-access compilation of previously reported isotopic measurements (n = 28,374) from bioarchaeological samples in North America (i.e., Canada, Greenland, Mexico, and the United States of America) covering a time-frame of more than 12,000 years.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Department of Ecology and Coastal Management, Instituto de Ciencias Marinas de Andalucía (ICMAN-CSIC), Avda. República Saharaui, 2, Puerto Real, Cadiz, 11510, Spain; Associate Research Unit "Blue Growth", Spanish National Research Council (CSIC) - Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA), Cadiz, Spain. Electronic address:
The variability in trophic position and carbon isotopic signatures can provide information about their dietary flexibility and its ability to adapt to changing environmental conditions. The impact of the invasive blue crab Callinectes sapidus was assessed by estimating its trophic position and isotopic niche using stable isotopes (δ³C, δ⁵N, δ³⁴S) across different invaded Atlantic coastal areas. This study, the first of its kind in the eastern Atlantic range, reveals the crab's omnivorous behavior with a wide trophic position (TP = 2-4), consistent with findings from its native range.
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