Publications by authors named "Beatriz F Araujo"
Article Synopsis
- During Arctic spring, halogen radicals oxidize elemental mercury, which is then deposited to the cryosphere, leading to increased mercury levels in the atmosphere during summer.
- The study tracks mercury isotope variability and finds that the summer peak in mercury levels mainly consists of re-emission from spring deposits, rather than significant contributions from terrestrial sources.
- The research suggests that while terrestrial mercury inputs are significant, they primarily remain within the marine ecosystem of the Arctic Ocean, potentially impacting local food webs rather than contributing greatly to global atmospheric mercury levels.
The present study performed geochemical fractioning of major and minor elements in a cross-shelf gradient of the Abrolhos Bank, where the largest and most diverse coral reefs in the South Atlantic are concentrated. The fractioning was performed using sequential extractions to determine the degree of availability and toxicity of the elements. The mobility pattern of the elements investigated were in the following order: Ca > Mn > Pb > Cr > Zn > Fe > V > Cu > Ba>Al > Ni > Ti.
View Article and Find Full Text PDFTotal mercury (THg) and δN were analysed in liver and muscle of juvenile green turtles (Chelonia mydas) from a foraging site in southeastern Brazil (~23°S) to evaluate contamination levels and make inferences about the timescale that animals were recruited from oceanic to coastal waters. The values for THg and δN in liver and muscle were 432.2 and 72.
View Article and Find Full Text PDFMercury (Hg) may originate from both anthropogenic and natural sources. The measurement of spatial and temporal variations of Hg isotope ratios in sediments may enable source identification and tracking of environmental processes. In this study we establish the distribution of mercury concentrations and mercury isotope ratios in surface sediments of three transects along the continental shelf and slope in Campos Basin-RJ-Brazil.
View Article and Find Full Text PDFArticle Synopsis
- Large rivers, like the Amazon, significantly disrupt reef distributions on tropical shelves by affecting salinity, pH, light penetration, and sedimentation over a large area of the North Atlantic.
- Despite these harsh conditions, a complex carbonate system thrives off the Amazon's mouth, characterized by unique hard-bottom structures, originating from sedimentation during low sea levels and continuing in certain areas.
- These carbonate structures support diverse marine life, including sponges and filter feeders, and act as a connectivity corridor for reef-associated species, offering insights into how tropical reefs can adapt to challenging conditions, which are becoming more common globally.