Mercury (Hg) burdens in top-predator fish differ substantially between adjacent South Carolina Coastal Plain river basins with similar wetlands coverage. In the Congaree River, floodwaters frequently originate in the Blue Ridge and Piedmont regions, where wetlands coverage and surface water dissolved methylmercury (MeHg) concentrations are low. Piedmont-driven flood events can lead to downward hydraulic gradients in the Coastal Plain riparian wetland margins, inhibiting MeHg transport from wetland sediments, and decreasing MeHg availability in the Congaree River habitat. In the adjacent Edisto River basin, floodwaters originate only within Coastal Plain sediments, maintaining upward hydraulic gradients even during flood events, promoting MeHg transport to the water column, and enhancing MeHg availability in the Edisto River habitat. These results indicate that flood hydrodynamics contribute to the variability in Hg vulnerability between Coastal Plain rivers and that comprehensive regional assessment of the relationship between flood hydrodynamics and Hg risk in Coastal Plain streams is warranted.
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http://dx.doi.org/10.1021/es102917j | DOI Listing |
J Exp Biol
January 2025
Marine Science Program, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST); Thuwal, Saudi Arabia.
Coastal deoxygenation poses a critical threat to tropical coral reefs. Dissolved oxygen (DO) depletion can cause hypoxia-induced stress and mortality for scleractinian corals. Coral hypoxic responses are species-specific and likely modulated by the duration and severity of low-DO conditions, although the physiological mechanisms driving hypoxia tolerance are not fully understood.
View Article and Find Full Text PDFACS Environ Au
January 2025
Biological and Agricultural Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States.
The U.S. Clean Water Act is believed to have driven widespread decreases in pollutants from point sources and developed areas, but has not substantially affected nutrient pollution from agriculture.
View Article and Find Full Text PDFWater Res
January 2025
Key Laboratory of Groundwater Quality and Health (China University of Geosciences), Ministry of Education, Wuhan 430078, China; State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution, School of Environmental Studies, Wuhan 430078, China.
The contamination of groundwater with geogenic ammonium (NH) across various geological backgrounds has garnered significant attention, particularly in coastal aquifer systems. However, there remains a gap in our understanding of the mechanisms governing the spatial variability of NH in coastal groundwater at a macroscopic scale. In this study, we collected the sediment samples from two boreholes corresponding to high-NH-N and low-NH-N groundwater.
View Article and Find Full Text PDFInsects
December 2024
Department of Entomology, Texas A&M AgriLife Research, 10345 State HWY 44, Corpus Christi, TX 78406, USA.
(Theobald) (Hemiptera: Aphididae), commonly called the sorghum aphid, is an invasive pest of sorghum () (L.) in North America. It was first observed in 2013 along the Gulf Coastal Plains ecoregion of Texas, Louisiana (USA), and Mexico, where it quickly established itself as an economically important pest within a few years.
View Article and Find Full Text PDFFront Vet Sci
December 2024
Department of Zoology, Abdul Wali Khan University Mardan, Mardan, Khyber Pakhtunkhwa, Pakistan.
There is limited information on the occurrence of and ticks, as well as associated and species in Pakistan. Addressing this knowledge gap, the current study aimed at morphomolecular confirmation of these ticks and molecular assessment of associated Rickettsiales bacteria (, and spp.) in Balochistan, Pakistan.
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