Article
Engineering, Marine
Michael S. Owens, Stephen P. Kelly, Thomas A. Frankovich, David T. Rudnick, James W. Fourqurean, Jeffrey C. Cornwell
Summary: The study estimated the net exchange of nitrogen and phosphorus species in estuarine lakes, revealing high efflux of NH4+ in dark conditions and significantly decreased efflux in light conditions. The presence of Chara hornemannii Wallman was found to have a large impact on NH4+ efflux, and it is expected that increased freshwater flow from the Everglades will influence NH4+ release in lakes.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Environmental Sciences
Ilona Sekudewicz, Michal Gasiorowski
Summary: The research revealed a negative correlation between Cs-137 activity concentrations and sediment grain size, with significant amounts of Cs-137 detected in the deeper parts of the lake bottom. Turawa Lake may serve as a significant trap for Cs-137 polluted sediments.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Water Resources
Tessa Bermarija, Lindsay Johnston, Chris Greene, Barret Kurylyk, Rob Jamieson
Summary: Study region: Halifax, Nova Scotia, Canada. Study focus: Many lakes in the Halifax region are facing the issue of elevated chloride (Cl-) levels due to deicing salt application. In this study, geospatial analysis and linear regression methods were used to identify the main contributing factors to high Cl- concentrations in lakes. A mass balance model was also developed to estimate Cl- loading rates for different land use categories. The findings provide new hydrological insights for the region and support predictive modeling for future development impacts.
JOURNAL OF HYDROLOGY-REGIONAL STUDIES
(2023)
Article
Geochemistry & Geophysics
Jinshu Yan, Neha Sharma, Elaine D. Flynn, Daniel E. Giammar, Grace E. Schwartz, Scott C. Brooks, Pamela Weisenhorn, Kenneth M. Kemner, Edward J. O'Loughlin, Daniel Kaplan, Jeffrey G. Catalano
Summary: The study suggests that trace metal speciation in freshwater wetland soils and stream sediments is consistently dominated by a small set of recurring components, distinct for each metal, indicating a general geochemical phenomenon in anoxic soils and sediments with trace metals at background concentrations.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Engineering, Civil
Joel Blackburn, Jean-Christophe Comte, Gez Foster, Christopher Gibbins
Summary: This research focuses on a small alluvial fan in the temperate, high rainfall Lake District of North West England, where an ephemeral stream plays a key role in supplying water and sediment to the River Ehen. By combining high spatial resolution geophysics, outcrop data, and hydrological data, the study characterizes the hydrogeological properties of the alluvial fan and develops a conceptual model to understand how water and sediment supply to the River Ehen is affected.
JOURNAL OF HYDROLOGY
(2021)
Article
Astronomy & Astrophysics
Kaj Sand-Jensen, Tenna Riis, Johan Emil Kjaer, Kenneth Thoro Martinsen
Summary: Streams in cultivated lowlands are often saturated with CO2, but the concentrations decrease downstream with rising water temperature, chlorophyll a concentration, and decreasing groundwater inputs. CO2 concentrations at the outlet of lakes can be reduced due to phytoplankton uptake and atmospheric loss. Plant uptake of CO2 is observed to occur in summer and in the afternoons. Sites with deeper water and low gas transfer velocity retain high CO2 concentrations. The variation in CO2 emission rates in fluvial networks is influenced by various physical, chemical and biological processes.
EARTH AND SPACE SCIENCE
(2022)
Article
Geography, Physical
Xue Zhao, Xiaolin Hou, Zhao Huang, Chengjun Zhang, Peng Cheng
Summary: Understanding hydrological changes in the past 2 kyr is crucial for determining the impact and causes of climate change, especially in arid areas. Sediment analysis provides valuable information for reconstructing past hydrology, but there are challenges in selecting appropriate proxies and interpreting their implications in specific lake environments. This study analyzes iodine and uranium concentrations in a sediment core from Keluke Lake, China, and finds a significant correlation between the two elements, suggesting their potential as hydrological proxies for studying dry-wet changes over the past 2200 years.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Engineering, Environmental
Lulu Mao, Wenbo Ren, Xitao Liu, Mengchang He, Chunye Lin, Ying Zhong, Yang Tang, Wei Ouyang
Summary: In this study, the total mercury (THg) content and mercury isotope composition in sediments in the Lianxi River, Zijiang River, and South Dongting Lake were investigated to identify and quantify multiple mercury sources and evaluate mercury environmental processes. The results showed that the THg content, delta Hg-202, and Delta Hg-199 values in the sediments varied from 48.22 to 4284.32 μg/kg, 1.33 to 0.04‰, and 0.25 to 0.03‰, respectively. The sediments from the Lianxi River, Zijiang River, and South Dongting Lake exhibited distinct mercury isotope characteristics, indicating significant variations in dominant mercury sources in these regions. Source apportionment based on MixSIAR revealed that mercury in sediments mainly originated from industrial activities, with non-ferrous metal smelting being the dominant industrial mercury contributor in the Lianxi River. Compared to the Lianxi River, the relative contribution of mercury from industrial activities significantly decreased, while the relative contributions of mercury from background releases significantly increased in the Zijiang River and South Dongting Lake.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Environmental Sciences
Wolfgang Jansen
Summary: This study measured total mercury concentrations in lake sturgeon from five river systems in Manitoba, Canada. The concentrations were positively related to fish length and age, and the composition of fish diet was found to affect mercury concentrations. The study suggests that as lake sturgeon populations recover and harvest rates potentially increase, consumption of larger individuals should be limited.
ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
(2023)
Article
Environmental Sciences
Isabella A. Oleksy, Sarah M. Collins, Samuel J. Sillen, Simon N. Topp, Miles Austin, Edward K. Hall, Catherine M. O'Reilly, Xiao Yang, Matthew R. Ross
Summary: Global change may affect ecological changes in high-elevation lakes and reservoirs. Remote sensing imagery provides a useful tool to evaluate spatiotemporal patterns. This study used Landsat data to analyze lake color changes in the U.S. Rocky Mountains region. Most lakes in the region are blue, while green/brown lakes are found in relatively shallow sloped watersheds. Limited evidence of lakes shifting from blue to green states was found, with some lakes trending towards bluer wavelengths. Urbanized, human population centers tend to have lakes shifting towards bluer wavelengths.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Talia Koll-Egyed, Jeffrey A. Cardille, Eliza Deutsch
Summary: This study explores the opportunities and limitations of using median values of Landsat 8 satellite images to estimate CDOM, comparing models created with a broad view of satellite image availability versus those emphasizing a tight timing between field sampling and satellite overpass dates. The research found that models trained on median band values from multiple summer seasons performed better than those constrained to a 30-day time window, indicating the potential of dense satellite imagery for understanding relationships between in situ CDOM and satellite reflectance data at a national scale.
Article
Chemistry, Analytical
Dhurba Raj Pandey, Catherine Polik, Rose M. Cory
Summary: In Lake Erie, the occurrence of harmful algal blooms (HABs) is related to high concentrations of hydrogen peroxide (H2O2). The production of H2O2 in Lake Erie is influenced by the chromophoric fraction of dissolved organic matter (CDOM) through photochemical reactions. However, the exact controls of H2O2 production from CDOM remain unclear. By measuring phiH2O2,lambda and CDOM concentration in Lake Erie, this study found that the variability in rates of photochemical H2O2 production is predominantly influenced by phiH2O2,lambda and CDOM concentration. However, there are still other unknown factors controlling H2O2 production in Lake Erie.
ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS
(2022)
Article
Environmental Sciences
Leilei Bai, Xin Liu, Ke Hua, Linqi Tian, Changhui Wang, Helong Jiang
Summary: This study investigated the impact of aquatic plant and algal biomass on the microbial processing of organic matter and the biodegradation of 17 alpha-ethinylestradiol (EE2) in anoxic sediments. The results showed that increased concentrations of organic matter promoted microbial activity and carbon mineralization, leading to higher EE2 biodegradation efficiency. Additionally, the presence of certain compounds accelerated the redox cycling of iron and organic substrates, further enhancing EE2 biodegradation.
ENVIRONMENTAL POLLUTION
(2022)
Article
Environmental Sciences
Tyler J. Harrow-Lyle, Wai Ying Lam, Erik J. S. Emilson, Robert W. Mackereth, Carl P. J. Mitchell, Stephanie J. Melles
Summary: Methyl mercury (MeHg) concentrations in boreal headwater streams in Ontario, Canada are influenced by natural processes and disturbances such as forestry management. This study used a structural equation modelling approach to assess the impact of catchment characteristics and stream water chemistry on MeHg concentrations in the Dryden - Wabigoon Forest region. The results identified nitrate concentrations, water temperature, and latent watershed characteristics as important drivers of MeHg concentrations. Two plausible pathways for MeHg concentration were described: indirect effect of forest-derived nutrients increasing in-situ MeHg production, and direct supply of MeHg from inundated soils following precipitation and inundation events.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Ecology
Allison M. Herreid, Adam S. Wymore, Ruth K. Varner, Jody D. Potter, William H. McDowell
Summary: Inland waters, especially streams, are significant sources of greenhouse gases such as CO2, CH4, and N2O. This study found spatial and temporal variability in GHG concentrations in 20 streams in New England, USA, and identified unique predictor variables for each gas. Developing an understanding of the factors controlling GHG dynamics in streams can help assess and predict how fluvial ecosystems will respond to changes in climate and land use.