Article
Ecology
Joao Henrique F. Amaral, Jacob R. Gaddy, Thomas S. Bianchi, Todd Z. Osborne, Susan Newman, Jacob Dombrowski, Elise S. Morrison
Summary: The study found that dissolved organic matter (DOM) plays an important role in the phosphorus (P) and nitrogen (N) cycle in treatment wetlands. However, the examination of coupled biogeochemical cycling in treatment wetlands has been limited. The research also showed that solar exposure alters DOM turnover and its relationship with nutrient concentrations, and that the DOM of treatment wetland inflow water is predominantly composed of terrestrial sources.
ECOLOGICAL ENGINEERING
(2023)
Article
Environmental Sciences
Yanan Liu, Jingya Xue, Zhifan Gui, Lu Zhang, Xiaolong Yao
Summary: This study investigates the photoreactivity of dissolved organic matter (DOM) from different sources in the Lake Taihu basin. The results show that the original composition and sources of DOM are closely related to its photoreactivity. DOM from macrophytes releases soluble components under light exposure, while DOM with higher aromacity shows photobleaching effects and increased humification degree. Allochthonous anthropogenic DOM exhibits stronger photo-ammonification. The form of inorganic nutrient releases during DOM photolysis also varies with the original DOM sources.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Environmental Sciences
Stephanie M. Berg, Benjamin D. Peterson, Katherine D. McMahon, Christina K. Remucal
Summary: This study evaluates the composition of dissolved organic matter (DOM) in Lake Mendota as a function of time and depth. The researchers analyze dissolved organic carbon concentrations and optical properties of samples collected from June to November, and use Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) to investigate DOM composition at the molecular level. The results show that DOM composition varies both temporally and with depth, with photochemical reactions and redox conditions playing important roles. The findings have implications for understanding the flux of CO2 in lakes and the impact of lake eutrophication.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2022)
Article
Limnology
Yongqiang Zhou, Xiaolong Yao, Lei Zhou, Zhonghua Zhao, Xiaolong Wang, Kyoung-Soon Jang, Wei Tian, Yunlin Zhang, David C. Podgorski, Robert G. M. Spencer, Dolly N. Kothawala, Erik Jeppesen, Fengchang Wu
Summary: Large rivers, such as the Yangtze River, serve as crucial pathways for transporting carbon to the ocean. This study found that urbanization and stormwater periods can increase the export of organic-rich substances and household effluents along the river continuum. The results highlight the importance of protecting the watershed to prevent changes in ecosystem function and carbon cycling due to increased organic carbon loading and altered composition.
LIMNOLOGY AND OCEANOGRAPHY
(2021)
Article
Geosciences, Multidisciplinary
Jesse Alan Roebuck, Kevin D. Bladon, David Donahue, Emily B. Graham, Samantha Grieger, Karl Morgenstern, Matthew J. Norwood, Katie A. Wampler, Lisa Erkert, Lupita Renteria, Robert Danczak, Susan Fricke, Allison N. Myers-Pigg
Summary: The warmer and drier climate has led to an increase in large, high severity wildfires in the Pacific Northwest, raising concerns about water quality and ecosystem recovery. This study quantified the spatiotemporal patterns of dissolved organic matter (DOM) chemistry in streams burned by wildfires in Oregon, USA in 2020. The results showed that the composition of DOM was temporally variable and linked with burn severity, suggesting distinct gradients of burn severity impact DOM dynamics immediately following fire activity.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Wenwen Zhao, Yuan Xin, Zhongsheng Zhang, Xuehui Zhang, Haitao Wu
Summary: Little is known about the coupling between mercury (Hg) methylation and soil organic matter decomposition in degraded permafrost in high northern latitudes where climate warming is occurring rapidly. In this study, we conducted an anoxic warming incubation experiment for 87 days to explore the interactions between soil organic matter (SOM) mineralization, dissolved organic matter (DOM), and methylmercury (MeHg) production. The results revealed significant promotion effects of warming on MeHg production, as well as increased greenhouse gas emissions and enhanced DOM fluorescence intensities. These findings highlight the complex relationships between warming, greenhouse gas emissions, and MeHg production in permafrost marshes.
ENVIRONMENTAL RESEARCH
(2023)
Article
Environmental Sciences
Ganghui Tong, Xueling Yang, Yun Li, Meng Jin, Xubiao Yu, Ying Huang, Rongyue Zheng, Jun-Jian Wang, Huan Chen
Summary: Sunlight plays a significant role in water ecosystems, but the widespread air pollutant, haze, affects the photochemical transformation of dissolved organic matter (CDOM). This study conducted an experiment in a city in China frequently affected by haze pollution and found that haze reduced the intensity of UV light and decreased the loss of dissolved organic carbon. The study also observed that haze influenced the bleaching of CDOM, and UV intensity played a critical role in the composition characteristics of CDOM. Therefore, long-term and large-scale haze may adversely impact water ecosystems through pollutant/nutrient accumulation.
ENVIRONMENTAL RESEARCH
(2022)
Article
Environmental Sciences
Katherine M. Wardinski, Erin R. Hotchkiss, C. Nathan Jones, Daniel L. McLaughlin, Brian D. Strahm, Durelle T. Scott
Summary: Hydrologic processes play a critical role in the carbon processing and export in wetland ecosystems, especially in the transport and transformation of soil-derived dissolved organic matter (DOM). This study found that different soil horizons have distinct contributions to DOM transport in wetlands, with organic horizons being the most significant source. Understanding the behavior and impacts of DOM in wetland ecosystems, particularly in the context of climate change, is of great importance.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2022)
Article
Environmental Sciences
Sarah Ellen Johnston, Kerri Finlay, Robert G. M. Spencer, David E. Butman, Mackenzie Metz, Robert Striegl, Matthew J. Bogard
Summary: Zooplankton communities release chemically complex dissolved organic matter (DOM) with significant ecological and biogeochemical contributions to aquatic ecosystems, but this source is often overlooked. This study reveals the composition of zooplankton-derived DOM inputs, highlighting the rich chemical diversity of linkages between animals and lower trophic levels.
Article
Environmental Sciences
Norbert Kamjunke, Liza-Marie Beckers, Peter Herzsprung, Wolf von Tumpling, Oliver Lechtenfeld, Joerg Tittel, Ute Risse-Buhl, Michael Rode, Alexander Wachholz, Rene Kallies, Tobias Schulze, Martin Krauss, Werner Brack, Sara Comero, Bernd Manfred Gawlik, Hello Skejo, Simona Tavazzi, Giulio Mariani, Dietrich Borchardt, Markus Weitere
Summary: This study investigated autotrophic processes, heterotrophic carbon utilization, and micropollutant concentrations in the River Elbe, Germany, using a Lagrangian sampling design. The results showed that under base flow conditions, there was an increase in phytoplankton biomass and photosynthesis from upstream to downstream, while concentrations of dissolved macronutrients decreased. Bacterial abundance and production increased less than in wetter years, and there were changes in bacterial community composition downstream. DOM components increased due to microbial production, while some pollutants showed higher concentrations downstream. However, their magnitudes were not distinctly different from conditions at medium discharges.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Michael G. G. Novak, Antonio Mannino, J. Blake Clark, Peter Hernes, Maria Tzortziou, Robert G. M. Spencer, Anne M. M. Kellerman, Brice Grunert
Summary: Changes in precipitation and snowmelt timing in Arctic landscapes have led to warming and increased moisture, resulting in altered runoff and river discharge patterns. This study focuses on the mobilization and transport of dissolved organic matter (DOM) to Arctic coastal seas, and presents measurements of dissolved organic carbon (DOC) and chromophoric DOM (CDOM) in several river systems. The results show consistent seasonal and spatial variations in DOC and CDOM concentrations in the Arctic coastal systems. The study also provides insights into the transformations of DOM in river plumes and the effects of various processes during low river discharge periods.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Romera-Castillo Cristina, Mallenco-Fornies Rebeca, Saa-Yanez Marola, Alvarez-Salgado Xose Anton
Summary: A study found that petrol-based plastics released fluorescent dissolved organic matter (FDOM) that can be utilized by microbes in the ocean, while biodegradable PLA did not release FDOM. The amount of dissolved organic carbon (DOC) released by PLA was similar to petrol-based plastics, indicating comparable microbial bioavailability. Therefore, caution should be taken when dealing with biodegradable plastics as not all types degrade in the ocean.
MARINE ENVIRONMENTAL RESEARCH
(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
Environmental Sciences
Stephanie Shousha, Roxane Maranger, Jean-Francois Lapierre
Summary: This study quantified the changes in dissolved organic matter (DOM) composition and nutrient forms along a river with different land use and seasonal patterns. The results showed significant spatial and temporal shifts in DOM composition associated with different nutrient forms. These changes indicated contrasting loading and processing potential depending on land use and seasonal patterns.
Article
Engineering, Environmental
Chen Zhao, Xinyue Xu, Hongmei Chen, Fengwen Wang, Penghui Li, Chen He, Quan Shi, Yuanbi Yi, Xiaomeng Li, Siliang Li, Ding He
Summary: Photochemical reactions are important in altering the chemistry of dissolved organic matter (DOM). This study used machine learning to integrate existing irradiation experiments and gain new insights into the transformation processes of estuarine DOM. Irradiation experiments provide valuable information on the photochemical reactivity of molecules, but the inconsistent fate of irradiated molecules in different experiments hinders our understanding of the roles played by photochemical reactions, which cannot be properly addressed by traditional approaches.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Heileen Hsu-Kim, Chris S. Eckley, Dario Acha, Xinbin Feng, Cynthia C. Gilmour, Sofi Jonsson, Carl P. J. Mitchell
Article
Environmental Sciences
James P. Sanders, Natasha A. Andrade, Charles A. Menzie, C. Bennett Amos, Cynthia C. Gilmour, Elizabeth A. Henry, Steven S. Brown, Upal Ghosh
ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
(2018)
Article
Environmental Sciences
Cynthia Gilmour, Tyler Bell, Ally Soren, Georgia Riedel, Gerhardt Riedel, Dianne Kopec, Drew Bodaly, Upal Ghosh
SCIENCE OF THE TOTAL ENVIRONMENT
(2018)
Article
Environmental Sciences
Cynthia Gilmour, James Tyler Bell, Ally Bullock Soren, Georgia Riedel, Gerhardt Riedel, A. Dianne Kopec, R. A. Bodaly
SCIENCE OF THE TOTAL ENVIRONMENT
(2018)
Article
Microbiology
Cynthia C. Gilmour, Allyson L. Bullock, Alyssa McBurney, Mircea Podar, Dwayne A. Elias
Article
Engineering, Environmental
Geoff A. Christensen, Caitlin M. Gionfriddo, Andrew J. King, James G. Moberly, Carrie L. Miller, Anil C. Somenahally, Stephen J. Callister, Heather Brewer, Mircea Podar, Steven D. Brown, Anthony Palumbo, Craig C. Brandt, Ann M. Wymore, Scott C. Brooks, Chiachi Hwang, Matthew W. Fields, Judy D. Wall, Cynthia C. Gilmour, Dwayne A. Elias
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2019)
Article
Environmental Sciences
James P. Sanders, Alyssa McBurney, Cynthia C. Gilmour, Grace E. Schwartz, Spencer Washburn, Susan B. Kane Driscoll, Steven S. Brown, Upal Ghosh
ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
(2020)
Review
Environmental Sciences
Chris S. Eckley, Cynthia C. Gilmour, Sarah Janssen, Todd P. Luxton, Paul M. Randall, Lindsay Whalin, Carrie Austin
SCIENCE OF THE TOTAL ENVIRONMENT
(2020)
Article
Microbiology
Cynthia C. Gilmour, Ally Bullock Soren, Caitlin M. Gionfriddo, Mircea Podar, Judy D. Wall, Steven D. Brown, Joshua K. Michener, Maria Soledad Goni Urriza, Dwayne A. Elias
Summary: ND132T strain, isolated from Chesapeake Bay, USA, is a sulfate-reducing and mercury-methylating bacterium with high levels of mercury methylation. It belongs to the genus Pseudodesulfovibrio and has been proposed as a new species, Pseudodesulfovibrio mercurii.
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY
(2021)
Article
Multidisciplinary Sciences
Paul J. Blanchfield, John W. M. Rudd, Lee E. Hrenchuk, Marc Amyot, Christopher L. Babiarz, Ken G. Beaty, R. A. Drew Bodaly, Brian A. Branfireun, Cynthia C. Gilmour, Jennifer A. Graydon, Britt D. Hall, Reed C. Harris, Andrew Heyes, Holger Hintelmann, James P. Hurley, Carol A. Kelly, David P. Krabbenhoft, Steve E. Lindberg, Robert P. Mason, Michael J. Paterson, Cheryl L. Podemski, Ken A. Sandilands, George R. Southworth, Vincent L. St Louis, Lori S. Tate, Michael T. Tate
Summary: The 15-year experiment conducted to reduce fish MeHg concentrations by decreasing Hg additions to a boreal lake and its watershed demonstrated that any reduction in Hg loadings to lakes, whether from direct deposition or runoff, will have immediate benefits to fish consumers.
Article
Environmental Sciences
Spencer J. Washburn, Jada Damond, James P. Sanders, Cynthia C. Gilmour, Upal Ghosh
Summary: This study validates a novel polymeric equilibrium passive sampler for estimating aqueous monomethylmercury (MeHg) concentrations. The sampler is comprised of agarose gel with embedded activated carbon particles (ag+AC). The results show that the sampler can accurately measure environmentally relevant MeHg species concentrations and achieve equilibrium measurements within a reasonable time frame.
ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Eric Capo, Benjamin D. Peterson, Minjae Kim, Daniel S. Jones, Silvia G. Acinas, Marc Amyot, Stefan Bertilsson, Erik Bjoern, Moritz Buck, Claudia Cosio, Dwayne A. Elias, Cynthia Gilmour, Marisol Goni-Urriza, Baohua Gu, Heyu Lin, Yu-Rong Liu, Katherine McMahon, John W. Moreau, Jarone Pinhassi, Mircea Podar, Fernando Puente-Sanchez, Pablo Sanchez, Veronika Storck, Yuya Tada, Adrien Vigneron, David A. Walsh, Marine Vandewalle-Capo, Andrea G. Bravo, Caitlin M. Gionfriddo
Summary: Researchers have proposed a standardized protocol for detecting, identifying, and quantifying hgc genes from metagenomes, and have created a database containing information on hgc genes. They have also developed a user-friendly bioinformatic pipeline for accurately characterizing hgc genes from environmental samples. The results show that both approaches have similar efficiency in most environments, except for high diversity environments where the coassembly approach is preferred.
MOLECULAR ECOLOGY RESOURCES
(2023)
Article
Biotechnology & Applied Microbiology
Caitlin M. Gionfriddo, Ally Bullock Soren, Ann M. Wymore, D. Sean Hartnett, Mircea Podar, Jerry M. Parks, Dwayne A. Elias, Cynthia C. Gilmour
Summary: This study demonstrates a connection between microbial mercury methylation and arsenic resistance, shedding light on the evolution and transcriptional regulation of hgcAB genes.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Chemistry, Analytical
Grace E. Schwartz, James P. Sanders, Alyssa M. McBurney, Steven S. Brown, Upal Ghosh, Cynthia C. Gilmour
ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS
(2019)
Article
Biotechnology & Applied Microbiology
Geoff A. Christensen, Anil C. Somenahally, James G. Moberly, Carrie M. Miller, Andrew J. King, Cynthia C. Gilmour, Steven D. Brown, Mircea Podar, Craig C. Brandt, Scott C. Brooks, Anthony V. Palumbo, Judy D. Wall, Dwayne A. Elias
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2018)