Article
Environmental Sciences
Gabriel Dulaquais, Pierre Fourrier, Cecile Guieu, Leo Mahieu, Ricardo Riso, Pascal Salaun, Chloe Tilliette, Hannah Whitby
Summary: The high N-2 fixation rate in the Lau Basin of the western tropical South Pacific Ocean is fueled by iron released from shallow hydrothermal systems. This study provides new data on the distribution and bioavailability of soluble ubiquitous humic-like ligands (L-FeHS) and their associated dissolved iron (DFe) in the area. The results show that L-FeHS are heterogenous ligands with both strong and intermediate binding sites.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Multidisciplinary Sciences
Mikhail M. Latonin, Leonid P. Bobylev, Igor L. Bashmachnikov, Richard Davy
Summary: This study investigates the characteristics of high-latitude atmospheric meridional energy transport in the Arctic climate system. Analysis of heat fluxes reveals opposing features in the Eastern and Western Hemispheres, with sensible heat transport dominating in the Western Hemisphere and latent heat transport dominating in the Eastern Hemisphere. Additionally, a robust anti-phase dipole pattern is detected in the entire troposphere. The study shows that the Arctic gains internal energy mainly through latent heat transport.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Yoshiko Kondo, Rise Bamba, Hajime Obata, Jun Nishioka, Shigenobu Takeda
Summary: The research found uneven distribution of dissolved organic ligands between western and eastern stations in the subarctic Pacific, with higher concentration of organic ligands in the lower part of subarctic Pacific intermediate water at the western station. However, a more detailed size-fractionated treatment showed no significant difference in the distribution of soluble ligands between western and eastern stations. This suggests that organic and inorganic colloid formations are potentially essential for Fe transport mechanisms in the subarctic Pacific.
SCIENTIFIC REPORTS
(2021)
Article
Oceanography
Tatiana Williford, Rainer M. W. Amon, Karl Kaiser, Ronald Benner, Colin Stedmon, Dorothea Bauch, Jessica N. Fitzsimmons, Loes J. A. Gerringa, Robert Newton, Dennis A. Hansell, Mats A. Granskog, Laramie Jensen, Luis M. Laglera, Angelica Pasqualini, Benjamin Rabe, Heather Reader, Michiel Rutgers van der Loeff, Ge Yan
Summary: This study investigates the distribution of dissolved organic matter (DOM) and its impact on the distribution of trace elements in different water masses of the Arctic Ocean. The findings suggest that DOM fluorescence closely follows the isopycnals, indicating the influence of sea-ice formation and melt on DOM distribution. Terrigenous and marine DOM components are carriers of dissolved Fe, Ni, and Cu from the Eurasian shelves into the central Arctic Ocean.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Geochemistry & Geophysics
Xiaoyu Chen, Hojong Seo, Heejun Han, Junhyeong Seo, Taejin Kim, Guebuem Kim
Summary: The transportation of terrestrial trace elements to the ocean has significant impacts on their biogeochemical behaviors, global carbon cycling, and ecosystem changes. Most terrestrial dissolved trace elements are scavenged in estuarine and coastal waters before reaching the open ocean due to their particle-reactive nature. The behavior of trace elements and rare earth elements in a coastal embayment with long water residence time was investigated, showing intense depletion of inorganic nutrients in the bay, notable REE fractionation, and higher concentrations of trace elements in lower salinity waters with positive correlations with humic substances. The study suggests that terrestrial trace elements associated with humic substances may survive particle scavenging and biological consumption in the coastal mixing zone, serving as important sources of trace elements to the open ocean globally.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Engineering, Environmental
Meiling Zhu, Zhanhua Zhang, Tong Zhang, Thilo Hofmann, Wei Chen
Summary: Nanoplastics are a growing environmental concern due to their ability to acquire an eco-corona in aquatic environments. The properties of the eco-corona and its impact on nanoplastics transport vary with the surface functionality of nanoplastics and sources of macromolecules. The eco-corona inhibits the deposition of nanoplastics mainly through steric repulsion, and a higher mass of larger-sized macromolecules results in greater transport enhancement.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Mitsuhide Sato, Natsuki Ogata, Kuo Hong Wong, Hajime Obata, Shigenobu Takeda
Summary: The experiment revealed that solar irradiation can significantly impact the biogeochemical cycling of trace metals in the open ocean, leading to the rapid decomposition of iron- and copper-binding ligands. The competition between ligands for iron and copper ions, as well as the potential influence of sunlight on their bioavailability, may be important factors to consider.
Article
Environmental Sciences
Alina Guzeva
Summary: This study comprehensively investigates the geochemical and environmental roles of humic acids in sediments from urbanized lakes in the Arctic region. The findings reveal specific features of humic acids in these aquatic ecosystems, including slowed humification due to cold climatic conditions and water pollution. The immature and high-oxygen molecules of humic acids actively leach toxic metals from sediments, while stable organometallic compounds form due to the high percentage of dispersed organic matter and structural flexibility of the acids. The geochemical composition and enrichment of sediments by trace elements and hydrocarbons significantly influence the interaction between metals and humic acids.
ENVIRONMENTAL MONITORING AND ASSESSMENT
(2022)
Article
Engineering, Environmental
Xiangqin Wang, Yanhong Du, Fangbai Li, Liping Fang, Tingting Pang, Weijian Wu, Chuanping Liu, Lei Chen
Summary: A new strategy of complexing Fe(II) with organic matter (Fe-OM) was developed to regulate target gene expression responsible for Cd absorption in roots and leaves of rice plants, significantly reducing grain Cd content from 0.48 mg kg(-1) to 0.25 mg kg(-1). The downregulation of OsNramp1 and OsNramp5 in roots/stems and upregulation of OsLCT1 in leaves contributed to the mitigation of Cd accumulation in grains. This work provides a promising approach to alleviate Cd accumulation in rice grains through targeted gene regulation in specific tissues.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Oceanography
James Morison, Ron Kwok, Suzanne Dickinson, Roger Andersen, Cecilia Peralta-Ferriz, David Morison, Ignatius Rigor, Sarah Dewey, John Guthrie
Summary: The study shows that the cyclonic mode of Arctic Ocean surface circulation is influenced by the Arctic Oscillation, with changes occurring with variations in the AO value. The complex cyclonic mode includes effects such as increased sea ice export, increased freshwater, and freshened Beaufort Sea.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2021)
Article
Environmental Sciences
Camila Fiaux Sukekava, Carlos Francisco Ferreira de Andrade, Luis Felipe Hax Niencheski, Marcio Silva de Souza, Luis M. Laglera
Summary: We investigated the concentrations and speciation of macronutrients and dissolved iron (DFe) in the South Brazil Bight during a coastal downwelling episode. The dominant NE winds and water convergence led to coastal downwelling, which resulted in high turbidity, deepening of nutrients, and bulging of isolines over the shelf and slope. Our measurements showed disentangled cycles of macronutrients, DFe, and iron ligands, with high DFe concentrations at the surface indicating aerial deposition and significant contributions from sediment and resuspended colloids. Iron ligand concentrations were higher than DFe concentrations and mainly derived from local biological processes. The injection of iron-humic complexes during summer upwelling episodes may contribute to the persistent high chlorophyll meanders over the shelf edge.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Microbiology
Thomas Grevesse, Celine Gueguen, Vera E. Onana, David A. Walsh
Summary: This study investigated the metabolic pathways and bacterial taxa involved in aromatic compound degradation in the microbiomes of the Arctic Ocean. The results showed that Arctic Ocean microbiomes have the ability to metabolize humic substances of terrestrial origin and that this is an adaptive trait. Future increases in terrestrial organic matter input may enhance the importance of aromatic compound processing bacteria in the Arctic Ocean carbon and nutrient cycles.
Article
Green & Sustainable Science & Technology
Gricel Alcira Portillo Miranda, Tavares Araruna Junior, Eduardo de Albuquerque Brocchi, Hongtao Wang
Summary: The research shows that humic substances obtained from recycling mineral coal tailings can reduce the environmental impact of mining and increase soil stability. The long-term stability advantage of humic substances is clear, and their effects on stability are more pronounced over a longer period of time.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Environmental Sciences
Hao Liu, Tuo Zhang, Yan'an Tong, Qihong Zhu, Daoyou Huang, Xibai Zeng
Summary: Humic substances and calcareous substances are important components in soil and can affect the mobility of metals. This study developed a new remediation scheme for cadmium-contaminated soil by coupling humic substances and calcareous substances. The results showed that this approach effectively reduced the bioavailable cadmium concentration in soil and decreased cadmium accumulation in rice tissues.
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
(2022)
Article
Multidisciplinary Sciences
Cesc Gordo-Vilaseca, Fabrice Stephenson, Marta Coll, Charles Lavin, Mark John Costello
Summary: Observed range shifts of numerous species into the Arctic and sub-Arctic seas due to ocean warming have led to an increase in local and regional species richness, driven by an increase in sea bottom temperature. While the probability of occurrence for Arctic species generally declined over time, the enrichment of the Arctic and sub-Arctic marine fauna is attributed to an increase in species from southern latitudes, consistent with climate change.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Chemistry, Analytical
Camila Sukekava, Javier Downes, Hans A. Slagte, Loes J. A. Gerringa, Luis M. Laglera
Article
Geosciences, Multidisciplinary
Luis M. Laglera, A. Tovar-Sanchez, C. F. Sukekava, H. Naik, S. W. A. Naqvi, D. A. Wolf-Gladrow
JOURNAL OF MARINE SYSTEMS
(2020)
Article
Oceanography
Hans A. Slagter, Luis M. Laglera, Camila Sukekava, Loes J. A. Gerringa
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2019)
Article
Biochemistry & Molecular Biology
Sebastian Boeckmann, Florian Koch, Bettina Meyer, Franziska Pausch, Morten Iversen, Ryan Driscoll, Luis Miguel Laglera, Christel Hassler, Scarlett Trimborn
Summary: This study found that in the Southern Ocean, iron released from fecal pellets of salps is more bioavailable to phytoplankton compared to krill fecal pellets, potentially strengthening future iron utilization in the region. This shift may have negative impacts on the ecosystem and climate change in the Southern Ocean.
Article
Environmental Sciences
Luis M. Laglera, Hema Uskaikar, Christine Klaas, S. Wajih A. Naqvi, Dieter A. Wolf-Gladrow, Antonio Tovar-Sanchez
Summary: The redox speciation of iron was investigated during the iron fertilization LOHAFEX by comparing chemiluminescence assays of filtered and unfiltered samples. It was found that higher chemiluminescence in unfiltered samples may be attributed to Fe(II) adsorbed onto biological particles. The study also showed that dissolved and particulate Fe(II) increased initially and then decreased back to initial levels during LOHAFEX. The chemiluminescence analysis revealed strong gradients in unfiltered samples, which were significantly correlated to biomass and photosynthetic efficiency, suggesting biological control.
MARINE POLLUTION BULLETIN
(2022)
Article
Oceanography
Tatiana Williford, Rainer M. W. Amon, Karl Kaiser, Ronald Benner, Colin Stedmon, Dorothea Bauch, Jessica N. Fitzsimmons, Loes J. A. Gerringa, Robert Newton, Dennis A. Hansell, Mats A. Granskog, Laramie Jensen, Luis M. Laglera, Angelica Pasqualini, Benjamin Rabe, Heather Reader, Michiel Rutgers van der Loeff, Ge Yan
Summary: This study investigates the distribution of dissolved organic matter (DOM) and its impact on the distribution of trace elements in different water masses of the Arctic Ocean. The findings suggest that DOM fluorescence closely follows the isopycnals, indicating the influence of sea-ice formation and melt on DOM distribution. Terrigenous and marine DOM components are carriers of dissolved Fe, Ni, and Cu from the Eurasian shelves into the central Arctic Ocean.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Environmental Sciences
Camila Fiaux Sukekava, Carlos Francisco Ferreira de Andrade, Luis Felipe Hax Niencheski, Marcio Silva de Souza, Luis M. Laglera
Summary: We investigated the concentrations and speciation of macronutrients and dissolved iron (DFe) in the South Brazil Bight during a coastal downwelling episode. The dominant NE winds and water convergence led to coastal downwelling, which resulted in high turbidity, deepening of nutrients, and bulging of isolines over the shelf and slope. Our measurements showed disentangled cycles of macronutrients, DFe, and iron ligands, with high DFe concentrations at the surface indicating aerial deposition and significant contributions from sediment and resuspended colloids. Iron ligand concentrations were higher than DFe concentrations and mainly derived from local biological processes. The injection of iron-humic complexes during summer upwelling episodes may contribute to the persistent high chlorophyll meanders over the shelf edge.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Multidisciplinary Sciences
Sheisa F. d. Sierpinski, Luis Miguel Laglera Baquer, Cesar C. Martins, Marco Tadeu Grassi
Summary: This study investigated dissolved iron concentrations and speciation in surface seawater samples collected in Admiralty Bay, Antarctica during the austral summer of 2020. The technique of competitive ligand exchange/adsorptive cathodic stripping voltammetry was evaluated and found to be sensitive, with an LOD of 14 pmol L-1. The physicochemical parameters were consistent with previous studies, except for the higher temperature, possibly due to global warming. The relatively high iron concentrations suggest a local source of iron from upwelling sediments and ice-melting waters, which supports phytoplankton growth.
ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS
(2023)
Article
Ecology
Loes J. A. Gerringa, Martha Gledhill, Indah Ardiningsih, Niels Muntjewerf, Luis M. Laglera
Summary: Competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-AdCSV) is used to determine the conditional concentration and the conditional binding strength of dissolved organic Fe-binding ligands. Different applications show similar trends but differ in the values obtained. The study compares the binding of different added ligands to natural binding ligands and suggests limitations in the approach for estimating ligand concentrations accurately.