Article
Agronomy
Zhang Wei, Thomas M. R. Maxwell, Brett Robinson, Nicholas Dickinson
Summary: This study investigates whether species coexistence can improve nutrient uptake in mid-altitude grasslands, and the results suggest that species combinations can facilitate mutual nutrient acquisition.
Article
Environmental Sciences
Abigail J. R. Smith, Lavenia Ratnarajah, Thomas M. Holmes, Kathrin Wuttig, Ashley T. Townsend, Karen Westwood, Martin Cox, Elanor Bell, Stephen Nicol, Delphine Lannuzel
Summary: Despite widespread iron (Fe) limitation in the Southern Ocean, intense phytoplankton blooms are observed around productive coastal regions such as the Mertz Polynya. Investigations in the Mertz Glacier Region identified Circumpolar Deep Water (CDW) and shelf sediment resuspension in modified CDW as the sources of dissolved Fe (dFe) over the study period. Microbial Fe remineralization was evident where nutrient-rich water met highly oxygenated waters over the continental shelf, and reduced Fe concentrations in the mixed layer and euphotic zones suggested rapid biological uptake prior to sampling.
GLOBAL BIOGEOCHEMICAL CYCLES
(2021)
Article
Biology
Andrew Gangidine, Malcolm R. Walter, Jeff R. Havig, Clive Jones, Daniel M. Sturmer, Andrew D. Czaja
Summary: Elevated concentrations of trace elements found in microfossils from mid-Paleozoic hot spring deposits in Australia provide new evidence for their application as biosignatures, potentially aiding in the search for extraterrestrial life.
Article
Agronomy
Zhang Wei, Thomas M. R. Maxwell, Brett Robinson, Nicholas Dickinson
Summary: This study investigates the coexistence of native and exotic plants in New Zealand's grasslands. The research finds that grasses and legumes benefit from growing together, leading to increased productivity and nutrient uptake. The combination of exotic grasses and white clover has the most significant effects. The study also shows that the nutrient uptake differs with different combinations of legumes and grasses, indicating a mutual exploitation of soil nutrients. However, native tussock grass obtains fewer nutrients when growing with exotic legumes.
Review
Engineering, Marine
Daniel M. Alongi
Summary: High mangrove productivity is sustained by rapid utilization and maximum storage of nutrients. Macronutrient cycling is interlinked with micronutrient cycling, closely related to geochemical processes. Mangroves, being limited by various nutrients, play a significant role in oceanic Mn and Mo cycles.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Environmental Sciences
Donato Giovannelli
Summary: Biogeochemistry is influenced by a small group of microbial-encoded proteins with redox-sensitive transition metals. Understanding the impact of metal distribution and availability on microbial diversity will provide crucial insights into the coevolution of Earth and life.
NATURE REVIEWS EARTH & ENVIRONMENT
(2023)
Article
Environmental Sciences
Mohammad Nuruzzama, Waliur Rahaman, Rahul Mohan
Summary: Coastal lakes in Antarctica receive significant amounts of ions and trace elements during the austral summer, with dissolved concentrations lower than average seawater. Sea-salt spray and chemical weathering are dominant sources, while phosphate and molybdenum act as limiting nutrients. Dissolved copper plays a key role in organic matter decomposition, and excess barium in lake sediments suggests significant removal during transport.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Geochemistry & Geophysics
Jessica L. Oster, Aaron K. Covey, Corey R. Lawrence, Max G. Giannetta, Jennifer L. Druhan
Summary: Karst systems are valuable for studying variations in Critical Zone processes, as they offer insight into interactions between water and various geological features. This study focuses on trace element variations in cave seepage waters, with Mg/Ca and Sr/Ca affected by limestone dissolution and calcite precipitation, while Ba/Ca values are influenced by effective rainfall, serving as a consistent metric for limestone dissolution and calcite precipitation in the cave system.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Chemistry, Analytical
Maite Bueno, Bastien Duval, Emmanuel Tessier, Andrea Romero-Rama, Leire Kortazar, Luis Angel Fernandez, Alberto de Diego, David Amouroux
Summary: This study investigates the distribution and speciation of selenium in alpine lakes, revealing the prevalence of selenate and the influence of erosion and dissolution on selenium concentration. Furthermore, long-range transport and wet atmospheric deposition are identified as significant sources of selenium in lake waters.
ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS
(2022)
Article
Soil Science
Aakriti Sharma, Joseph Guinness, Amanda Muyskens, Matthew L. Polizzotto, Montserrat Fuentes, Dean Hesterberg
Summary: This study aimed to infer the chemical elements and solids that contribute to As binding in soil samples from different environments. The results showed that Fe and possibly Al (hydr)oxides dominate the immobilization of As, with varying contributions from Zn, Ti, Cu, or Mn.
Article
Geochemistry & Geophysics
Marie-Christine Lafreniere, Jean-Francois Lapierre, Dominic E. Ponton, Francois Guillemette, Marc Amyot
Summary: In order to meet the demand for green and digital technologies, the production of rare earth elements (REEs) has increased significantly. However, the fate of REEs in large rivers with various gradients remains poorly understood.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Environmental Sciences
Paula Renata Muniz Araujo, Caroline Miranda Biondi, Clistenes Williams Araujo do Nascimento, Fernando Bruno Vieira da Silva, Tiago Osorio Ferreira, Silvia Fernanda de Alcantara
Summary: Heavy metal-contaminated wastes pose a threat to the biodiverse mangrove forests. A study in Botafogo estuary, Brazil, evaluated the distribution of heavy metals in soils, ecological and human health risks, and metal contents in soil fractions and mangrove organisms. The study found that metal concentrations exceeded background levels, but were deemed safe for the environment and human beings.
MARINE POLLUTION BULLETIN
(2022)
Article
Environmental Sciences
Nairana Santos Fraga, Agnaldo Silva Martins, Adalto Bianchini, Derek R. Faust, Haruya Sakai, Cinthia Carneiro da Silva, A. Alonso Aguirre
Summary: Pollution poses a major threat to marine life, and trace elements are highly toxic pollutants in this environment. Zinc, an essential trace element for biota, becomes toxic at high concentrations. Sea turtles, with their longevity and widespread distribution, are good bioindicators for trace element pollution, accumulating these elements in their tissues over the years. This study compared the bioaccumulation of zinc in the liver, kidney, and muscles of 35 green sea turtles from Brazil, Hawaii, the USA (Texas), Japan, and Australia. The results showed that zinc was present in all specimens, with the highest concentrations in the liver and kidneys. The findings of equal zinc values in the liver suggest a pantropical distribution pattern for this metal, possibly due to its essential nature and bioavailability in marine environments. This study highlights the importance of understanding the distribution patterns of trace elements in marine biota for conservation purposes and suggests that green turtles can serve as useful sentinel species.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Geology
Allan Wilson, Robert Bolhar
Summary: The only known natural samples of high-pressure mantle constituents are mineral inclusions in diamonds, and their origin and formation have been a subject of debate. By analyzing trace elements in olivine crystals from South Africa, researchers have found evidence suggesting that these crystals formed in the deep upper mantle and potentially in the mantle transition zone. These findings provide insights into Earth's early mantle evolution and the formation of ancient continental and oceanic crust.
Article
Geochemistry & Geophysics
M. Sieber, T. M. Conway, G. F. de Souza, C. S. Hassler, M. J. Ellwood, D. Vance
Summary: Iron (Fe) is an essential micronutrient in the Southern Ocean, with distinct isotopic characteristics at different depths and sources in various regions. Areas near hydrothermal vents, islands, and continental shelves have significant influences on iron distribution and isotopic composition.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Environmental Sciences
Zvi Steiner, William M. Landing, Madeleine S. Bohlin, Mervyn Greaves, Satya Prakash, P. N. Vinayachandran, Eric P. Achterberg
Summary: Lithium concentrations in the ocean are closely related to the inorganic silicate cycle and carbon cycle. The residence time of lithium may be shorter than previously estimated.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Environmental Sciences
Chris M. Marsay, William M. Landing, Devon Umstead, Claire P. Till, Robert Freiberger, Jessica N. Fitzsimmons, Nathan T. Lanning, Alan M. Shiller, Mariko Hatta, Rebecca Chmiel, Mak Saito, Clifton S. Buck
Summary: Atmospheric deposition is a major source of micronutrient trace elements in the surface ocean. This study assesses the contribution of sea spray aerosol (SSA) to aerosol trace element loading, finding that only vanadium has a significant SSA contribution. The study highlights the limitations in measuring trace elements in SSA and the potential for overestimating new trace element inputs from atmospheric deposition.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Environmental Sciences
Nicholas J. Hawco, Alessandro Tagliabue, Benjamin S. Twining
Summary: A new global biogeochemical model has revealed that manganese deficiency limits the maximal growth rates of over half of the phytoplankton in the Southern Ocean. Manganese limitation is most extensive during the austral spring and is influenced by phytoplankton traits and the inhibition of manganese uptake by high zinc concentrations in the Antarctic waters. The expanded range of manganese limitation under increased iron supply during past glacial periods reduces the response of the biological carbon pump.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Limnology
Nicholas J. Hawco, Shun-Chung Yang, Paulina Pinedo-Gonzalez, Erin E. Black, Jennifer Kenyon, Sara Ferron, Xiaopeng Bian, Seth G. John
Summary: This study investigates the cycling rate of iron in the North Pacific Subtropical Gyre at Station ALOHA and finds that iron has a high recycling efficiency in the oligotrophic ocean, even in ecosystems that are not clearly iron-limited. These findings are important for a deeper understanding of the mechanisms and limiting factors of iron cycling in the marine environment.
LIMNOLOGY AND OCEANOGRAPHY
(2022)
Article
Environmental Sciences
Matthias Sieber, Nathan T. Lanning, Zachary B. Bunnell, Xiaopeng Bian, Shun-Chung Yang, Chris M. Marsay, William M. Landing, Clifton S. Buck, Jessica N. Fitzsimmons, Seth G. John, Tim M. Conway
Summary: This study investigates the distribution and controlling factors of cadmium in the surface and deep waters of the Pacific region. The results show a significant disparity between Cd-rich high-nutrient low-chlorophyll waters in the north and Cd-depleted waters in the subtropical and equatorial Pacific. Southern Ocean processes and water mass mixing are found to be the dominant control on Pacific Cd distributions.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Limnology
Shannon M. M. Burns, Randelle M. M. Bundy, William Abbott, Zuzanna Abdala, Alexa R. R. Sterling, P. Dreux Chappell, Bethany D. D. Jenkins, Kristen N. N. Buck
Summary: This study examined the relationship between phytoplankton growth and dissolved concentrations of iron, manganese, cobalt, nickel, copper, zinc, and cadmium in the Southern Ocean. The results showed that manganese was a secondary limiting nutrient both onshore and offshore, and there was no co-limitation of iron and vitamin B-12. The uptake of metals relative to soluble reactive phosphorus was closely related to initial dissolved metal to phosphorus ratio.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Article
Geosciences, Multidisciplinary
P. N. Sedwick, B. M. Sohst, K. N. Buck, S. Caprara, R. J. Johnson, D. C. Ohnemus, L. E. Sofen, A. Tagliabue, B. S. Twining, T. E. Williams
Summary: Constraining the role of dust deposition in regulating the concentration of iron in surface ocean waters requires understanding the flux of seawater-soluble iron in aerosols and the replacement time of dissolved iron in the euphotic zone. This study estimates these quantities using DFe data from the Bermuda Atlantic Time-series Study region and measurements of iron in aerosols and rain from Bermuda in 2019. The results suggest a seasonal variation in surface DFe concentrations and a mean euphotic-zone residence time of 0.8-1.9 years for DFe with respect to aeolian input.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Mathilde Dugenne, Mary R. R. Gradoville, Matthew J. J. Church, Samuel T. T. Wilson, Uri Sheyn, Matthew J. J. Harke, Karin M. M. Bjorkman, Nicholas J. J. Hawco, Annette M. M. Hynes, Francois Ribalet, David M. M. Karl, Edward F. F. DeLong, Sonya T. T. Dyhrman, E. Virginia Armbrust, Seth John, John M. M. Eppley, Katie Harding, Brittany Stewart, Ana M. M. Cabello, Kendra A. A. Turk-Kubo, Mathieu Caffin, Angelicque E. E. White, Jonathan P. P. Zehr
Summary: We sampled mesoscale cyclones and anticyclones in the North Pacific Subtropical Gyre in 2017 and 2018 and compared our observations with seasonal patterns from the Hawaii Ocean Time-series (HOT) program. We found that N-2 fixation rates (NFRs) were significantly high in the centers of anticyclones compared to previous observations. The increase in NFRs in 2017 was linked to high concentrations of the diazotroph Crocosphaera.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Limnology
Jiwoon Park, Bryndan P. Durham, Rebecca S. Key, Ryan D. Groussman, Zinka Bartolek, Paulina Pinedo-Gonzalez, Nicholas J. Hawco, Seth G. John, Michael C. G. Carlson, Debbie Lindell, Lauren W. Juranek, Sara Ferron, Francois Ribalet, E. Virginia Armbrust, Anitra E. Ingalls, Randelle M. Bundy
Summary: Siderophores are important iron-binding molecules that microbes use to obtain iron from their surroundings. This study investigated the concentrations and types of siderophores in different regions of the North Pacific Ocean and found higher concentrations in the iron-replete region compared to the iron-deplete region. Various types of siderophores were identified, indicating diverse production and usage of siderophores across latitude and depth. The presence of siderophore biosynthesis and uptake genes and transcripts further suggests active iron uptake by local bacterial communities.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Article
Multidisciplinary Sciences
Thomas J. Ryan-Keogh, Sandy J. Thomalla, Pedro M. S. Monteiro, Alessandro Tagliabue
Summary: Southern Ocean primary productivity is affected by light and iron limitation, but the factors determining iron availability, accessibility, and demand are uncertain. In this study, we analyzed long-term data collected by Biogeochemical Argo floats and ship-based platforms to examine the effects of iron stress on phytoplankton photophysiology. We observed a significant multidecadal trend of increasing iron stress and declining regional net primary production. This trend is attributed to changes in the Southern Ocean mixed-layer physics and complex biological and chemical feedback, highlighting important ongoing changes in the Southern Ocean carbon cycle.
Article
Geosciences, Multidisciplinary
Nicholas J. Hawco, Rhea K. Foreman
Summary: The expansion of oxygen deficient zones (ODZs) is expected to be a major consequence of anthropogenic climate change. In this study, the researchers investigated the cobalt flux to Equatorial Pacific sediments as a novel record of ODZ extent. The results suggest that ODZ expansion is linked to colder climates and support the claim that ongoing deoxygenation may be a transient response to warming.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Biodiversity Conservation
Alessandro Tagliabue, Benjamin S. Twining, Nicolas Barrier, Olivier Maury, Manon Berger, Laurent Bopp
Summary: Climate change scenarios indicate the need for large-scale carbon dioxide removal to combat global warming, putting the focus back on ocean iron fertilization (OIF). However, our study shows that while OIF can increase carbon sequestration, it may also intensify the decline of tropical ocean productivity and ecosystem biomass, with limited impact on atmospheric CO2. The interaction between OIF and ongoing climate change could lead to reduced animal biomass in tropical regions, particularly in coastal exclusive economic zones (EEZs), which could have implications for fisheries.
GLOBAL CHANGE BIOLOGY
(2023)
Article
Multidisciplinary Sciences
Alessandro Tagliabue, Kristen N. N. Buck, Laura E. E. Sofen, Benjamin S. S. Twining, Olivier Aumont, Philip W. W. Boyd, Salvatore Caprara, William B. B. Homoky, Rod Johnson, Daniela Konig, Daniel C. C. Ohnemus, Bettina Sohst, Peter Sedwick
Summary: Iron is important in regulating the ocean carbon cycle, with organic ligands playing a crucial role in stabilizing dissolved iron concentrations. However, the role of authigenic iron phases and the inconsistencies observed in dissolved iron cycling challenge the primary control of ligands. Through a study in the Bermuda Atlantic Time-series Study (BATS) region, it was found that upper-ocean dissolved iron dynamics are decoupled from ligands, indicating the need for a mechanism that allows dissolved iron to escape ligand stabilization and form a reservoir of settling iron particles. When this mechanism was implemented in a global-scale biogeochemical model, it successfully reproduced seasonal iron-cycle dynamics and global datasets where previous models failed.
Article
Ecology
Garrett Sharpe, Liang Zhao, Meredith G. Meyer, Weida Gong, Shannon M. Burns, Allesandro Tagliabue, Kristen N. Buck, Alyson E. Santoro, Jason R. Graff, Adrian Marchetti, Scott Gifford
Summary: Synechococcus, the most abundant cyanobacteria in high latitude regions, plays a significant role in annual marine net primary productivity. However, the uneven sampling of Synechococcus populations across the ocean, particularly in high-latitude, High Nutrient Low Chlorophyll (HNLC) regions, has limited our understanding of their adaptations to iron limitation and their influence on carbon, nitrogen, and iron cycles. This study focuses on Synechococcus populations in the subarctic North Pacific, a well-characterized HNLC region, and reveals their dependence on ammonium and other forms of recycled nitrogen, leading to reduced iron requirements. The findings have important implications for modeling the contribution of cyanobacteria to primary production and carbon export.
ISME COMMUNICATIONS
(2023)