Article
Ecology
Tereza Novotna Jaromerska, Jakub Trubac, Krzysztof Zawierucha, Lenka Vondrovicova, Miloslav Devetter, Jakub D. Zarsky
Summary: This study presents data on the isotopic composition of tardigrades, rotifers, and cryoconite from High Arctic glaciers in Svalbard, discussing their role in a cryoconite hole trophic network. Differences in isotopic values between consumers and organic matter in cryoconite were found, indicating the need for further investigation into the particular diets and isotopic ratios of cryoconite consumers. The study introduces the first observation of carbon and nitrogen stable isotopic composition of top consumers in cryoconite holes, paving the way for future studies on supraglacial trophic networks.
Article
Environmental Sciences
Meilian Chen, Ji-Hoon Kim, Sungwook Hong, Yun Kyung Lee, Moo Hee Kang, Young Keun Jin, Jin Hur
Summary: The study revealed higher levels of terrestrial inputs and glaciofluvial runoffs in the Arctic fjords, especially in the southern Hornsund fjord. Extremely high levels of protein-like fluorescence were observed in summer at partially sea ice-covered fjords, consistent with near-ubiquity ice-edge blooms observed in the Arctic.
Article
Biodiversity Conservation
Barbara Oleszczuk, Marc J. Silberberger, Katarzyna Grzelak, Aleksandra Winogradow, Christine Dybwad, Ilka Peeken, Ingrid Wiedmann, Monika Kedra
Summary: This study examines the benthic food-web structure in the European sector of the Arctic Ocean and finds that the structure differs among different habitats and between macro- and meiofauna components. These differences are related to the quality and quantity of organic matter.
ECOLOGICAL INDICATORS
(2023)
Article
Limnology
Bo Barker Jorgensen, Katja Laufer, Alexander B. Michaud, Laura M. Wehrmann
Summary: The fjord ecosystems of the high Arctic are distinct from those of temperate latitudes due to the influence of glaciers, icebergs, sea ice, and permanently low temperatures. Sediment microbiology and biogeochemical processes in these fjords are mainly influenced by glacier-derived rock flour rich in metal oxides and plankton-derived marine organic matter. The balance between dominant sediment microbial processes changes along transects out through the fjords, reflecting the varying impact of glacier-derived and plankton-derived materials.
LIMNOLOGY AND OCEANOGRAPHY
(2021)
Article
Oceanography
Magdalena Krajewska, Ludwik Lubecki, Ma lgorzata Szymczak-Zyla
Summary: This study investigates the origin of organic matter deposited in surface sediments in Arctic fjords using a multiproxy approach based on lipid biomarkers. The findings reveal contributions from multiple marine and land-based sources and significant differences between fjords in terms of biogenic organic matter, specific phytoplankton genera, and bio-advection intensity related to warm Atlantic Water inflows.
CONTINENTAL SHELF RESEARCH
(2023)
Article
Environmental Sciences
Heng Xiao, Changping Mao, Shuai Wang, Zhimin Jia, Wenbo Rao
Summary: The construction of the Three Gorges Dam has altered the hydrology and sediment trapping in the Three Gorges Reservoir, resulting in changes in the composition and export of organic matter in the Yangtze River. Surface sediment samples from the reservoir were analyzed to determine the seasonal variations and sources of organic matter, with results showing that soil organic matter, river plankton, and aquatic vascular plants are the main sources. The analysis of nitrogen isotopes further revealed the presence of external pollutants, mainly from nitrogen fertilizers and domestic sewage. This study highlights the need for fine nitrogen management to reduce pollution in the Three Gorges Reservoir.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Multidisciplinary Sciences
Katja Laufer-Meiser, Alexander B. Michaud, Markus Maisch, James M. Byrne, Andreas Kappler, Molly O. Patterson, Hans Roy, Bo Barker Jorgensen
Summary: The Arctic has the highest warming rates on Earth, and the glacial fjord ecosystems are sensitive to this warming, impacting iron cycling and bioavailability. Glacial retreat may reduce the flux of iron to coastal marine ecosystems, affecting biogeochemical processes. Further research is needed to fully understand the impacts of a melting Arctic on marine ecosystems.
NATURE COMMUNICATIONS
(2021)
Article
Limnology
Lisa C. Herbert, Qingzhi Zhu, Alexander B. Michaud, Katja Laufer-Meiser, Christopher K. Jones, Natascha Riedinger, Zachery S. Stooksbury, Robert C. Aller, Bo Barker Jorgensen, Laura M. Wehrmann
Summary: The study investigated the variation and influencing factors of benthic iron fluxes in Arctic fjords of Svalbard, finding that sedimentation rates and availability of organic carbon have significant impacts on benthic Fe2+ flux. With ongoing climate warming, an increase in benthic Fe2+ flux is predicted in some fjords due to reduced sea ice cover, while a decrease in Fe2+ flux is expected in other regions with the retreat of tidewater glaciers, potentially exacerbating Fe limitation of primary productivity in the Arctic Ocean.
LIMNOLOGY AND OCEANOGRAPHY
(2021)
Article
Marine & Freshwater Biology
Valentin Kokarev, Mathieu Tachon, Marthe Austad, Maeve McGovern, Henning Reiss
Summary: The study found significant differences in macrobenthic community composition among three deep, sub-Arctic fjords, with each fjord hosting a distinct benthic community characterized by differences in total abundance, biomass, and species diversity. A slight mouth-to-head pattern of community distribution was observed in the fjord with a shallow sill.
ESTUARINE COASTAL AND SHELF SCIENCE
(2021)
Article
Geosciences, Multidisciplinary
Jochen Knies
Summary: This work reports on the coupling of dinitrogen fixation and denitrification in oxygen-deficient waters of the Arctic Ocean during the Paleogene. The coupling fertilized marine phytoplankton growth and favored organic carbon burial. The study also indicates a shift in the main source of biologically available nitrogen due to changing nutrient availability and suggests that the Arctic Ocean has been fully ventilated since the early Neogene.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Soil Science
Saskia Klink, Adrienne B. Keller, Andreas J. Wild, Vera L. Baumert, Matthias Gube, Eva Lehndorff, Nele Meyer, Carsten W. Mueller, Richard P. Phillips, Johanna Pausch
Summary: The study suggests that fungal residues, rather than plant residues, are the source of the most stable organic matter pool, and altering fungal communities may enhance long-term soil carbon storage.
SOIL BIOLOGY & BIOCHEMISTRY
(2022)
Article
Plant Sciences
Dany Croteau, Thomas Lacour, Nicolas Schiffrine, Philippe-Israel Morin, Marie-Helene Forget, Flavienne Bruyant, Joannie Ferland, Augustin Lafond, Douglas A. Campbell, Jean-Eric Tremblay, Marcel Babin, Johann Lavaud
Summary: The diatom communities in the Arctic Ocean exhibit different adaptation strategies based on changes in light environment, driving seasonal taxonomic succession. These adaptation strategies are aligned with changes in light intensity, leading to the dominance of different diatom species in different habitats throughout the seasons.
JOURNAL OF ECOLOGY
(2022)
Article
Environmental Sciences
Emilia Trudnowska, Katarzyna Draganska-Deja, Slawomir Sagan, Katarzyna Blachowiak-Samolyk
Summary: This study analyzes and maps the distribution patterns and internal structure of particles and plankton in two Arctic fjords. It finds that patches of particles and plankton generally occupy a small portion of the water column and have higher concentrations than the background. The size and shape of these patches vary, and they are related to glacier runoff, eddies, and chlorophyll fluorescence hot spots.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Ronald Amundson, Jennifer V. Mills, Laura N. Lammers, Matti Barthel, Nora Gallarotti, Johan Six, Gerhard Gebauer, Greg E. Maurer
Summary: The stable isotopes of nitrogen (N) and oxygen (O) in soil and soil-respired N2O are being measured, but there is a lack of theoretical framework to interpret the data. This study uses a diffusion/reaction model to demonstrate how soil processes influence the profiles and fluxes of soil N2O and its isotopes. The results suggest that the isotope composition of soil N2O flux is dependent on the net flux rate and the difference in isotope composition between the atmosphere and the biological source.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Environmental Sciences
P. Vinsova, T. J. Kohler, M. J. Simpson, I Hajdas, J. C. Yde, L. Falteisek, J. D. Zarsky, T. Yuan, V Tejnecky, F. Mercl, E. Hood, M. Stibal
Summary: This study investigates the characteristics of sediments from retreating Arctic glaciers and their organic matter sources and biogeochemical processes. The results indicate that subglacial sediments contain high amounts of bioavailable phosphorus but lack accessible carbon substrates, with organic matter mainly originating from terrestrial vascular plants and being influenced by resident microbial communities.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Plant Sciences
Theo Sciandra, Marie-Helene Forget, Flavienne Bruyant, Marine Beguin, Thomas Lacour, Chris Bowler, Marcel Babin
Summary: The polar night at high latitudes poses a challenge to photosynthetic organisms. This study used flow cytometry to investigate the acclimation of a population of diatoms to darkness and found distinct subpopulations with specific traits. The survival of these diatoms in darkness relied on reduction of metabolic activity and consumption of carbon reserves.
JOURNAL OF PHYCOLOGY
(2022)
Article
Limnology
Julien Thebault, Aurelie Jolivet, Matthieu Waeles, Helene Tabouret, Sophie Sabarot, Christophe Pecheyran, Aude Leynaert, Klaus Peter Jochum, Bernd R. Schone, Lukas Frohlich, Valentin Siebert, Erwan Amice, Laurent Chauvaud
Summary: Human activities are increasingly impacting phytoplankton dynamics in coastal ecosystems globally, but there are major disparities among sites and through time. Studying chemical information archived in shells of Pecten maximus can provide insights into phytoplankton dynamics over larger scales.
LIMNOLOGY AND OCEANOGRAPHY
(2022)
Article
Environmental Sciences
Xose Anxelu G. Moran, Francisca C. Garcia, Anders Rostad, Luis Silva, Najwa Al-Otaibi, Xabier Irigoien, Maria Ll. Calleja
Summary: Research suggests that the ocean's mesopelagic zone receives a consistent supply of labile DOM from the diel vertical migration of fishes, enabling a highly active community of heterotrophic prokaryotes. Heterotrophic prokaryotes in the mesopelagic layer are more efficient at converting extant DOM into new biomass during the day compared to night.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Microbiology
Luis Silva, Maria Ll. Calleja, Tamara M. Huete-Stauffer, Snjezana Ivetic, Mohd I. Ansari, Miguel Viegas, Xose Anxelu G. Moran
Summary: This study investigated the dynamics of heterotrophic bacterioplankton in relation to different dissolved organic matter (DOM) pools in tropical coastal waters. The results showed that protistan grazers controlled bacterial abundance and growth, while specific growth rates were influenced by bottom-up factors.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Clement Bertin, Atsushi Matsuoka, Antoine Mangin, Marcel Babin, Vincent Le Fouest
Summary: This study combines riverine tDOC concentrations with satellite estimates to assess the tDOC export from Arctic deltas. The results highlight the significant seasonal and temporal variations in tDOC concentrations and fluxes.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Environmental Sciences
Marc J. Silberberger, Katarzyna Koziorowska-Makuch, Zuzanna Borawska, Marta Szczepanek, Monika Kedra
Summary: Benthic communities and sediment parameters were found to play a dominant role in shaping oxygen and DIC fluxes, while highly variable DOC fluxes could not be explained. DIC fluxes were partly decoupled from oxygen fluxes, influenced by carbonate dissolution, anaerobic respiration, and submarine groundwater discharge.
ESTUARIES AND COASTS
(2022)
Article
Marine & Freshwater Biology
Zuzanna Borawska, Beata Szymczycha, Marc J. Silberberger, Katarzyna Koziorowska-Makuch, Marta Szczepanek, Monika Kedra
Summary: Spatial and seasonal changes in benthic fluxes of dissolved silica (DSi) were investigated in the southern Baltic Sea. The study found that sediments with high mud content had the highest fluxes in autumn, while sandy sediments showed no clear seasonal patterns. Biological factors were key explanatory variables in shallow enclosed areas, while environmental factors played a larger role in open areas. The study also highlighted the importance of benthic fluxes in the marine Si cycle.
ESTUARINE COASTAL AND SHELF SCIENCE
(2022)
Article
Microbiology
Mohd Ikram Ansari, Maria Li Calleja, Luis Silva, Miguel Viegas, David Kamanda Ngugi, Tamara Megan Huete-Stauffer, Xose Anxelu G. Moran
Summary: Autotrophic and heterotrophic bacterioplankton play essential roles in the biogeochemistry of tropical ecosystems. This study provides a high-frequency assessment of bacterial community dynamics and the associated environmental factors in Red Sea coastal waters. The results reveal the importance of temperature, chlorophyll-a, and dissolved organic carbon concentration in shaping bacterial abundance and diversity patterns.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Green & Sustainable Science & Technology
Emma Michaud, Adelaide Aschenbroich, Olivier Gauthier, Francois Fromard, Josephine Y. Aller, Robert C. Aller, Guillaume Brunier, Edward J. Anthony, Antoine Gardel, Vincent Le Garrec, Aude Leynaert, Gerard Thouzeau
Summary: This study characterizes the impact of early mangrove development on benthic infaunal assemblages and suggests that spatial variables play a role in shaping benthic diversity patterns. Understanding mangrove dynamics at suitable spatial scales is crucial for mangrove management and restoration plans.
Article
Chemistry, Medicinal
Sebastien Guerin, Laura Raguenes, Dany Croteau, Marcel Babin, Johann Lavaud
Summary: This study investigated the potential of the polar diatom Fragilariopsis cylindrus in producing fucoxanthin (Fx) and the inter-convertible couple diadinoxanthin-diatoxanthin (Ddx+Dtx) by manipulating the growth light climate and temperature. The results showed that F. cylindrus is well-suited for Fx and Ddx+Dtx production under conditions of low temperature and light intensity, reaching similar productivity levels as temperate counterparts.
Article
Biochemistry & Molecular Biology
Caroline Vernette, Julien Lecubin, Pablo Sanchez, Shinichi Sunagawa, Tom O. Delmont, Silvia G. Acinas, Eric Pelletier, Pascal Hingamp, Magali Lescot
Summary: Testing hypothesis about the biogeography of genes requires significant hardware resources and programming skills. The new release of 'Ocean Gene Atlas' (OGA2) is a freely available online service to mine large and complex marine environmental genomic databases.
NUCLEIC ACIDS RESEARCH
(2022)
Article
Limnology
Maria Lopez-Acosta, Manuel Maldonado, Jacques Grall, Axel Ehrhold, Celia Sitja, Cristina Galobart, Fiz F. Perez, Aude Leynaert
Summary: In coastal systems, the contribution of diatoms to the silicon cycle is well-known, while the contribution of benthic silicifiers such as sponges has rarely been studied. This study quantified the silicon fluxes and stocks of sponge fauna in the Bay of Brest, France. The findings indicate that sponge silicon stocks are much larger than diatom stocks and have a slower turnover rate. However, it is unclear whether the silicon budget of the Bay is at steady state.
LIMNOLOGY AND OCEANOGRAPHY
(2022)
Article
Microbiology
Abbrar Labban, Ahmed A. Shibl, Maria Ll. Calleja, Pei-Ying Hong, Xose Anxelu G. Moran
Summary: This study investigated the growth and gene expression changes of a Prochlorococcus strain from the Red Sea under different temperatures. The results showed that the growth rate and cell size of the Prochlorococcus increased significantly with temperature. However, at 30 degrees C, genes involved in carbon fixation and photosynthetic electron transport were downregulated, indicating a temperature response mechanism. The study suggests that Prochlorococcus can modulate its gene expression to adapt to lower temperatures but is unable to cope with temperatures exceeding 30 degrees C.
ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Ecology
Dag L. Aksnes, Anita S. Lotvedt, Christian Lindemann, Maria Li Calleja, Xose Anxelu G. Moran, Stein Kaarvedt, T. Frede Thingstad
Summary: This study reveals the important role of mesopelagic fishes and invertebrates in the biological carbon pump through their effects on various fluxes. By analyzing a depth-resolved food-web model, researchers found that these organisms have a significant impact on carbon export and sequestration. The results indicate that fish diel vertical migration enhances carbon sequestration and influences the relative contribution of different fluxes through microbial food-web cascades.
MARINE ECOLOGY PROGRESS SERIES
(2023)
Article
Environmental Sciences
Julien Laliberte, Eric Rehm, Borge Hamre, Clemence Goyens, Donald K. Perovich, Marcel Babin
Summary: This study successfully derived the photosynthetically available radiation (PAR) albedo of Arctic sea ice using the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite product. By training a predictive model based on a principal component analysis with in situ and simulated data, accurate PAR albedo estimates were obtained for different types of sea ice surfaces. This model can be applied to investigate the partitioning of PAR in the Arctic Ocean and enhance the understanding of marine primary producers.
ELEMENTA-SCIENCE OF THE ANTHROPOCENE
(2022)