Article
Geosciences, Multidisciplinary
Yang Xiang, Paul D. Quay, Rolf E. Sonnerup, Andrea J. Fassbender
Summary: The study finds that in the North Pacific and North Atlantic subtropical gyres, deep phosphate contributes about 60% of the total phosphorus supply. Dissolved organic matter and zooplankton excretion are important pathways for phosphorous export at these sites.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Oceanography
Kimberley L. Drouin, M. Susan Lozier, William E. Johns
Summary: Previous studies have suggested that the South Atlantic subtropical gyre has been expanding, shifting poleward, and intensifying. Investigating from an observational standpoint, analyzing seasonal and interannual variability, and long-term trends. The gyre strength follows seasonal heating and cooling, largely influenced by sea surface height gyre maximum, while ocean mass variability is driven by wind stress curl and out of phase with the steric signal. Interannual changes to the southern boundary and gyre strength are related to wind stress curl.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Review
Marine & Freshwater Biology
Ingrid Chorus, Elly Spijkerman
Summary: Reynolds elegantly synthesized the impact of limitation and co-limitation on phytoplankton communities, emphasizing that reducing P concentration is sufficient to mitigate eutrophication, but increasing N concentration may also be beneficial in certain circumstances. Research on stoichiometry and co-limitation serves to enhance our understanding of phytoplankton ecophysiology and community ecology.
Article
Oceanography
Kenneth S. Johnson, Matthew R. Mazloff, Mariana B. Bif, Yuichiro Takeshita, Hans W. Jannasch, Tanya L. Maurer, Joshua N. Plant, Ariane Verdy, Peter M. Walz, Stephen C. Riser, Lynne D. Talley
Summary: Measurements of pH and nitrate were used to study the ratios of dissolved inorganic carbon (DIC) and nitrate (NO3) uptake in the Southern Ocean during the spring to summer bloom period. The effects of atmospheric CO2 exchange and mixing were separated from phytoplankton uptake using the B-SOSE model. The corrected, in situ biological uptake ratio (C:N) was found to be similar to the Redfield Ratio (RR), with a few exceptions.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Geography, Physical
Dirk Nuernberg, Tabitha Riff, Andre Bahr, Cyrus Karas, Karl Meier, Joerg Lippold
Summary: This study shows that the subsurface temperature and salinity in the tropical Atlantic are influenced by Salinity Maximum Water (SMW) and perturbations of the Atlantic Meridional Overturning Circulation (AMOC) during the last glacial cycle. The variations in subsurface conditions before -32.8 ka BP are attributed to the North Brazil Current (NBC) and changes in trade winds, migration of the Intertropical Convergence Zone, and moisture transport across Central America. Major re-organizations of the tropical Atlantic upper ocean-atmosphere system occurred at -32.8 ka BP and 21.8 ka BP, which were not mirrored by significant AMOC changes.
GLOBAL AND PLANETARY CHANGE
(2021)
Article
Geosciences, Multidisciplinary
F. E. Leonelli, M. Bellacicco, J. Pitarch, E. Organelli, B. Buongiorno Nardelli, V de Toma, C. Cammarota, S. Marullo, R. Santoleri
Summary: The North Atlantic Subtropical Gyre (NASTG) has experienced the fastest expansion of oligotrophic waters worldwide in response to ocean warming. The study demonstrates that ultra-oligotrophic waters are spatially expanding and increasing in frequency in the NASTG, shifting it to a dominant quasi-permanent ultra-oligotrophic condition, confirming the ongoing ocean desertification.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Oceanography
M. D. Perez-Hernandez, A. Hernandez-Guerra, L. Cana-Cascallar, C. Arumi-Planas, V. Cainzos, A. J. Gonzalez-Santana, M. A. Gutierrez-Guerra, A. Martinez-Marrero, A. Mosquera Gimenez, C. Presas Navarro, D. Santana-Toscano, P. Velez-Belchi
Summary: For the first time, four dedicated hydrographic cruises were carried out in 2015 around the Canary Islands to determine the seasonality of the flows at the eastern boundary of the North Atlantic Subtropical Gyre. The results show that the Canary Current has a seasonal behavior, flowing on the easternmost position in winter and on the westernmost position in fall. At the Lanzarote Passage, the dominant flow is southward except in fall, where a northward transport is observed.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Review
Oceanography
Feili Li, M. Susan Lozier, N. Penny Holliday, William E. Johns, Isabela A. Le Bras, Ben I. Moat, Stuart A. Cunningham, M. Femke de Jong
Summary: Continuous measurements from the OSNAP array provide the first estimates of trans-basin heat and salinity transports in the subpolar latitudes, with the Labrador Sea making significant contributions to salinity and freshwater changes in the region.
PROGRESS IN OCEANOGRAPHY
(2021)
Article
Environmental Sciences
F. Deman, D. Fonseca-Batista, A. Roukaerts, M. I. Garcia-Ibanez, E. Le Roy, E. P. D. N. Thilakarathne, M. Elskens, F. Dehairs, F. Fripiat
Summary: This study presents water column profiles of nitrogen and oxygen isotopic composition of nitrate during the GEOTRACES GA01 cruise in 2014. The distribution of nitrate isotopic composition suggests assimilation by phytoplankton as the main controlling process, with a clear relationship in the subpolar gyre between the degree of nitrate consumption and residual isotopic values.
GLOBAL BIOGEOCHEMICAL CYCLES
(2021)
Article
Environmental Sciences
Skylar D. Gerace, Adam J. Fagan, Francois W. Primeau, Allison R. Moreno, Paul Lethaby, Rodney J. Johnson, Adam C. Martiny
Summary: Climate warming may lead to ocean deoxygenation, however current models cannot fully explain the observed decline in oxygen levels. This study investigates the possibility that the respiration quotient, a measure of the ratio of oxygen consumed per organic carbon respired, varies with depth and may contribute to the unexplained oxygen loss. The findings suggest that understanding the respiration quotient at different depths could greatly improve global models.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Environmental Sciences
Chun-Hoe Chow, Yi-Chen Lin, Wee Cheah, Jen-Hua Tai
Summary: During June-July 2010, an unusual eastward flow known as the eastward cross-shore Kuroshio branch (ECKB) was observed near Taiwan, branching out from the Kuroshio Current in the western North Pacific. The ECKB carried high chlorophyll-a waters over 1000 km into the nutrient-poor North Pacific subtropical gyre, and was warmer and fresher than surrounding waters. The mechanism of the ECKB was linked to a surface cyclonic wind anomaly to the north, leading to the induction of an eastward flow bifurcating from the main stream of the northward-flowing Kuroshio Current.
Article
Biology
Cristina Fernandez-Gonzalez, Glen A. Tarran, Nina Schuback, E. Malcolm S. Woodward, Javier Aristegui, Emilio Maranon
Summary: Temperature and nutrient supply have interactive effects on phytoplankton growth and productivity in the oligotrophic ocean. Microcosm experiments in the tropical and subtropical Atlantic reveal that nutrient addition consistently increases chlorophyll a concentration and picophytoplankton biomass, while temperature changes have a smaller and more variable effect. Nutrient enrichment leads to increased picoeukaryote abundance, depressed Prochlorococcus abundance, and increased contribution of small nanophytoplankton to total biomass. Warming and nutrient addition synergistically stimulate light-harvesting capacity, with the largest biomass response observed in the warmed, nutrient-enriched treatment at the warmest and least oligotrophic location.
COMMUNICATIONS BIOLOGY
(2022)
Article
Engineering, Environmental
Xia Liu, Yun Li, Ruijie Shen, Min Zhang, Feizhou Chen
Summary: The response of diatoms to reduced nitrogen and high phosphorus concentration in a eutrophic lake was studied. The results showed that the growth of diatoms was more sensitive to nitrogen reduction, and their response to nitrogen changed with water temperature.
Article
Environmental Sciences
Shuzhen Wang, Kate Heal, Qin Zhang, Yuanchun Yu, Mulualem Tigabu, Shide Huang, Chuifan Zhou
Summary: This study investigates the interaction between soil chemistry, dissolved organic matter (DOM) components, and microbial communities along an elevation gradient in the Wuyi Mountains, China. The results show that soil DOM composition is associated with vegetation types, microbial community structure, and soil nutrient status. As elevation increases, the composition and characteristics of soil DOM change.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Oceanography
J. P. Siemer, F. Machin, A. Gonzalez-Vega, J. M. Arrieta, M. A. Gutierrez-Guerra, M. D. Perez-Hernandez, P. Velez-Belchi, A. Hernandez-Guerra, E. Fraile-Nuez
Summary: The global upper ocean has been warming with a decrease in productivity, but the Eastern North Atlantic subtropical gyre region has shown significant warming with decreasing chlorophyll-a and net primary production. There seems to be a general decreasing trend for Chl-a and NPP in permanent upwelling areas, resulting in a potential loss of global NPP. The expansion of oceanic desert areas and increase in unproductive days may be linked to the competitive relationship of stratification and wind stress in the Canary upwelling system.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Microbiology
Elisa Calvo-Martin, Eva Teira, Xose Anton Alvarez-Salgado, Carlos Rocha, Shan Jiang, Maider Justel-Diez, Juan Severino Pino Ibanhez
Summary: This study explores the microbial ecology of two neighboring but contrasting subterranean estuaries, revealing their microbial composition, abundance, heterotrophic production, and their geochemical drivers. The results show that different subterranean estuaries have different microbial community characteristics, which are closely related to the biogeochemical processes in these estuaries.
ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Ecology
Ernesto Villarino, James R. Watson, Guillem Chust, A. John Woodill, Benjamin Klempay, Bror Jonsson, Josep M. Gasol, Ramiro Logares, Ramon Massana, Caterina R. Giner, Guillem Salazar, X. Anton Alvarez-Salgado, Teresa S. Catala, Carlos M. Duarte, Susana Agusti, Francisco Mauro, Xabier Irigoien, Andrew D. Barton
Summary: This study conducted a comparative analysis of surface and deep ocean microbial communities and found that their spatial distribution is closely related to oceanic distance and environmental gradients. The dispersal rates and body sizes of prokaryotes and picoeukaryotes contributed to the differences in community similarity. In the deep ocean, both oceanic distance and environment played significant roles in shaping microbial spatial distribution, while in the surface ocean, the influence of the environment was stronger.
GLOBAL ECOLOGY AND BIOGEOGRAPHY
(2022)
Review
Oceanography
Markel Gomez-Letona, Javier Aristegui, Nauzet Hernandez-Hernandez, Xose Anton Alvarez-Salgado, Marta Alvarez, Erick Delgadillo, Maria Perez-Lorenzo, Eva Teira, Santiago Hernandez-Leon
Summary: Organic matter influences the composition and metabolism of marine prokaryotes. This study investigates the relationship between fluorescent dissolved organic matter and prokaryotic community composition in the deep ocean. The results show that water mass mixing, oxygen utilization, and productivity proxies are important factors explaining the distribution of different fluorescence components. The diversity and taxonomic composition of prokaryotic communities are found to vary between water masses, suggesting a link between community composition, oxygen utilization, and fluorescent dissolved organic matter.
PROGRESS IN OCEANOGRAPHY
(2022)
Article
Limnology
Markel Gomez-Letona, Javier Aristegui, Nauzet Hernandez-Hernandez, Maria Perez-Lorenzo, Xose Anton Alvarez-Salgado, Eva Teira, Marta Sebastian
Summary: This study investigates the vertical connectivity between surface productivity regimes and deep ocean prokaryotic communities. The results show that higher prokaryotic abundances and viabilities, as well as smaller cell sizes, are observed below highly productive surface waters. However, leucine uptake rates in deep waters do not show a clear relationship with surface productivity.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Article
Environmental Sciences
Xose Anton Alvarez-Salgado, Maria Jose Fernandez-Reiriz, Isabel Fuentes-Santos, Luis T. Antelo, Antonio A. Alonso, Uxio Labarta
Summary: Assessing the carbon footprint of marine bivalve aquaculture requires considering the CO2 emissions from capital goods, aquaculture operations, and the metabolic CO2 budget of the cultured species. This study presents the metabolic CO2 budget for mussel aquaculture in the Northwest Iberian upwelling, incorporating environmental, biochemical, and metabolic data. The estimates vary depending on the individual mussels' seeding time and harvesting size, with the carbon footprint associated with mussel shell remaining constant at 365 kg CO2 per ton of shell and the carbon footprint associated with mussel flesh ranging from 92 to 578 kg CO2 per ton of mussel flesh.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Cristina Romera-Castillo, Jonathan Heras, Marta Alvarez, X. Anton Alvarez-Salgado, Gadea Mata, Eduardo Saenz-de-Cabezon
Summary: The distribution of non-conservative variables in the deep open ocean is influenced by the circulation and mixing of water masses and ongoing biological and geochemical processes. Estimating the contribution of different water masses is useful for understanding their distribution and separating the physical and biogeochemical components of variable variability. Machine learning models can be used to solve water mass mixing and provide real-time results, expanding knowledge of water mass composition and distribution in the ocean.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Patrizia Stipcich, Pedro Beca-Carretero, Xose Anton Alvarez-Salgado, Eugenia T. Apostolaki, Niki Chartosia, Pavlos Theofilos Efthymiadis, Carlos E. Jimenez, Gabriella La Manna, Arianna Pansini, Elena Principato, Vasilis Resaikos, Dagmar B. Stengel, Giulia Ceccherelli
Summary: The nutritional content of primary producers has an impact on the entire food web. This study investigated the changes in nutritional value of the endemic Mediterranean seagrass Posidonia oceanica associated with temperature rise and the occurrence of marine heat waves. The results showed a decrease in unsaturated fatty acids and C/N ratio, as well as an increase in monounsaturated fatty acids and nitrogen content during marine heat waves. However, the leaf biochemical composition seemed to be adapted to local water temperature, with only a few significant changes observed during marine heat waves. Future increases in temperature and frequency of marine heat waves may lead to changes in the nutritional value and palatability of seagrass leaves.
MARINE ENVIRONMENTAL RESEARCH
(2023)
Article
Microbiology
Maider Justel-Diez, Erick Delgadillo-Nuno, Alberto Gutierrez-Barral, Paula Garcia-Otero, Isaac Alonso-Barciela, Pablo Pereira-Villanueva, Xose Anton Alvarez-Salgado, Alberto Velando, Eva Teira, Emilio Fernandez
Summary: This study investigated the role of seabird guano in marine ecosystem functioning by adding different concentrations of gull guano to microbial communities collected from coastal waters in NW Spain. Results showed that guano stimulated the growth of certain bacteria and diatoms, and increased chlorophyll a concentration. The study also revealed that guano altered the phytoplankton-bacteria interaction from neutral to positive in low-nutrient environments, but from positive to neutral in high-nutrient environments.
ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Engineering, Environmental
Shuaidong Li, Lize Meng, Chu Zhao, Yu Gu, Robert G. M. Spencer, Xose Anton Alvarez-Salgado, Anne M. Kellerman, Amy M. McKenna, Tao Huang, Hao Yang, Changchun Huang
Summary: This study investigates the composition and transformation of dissolved organic matter (DOM) in the Yangtze River during long-distance transport and seasonal cycle. The results show that the concentration of dissolved organic carbon (DOC) in the Yangtze River is relatively low, indicating a significant contribution from allochthonous sources. The composition of DOM changes with the slowing water flow and changing hydrological conditions. This research provides important insights into the biogeochemical cycling of DOM in a large river.
Article
Oceanography
Oscar Sepulveda Steiner, Alexander L. Forrest, Jasmin B. T. McInerney, Bieito Fernandez Castro, Sebastien Lavanchy, Alfred Wuest, Damien Bouffard
Summary: Recent research has used microstructure turbulence measurements to improve our understanding of energy distribution in lakes and how it relates to vertical fluxes. However, a lack of lake-wide turbulence measurements hampers our ability to accurately assess these energy budgets on a large scale. In this study, an autonomous underwater glider was used to measure turbulence in Lake Geneva, revealing spatial variability and the important role of the slope region in mixing and energy dissipation.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Oceanography
M. Segura-Noguera, X. A. Alvarez-Salgado, S. Siedlecki, B. R. Hales
Summary: This study found that the concentrations of inorganic nitrogen may increase in coastal waters after the bloom of phytoplankton and the cessation of upwelling favorable winds. Additionally, the loss of nitrogen was found to occur mainly in particle-rich, low oxygen waters, rather than only in seafloor sediments. These findings emphasize the importance of considering the complete nitrogen cycle in water columns, rather than focusing solely on individual nutrients.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Environmental Sciences
E. Jerusalen-Lleo, M. Nieto-Cid, I. Fuentes-Santos, Thorsten Dittmar, X. A. Alvarez-Salgado
Summary: Our knowledge of the composition of ocean dissolved organic matter (DOM) is limited due to its molecular diversity, low individual compound concentration, and high ionic strength of ocean waters. Solid phase extraction (SPE) using styrene divinyl benzene polymer cartridges (PPL) is the most commonly used method to concentrate DOM. In this study, we investigate the efficiency and selectivity of SPE-PPL in extracting DOM from Arctic, Mediterranean, and Antarctic waters in the Cape Vert Frontal Zone (CVFZ). We found that the extraction efficiencies varied for different DOM pools and displayed significant differences among water masses.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Limnology
Esperanza Broullon, Peter J. S. Franks, Bieito Fernandez Castro, Miguel Gilcoto, Antonio Fuentes-Lema, Maria Perez-Lorenzo, Emilio Fernandez, Beatriz Mourino-Carballido
Summary: A study found that the high productivity of long, narrow bays may be due to the rapid rise of nutrient-rich isopycnals into the euphotic zone during upwelling pulses, triggering fast nutrient uptake and chlorophyll production. The tight coupling between physical and biological processes driven by wind forcing could explain the higher productivity of these bays.
LIMNOLOGY AND OCEANOGRAPHY LETTERS
(2023)
Article
Environmental Sciences
Juan Severino Pino Ibanhez, Xose Anton Alvarez-Salgado, Carlos Rocha
Summary: The study found that the water sources in the Ria de Vigo catchment have high levels of radon (Rn-222), which may have negative effects on health. During the dry season, the radon levels in the water sources are nearly double compared to the wet season, leading to a total effective dose of radiation that exceeds the recommended limit when consuming untreated groundwater. Therefore, it is recommended to implement measures such as radon remediation during the dry season to protect the health of residents.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Geosciences, Multidisciplinary
Zhibo Shao, Yangchun Xu, Hua Wang, Weicheng Luo, Lice Wang, Yuhong Huang, Nona Sheila R. Agawin, Ayaz Ahmed, Mar Benavides, Mikkel Bentzon-Tilia, Ilana Berman-Frank, Hugo Berthelot, Isabelle C. Biegala, Mariana B. Bif, Antonio Bode, Sophie Bonnet, Deborah A. Bronk, Mark V. Brown, Lisa Campbell, Douglas G. Capone, Edward J. Carpenter, Nicolas Cassar, Bonnie X. Chang, Dreux Chappell, Yuh-ling Lee Chen, Matthew J. Church, Francisco M. Cornejo-Castillo, Amalia Maria Sacilotto Detoni, Scott C. Doney, Cecile Dupouy, Marta Estrada, Camila Fernandez, Bieito Fernandez-Castro, Debany Fonseca-Batista, Rachel A. Foster, Ken Furuya, Nicole Garcia, Kanji Goto, Jesus Gago, Mary R. Gradoville, M. Robert Hamersley, Britt A. Henke, Cora Horstmann, Amal Jayakumar, Zhibing Jiang, Shuh-Ji Kao, David M. Karl, Leila R. Kittu, Angela N. Knapp, Sanjeev Kumar, Julie LaRoche, Hongbin Liu, Jiaxing Liu, Caroline Lory, Carolin R. Loscher, Emilio Maranon, Lauren F. Messer, Matthew M. Mills, Wiebke Mohr, Pia H. Moisander, Claire Mahaffey, Robert Moore, Beatriz Mourino-Carballido, Margaret R. Mulholland, Shin-ichiro Nakaoka, Joseph A. Needoba, Eric J. Raes, Eyal Rahav, Teodoro Ramirez-Cardenas, Christian Furbo Reeder, Lasse Riemann, Virginie Riou, Julie C. Robidart, Vedula V. S. S. Sarma, Takuya Sato, Himanshu Saxena, Corday Selden, Justin R. Seymour, Dalin Shi, Takuhei Shiozaki, Arvind Singh, Rachel E. Sipler, Jun Sun, Koji Suzuki, Kazutaka Takahashi, Yehui Tan, Weiyi Tang, Jean-Eric Tremblay, Kendra Turk-Kubo, Zuozhu Wen, Angelicque E. White, Samuel T. Wilson, Takashi Yoshida, Jonathan P. Zehr, Run Zhang, Yao Zhang, Ya-Wei Luo
Summary: This study presents an updated version (version 2) of the global oceanic diazotroph database, which significantly increases the number of in situ diazotrophic measurements and provides more detailed insights into nitrogen fixation in the global ocean. Version 2 yields significantly higher estimates of nitrogen fixation rates compared to version 1, particularly in the South Pacific and North Atlantic regions. Furthermore, additional data sheets for non-cyanobacterial diazotrophs and cell-specific N2 fixation rates have been included in version 2, enhancing the database's comprehensiveness.
EARTH SYSTEM SCIENCE DATA
(2023)