Article
Microbiology
Ryan D. Groussman, Sacha N. Coesel, Bryndan P. Durham, E. Virginia Armbrust
Summary: The study investigated the transcriptional abundance profiles of eukaryotic plankton in the North Pacific Subtropical Gyre over a 4-day diel time series. It found that different genera of protists exhibit varying levels of diel periodicity in transcript abundances, with haptophyte and ochrophyte genera showing the greatest partitioning of their transcriptomes. Key metabolic pathways, such as photosynthesis, carbon fixation, and fatty acid biosynthesis, displayed peak activity at different times of the day, reflecting the adaptation of the protist community to the daily flux of matter and energy in the gyre ecosystem.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Multidisciplinary Sciences
Lei Zhou, Shihui Huang, Jiayi Gong, Peng Xu, Xiande Huang
Summary: This study utilized metagenomic sequencing datasets to construct MAGs from 30 subtropical estuaries in South China, revealing that these genomes are dominated by taxa assigned to the phylum Proteobacteria, Bacteroidota, and Actinobacteriota. This provides valuable insights into the diversity, phylogenetic history, and metabolic potential of microbiota in estuaries, enhancing our understanding of their structure, function, evolution, and adaptation to extreme conditions in the estuarine ecosystem.
Article
Environmental Sciences
Natalya Evans, Juliana Tichota, Wendi Ruef, James Moffett, Allan Devol
Summary: Climate change is expected to strengthen ocean Oxygen Deficient Zones (ODZs). A 50-year time series in the Eastern Tropical North Pacific (ETNP) ODZ revealed a 30% increase in strength from 1994 to 2019, with different factors influencing fixed nitrogen loss between core and deep ODZ layers. The recent rapid increase in ODZ strength, based on sedimentary records, suggests a potential link to climate change, but further monitoring is needed.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Environmental Sciences
Montserrat Aldunate, Peter von Dassow, Cristian A. Vargas, Osvaldo Ulloa
Summary: Anoxic marine zones have distinct characteristics compared to oxygen minimum zones, with the development of a secondary chlorophyll maximum playing an important role in the particulate organic carbon. Photosynthesis can exceed chemoautotrophic activity when sufficient light and Prochlorococcus are present.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Microbiology
J. Michael Beman, Sonia Marie Vargas, Samantha Vazquez, Jesse Mac Wilson, Angela Yu, Ariadna Cairo, Elisabet Perez-Coronel
Summary: The study reveals that the assembly and activity of microbial communities in Oceanic oxygen minimum zones (OMZs) are influenced by oceanographic and biogeochemical factors, showing predictable patterns with depth and between stations. While similar factors impact the active community, diversity is significantly lower within the OMZ. Active microbiological networks can track specific gradients or features, such as subsurface ammonium and nitrite maxima.
ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Limnology
Natalya Evans, Juliana Tichota, James W. Moffett, Allan H. Devol
Summary: Nitrite is a crucial intermediate in the ocean's fixed nitrogen loss and accumulates in Oxygen Deficient Zones (ODZs). Recent research has found significant reoxidation of nitrite back to nitrate, impacting the global nitrogen cycle. Analysis of basin-scale data reveals extensive nitrite reoxidation across the Eastern Tropical North Pacific (ETNP) ODZ. The study also highlights metabolic switching points and high spatiotemporal variability in nitrite reoxidation. This analysis provides valuable insights into the recycling of fixed nitrogen in the ETNP.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Article
Environmental Sciences
Gerd Krahmann, Damian L. Arevalo-Martinez, Andrew W. Dale, Marcus Dengler, Anja Engel, Nicolaas Glock, Patricia Grasse, Johannes Hahn, Helena Hauss, Mark J. Hopwood, Rainer Kiko, Alexandra N. Loginova, Carolin R. Loescher, Marie Massmig, Alexandra-Sophie Roy, Renato Salvatteci, Stefan Sommer, Toste Tanhua, Hela Mehrtens
Summary: Funded by the German Research Foundation, the research project 'SFB 754, Climate - Biogeochemistry Interactions in the Tropical Ocean' aimed to investigate climate-biogeochemistry interactions in the tropical ocean, with a focus on oxygen distribution processes. Over three 4-year funding phases, a consortium of over 150 scientists conducted 34 major research cruises, collecting extensive physical, biological, chemical, and meteorological data, with an agreed common data policy ensuring openness in data publication.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Environmental Sciences
Jarek Kwiecinski, Andrew R. Babbin
Summary: This passage discusses the importance of oxygen deficient zones in the global oceans and highlights the lack of resolution in modern ODZs due to a lack of direct sampling and errors in processing.
GLOBAL BIOGEOCHEMICAL CYCLES
(2021)
Article
Oceanography
Karthik Balaguru, Luke P. Van Roekel, L. Ruby Leung, Milena Veneziani
Summary: This study systematically evaluates the warm sea surface temperature bias in the Subtropical Eastern North Pacific using the Energy Exascale Earth System Model version 1 (E3SM). The high-resolution version of the model shows improved nearshore SST bias but a stronger offshore bias. Mixed-layer heat budget analysis suggests that errors in surface radiative fluxes and positive biases in horizontal heat advection contribute to the SST bias at high resolution. Analysis of HighResMIP models indicates that the shift in the SST bias location with increasing spatial resolution is not unique to E3SM.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Environmental Sciences
Jaime Farber Lorda, Bertrand Farber Data
Summary: The vertical distribution of zooplankton in the Eastern Tropical North Pacific is limited by oxygen, particularly in the Oxygen Minimum Zone. Zooplankton carbon density remains relatively constant above 100 meters depth, and is available during both day and night.
MARINE ENVIRONMENTAL RESEARCH
(2023)
Article
Meteorology & Atmospheric Sciences
Hirohiko Masunaga
Summary: In this study, the behavior of ITCZ convection near the eastern Pacific was investigated through analysis of satellite observations and reanalysis data. The study found that when precipitation peaks at the ITCZ center, there is a prominent positive peak in diabatic forcing, while when convection develops at the ITCZ edges, there is only a weak diabatic forcing but an import of moist static energy.
JOURNAL OF CLIMATE
(2023)
Article
Environmental Sciences
Zhongjing Jiang, Jing Li, Xiao Lu, Cheng Gong, Lin Zhang, Hong Liao
Summary: The study reveals that surface ozone pollution in eastern China during summer is significantly influenced by the variability of the Western Pacific Subtropical High (WPSH), impacting the ozone concentrations in different regions. Chemistry plays a decisive role in leading the ozone changes among processes, with natural emissions from biogenic and soil sources accounting for around 30% of the total surface ozone changes.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2021)
Article
Biotechnology & Applied Microbiology
Morgan D. Linney, John M. Eppley, Anna E. Romano, Elaine Luo, Edward F. DeLong, David M. Karl
Summary: With advances in metagenomic sequencing, this study characterized exocellular free DNA in diverse environmental systems, providing new perspectives on potential ecological dynamics and dimensions for experimental investigations. The study used a newly developed method to separate free DNA from cells, viruses, and vesicles, enabling independent characterization of each fraction. The composition and sources of free DNA in different regions of the water column were examined, revealing implications for dissolved organic matter cycling and export.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Environmental Sciences
Youjia Zou, Xiangying Xi
Summary: There are conflicting theories about the driver of the ongoing cooling in the eastern Pacific, with discussions focusing on increased heat uptake in the ocean, prolonged solar minimum, and changes in atmospheric water vapor and aerosols. Recent studies argue that strengthening easterly trade winds are responsible for the cooling, but observational data suggests that this may not be the case outside of the central tropical Pacific. The persistence of cooling in the eastern Pacific is directly linked to the eastward displacement of the Southeast Pacific Subtropical Anticyclone, creating pressure gradients and stronger winds that contribute to hiatus decades.
ENVIRONMENTAL RESEARCH LETTERS
(2021)
Article
Multidisciplinary Sciences
Yancheng Zhang, Xufeng Zheng, Deming Kong, Hong Yan, Zhonghui Liu
Summary: Research suggests that the North Pacific Subtropical Gyre circulation has intensified since 3000-4000 years ago, linked to the southward migration of the Intertropical Convergence Zone. This intensification may be due to cooling of the Holocene oceans, with implications that future global warming could weaken this circulation.
NATURE COMMUNICATIONS
(2021)
Article
Microbiology
Dean Vik, Maria Consuelo Gazitua, Christine L. Sun, Ahmed A. Zayed, Montserrat Aldunate, Margaret R. Mulholland, Osvaldo Ulloa, Matthew B. Sullivan
Summary: This study provides an ecological baseline for viral community structure, drivers, and population variability in Oxygen Minimum Zones (OMZs) in the Eastern Tropical South Pacific. Viral communities clustered into six groups based on oceanographic features, with oxygen concentration being the predominant environmental feature driving viral community structure. The alpha and beta diversity of viral communities in the anoxic zone were lower than in surface waters, mirroring the low microbial diversity seen in other studies.
ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Ecology
M. Consuelo Gazitua, Dean R. Vik, Simon Roux, Ann C. Gregory, Benjamin Bolduc, Brittany Widner, Margaret R. Mulholland, Steven J. Hallam, Osvaldo Ulloa, Matthew B. Sullivan
Summary: Viruses play a crucial role in marine ecosystems by reprogramming microbial metabolism through auxiliary metabolic genes (AMGs). A study found that viruses in Eastern Tropical South Pacific OMZ waters can impact nitrogen cycling processes, suggesting their significant contribution to global nitrogen loss.
Article
Multidisciplinary Sciences
Osvaldo Ulloa, Carlos Henriquez-Castillo, Salvador Ramirez-Flandes, Alvaro M. Plominsky, Alejandro A. Murillo, Connor Morgan-Lang, Steven J. Hallam, Ramunas Stepanauskas
Summary: Prochlorococcus, the most abundant photosynthetic organisms in the modern ocean, influence elemental cycling and energy flow. Research suggests that Prochlorococcus may have diverged from other cyanobacteria under low-oxygen conditions and transitioned from phycobilisomes to transmembrane chlorophyll complexes. These findings are crucial for understanding the ecology and evolution of this genus.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Marine & Freshwater Biology
Carlos Henriquez-Castillo, Belen Franco-Cisterna, Alejandro A. Murillo, Osvaldo Ulloa, Ramiro Riquelme-Bugueno
Summary: The study compared the performance of FC-CS-sequencing and total DNA extraction-sequencing in characterizing the stomach microbiota of krill, revealing that FC-CS was more effective in obtaining microbial information from the stomach.
JOURNAL OF CRUSTACEAN BIOLOGY
(2021)
Article
Environmental Sciences
Montserrat Aldunate, Peter von Dassow, Cristian A. Vargas, Osvaldo Ulloa
Summary: Anoxic marine zones have distinct characteristics compared to oxygen minimum zones, with the development of a secondary chlorophyll maximum playing an important role in the particulate organic carbon. Photosynthesis can exceed chemoautotrophic activity when sufficient light and Prochlorococcus are present.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Edson Piscoya, Peter von Dassow, Montserrat Aldunate, Cristian A. Vargas
Summary: The vertical distribution of phytoplankton in marine ecosystems is influenced by temperature, oxygen, and carbonate chemistry parameters. Low pH/low O-2 conditions also have an impact on the vertical distribution of nanophytoplankton.
MARINE ENVIRONMENTAL RESEARCH
(2022)
Article
Environmental Sciences
Carlos Henriquez-Castillo, Alvaro M. Plominsky, Salvador Ramirez-Flandes, Anthony D. Bertagnolli, Frank J. Stewart, Osvaldo Ulloa
Summary: This study reveals the significant role of Alteromonas in marine microbial communities, particularly in carbon cycling, under both oxygenated and suboxic conditions. The metatranscriptomic analysis suggests a coupling of Alteromonas iron and carbon metabolisms in Oxygen Minimum Zones.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Limnology
Jane C. Y. Wong, John A. Raven, Montserrat Aldunate, Sebastian Silva, Juan Diego Gaitan-Espitia, Cristian A. Vargas, Osvaldo Ulloa, Peter von Dassow
Summary: Phytoplankton play a crucial role in marine biogeochemistry and ecosystems, but their response to deoxygenation is not well-studied. A review of available information on phytoplankton in oxygen minimum zones (OMZs) reveals that surface phytoplankton disappear and are replaced by unique cyanobacteria lineages below the oxycline. Several factors, including top-down grazing, respiratory demand, and irradiance, cannot fully explain this vertical structure, suggesting a potential dependence on O2-dependent pathways.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Article
Multidisciplinary Sciences
Julia Anstett, Alvaro M. Plominsky, Edward F. DeLong, Alyse Kiesser, Klaus Juergens, Connor Morgan-Lang, Ramunas Stepanauskas, Frank J. Stewart, Osvaldo Ulloa, Tanja Woyke, Rex Malmstrom, Steven J. Hallam
Summary: Oxygen-deficient marine waters known as OMZs or AMZs are common oceanographic features that host microorganisms adapted to low oxygen conditions. The metabolic interactions of these microorganisms drive biogeochemical cycles and impact nitrogen loss and trace gas production and consumption. With the expansion and intensification of oxygen-deficient waters due to global warming, studying microbial communities in these areas is important for understanding the effects of climate change on marine ecosystem functions and services.
Article
Environmental Sciences
Sornsiri Phongphattarawat, Heather A. A. Bouman, Michael W. W. Lomas, Shubha Sathyendranath, Glen A. A. Tarran, Osvaldo Ulloa, Mikhail V. V. Zubkov
Summary: Information on phytoplankton pigments provides valuable insights into the ecophysiological state of primary producers and energy flow in aquatic ecosystems. Analyses of AFC cell counts and HPLC pigment concentrations reveal variations in pigment ratios and photoacclimation in different oceanic regions. These findings have important implications for mapping the biogeography and photoacclimatory state of subtropical phytoplankton communities and understanding their response to climate change.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Limnology
Isabelle Cox, Robert J. W. Brewin, Giorgio Dall'Olmo, Katy Sheen, Shubha Sathyendranath, Rafael Rasse, Osvaldo Ulloa
Summary: Using data from the BGC-Argo float, this study investigates the dynamics of a unique phytoplankton community adapted to low-oxygen conditions in the eastern tropical North Pacific. The study finds that this community, C-3, contributes significantly to integrated stocks of chlorophyll a and particulate backscattering, despite having lower peak biomass compared to C-2. C-3 thrives in a habitat characterized by lower temperature, higher density, lower light, lower oxygen, and higher salinity.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Article
Environmental Sciences
Edgart Flores, Igor Fernandez-Urruzola, Sebastian I. Cantarero, Matias Pizarro-Koch, Matthias Zabel, Julio Sepulveda, Osvaldo Ulloa
Summary: This study provides new insights into the sources and distribution of organic matter (OM) in the Atacama Trench. The results indicate that the majority of OM in the trench comes from deep-sea sediments rather than the surface ocean. These findings are important for understanding carbon cycling and predicting climate change.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2023)
Article
Ecology
Edgart Flores, Sebastian Cantarero, Paula Ruiz-Fernandez, Nadia Dildar, Matthias Zabel, Osvaldo Ulloa, Julio Sepulveda
Summary: Elevated organic matter concentrations are found in hadal surface sediments, but the origin of this material remains unclear. By analyzing the composition and distribution of cellular membrane intact polar lipids (IPLs) extracted from the sediments of the Atacama Trench, it was found that IPLs in hadal sediments mainly derive from in situ microbial production and biomass. They also discovered lipid characteristics that resemble physiological adaptation to high pressure and low temperature.
Article
Oceanography
Jason A. Law, Robert H. Weisberg, Yonggang Liu, Dennis A. Mayer, Jeffrey C. Donovan
Summary: Time series data from a moored array of sensors are used to describe the long-term mean circulation and seasonal variations on the West Florida Continental Shelf. The observations reveal a coherent shelf-wide circulation pattern with alongshore and down-coast flow, and a coastal jet separating an upwelling region from a downwelling region influenced by the deeper ocean.
DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY
(2024)