黑料视频

Source: Wiley Online Library 
Authors: Valerio Micaroni et al.
DOI: 10.1111/gcb.16013

Abstract

"Ocean deoxygenation is one of the major consequences of climate change. In coastal waters, this process can be exacerbated by eutrophication, which is contributing to an alarming increase in the so-called 鈥榙ead zones鈥� globally. Despite its severity, the effect of reduced dissolved oxygen has only been studied for a very limited number of organisms, compared to other climate change impacts such as ocean acidification and warming. [...]."

Source: Nature 
Authors: Maggie D. Johnson et al.
DOI: 10.1038/s41467-021-24777-3

Abstract

"Loss of oxygen in the global ocean is accelerating due to climate change and eutrophication, but how acute deoxygenation events affect tropical marine ecosystems remains poorly understood. Here we integrate analyses of coral reef benthic communities with microbial community sequencing to show how a deoxygenation event rapidly altered benthic community composition and microbial assemblages in a shallow tropical reef ecosystem. Conditions associated with the event precipitated coral bleaching and mass mortality, causing a 50% loss of live coral and a shift in the benthic community that persisted a year later. [...]."

Source: Science Direct
Authors: Fanny Chenillat et al.
DOI: 10.1016/j.marpolbul.2021.112116

Abstract

"Marine plastic pollution is a global issue, from the shores to the open ocean. Understanding the pathway and fate of plastic debris is fundamental to manage and reduce plastic pollution. Here, the fate of floating plastic pollution discharged along the coasts is studied by comparing two sources, one based on river discharges and the other on mismanaged waste from coastal populations, using a Lagrangian numerical analysis in a global ocean circulation model. [...]."

Source: Science Direct
Authors: Xin-Yi Gao et al.
DOI: 10.1016/j.cjph.2020.11.017

Abstract

"In oceanography, acoustics and hydrodynamics, people pay attention to the Burgers-type equations for different wave processes, one of which is an extended coupled (2+1)-dimensional Burgers system hereby under investigation. Based on the scaling transformation, Bell polynomials, Hirota operators and symbolic computation, we structure out two hetero-B盲cklund transformations, each of which to a solvable linear partial differential equation, and construct two sets of the bilinear forms, with the relevant one- and two-soliton solutions. [...]."

Source: Science Direct
Authors: Skye Yunshu Tian et al.
DOI: 10.1016/j.gloplacha.2021.103649

Abstract

"The Paleocene-Eocene Thermal Maximum (PETM), the most well-studied transient hyperthermal event in Earth history, is characterized by prominent and dynamic changes in global marine ecosystems. Understanding such biotic responses provides valuable insights into future scenarios in the face of anthropogenic warming. However, evidence of the PETM biotic responses is largely biased towards deep-sea records, whereas shallow-marine evidence remains scarce and elusive. Here we investigate a shallow-marine microfaunal record from Maryland, eastern United States, to comprehensively document the shallow-marine biotic response to the PETM. [...]."

Source: Science Direct
Authors: K.S. Stenger et al.
DOI: 10.1016/j.envpol.2021.118130

Abstract

"Microplastics pollution in marine environments is concerning. Microplastics persist and accumulate in various sections of the ocean where they present opportunity for micropollutant accumulation and microbial colonisation. Even though biofilm formation on plastics was first reported in the 1970's, it is only in recent years were plastic associated biofilms have gained research attention. [...]."

Source: Wiley Online Library
Authors: Taimoor Sohail et al.
DOI: 10.1029/2020GL091439

Abstract

"The ocean has absorbed approximately 90% of the accumulated heat in the climate system since 1970. As global warming accelerates, understanding ocean heat content changes and tracing these to surface heat input is increasingly important. We introduce a novel framework by organizing the ocean into temperature-percentiles from warmest to coldest, allowing us to trace ocean temperature changes to changes in surface fluxes and mixing. [...]."

Source: Nature
Authors: Jussi Hovikoski et al.
DOI: 10.1038/s43247-021-00249-w

Abstract

"The paleoenvironmental and paleogeographic development of the Norwegian鈥揋reenland seaway remains poorly understood, despite its importance for the oceanographic and climatic conditions of the Paleocene鈥揈ocene greenhouse world. Here we present analyses of the sedimentological and paleontological characteristics of Paleocene鈥揈ocene deposits (between 63 and 47 million years old) in northeast Greenland, and investigate key unconformities and volcanic facies observed through seismic reflection imaging in offshore basins. [...]."

Source: American Meteorological Society 
Authors: Hyodae Seo et al.
DOI: 10.1175/JCLI-D-21-0142.1

Abstract

"This study examines the role of the relative wind (RW) effect (wind relative to ocean current) in the regional ocean circulation and extratropical storm track in the south Indian Ocean. Comparison of two high-resolution regional coupled model simulations with and without the RW effect reveals that the most conspicuous ocean circulation response is the significant weakening of the overly energetic anticyclonic standing eddy off Port Elizabeth, South Africa, a biased feature ascribed to upstream retroflection of the Agulhas Current (AC). [...]."

Source: Wiley Online Library
Authors: Hugh St.C. O'Neill
DOI: 10.1002/9781119473206.ch10

Abstract

"A thermodynamic model to calculate the sulfide content at sulfide saturation or SCSS of basaltic and intermediate composition silicate melts has been built from four independently measurable thermodynamic entities, namely the standard state Gibbs free energy of the saturation reaction, the 鈥渟ulfide capacity鈥�, and the activities of FeO in the silicate melt and of FeS in the coexisting sulfide. [...]."

Source: Nature 
Authors: Pamela A. Fern谩ndez et al.
DOI: 10.1038/s41598-021-82094-7

Abstract

"The capacity of marine organisms to adapt and/or acclimate to climate change might differ among distinct populations, depending on their local environmental history and phenotypic plasticity. Kelp forests create some of the most productive habitats in the world, but globally, many populations have been negatively impacted by multiple anthropogenic stressors. Here, we compare the physiological and molecular responses to ocean acidification (OA) and warming (OW) of two populations of the giant kelp Macrocystis pyrifera from distinct upwelling conditions (weak vs strong). [...]."

Source: Nature 
Authors: Kenneth S. Johnson & Mariana B. Bif 
DOI: 10.1038/s41561-021-00807-z

Abstract

"The biological transformation of dissolved inorganic carbon to organic carbon during photosynthesis in the ocean, marine primary production, is a fundamental driver of biogeochemical cycling, ocean health and Earth鈥檚 climate system. The organic matter created supports oceanic food webs, including fisheries, and is an essential control on atmospheric carbon dioxide levels. Marine primary productivity is sensitive to changes due to climate forcing, but observing the response at the global scale remains a major challenge. [...]."

Source: Frontiers in Environmental Science
Authors: Karen Evans et al. 
DOI: 10.3389/fenvs.2021.626532

Abstract

"The ocean provides essential services to human wellbeing through climate regulation, provision of food, energy and livelihoods, protection of communities and nurturing of social and cultural values. Yet despite the ocean鈥檚 key role for all life, it is failing as a result of unsustainable human practices. The first global integrated assessment of the marine environment, produced by the United Nations under The Regular Process for Global Reporting and Assessment of the State of the Marine Environment, including Socioeconomic Aspects (the World Ocean Assessment), identified an overall decline in ocean health. [...]."

Source: Bjerknes Centre 
Authors: Anne Gro Vea Salvanes & Elin Darelius 

Abstract

"Loss of oxygen and expansion of oxygen depleted environments have been witnessed in both coastal and open-ocean systems since the middle of the 20th century, and ocean modelling predicts continuing decease by the year 2100. Oxygen depletion occurs thus during the same time epoch as global warming. Increased knowledge on how and why oxygen varies in space and time shapes the biogeochemical and ecological structure of marine systems and will be needed for future predictions of marine productivity. [...]."
 

Source: The Royal Society 
Authors: Elisa Thoral et al.
DOI: 10.1098/rsbl.2020.0759

Abstract

"Aerobic metabolism of aquatic ectotherms is highly sensitive to fluctuating climates. Many mitochondrial traits exhibit phenotypic plasticity in response to acute variations in temperature and oxygen availability. These responses are critical for understanding the effects of environmental variations on aquatic ectotherms' performance. Using the European seabass, Dicentrarchus labrax, we determined the effects of acute warming and deoxygenation in vitro on mitochondrial respiratory capacities and mitochondrial efficiency to produce ATP (ATP/O ratio). [...]."

Source: Science 
Authors: Lourens J. J. Meijer et al.
DOI: 10.1126/sciadv.aaz5803

Abstract

"Plastic waste increasingly accumulates in the marine environment, but data on the distribution and quantification of riverine sources required for development of effective mitigation are limited. Our model approach includes geographically distributed data on plastic waste, land use, wind, precipitation, and rivers and calculates the probability for plastic waste to reach a river and subsequently the ocean. This probabilistic approach highlights regions that are likely to emit plastic into the ocean. [...]."

Source: Science
Authors: Carlos M. Duarte et al.
DOI: 10.1126/science.aba4658

Abstract

"Oceans have become substantially noisier since the Industrial Revolution. Shipping, resource exploration, and infrastructure development have increased the anthrophony (sounds generated by human activities), whereas the biophony (sounds of biological origin) has been reduced by hunting, fishing, and habitat degradation. Climate change is affecting geophony (abiotic, natural sounds). [...]."

Source: Science Direct
Authors: Grant C. Pitcher et al.
DOI: 10.1016/j.pocean.2021.102613

Abstract

"The epoch of the Anthropocene, a period during which human activity has been the dominant influence on climate and the environment, has witnessed a decline in oxygen concentrations and an expansion of oxygen-depleted environments in both coastal and open ocean systems since the middle of the 20th century. This paper provides a review of system-specific drivers of low oxygen in a range of case studies representing marine systems in the open ocean, on continental shelves, in enclosed seas and in the coastal environment. [...]."

Source: Nature
Authors: Alyse A. Larkin et al.
DOI: 10.1038/s41597-021-00889-9

Abstract

"Detailed descriptions of microbial communities have lagged far behind physical and chemical measurements in the marine environment. Here, we present 971 globally distributed surface ocean metagenomes collected at high spatio-temporal resolution. Our low-cost metagenomic sequencing protocol produced 3.65 terabases of data, where the median number of base pairs per sample was 3.41 billion. [...]."

Source: Wiley Online Library
Authors: Fabrice Lacroix et al.
DOI: 10.1029/2020GB006603

Abstract

"The contribution of continental shelves to the marine carbon cycle is still poorly understood. Their preindustrial state is, for one, essentially unknown, which strongly limits the quantitative assessment of their anthropogenic perturbation. To date, approaches developed to investigate and quantify carbon fluxes on continental shelves have strongly simplified their physical and biogeochemical features. [...]."

Source: Science Direct
Authors: Meiling Yin et al.
DOI: 10.1016/j.orggeochem.2021.104268

Abstract

"The bacterial biomarker group of bacteriohopanepolyols (BHPs) has shown a significant potential to track terrestrial inputs and to respond to environmental changes. A total of 12 BHPs were detected in surface sediments of the East China Sea (ECS), with the contents of 3.79鈥�361 渭g/g TOC. The spatial distribution patterns and correlation analyses of bacteriohopanetetrol (BHT) and soil marker BHPs in sediments of the ECS indicate that they were mainly derived from marine autochthonous and terrestrial sources, respectively. [...]."

Source: Science Direct
Authors: Jiamei Wang et al.
DOI: 10.1016/j.jnucmat.2020.152603

Abstract

"The stress corrosion cracking behavior of alloy 600 was studied in high temperature water at 288掳C to 360掳C. The effects of dissolved oxygen (DO) and dissolved hydrogen (DH) on crack growth rate (CGR) are discussed. Results show that the CGR of alloy 600 in hydrogenated water (at the Ni/NiO phase boundary) is about 2-200 times higher than in 2 ppm O2 oxygenated water at 325掳C and 360掳C, while the opposite behavior was observed at 288掳C. [...]."

Source: Science Direct
Authors: M. Civel-Mazens et al.
DOI: 10.1016/j.quascirev.2020.106711

Abstract

"The oceanography of the western Indian sector of the Southern Ocean is extremely complex due to the presence of several subantartic islands and plateaus that alter the zonal flow of the Antarctic Circumpolar Current. The circulation is even more complex around the Kerguelen Islands (KI) as the hydrological fronts merge with the Agulhas Return Current, the latter transporting warm surface waters from the low latitudes to the Subantarctic Zone (SAZ) east of KI. [...]."

Source: Nature 
Authors: Natalie H. N. Low et al.
DOI: 10.1038/s41598-021-89928-4

Abstract

"Declining oxygen is one of the most drastic changes in the ocean, and this trend is expected to worsen under future climate change scenarios. Spatial variability in dissolved oxygen dynamics and hypoxia exposures can drive differences in vulnerabilities of coastal ecosystems and resources, but documentation of variability at regional scales is rare in open-coast systems. [...]."

Source: Springer Link
Authors: Bin Kang et al.
DOI: 10.1007/s10641-021-01130-7

Abstract

"We report a sudden explosive rise in abundance off southeastern China of a fish species that is hypoxia-tolerant, Bombay duck (Harpadon nehereus, Family Synodontidae), belonging to an Order (the Aulopiformes) encompassing overwhelmingly deep-sea fishes, but which predominantly occurs in coastal water. We suggest that this is made possible by the very high water content of its muscle and other tissues (about 90%, vs 75鈥�80% for other coastal fish), which reduces its oxygen requirements and allows it to outcompete other fish in low-oxygen neritic and estuarine waters. [...]."

Source: Wiley Online Library
Authors: Xiang Xiao et al.
DOI: 10.1111/1758-2229.12915 

Abstract

"Oceans cover approximately 70% of the Earth鈥檚 surface, and microbes comprise ~90% of the ocean biomass and are regarded as an important 鈥榟idden鈥� driver of essential elemental cycling, such as carbon cycling, in the oceans (Karl, 2007; Salazar and Sunagawa, 2017). Although the general public 鈥� even many scientists 鈥� think of the oceans as unified, stable water systems, they contain varied environments, including extreme environments such as oxygen-deficient zones, oligotrophic open ocean, polar water regions, deep ocean [...]."

Source: Wiley Online Library
Authors: Grace K. Saba et al.
DOI: 10.1002/lno.11709

Abstract

"Fishes are the dominant vertebrates in the ocean, yet we know little of their contribution to carbon export flux at regional to global scales. We synthesize the existing information on fish-based carbon flux in coastal and pelagic waters, identify gaps and challenges in measuring this flux and approaches to address them, and recommend research priorities. [...]."

Source: Frontiers in Marine Science
Authors: Carsten Spisla et al.
DOI: 10.3389/fmars.2020.611157

Abstract

"The oceans鈥� uptake of anthropogenic carbon dioxide (CO2) decreases seawater pH and alters the inorganic carbon speciation 鈥� summarized in the term ocean acidification (OA). Already today, coastal regions experience episodic pH events during which surface layer pH drops below values projected for the surface ocean at the end of the century. Future OA is expected to further enhance the intensity of these coastal extreme pH events. [...]."

Source: Nature
Authors: Daniel Gonz谩lez-Fern谩ndez et al.
DOI: 10.1038/s41893-021-00722-6

Abstract

"Riverine systems act as converging pathways for discarded litter within drainage basins, becoming key elements in gauging the transfer of mismanaged waste into the ocean. However, riverine litter data are scarce and biased towards microplastics, generally lacking information about larger items. Based on the first ever database of riverine floating macrolitter across Europe, we have estimated that between 307 and 925 million litter items are released annually from Europe into the ocean. [...]."

Source: Wiley Online Library
Authors: Male K枚ster et al.
DOI: 10.1029/2020GC009585

Abstract

"Biogeochemical processes in subseafloor sediments are closely coupled to global element cycles. To improve the understanding of changes in biogeochemical conditions on geological timescales, we investigate sediment cores from a 1,180 m deep hole in the Nankai Trough offshore Japan (Site C0023) drilled during International Ocean Discovery Program Expedition 370. During its tectonic migration from the Shikoku Basin to the Nankai Trough over the past 15 Ma, Site C0023 has experienced significant changes in depositional, thermal, and geochemical conditions. [...]."

Source: Frontiers in Marine Science
Authors: S. Wajih A. Naqvi
DOI: 10.3389/fmars.2021.624322

Abstract

"This article describes oxygen distributions and recent deoxygenation trends in three marginal seas 鈥� Persian Gulf and Red Sea in the Northwestern Indian Ocean (NWIO) and Andaman Sea in the Northeastern Indian Ocean (NEIO). Vertically mixed water column in the shallow Persian Gulf is generally well-oxygenated, especially in winter. Biogeochemistry and ecosystems of Persian Gulf are being subjected to enormous anthropogenic stresses including large loading of nutrients and organic matter, enhancing oxygen demand and causing hypoxia (oxygen < 1.4 ml l鈥�1) in central and southern Gulf in summer. [...]."

Source: Science Direct
Authors: E.D. S谩nchez-P茅rez et al.
DOI: 10.1016/j.jmarsys.2021.103607

Abstract

"The changes in temperature and dissolved oxygen concentration in the Pacific Ocean in the northern region of the shallow oxygen minimum zone (OMZ) off Mexico were analyzed on the basis of the Word Ocean Database and a series of oceanographic cruises (LEGOZ-Mex). In order to test the changes in both parameters between two similar oceanographic scenarios according to the Pacific Decadal Oscillation (PDO), a comparison was made between the last two cool PDO phases of 1962鈥�1974 and 2002鈥�2012 when conditions might be expected to be relatively similar. [...]."

Source: Wiley Online Library
Authors: Samuel J. Billheimer et al.
DOI: 10.1029/2020GB006824

Abstract

"Seasonal oxygen structure and utilization in the Sargasso Sea are characterized using nine profiling floats with oxygen 2021 sensors (years 2005鈥�2008), deployed in an Eighteen Degree Water (EDW) experiment (CLIMODE). During autumn-winter when the mixed layer is deepening, oxygen increases from the surface to the base of the EDW at 400 m. [...]."

Source: Wiley Online Library
Authors: Caroline Vernette et al.
DOI: 10.1111/1755-0998.13322

Abstract

"The Ocean Barcode Atlas (OBA) is a user friendly web service designed for biologists who wish to explore the biodiversity and biogeography of marine organisms locked in otherwise difficult to mine planetary scale DNA metabarcode data sets. Using just a web browser, a comprehensive picture of the diversity of a taxon or a barcode sequence is visualized graphically on world maps and interactive charts. [...]."

Source: Science Direct
Authors: Fahim Ullah Khan et al.
DOI: 10.1016/j.marpolbul.2020.111869

Abstract

"In the present study, the combined effects of pH, dissolved oxygen (DO) and temperature levels on the antioxidant responses of the mussel Mytilus coruscus were evaluated. Mussels were exposed to two pH (8.1, 7.7-acidification), two DO (6 mg L鈭�1, 2 mg L鈭�1-hypoxia) and two temperature levels (20 掳C, 30 掳C-warming) for 30 days. [...]."

Source: PNAS
Authors: Florian Kurzweil et al.
DOI: 10.1073/pnas.2023544118

Abstract

"Free oxygen represents an essential basis for the evolution of complex life forms on a habitable Earth. The isotope composition of redox-sensitive trace elements such as tungsten (W) can possibly trace the earliest rise of oceanic oxygen in Earth鈥檚 history. However, the impact of redox changes on the W isotope composition of seawater is still unknown. Here, we report highly variable W isotope compositions in the water column of a redox-stratified basin (未186/184W between +0.347 and +0.810 鈥�) that contrast with the homogenous W isotope composition of the open ocean (refined 未186/184W of +0.543 卤 0.046 鈥�). [...]."

Source: Wiley Online Library
Authors: Ben P. Harvey et al.
DOI: 10.1111/gcb.15455

Abstract

"Long-term exposure to CO2-enriched waters can considerably alter marine biological community development, often resulting in simplified systems dominated by turf algae that possess reduced biodiversity and low ecological complexity. Current understanding of the underlying processes by which ocean acidification alters biological community development and stability remains limited, making the management of such shifts problematic. [...]."

Source: Frontiers in Marine Science
Authors: Ariadna Mecho et al.
DOI: 10.3389/fmars.2021.574780

Abstract

"Mesophotic ecosystems (50鈥�400 m depth) of the southeastern Pacific have rarely been studied because of the logistical challenges in sampling across this remote zone. This study assessed how oxygen concentrations and other environmental predictors explain variation in echinoderm assemblages at these mesophotic systems, where this group is among the predominant fauna. [...]."

Source: Ocean Science
Authors: Olaf Duteil et al.
DOI: 10.5194/os-17-1489-2021

Abstract

"It is well known that Intermediate Water Masses (IWM) are sinking in high latitudes and ventilate the lower thermocline (500鈥�1500鈥塵 depth). We here highlight how the IWM oxygen content and the IWM pathway along the Equatorial Intermediate Current System (EICS) towards the eastern tropical Pacific ocean are essential for the supply of oxygen to the lower thermocline and the Oxygen Minimum Zones (OMZs). [...]."

Source: PNAS
Authors: Faycal Kessouri et al.
DOI: 10.1073/pnas.2018856118

Abstract

"Global change is leading to warming, acidification, and oxygen loss in the ocean. In the Southern California Bight, an eastern boundary upwelling system, these stressors are exacerbated by the localized discharge of anthropogenically enhanced nutrients from a coastal population of 23 million people. Here, we use simulations with a high-resolution, physical鈥揵iogeochemical model to quantify the link between terrestrial and atmospheric nutrients, organic matter, and carbon inputs and biogeochemical change in the coastal waters of the Southern California Bight. [...]."

Source: Wiley Online Library
Authors: B. B. Cael 
DOI: 10.1002/lol2.10196

Abstract

"Primary production (PP) is fundamental to ocean biogeochemistry, but challengingly variable. Satellite models are unique tools for investigating PP, but are difficult to compare and validate because of the scale separation between in situ and remote measurements, which also are rarely coincident. Here, I argue that satellite estimates should be log-skew-normally distributed, because of this scale separation and because PP measurements are log-normally distributed. [...]."

Source: Springer Link
Authors: Kirsty L. Nash et al.
DOI: 10.1007/s11160-021-09635-1

Abstract

"The oceans face a range of complex challenges for which the impacts on society are highly uncertain but mostly negative. Tackling these challenges is testing society鈥檚 capacity to mobilise transformative action, engendering a sense of powerlessness. Envisaging positive but realistic visions of the future, and considering how current knowledge, resources, and technology could be used to achieve these futures, may lead to greater action to achieve sustainable transformations. [...]."

Source: Earth System Science Data
Authors: Marzieh H. Derkani et al.
DOI: 10.5194/essd-13-1189-2021

Abstract

"The Southern Ocean has a profound impact on the Earth's climate system. Its strong winds, intense currents, and fierce waves are critical components of the air鈥搒ea interface and contribute to absorbing, storing, and releasing heat, moisture, gases, and momentum. Owing to its remoteness and harsh environment, this region is significantly undersampled, hampering the validation of prediction models and large-scale observations from satellite sensors. [...]."

Source: Science Direct
Authors: Xi Xiao et al
DOI: 10.1016/j.scitotenv.2021.145192

Abstract

"Seaweed farming has been proposed as a strategy for adaptation to ocean acidification, but evidence is largely lacking. Changes of pH and carbon system parameters in surface waters of three seaweed farms along a latitudinal range in China were compared, on the weeks preceding harvesting, with those of the surrounding seawaters. Results confirmed that seaweed farming is efficient in buffering acidification, with Saccharina japonica showing the highest capacity of 0.10 pH increase within the aquaculture area, followed by Gracilariopsis lemaneiformis (螖pH = 0.04) and Porphyra haitanensis (螖pH = 0.03). [...]."

Source: Springer Link
Authors: Shouwei Li et al.
DOI: 10.1007/s00382-021-05803-y

Abstract

"Atmospheric ozone concentrations have dramatically changed in the last five decades of past century. Herein we explore the effects of historical ozone changes that include stratospheric ozone depletion on Southern Ocean heat uptake and storage, by comparing CESM1 large ensemble simulations with fixed-ozone experiment. During 1958鈥�2005, the ozone changes contribute to about 50% of poleward intensification of the Southern Hemisphere westerly winds in historical simulations, which intensifies the Deacon Cell and residual meridional overturning circulation, thus contributing to heat redistribution in the Southern Ocean. [...]."

Source: Science Direct
Authors: Alexander J.P. Houben et al.
DOI: 10.1016/j.palaeo.2020.110191

Abstract

"The Toarcian Oceanic Anoxic Event (T-OAE, ~183 Ma) represents a well-known episode of organic-rich deposition, which is accompanied by a substantial negative carbon-isotope excursion (CIE). Underpinning the relationships between the carbon-cycle perturbation, ocean anoxia, primary productivity feedbacks and the enrichment of sedimentary organic carbon remains a major challenge. [...]."

"The  webinar series is a regular online seminar series that focuses on the depletion of oxygen in the marine environment 鈥� ocean deoxygenation. Organised and hosted by , each one-hour webinar is run by a guest moderator and two invited speakers. To support the diversity of the scientific community, the webinar series aims for an equal balance of early-career and senior scientists, gender, and geographical representation."

GO2NE Webinar 23 September 2021 No 9

Moderator:
Dimitri Gutierrez Aguilar
Instituto del Mar del Per煤

Speakers:
Dante Espinoza-Morriberon
Instituto del Mar del Per煤
"Numerical modelling of oxygen variability and deoxygenation trends in the Southeastern Pacific"

Renato Salvattec
 Kiel University, Germany
"Paleoceanographic evidence for smaller fish species in a warm and oxygen-poor ocean"

You can watch the GO₂NE Webinar 23 September 2021 No 9 recording .

Source: Annual Reviews 
Authors: Katye E. Altieri et al.
DOI: 10.1146/annurev-earth-083120-052147

Abstract

"The budget of reactive nitrogen (Nr; oxidized and reduced inorganic and organic forms of nitrogen) has at least doubled since the preindustrial era due to human activities. Excess Nr causes significant detrimental effects on many terrestrial and aquatic ecosystems; less is known about the impact on the open ocean. Nr deposition may already rival biological N2 fixation quantitatively and will likely continue to rise. [...]."

Source: Frontiers in Marine Science
Authors: Andr茅s C贸zar et al.
DOI: 10.3389/fmars.2021.571796

Abstract

"Windrow is a long-established term for the aggregations of seafoam, seaweeds, plankton and natural debris that appear on the ocean surface. Here, we define a 鈥渓itter windrow鈥� as any aggregation of floating litter at the submesoscale domain (<10 km horizontally), regardless of the force inducing the surface convergence, be it wind or other forces such as tides or density-driven currents. The marine litter windrows observed to date usually form stripes from tens up to thousands of meters long, with litter densities often exceeding 10 small items (<2 cm) per m2 or 1 large item (>2 cm) per 10 m2. [...]."

Source: Science
Authors: Evan M. Smith et al.
DOI: 10.1126/sciadv.abe9773

Abstract

"Subducting tectonic plates carry water and other surficial components into Earth鈥檚 interior. Previous studies suggest that serpentinized peridotite is a key part of deep recycling, but this geochemical pathway has not been directly traced. Here, we report Fe-Ni鈥搑ich metallic inclusions in sublithospheric diamonds from a depth of 360 to 750 km with isotopically heavy iron (未56Fe = 0.79 to 0.90鈥�) and unradiogenic osmium (187Os/188Os = 0.111). [...]."

Source: Wiley Online Library
Authors: Marie Ma脽mig & Anja Engel
DOI: 10.1029/2020JG006048

Abstract

"Microbial degradation of dissolved organic matter (DOM) contributes to the formation and preservation of oxygen minimum zones (OMZs) in the ocean, but information on the spatial distribution and molecular composition of DOM in OMZ regions is scarce. We quantified molecular components of DOM that is, dissolved amino acids (DAA) and dissolved combined carbohydrates (DCCHO), in the upwelling region off Peru. [...]."

Source: Springer Link
Authors: Jesamine C. Bartlett et al.
DOI: 10.1007/s00300-020-02792-2

Abstract

"The non-native midge Eretmoptera murphyi is Antarctica鈥檚 most persistent non-native insect and is known to impact the terrestrial ecosystems. It inhabits by considerably increasing litter turnover and availability of soil nutrients. The midge was introduced to Signy Island, South Orkney Islands, from its native South Georgia, and routes of dispersal to date have been aided by human activities, with little known about non-human-assisted methods of dispersal. [...]."

Source: Springer Link
Authors: Alessandro Orio et al.
DOI: 10.1007/s13280-021-01572-4

Abstract

"The intensified expansion of the Baltic Sea鈥檚 hypoxic zone has been proposed as one reason for the current poor status of cod (Gadus morhua) in the Baltic Sea, with repercussions throughout the food web and on ecosystem services. We examined the links between increased hypoxic areas and the decline in maximum length of Baltic cod, a demographic proxy for services generation. [...]."

Source: PNAS
Authors: Christopher E. Cornwall et al.
DOI: 10.1073/pnas.2015265118

Abstract

"Ocean warming and acidification threaten the future growth of coral reefs. This is because the calcifying coral reef taxa that construct the calcium carbonate frameworks and cement the reef together are highly sensitive to ocean warming and acidification. However, the global-scale effects of ocean warming and acidification on rates of coral reef net carbonate production remain poorly constrained despite a wealth of studies assessing their effects on the calcification of individual organisms. [...]."

Source: Nature 
Authors: Qi Shu et al.
DOI: 10.1038/s41467-021-23321-7

Abstract

"As a cooling machine of the Arctic Ocean, the Barents Sea releases most of the incoming ocean heat originating from the North Atlantic. The related air-sea heat exchange plays a crucial role in both regulating the climate and determining the deep circulation in the Arctic Ocean and beyond. It was reported that the cooling efficiency of this cooling machine has decreased significantly. In this study, we find that the overall cooling efficiency did not really drop: When the cooling efficiency decreased in the southern Barents Sea, it increased in the northern Barents and Kara Seas, indicating that the cooling machine has expanded poleward. [...]."

Source: Biogeosciences
Authors: Kyra A. St. Pierre et al.
DOI: 10.5194/bg-18-3029-2021

Abstract

"In coastal regions, rivers and streams may be important sources of nutrients limiting to primary production in marine waters; however, sampling is still rarely conducted across the land-to-ocean aquatic continuum, precluding conclusions from being drawn about connectivity between freshwater and marine systems. Here we use a more-than-4-year dataset (2014鈥�2018) of nutrients (nitrogen, phosphorus, silica, iron) and dissolved organic carbon spanning streams draining coastal watersheds and nearshore marine surface waters along the Central Coast of British Columbia, Canada, at the heart of the North Pacific coastal temperate rainforest region. [...]."

Source: Ocean Science
Authors: Jakub Vel铆msk媒 et al.
DOI: 10.5194/os-17-383-2021

Abstract

"Marine electromagnetic (EM) signals largely depend on three factors: flow velocity, Earth's main magnetic field, and seawater's electrical conductivity (which depends on the local temperature and salinity). Because of this, there has been recent interest in using marine EM signals to monitor and study ocean circulation. Our study utilizes voltage data from retired seafloor telecommunication cables in the Pacific Ocean to examine whether such cables could be used to monitor circulation velocity or transport on large oceanic scales. We process the cable data to isolate the seasonal and monthly variations and then evaluate the correlation between the processed data and numerical predictions of the electric field induced by an estimate of ocean circulation. [...]."

Source: American Meteorological Society
Authors: Navid C. Constantinou & Andrew McC. Hogg
DOI: 10.1175/JCLI-D-20-0962.1

Abstract

"Atmosphere and ocean are coupled via air鈥搒ea interactions. The atmospheric conditions fuel the ocean circulation and its variability, but the extent to which ocean processes can affect the atmosphere at decadal time scales remains unclear. In particular, such low-frequency variability is difficult to extract from the short observational record, meaning that climate models are the primary tools deployed to resolve this question. Here, we assess how the ocean鈥檚 intrinsic variability leads to patterns of upper-ocean heat content that vary at decadal time scales. [...]."

Source: Wiley Online Library
Authors: D. A. Putrasahan et al.
DOI: 10.1029/2020GL092049

Abstract

"The magnitude of global mean surface temperature (GMST) response to increasing atmospheric CO2 concentrations is affected by the efficiency of ocean heat uptake, which in turn can be affected by oceanic mesoscale eddies. Using the Max Planck Institute 鈥� Earth System Model (MPI鈥怑SM1.2), we find that resolving eddies leads to a 鈭�0.1掳C cooler response of GMST to an abrupt CO₂ quadrupling, which is related to a larger rate of heat uptake by an eddying ocean. [...]."

Source: Earth System Science Data 
Authors: Le Xie et al.
DOI: 10.5194/essd-13-1251-2021

Abstract

"Virioplankton are a key component of the marine biosphere in maintaining diversity of microorganisms and stabilizing ecosystems. They also contribute greatly to nutrient cycles/cycling by releasing organic matter after lysis of hosts. In this study, we constructed the first global viral oceanography database (gVOD) by collecting 10鈥�931 viral abundance (VA) data and 727 viral production (VP) data, along with host and relevant oceanographic parameters when available. Most VA data were obtained in the North Atlantic (32鈥�%) and North Pacific (29鈥�%) oceans, while the southeast Pacific  Pacific and Indian oceans were quite undersampled. [...]."

Source: Science Direct
Authors: Jian-Long Li et al.
DOI: 10.1016/j.scitotenv.2021.147449

Abstract

"The photodegradation of dissolved organic sulfur (DOS) is a potential source of aqueous sulfate and its chemical precursors in surface water. However, the photochemical fate of DOS and factors that control its fate still remain unclear. Herein, we employed a DOS model featuring a photosensitizer (humic acids, HA) to investigate the photochemical degradation pathways of DOS in various natural water sources, from which we observed the substantial photosensitized formation of sulfate, methanesulfonic acid (MSA), carbonyl sulfide (COS), and carbon disulfide (CS2). [...]."

Source: Nature 
Authors: Florian Le Pape et al.
DOI: 10.1038/s41467-021-22591-5

Abstract

"Wind driven ocean wave-wave interactions produce continuous Earth vibrations at the seafloor called secondary microseisms. While the origin of associated Rayleigh waves is well understood, there is currently no quantified explanation for the existence of Love waves in the most energetic region of the microseism spectrum (3鈥�10鈥塻). Here, using terrestrial seismic arrays and 3D synthetic acoustic-elastic simulations combined with ocean wave hindcast data, we demonstrate that, observed from land, our general understanding of Rayleigh and Love wave microseism sources is significantly impacted by 3D propagation path effects. [...]."

Source: American Meteorological Society 
Authors: Lisa N. Murphy et al.
DOI: 10.1175/JCLI-D-20-0167.1

Abstract

"This paper attempts to enhance our understanding of the causes of Atlantic Multidecadal Variability, the AMV. Following the literature, we define the AMV as the SST averaged over the North Atlantic basin, linearly detrended and low-pass filtered. There is an ongoing debate about the drivers of the AMV, which include internal variability generated from the ocean or atmosphere (or both), and external radiative forcing. We test the role of these factors in explaining the time history, variance, and spatial pattern of the AMV using a 41-member ensemble from a fully coupled version of CESM and a 10-member ensemble of the CESM atmosphere coupled to a slab ocean. [...]."

Source: ZDF

"Im Meer gibt es immer mehr Stellen, in denen es kaum noch Sauerstoff gibt: sogenannte "Todeszonen". Wir erkl盲ren euch, warum das ein Problem ist."

Source: Nature  
Authors: K. Kvale et al.
DOI: 10.1038/s41467-021-22554-w

Abstract

"Global warming has driven a loss of dissolved oxygen in the ocean in recent decades. We demonstrate the potential for an additional anthropogenic driver of deoxygenation, in which zooplankton consumption of microplastic reduces the grazing on primary producers. In regions where primary production is not limited by macronutrient availability, the reduction of grazing pressure on primary producers causes export production to increase. [...]."

Source: Nature 
Authors: Andreas Oschlies 
DOI: 10.1038/s41467-021-22584-4

Abstract

"Less than a quarter of ocean deoxygenation that will ultimately be caused by historical CO2 emissions is already realized, according to millennial-scale model simulations that assume zero CO2 emissions from year 2021 onwards. About 80% of the committed oxygen loss occurs below 2000鈥塵 depth, where a more sluggish overturning circulation will increase water residence times and accumulation of respiratory oxygen demand. According to the model results, the deep ocean will thereby lose more than 10% of its pre-industrial oxygen content even if CO2 emissions and thus global warming were stopped today. [...]."

Source: Nature 
Authors: Sol猫ne Irion et al.
DOI: 10.1038/s41396-021-00915-z

Abstract

"Phytoplankton is composed of a broad-sized spectrum of phylogenetically diverse microorganisms. Assessing CO2-fixation intra- and inter-group variability is crucial in understanding how the carbon pump functions, as each group of phytoplankton may be characterized by diverse efficiencies in carbon fixation and export to the deep ocean. We measured the CO2-fixation of different groups of phytoplankton at the single-cell level around the naturally iron-fertilized Kerguelen plateau (Southern Ocean), known for intense diatoms blooms suspected to enhance CO2 sequestration. [...]."

Source: Nature 
Authours: Ana H. Lobo et al.
DOI: 10.1038/s41561-021-00706-3

Abstract

"Enceladus is believed to have a saltwater global ocean, heated at the ocean鈥揷ore interface and losing heat to the floating ice shell above. This configuration suggests an important role for vertical convection. The ice shell has dramatic meridional thickness variations that, in steady state, must be sustained by the ocean circulation against processes acting to remove these anomalies. This could be achieved through spatially separated regions of freezing and melting at the ocean鈥搃ce interface. [...]."

Source: Nature
Authors: L. Caesar et al.
DOI: 10.1038/s41561-021-00699-z

Abstract

"The Atlantic Meridional Overturning Circulation (AMOC)鈥攐ne of Earth鈥檚 major ocean circulation systems鈥攔edistributes heat on our planet and has a major impact on climate. Here, we compare a variety of published proxy records to reconstruct the evolution of the AMOC since about AD鈥�400. A fairly consistent picture of the AMOC emerges: after a long and relatively stable period, there was an initial weakening starting in the nineteenth century, followed by a second, more rapid, decline in the mid-twentieth century, leading to the weakest state of the AMOC occurring in recent decades. [...]."

Source: Nature 
Authors: Peter S. Ross et al.
DOI: 10.1038/s41467-020-20347-1

Abstract

"Microplastics are increasingly recognized as ubiquitous global contaminants, but questions linger regarding their source, transport and fate. We document the widespread distribution of microplastics in near-surface seawater from 71 stations across the European and North American Arctic - including the North Pole. We also characterize samples to a depth of 1,015鈥塵 in the Beaufort Sea. Particle abundance correlated with longitude, with almost three times more particles in the eastern Arctic compared to the west. [...]."

Source: Nature
Authors: N. V. Patin et al.
DOI: 10.1038/s41396-021-00917-x

Abstract

"Exploration of oxygen-depleted marine environments has consistently revealed novel microbial taxa and metabolic capabilities that expand our understanding of microbial evolution and ecology. Marine blue holes are shallow karst formations characterized by low oxygen and high organic matter content. They are logistically challenging to sample, and thus our understanding of their biogeochemistry and microbial ecology is limited. We present a metagenomic and geochemical characterization of Amberjack Hole on the Florida continental shelf (Gulf of Mexico). [...]."

Source: Science
Authors: Helen M. Williams et al.
DOI: 10.1126/sciadv.abc7394

Abstract

"The differentiation of Earth ~4.5 billion years (Ga) ago is believed to have culminated in magma ocean crystallization, crystal-liquid separation, and the formation of mineralogically distinct mantle reservoirs. However, the magma ocean model remains difficult to validate because of the scarcity of geochemical tracers of lower mantle mineralogy. The Fe isotope compositions (未57Fe) of ancient mafic rocks can be used to reconstruct the mineralogy of their mantle source regions. We present Fe isotope data for 3.7-Ga metabasalts from the Isua Supracrustal Belt (Greenland). [...]."

Source: Science Direct
Authors: Saba Sadiq et al.
DOI: 10.1016/j.jclepro.2020.123790

Abstract

"Lean Manufacturing (LM) has traditionally helped industries in removing the non-value-added processes to achieve operational excellence. Similarly, the blue ocean strategy helps organizations in creating an uncontested market space where the competition is irrelevant. The authors posit that the integration of two approaches helps in achieving holistic manufacturing excellence, and there is a paucity of approaches that integrate the two paradigms. In order to fill this research gap, the authors have developed an integrated framework that combines the concepts of lean manufacturing and blue ocean manufacturing (BOM), via a structured survey. [...]."

Source: Biogeosciences
Authors: Tereza Novotn谩 Jarom臎艡sk谩 et al.
DOI: 10.5194/bg-18-1543-2021

Abstract

"Arctic cryoconite holes represent highly biologically active aquatic habitats on the glacier surface characterized by the dynamic nature of their formation and functioning. The most common cryoconite apex consumers are the cosmopolitan invertebrates 鈥� tardigrades and rotifers. Several studies have highlighted the potential relevance of tardigrades and rotifers to cryoconite holes' ecosystem functioning. However, due to the dominant occurrence of prokaryotes, these consumers are usually out of the major scope of most studies aimed at understanding biological processes on glaciers. [...]."

Source: Nature
Authors: Enric Sala et al.
DOI: 10.1038/s41586-021-03371-z

Abstract

"The ocean contains unique biodiversity, provides valuable food resources and is a major sink for anthropogenic carbon. Marine protected areas (MPAs) are an effective tool for restoring ocean biodiversity and ecosystem services1,2, but at present only 2.7% of the ocean is highly protected3. This low level of ocean protection is due largely to conflicts with fisheries and other extractive uses. To address this issue, here we developed a conservation planning framework to prioritize highly protected MPAs in places that would result in multiple benefits today and in the future. [...]."

Source: American Meteorological Society
Authors: Adam Vaccaro et al.
DOI: 10.1175/JCLI-D-19-0814.1

Abstract

"Surface temperature is a vital metric of Earth鈥檚 climate state, but is incompletely observed in both space and time: over half of monthly values are missing from the widely used HadCRUT4.6 global surface temperature dataset. Here we apply GraphEM, a recently developed imputation method, to construct a spatially complete estimate of HadCRUT4.6 temperatures. GraphEM leverages Gaussian Markov random fields (aka Gaussian graphical models) to better estimate covariance relationships within a climate field, detecting anisotropic features such as land/ocean contrasts, orography, ocean currents and wave-propagation pathways. [...]."

Source: Springer Link
Authors: Takao Kawasaki et al.
DOI: 10.1007/s10872-020-00584-0

Abstract

"We investigate the control mechanisms of the deep Pacific Ocean circulation by introducing updated methods for parameterizing tidal mixing. The column-integrated rates of dissipation in near- and far-fields are derived from the tidal energy conversion and dissipation rates estimated by a high resolution tide model. In the calculation of the far-field mixing, its dependency on stratification is taken into account based on theoretical and observational knowledge.Unlike previous studies that did not take the stratification dependence into account, the far-field mixing does not function to significantly enhance the deep Pacific Ocean circulation. The deep Pacific Ocean circulation is also found to be insensitive to the decay scale height of the near-field mixing. [...]."

Source: Nature 
Authors: Andrei Polejack et al.
DOI: 10.1057/s41599-021-00729-6

Abstract

"The ocean provides important ecosystem services to society, but its health is in crisis due to the impacts of human activities. Ocean sustainability requires ambitious levels of scientific evidence to support governance and management of human activities that impact the ocean. However, due to the size, complexity and connectivity of the ocean, monitoring and data collection presupposes high investments, and nations need to cooperate to deliver the ambitious, costly science that is required to inform decisions. [...]."

Source: Annual Reviews
Authors: Laura Airoldi et al.
DOI: 10.1146/annurev-marine-032020-020015

Abstract

"Urban and periurban ocean developments impact 1.5% of the global exclusive economic zones, and the demand for ocean space and resources is increasing. As we strive for a more sustainable future, it is imperative that we better design, manage, and conserve urban ocean spaces for both humans and nature. We identify three key objectives for more sustainable urban oceans: reduction of urban pressures, protection and restoration of ocean ecosystems, and support of critical ecosystem services. We describe an array of emerging evidence-based approaches, including greening grayinfrastructure, restoring habitats, and developing biotechnologies. [...]." 

Source: Science Direct
Authors: Haiyang Wang et al.
DOI: 10.1016/j.precamres.2020.106085

Abstract

"Benthic oxygen oases linked to photosynthetic mats have been reported in modern anoxic aquatic systems. Benthic macroalgal blooms were common in stratified, anoxic Neoproterozoic oceans, leading us to hypothesize the existence of benthic oxygen oases at that time. This hypothesis has significant implications regarding the bioavailability of transition metals (e.g., Cu, Zn, Ni, Mo, V) and the distribution of aerobic eukaryotes in these oceans. However, little research has been directed toward testing the benthic oxygen oasis hypothesis in ancient anoxic marine systems. [...]."

Source: Geoscientific Model Development
Authors: Katherine A. Crichton et al. 
DOI: 10.5194/gmd-14-125-2021

Abstract

"Temperature is a master parameter in the marine carbon cycle, exerting a critical control on the rate of biological transformation of a variety of solid and dissolved reactants and substrates. Although in the construction of numerical models of marine carbon cycling, temperature has been long recognised as a key parameter in the production and export of organic matter at the ocean surface, its role in the ocean interior is much less frequently accounted for. There, bacteria (primarily) transform sinking particulate organic matter (POM) into its dissolved constituents and consume dissolved oxygen (and/or other electron acceptors such as sulfate). [...]."

Source: Science Direct
Authors: Fabrice Lambert et al.
DOI: 10.1016/j.epsl.2020.116675

Abstract

"The last time Earth's climate experienced geologically rapid global warming was associated with the last glacial termination, when atmospheric CO2 concentrations rose from 180 ppmv during the Last Glacial Maximum (LGM, 26-19 kaBP) to 鈭�260 ppmv by the early Holocene (12-8 kaBP). About one quarter of that difference is thought to be due to a stronger biological pump during glacial times, driven by increased aeolian dust deposition and hence greater iron availability in ocean surface waters. [...]."

Source: Nature 
Authors: Martin Ko拧钮谩k et al.
DOI: 10.1038/s42003-021-01714-0

Abstract

"A marked 120鈥塎y gap in the fossil record of vampire squids separates the only extant species (Vampyroteuthis infernalis) from its Early Cretaceous, morphologically-similar ancestors. While the extant species possesses unique physiological adaptations to bathyal environments with low oxygen concentrations, Mesozoic vampyromorphs inhabited epicontinental shelves. However, the timing of their retreat towards bathyal and oxygen-depleted habitats is poorly documented. Here, we document a first record of a post-Mesozoic vampire squid from the Oligocene of the Central Paratethys represented by a vampyromorph gladius. [...]."

Source: Annual Reviews
Authors: Sonya Legg
DOI: 10.1146/annurev-fluid-051220-043904

Abstract

"Oceanic lee waves are generated in the deep stratified ocean by the flow of ocean currents over sea floor topography, and when they break, they can lead to mixing in the stably stratified ocean interior. While the theory of linear lee waves is well established, the nonlinear mechanisms leading to mixing are still under investigation. Tidally driven lee waves have long been observed in the ocean, along with associated mixing, but observations of lee waves forced by geostrophic eddies are relatively sparse and largely indirect. [...]."

Source: Nature 
Authors: Ericka O. C. Coni et al.
DOI: 10.1038/s41558-020-00980-w

Abstract

"Poleward range extensions by warm-adapted sea urchins are switching temperate marine ecosystems from kelp-dominated to barren-dominated systems that favour the establishment of range-extending tropical fishes. Yet, such tropicalization may be buffered by ocean acidification, which reduces urchin grazing performance and the urchin barrens that tropical range-extending fishes prefer. Using ecosystems experiencing natural warming and acidification, we show that ocean acidification could buffer warming-facilitated tropicalization by reducing urchin populations (by 87%) and inhibiting the formation of barrens. [...]."

Source: Biogeosciences
Authors: Catherine V. Davis et al.
DOI: 10.5194/bg-18-977-2021

Abstract

"Oxygen-depleted regions of the global ocean are rapidly expanding, with important implications for global biogeochemical cycles. However, our ability to make projections about the future of oxygen in the ocean is limited by a lack of empirical data with which to test and constrain the behavior of global climatic and oceanographic models. We use depth-stratified plankton tows to demonstrate that some species of planktic foraminifera are adapted to life in the heart of the pelagic oxygen minimum zone (OMZ). In particular, we identify two species, Globorotaloides hexagonus and Hastigerina parapelagica, living within the eastern tropical North Pacific OMZ. The tests of the former are preserved in marine sediments and could be used to trace the extent and intensity of low-oxygen pelagic habitats in the fossil record. [...]."

Source: Springer Link
Authors: Rachel Kelly et al.
DOI: 10.1007/s11160-020-09625-9

Abstract

"Improved public understanding of the ocean and the importance of sustainable ocean use, or ocean literacy, is essential for achieving global commitments to sustainable development by 2030 and beyond. However, growing human populations (particularly in mega-cities), urbanisation and socio-economic disparity threaten opportunities for people to engage and connect directly with ocean environments. Thus, a major challenge in engaging the whole of society in achieving ocean sustainability by 2030 is to develop strategies to improve societal connections to the ocean. [...]."

Source: Nature
Authors: Xin Sun et al.
DOI: 10.1038/s41396-020-00852-3

Abstract

"Nitrite is a pivotal component of the marine nitrogen cycle. The fate of nitrite determines the loss or retention of fixed nitrogen, an essential nutrient for all organisms. Loss occurs via anaerobic nitrite reduction to gases during denitrification and anammox, while retention occurs via nitrite oxidation to nitrate. Nitrite oxidation is usually represented in biogeochemical models by one kinetic parameter and one oxygen threshold, below which nitrite oxidation is set to zero. [...]."

Source: Climate of the Past
Authors: Sam Sherriff-Tadano et al.
DOI: 10.5194/cp-17-95-2021

Abstract

"This study explores the effect of southward expansion of Northern Hemisphere (American) mid-glacial ice sheets on the global climate and the Atlantic Meridional Overturning Circulation (AMOC) as well as the processes by which the ice sheets modify the AMOC. For this purpose, simulations of Marine Isotope Stage (MIS) 3 (36鈥塳a) and 5a (80鈥塳a) are performed with an atmosphere鈥搊cean general circulation model. In the MIS3 and MIS5a simulations, the global average temperature decreases by 5.0 and 2.2鈥夆垬C, respectively, compared with the preindustrial climate simulation. [...]."

Source: Nature
Authors: Aidan Starr et al.
DOI: 10.1038/s41586-020-03094-7

Abstract

"The dominant feature of large-scale mass transfer in the modern ocean is the Atlantic meridional overturning circulation (AMOC). The geometry and vigour of this circulation influences global climate on various timescales. Palaeoceanographic evidence suggests that during glacial periods of the past 1.5 million years the AMOC had markedly different features from today1; in the Atlantic basin, deep waters of Southern Ocean origin increased in volume while above them the core of the North Atlantic Deep Water (NADW) shoaled2. An absence of evidence on the origin of this phenomenon means that the sequence of events leading to global glacial conditions remains unclear. [...]."

Source: GeoScienceWorld
Authors: Jordan A.G. Wostbrock & Zachary D. Sharp
DOI: 10.2138/rmg.2021.86.11

Abstract

"The field of stable isotope geochemistry began with the recognition that the oxygen isotope composition of ancient carbonates could be used as a paleothermometer (Urey 1947; Urey et al. 1951). As stated by Urey (1947), 鈥淎ccurate determinations of the Ol8 content of carbonate rocks could be used to determine the temperature at which they were formed鈥�. This concept was based on the temperature dependence for the oxygen isotope fractionation between calcite and water. [...]."

Source: Annual Reviews
Authors: Nancy Knowlton
DOI: 10.1146/annurev-marine-040220-101608

Abstract

"While the ocean has suffered many losses, there is increasing evidence that important progress is being made in marine conservation. Examples include striking recoveries of once-threatened species, increasing rates of protection of marine habitats, more sustainably managed fisheries and aquaculture, reductions in some forms of pollution, accelerating restoration of degraded habitats, and use of the ocean and its habitats to sequester carbon and provide clean energy. [...]."

Source: Nature 
Authors: Eduardo Sampaio et al.
DOI: 10.1038/s41559-020-01370-3

Abstract

"Over the past decades, three major challenges to marine life have emerged as a consequence of anthropogenic emissions: ocean warming, acidification and oxygen loss. While most experimental research has targeted the first two stressors, the last remains comparatively neglected. Here, we implemented sequential hierarchical mixed-model meta-analyses (721 control鈥搕reatment comparisons) to compare the impacts of oxygen conditions associated with the current and continuously intensifying hypoxic events (1鈥�3.5鈥塐₂鈥尘驳鈥塴^鈭�1) with those experimentally yielded by ocean warming (+4鈥壜癈) and acidification (鈭�0.4鈥塽nits) conditions on the basis of IPCC projections (RCP鈥�8.5) for 2100. [...]."

Source: Biogeosciences
Authors: Sigrid van Grinsven et al.
DOI: 10.5194/bg-18-3087-2021

Abstract

"Small boreal lakes are known to contribute significantly to global methane emissions. Lake Lovoj盲rvi is a eutrophic lake in Southern Finland with bottom water methane concentrations up to 2鈥塵M. However, the surface water concentration, and thus the diffusive emission potential, was low (<鈥�0.5鈥壩糓). We studied the biogeochemical processes involved in methane removal by chemical profiling and through incubation experiments. 未13C-CH4 profiling of the water column revealed methane-oxidation hotspots just below the oxycline and within the anoxic water column. In incubation experiments involving the addition of light and/or oxygen, methane oxidation rates in the anoxic hypolimnion were enhanced 3-fold, suggesting a major role for photosynthetically fueled aerobic methane oxidation. [...]."

Source: Nature 
Authors: Jens Terhaar et al.
DOI: 10.1038/s41467-020-20470-z

Abstract

"Net primary production (NPP) is the foundation of the oceans鈥� ecosystems and the fisheries they support. In the Arctic Ocean, NPP is controlled by a complex interplay of light and nutrients supplied by upwelling as well as lateral inflows from adjacent oceans and land. But so far, the role of the input from land by rivers and coastal erosion has not been given much attention. Here, by upscaling observations from the six largest rivers and using measured coastal erosion rates, we construct a pan-Arctic, spatio-temporally resolved estimate of the land input of carbon and nutrients to the Arctic Ocean. [...]."

Source: Nature
Authors: Claire M. Belcher et al.
DOI: 10.1038/s41467-020-20772-2

Abstract

"The source of oxygen to Earth鈥檚 atmosphere is organic carbon burial, whilst the main sink is oxidative weathering of fossil carbon. However, this sink is to insensitive to counteract oxygen rising above its current level of about 21%. Biogeochemical models suggest that wildfires provide an additional regulatory feedback mechanism. However, none have considered how the evolution of different plant groups through time have interacted with this feedback. [...]."

Source: Science Direct
Authors: Takashi Kikuchi et al.
DOI: 10.1016/j.polar.2021.100639

Abstract

"Ocean observation research theme under ArCS project, 鈥淭heme 4: Observational research on Arctic Ocean environmental changes鈥�, aimed to elucidate the status and trends of ongoing Arctic Ocean environmental changes and to evaluate their impacts on Arctic marine ecosystem and the global climate system. For these purposes, we conducted field observations, mooring observations, laboratory experiments, numerical modeling, and international collaborative research focusing on the Pacific Arctic Region (PAR) and from Pan-Arctic point of views. [...]."

Source: Biogeosciences
Authors: David Ford 
DOI: 10.5194/bg-18-509-2021

Abstract

"A set of observing system simulation experiments was performed. This assessed the impact on global ocean biogeochemical reanalyses of assimilating chlorophyll from remotely sensed ocean colour and in situ observations of chlorophyll, nitrate, oxygen, and pH from a proposed array of Biogeochemical-Argo (BGC-Argo) floats. Two potential BGC-Argo array distributions were tested: one for which biogeochemical sensors are placed on all current Argo floats and one for which biogeochemical sensors are placed on a quarter of current Argo floats. [...]."

Source: Biogeosciences
Authors: Derara Hailegeorgis et al.
DOI: 10.5194/bg-18-303-2021

Abstract

"The Canary Current System (CanCS) is a major eastern boundary upwelling system (EBUS), known for its high nearshore productivity and for sustaining a large fishery. It is also an important but not well quantified source of nitrogen to the adjacent oligotrophic subtropical gyre of the North Atlantic. Here, we use a Lagrangian modeling approach to quantify this offshore transport and investigate its timescales, reach and contribution to the fueling of productivity in the offshore regions. In our Lagrangian model, we release nearly 10 million particles off the northwestern African coast and then track all those that enter the nearshore region and upwell along the coast between 14 and 35鈭樷�塏. [...]."

Source: Nature 
Authors: Ellen Cliff et al.
DOI: 10.1038/s41561-020-00667-z

Abstract

"Deep ocean deoxygenation inferred from proxies has been used to support the hypothesis that a lower atmospheric carbon dioxide during glacial times was due to an increase in the strength of the ocean鈥檚 biological pump. This relies on the assumption that surface ocean oxygen (O2) is equilibrated with the atmosphere such that any O2 deficiency observed in deep waters is a result of organic matter respiration, which consumes O2 and produces dissolved inorganic carbon. However, this assumption has been shown to be imperfect because of disequilibrium. [...]."

Source: Biogeosciences
Authors: Lyla L. Taylor et al.
DOI: 10.5194/bg-18-169-2021

Abstract

"Meeting internationally agreed-upon climate targets requires carbon dioxide removal (CDR) strategies coupled with an urgent phase-down of fossil fuel emissions. However, the efficacy and wider impacts of CDR are poorly understood. Enhanced rock weathering (ERW) is a land-based CDR strategy requiring large-scale field trials. Here we show that a low 3.44鈥塼鈥塰a鈭�1 wollastonite treatment in an 11.8鈥塰a acid-rain-impacted forested watershed in New Hampshire, USA, led to cumulative carbon capture by carbonic acid weathering of 0.025鈥�0.13鈥塼鈥塁O2鈥塰a鈭�1 over 15 years. [...]."

Source: Science Direct
Authors: Andr茅 R.A. Lima et al.
DOI: 10.1016/j.jhazmat.2020.123796

Abstract

"Despite their representativeness, most studies to date have underestimated the amount of microfibers (MFs) in the marine environment. Therefore, further research is still necessary to identify key processes governing MF distribution. Here, the interaction among surface water temperature, salinity, currents and winds explained the patterns of MF accumulation. [...]."

Source: Science Direct 
Authors: Changjun Li et al.
DOI: 10.1016/j.scitotenv.2020.142629

Abstract

"Microplastics (MPs) have been documented in almost all marine environments, including coastal regions, the open ocean, and the deep sea. However, relatively little knowledge was available about MP pollution in the open ocean, especially the Indian Ocean. We conducted field observations at 36 stations in the Eastern Indian Ocean (EIO), using a typical manta trawl with a mesh size of 330 渭m for surface water sampling. Ours is the first study to obtained comprehensive and comparable baseline data about MPs in the EIO, including abundance, spatial distribution and characteristics. [...]."

Source: Science Direct
Authors: Hidetaka Hirata et al.
DOI: 10.1016/B978-0-12-818156-0.00014-9

Abstract

"Recent high-resolution observations and numerical simulations have revealed active roles of the ocean in the mid-latitude climate system. In this chapter, we review recent studies on the topic especially focusing on roles of strong oceanic warm currents and associated sea surface temperature (SST) frontal structures in the development of extratropical cyclones, which can cause extreme rainfall/snowfall. Speed of the warm strong ocean currents such as the Kuroshio/Kuroshio Extension and activities of associated mesoscale eddies have strong influence on SST and its meridional gradient that affect the cyclones鈥� development. [...]."

Source: Science Direct
Authors: Rachel Bezard et al.
DOI: 10.1016/j.gca.2020.10.009

Abstract

"Constraining the behaviour of Re and Os during eclogite melting is required to understand the Re and Os budget and 187Os/188Os of recycled slabs produced at warm subduction zones. It is particularly relevant to early Earth history, a period during which slab melting could have prevailed over dehydration due to higher mantle temperatures. There are however currently few constraints on Re and Os mobility during slab melting. Accordingly, we measured Os, Re and 187Os/188Os in primitive submarine lavas (Mg# 藘 0.6) from the western Aleutian Arc. [...]."

Source: Science Direct
Authors: D.S. Hardisty et al.
DOI: 10.1016/j.epsl.2020.116676

Abstract

"The relative abundance of the inorganic iodine species, iodide and iodate, are applied to characterize both modern and ancient marine oxygen deficient zones (ODZs). However, the rates and mechanisms responsible for in situ iodine redox transformations are poorly characterized, rendering iodine-based redox reconstructions uncertain. Here, we provide constraints on the rates and mechanisms of iodate reduction in the Eastern Tropical North Pacific (ETNP) offshore ODZ using a shipboard tracer鈥搃ncubation method. [...]."

Source: Biogeosciences
Authors: Genevieve Jay Brett et al.
DOI: 10.5194/bg-18-3123-2021

Abstract

"While there is agreement that global warming over the 21st century is likely to influence the biological pump, Earth system models (ESMs) display significant divergence in their projections of future new production. This paper quantifies and interprets the sensitivity of projected changes in new production in an idealized global ocean biogeochemistry model. The model includes two tracers that explicitly represent nutrient transport, light- and nutrient-limited nutrient uptake by the ecosystem (new production), and export via sinking organic particles. Globally, new production declines with warming due to reduced surface nutrient availability, as expected. [...]."

"The  webinar series is a regular online seminar series that focuses on the depletion of oxygen in the marine environment 鈥� ocean deoxygenation. Organised and hosted by , each one-hour webinar is run by a guest moderator and two invited speakers. To support the diversity of the scientific community, the webinar series aims for an equal balance of early-career and senior scientists, gender, and geographical representation."

GO2NE Webinar 28 April 2021 No 6

Moderator:
Jodie Rummer
College of Science and Engineering, James Cook University & ARC Centre of Excellence for Coral Reef Studies, Australia

Speakers:
Sarah Wolf
Department of Microbiology, Oregon State University, USA
"A microbe's point of view: coastal ocean deoxygenation" 

David Sims
Marine Biological Association Laboratory (MBA), Plymouth, & University of Southampton, NOCS, UK
"Caught in the middle? Ocean deoxygenation and longline fishing effects on pelagic sharks"

You can watch the GO₂NE Webinar 28 April 2021 No 6 recording .

Source: Biogeosciences
Authors: Gesa Meyer et al.
DOI: 10.5194/bg-18-3263-2021

Abstract

"Climate change in the Arctic is leading to shifts in vegetation communities, permafrost degradation and alteration of tundra surface鈥揳tmosphere energy and carbon (C) fluxes, among other changes. However, year-round C and energy flux measurements at high-latitude sites remain rare. This poses a challenge for evaluating the impacts of climate change on Arctic tundra ecosystems and for developing and evaluating process-based models, which may be used to predict regional and global energy and C feedbacks to the climate system. [...]."

Source: Science Direct
Authors: Wei Wei et al.
DOI: 10.1016/j.precamres.2020.106058

Abstract

"The mid-Proterozoic (1.8鈥�0.8 Ga) may have witnessed persistent and predominant anoxia at the Earth鈥檚 surface. However, recent studies suggest that there was a period around ~1.4 Ga where oxygen levels might have been transiently elevated, both in the atmosphere and oceans. In order to shed light on this debated topic, we analyzed rare earth elements plus Y (REY) and Cr isotope profiles of the carbonate rocks from the ~1.44-Gyr-old Tieling Formation consisting of the lower Daizhuangzi (DZZ) and upper Laohuding (LHD) Members at the Jixian section, North China. [...]."

"The  webinar series is a regular online seminar series that focuses on the depletion of oxygen in the marine environment 鈥� ocean deoxygenation. Organised and hosted by , each one-hour webinar is run by a guest moderator and two invited speakers. To support the diversity of the scientific community, the webinar series aims for an equal balance of early-career and senior scientists, gender, and geographical representation."

GO2NE Webinar 17 March 2021 No 5

Moderator:
Lisa Levin
Integrative Oceanography Division Scripps Institution of Oceanography, University of California, San Diego, USA

Speakers:
Lillian McCormick
Integrative Oceanography Division Scripps Institution of Oceanography, University of California, San Diego, USA
"The blinding truth: vision is highly sensitive to oxygen loss in the ocean"

Karin E. Limburg
State University of New York College of Environmental Science & Forestry, USA and Department of Aquatic Resources, Swedish Agricultural University

Liz LoGiudice
Resilience Communications and Consulting, LLC, USA
"The sound of hypoxia: Turning cod otolith data into sound and song with data sonification"

You can watch the GO₂NE Webinar 17 March 2021 No 5 recording .

Source: Biogeosciences
Authors: Sean Ridge & Galen McKinley
DOI: 10.5194/bg-18-2711-2021

Abstract

"Nearly every nation has signed the UNFCC Paris Agreement, committing to mitigate global anthropogenic carbon (C_ant) emissions and limit global mean temperature increase to 1.5鈥壜癈. A consequence of emission mitigation is reduced efficiency of ocean C_ant uptake, which is driven by mechanisms that have not been studied in detail. The historical pattern of continual increase in atmospheric CO₂ has resulted in a proportional increase in C_ant uptake. [...]."

Source: Science Direct
Authors: Samar Kumar Ghose et al.
DOI: 10.1016/j.dynatmoce.2020.101183

Abstract

"Latent Heat Flux (LHF) and Sensible Heat Flux (SHF) are the two important parameters in air-sea interactions and hence have significant implications for any coupled ocean-atmospheric model. These two fluxes are conventionally computed from met-ocean parameters using bulk aerodynamic formulations; or the Coupled Ocean Atmosphere Response Experiment (COARE) bulk flux algorithms. Here COARE 3.5 algorithm is used to estimate the heat flux from two Ocean Moored Buoy Network for northern Indian Ocean (OMNI) buoy met-ocean observations in Arabian Sea (AS) and the Bay of Bengal (BoB). [...]."

"The  webinar series is a regular online seminar series that focuses on the depletion of oxygen in the marine environment 鈥� ocean deoxygenation. Organised and hosted by , each one-hour webinar is run by a guest moderator and two invited speakers. To support the diversity of the scientific community, the webinar series aims for an equal balance of early-career and senior scientists, gender, and geographical representation."

GO2NE Webinar 17 February 2021 No 4

Moderator:
Prof. Marilaure Gr茅goire
University of Li猫ge, Belgium

Speakers:
Dr. Wenfei Ni
University of Maryland, USA
"Understanding the Long-Term Change of Chesapeake Bay Hypoxia: Impacts of Nutrient Management and Climate Change"

Prof. Daniel Conley
Lund University, Sweden
"Baltic Sea Hypoxia Takes Many Shapes and Sizes"

You can watch the GO₂NE Webinar 17 February 2021 No 4 recording .

Source: Science Direct
Authors: Meredith Burke et al.
DOI: 10.1016/j.aquaculture.2020.736143

Abstract

"Open ocean fish farming involves containment of cultured animals under environmental conditions influenced by seasonal variation and water quality. Recently, an important area of research focus has been on water quality monitoring to improve aquaculture management. The development of novel sensors that report in real-time is critical to improve the monitoring capacity of farms, while increasing the understanding of the dynamics of environmental variables. In this study, commercially available, real-time dissolved oxygen and temperature sensors were distributed in the center of 19 cages at a commercial Atlantic salmon (Salmo salar) farm located within Shelburne Bay, Nova Scotia (Canada) and four reference sites. [...]."

Source: Science Direct
Autors: R. Shuttleworth et al.
DOI: 10.1016/j.epsl.2020.116649

Abstract

"Over the last deglaciation there were two transient intervals of pronounced atmospheric CO2 rise; Heinrich Stadial 1 (17.5-15 kyr) and the Younger Dryas (12.9-11.5 kyr). Leading hypotheses accounting for the increased accumulation of CO2 in the atmosphere at these times invoke deep ocean carbon being released from the Southern Ocean and an associated decline in the global efficiency of the biological carbon pump. Here we present new deglacial surface seawater pH and CO2sw records from the Sub-Antarctic regions of the Atlantic and Pacific oceans using boron isotopes measured on the planktic foraminifera Globigerina bulloides. [...]."

"The  webinar series is a regular online seminar series that focuses on the depletion of oxygen in the marine environment 鈥� ocean deoxygenation. Organised and hosted by , each one-hour webinar is run by a guest moderator and two invited speakers. To support the diversity of the scientific community, the webinar series aims for an equal balance of early-career and senior scientists, gender, and geographical representation."

GO2NE Webinar 20 January 2021 No 3

Moderator:
Veronique Gar莽on
Legos, France

Speakers:
Dr. Laura Ramajo
Centro de Estudios Avanzados en Zonas Aridas (CEAZA), Chile
"The multi-stressor scenario of upwelling and their impacts on the Chilean scallop aquaculture"

Christopher J. Gobler, Ph.D.
Stony Brook University, USA
"Co-occurrence of hypoxia, harmful algal blooms, and other climate change stressors: Implications for aquatic life"

You can watch the GO₂NE Webinar 20 January 2021 No 3 recording .

Source: Biogeosciences
Authors: Elizabeth D. LaBone et al.
DOI: 10.5194/bg-18-487-2021

Abstract

"The hypoxic zone in the northern Gulf of Mexico varies spatially (area, location) and temporally (onset, duration) on multiple scales. Exposure to hypoxic dissolved oxygen (DO) concentrations (<鈥�2鈥塵g鈥塋^鈭�1) is often lethal and exposure to 2 to 4鈥塵g鈥塋^鈭�1 often causes the sublethal effects of decreased growth and fecundity on individuals of many fish species. We simulated the movement of individual fish within a high-resolution 3-D coupled hydrodynamic-water quality model (FVCOM-WASP) configured for the northern Gulf of Mexico to examine how spatial variability in DO concentrations would affect fish exposure to hypoxic and sublethal DO concentrations. [...]."