scholarly journals A novel approach reveals high zooplankton standing stock deep in the sea

2016 ◽  
Author(s):  
Alexander Vereshchaka ◽  
Galina Abyzova ◽  
Anastasia Lunina ◽  
Eteri Musaeva ◽  
Tracey T. Sutton
Keyword(s):  
Standing Stock ◽  
World Ocean ◽  
Deep Ocean ◽  
Biogeochemical Cycling ◽  
Ocean Basin ◽  
Zooplankton Biomass ◽  
Ocean Dynamics ◽  
Novel Approach ◽  
Basin Scale

Abstract. In a changing ocean there is a critical need to understand global biogeochemical cycling, particularly regarding carbon. We have made strides in understanding upper ocean dynamics, but the deep ocean interior (> 1000 m) is still largely unknown, despite representing the overwhelming majority of Earth's biosphere. Here we present a method for estimating deep-pelagic zooplankton biomass on an ocean-basin scale. In so doing we have made several new discoveries about the Atlantic, which likely apply to the World Ocean. First, zooplankton biomass in the upper bathypelagic domain is higher than expected, representing an inverted biomass pyramid. Second, the majority of this biomass comprises macroplanktonic shrimps, which have been historically underestimated. These findings, coupled with recent findings of increased global deep-pelagic fish biomass, revise our perspective on the role of the deep-pelagic fauna in oceanic biogeochemical cycling.

scholarly journals A novel approach reveals high zooplankton standing stock deep in the sea

2016 ◽  
Vol 13 (22) ◽  
pp. 6261-6271 ◽  
Author(s):  
Alexander Vereshchaka ◽  
Galina Abyzova ◽  
Anastasia Lunina ◽  
Eteri Musaeva ◽  
Tracey Sutton
Keyword(s):  
Standing Stock ◽  
World Ocean ◽  
Deep Ocean ◽  
Ocean Basin ◽  
Zooplankton Biomass ◽  
Ocean Dynamics ◽  
Factors Affecting ◽  
Novel Approach ◽  
Wet Biomass ◽  
Basin Scale

Abstract. In a changing ocean there is a critical need to understand global biogeochemical cycling, particularly regarding carbon. We have made strides in understanding upper ocean dynamics, but the deep ocean interior (> 1000 m) is still largely unknown, despite representing the overwhelming majority of Earth's biosphere. Here we present a method for estimating deep-pelagic zooplankton biomass on an ocean-basin scale. We have made several new discoveries about the Atlantic, which likely apply to the world ocean. First, multivariate analysis showed that depth and Chl were the basic factors affecting the wet biomass of the main plankton groups. Wet biomass of all major groups was significantly correlated with Chl. Second, zooplankton biomass in the upper bathypelagic domain is higher than expected. Third, the majority of this biomass comprises macroplanktonic shrimps, which have been historically underestimated. These findings, coupled with recent findings of increased global deep-pelagic fish biomass, suggest that the contribution of the deep-ocean pelagic fauna for biogeochemical cycles may be more important than previously thought.

The Role of Zooplankton in the Accumulation and Deposition of DuPont Edgemoor Waste (an Acid-Iron Waste) at a Deepwater Dumpsite in the Northwest Atlantic

1983 ◽  
Vol 40 (S2) ◽  
pp. s242-s247 ◽  
Author(s):  
Judith M. Capuzzo
Keyword(s):  
New York ◽  
Trace Metals ◽  
Ferric Oxide ◽  
Effective Means ◽  
Deep Ocean ◽  
Zooplankton Biomass ◽  
Particulate Phase ◽  
Fecal Pellets ◽  
Oxide Particles

DuPont Edgemoor waste derived from titanium dioxide production is a highly acidic solution of ferric chloride containing relatively high levels of several trace metals including Cr, V, Pb, Ni, Cu, and Cd. Approximately 3 × 105 t∙yr−1 are dumped at Deepwater Dumpsite 106, ~160 km southeast of Ambrose Light, New York. Chemical dispersion studies at the dumpsite indicate that ferric oxide precipitates in the waste plume and that other trace metals may become associated with this particulate phase. Ingestion of this particulate phase by copepods is a significant route of uptake for the waste-derived metals in the laboratory. Accumulation of the various metals by exposed copepods ranged from 10.8% above control values for Fe to 54.7% for Cu. The ratios of the various trace metals relative to Fe were only slightly enhanced in exposed copepods in comparison with control copepods but 1 to 2 orders of magnitude higher than the metal ratios of a 105 waste dilution. Enhancement of metal concentrations in fecal pellets produced by exposed copepods ranged from 25.0% above control values for Fe to 60.3% for Cu. Metal deposition through fecal pellet production appears to be an effective means of depurating Fe, Pb, Ni, and Cu by copepods exposed to Edgemoor waste but not for Cd, which could not be detected in fecal pellets. The greater density of fecal pellets compared with the ferric oxide particles could result in a more rapid sinking rate of waste-derived metals to the deep ocean. The flux of waste-derived metals through Zooplankton biomass and the contribution of Zooplankton in the biogeochemical cycling of metals at Deepwater Dumpsite 106 suggests that biological processes may be as important as advective processes in determining the fate of waste-derived metals.

scholarly journals Human-induced changes to the global ocean water masses and their time of emergence

2020 ◽  
Author(s):  
Yona Silvy ◽  
Eric Guilyardi ◽  
Jean-Baptiste Sallée ◽  
Paul Durack
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
World Ocean ◽  
Deep Ocean ◽  
Water Masses ◽  
Global Ocean ◽  
Ocean Water ◽  
Salinity Changes ◽  
Basin Scale ◽  
Zonal Average

<p>The World Ocean is rapidly changing, with global and regional modification of temperature and salinity evident at the surface and depth. These changes have widespread and irreversible impacts including sea-level rise, changes to the oxygen and carbon contents of the ocean interior, or changing habitats, diversity and resilience of ecosystems. While the most pronounced temperature and salinity changes are located in the upper few hundred metres, changes in water-masses at depth are already observed and will likely strengthen and persist in the future as water-masses form at the surface and propagate in the deep ocean along density surfaces, storing the anthropogenic signal away from the atmosphere for decades to millennia. Here, using 11 climate models, we define when anthropogenic temperature and salinity changes are expected to emerge from natural background variability in the ocean interior. On a basin-scale zonal average, the model simulations predict that in 2020, 20–55% of the Atlantic, Pacific and Indian basins have an emergent anthropogenic signal; reaching 40–65% in 2050, and 55–80% in 2080. The well-ventilated Southern Ocean water-masses emerge very rapidly, as early as the 1980s-1990s, while the Northern Hemisphere emerges in the 2010s to 2030s. Additionally, dedicated idealized simulations of the IPSL coupled climate model are examined to study the role of each separate surface forcing on the time scales associated with the patterns of temperature and salinity change under a global warming scenario, and the influence of excess versus redistributed heat and salt. Our results highlight the importance of maintaining and augmenting an ocean observing system capable of detecting and monitoring anthropogenic changes. </p>

scholarly journals Southern Ocean circulation

2005 ◽  
Vol 32 (2) ◽  
pp. 265-280 ◽  
Author(s):  
Stuart A. Cunningham
Keyword(s):  
Southern Ocean ◽  
Ocean Circulation ◽  
Antarctic Circumpolar Current ◽  
Three Dimensional ◽  
Deep Ocean ◽  
Ocean Basin ◽  
Ocean Dynamics ◽  
Circumpolar Current ◽  
Earth’S Climate ◽  
The Antarctic

The Discovery Investigations of the 1930s provided a compelling description of the main elements of the Southern Ocean circulation. Over the intervening years, this has been extended to include ideas on ocean dynamics based on physical principles. In the modern description, the Southern Ocean has two main circulations that are intimately linked: a zonal (west-east) circumpolar circulation and a meridional (north-south) overturning circulation. The Antarctic Circumpolar Current transports around 140 million cubic metres per second west to east around Antarctica. This zonal circulation connects the Atlantic, Indian and Pacific Oceans, transferring and blending water masses and properties from one ocean basin to another. For the meridional circulation, a key feature is the ascent of waters from depths of around 2,000 metres north of the Antarctic Circumpolar Current to the surface south of the Current. In so doing, this circulation connects deep ocean layers directly to the atmosphere. The circumpolar zonal currents are not stable: meanders grow and separate, creating eddies and these eddies are critical to the dynamics of the Southern Ocean, linking the zonal circumpolar and meridional circulations. As a result of this connection, a global three-dimensional ocean circulation exists in which the Southern Ocean plays a central role in regulating the Earth's climate.

ON EVALUATION OF THE ROLE OF THERMAL AND WIND FACTORS FOR A PHYSICAL MODEL OF THE WORLD OCEAN GENERAL CIRCULATION SYSTEM

2019 ◽  
Vol 47 (3) ◽  
pp. 80-91
Author(s):  
V. G. Neiman
Keyword(s):  
Physical Model ◽  
Ocean Circulation ◽  
General Circulation ◽  
World Ocean ◽  
Circulation System ◽  
The Public ◽  
The World ◽  
Almost All ◽  
Conceptual Foundations

The main content of the work consists of certain systematization and addition of longexisting, but eventually deformed and partly lost qualitative ideas about the role of thermal and wind factors that determine the physical mechanism of the World Ocean’s General Circulation System (OGCS). It is noted that the conceptual foundations of the theory of the OGCS in one form or another are contained in the works of many well-known hydrophysicists of the last century, but the aggregate, logically coherent description of the key factors determining the physical model of the OGCS in the public literature is not so easy to find. An attempt is made to clarify and concretize some general ideas about the two key blocks that form the basis of an adequate physical model of the system of oceanic water masses motion in a climatic scale. Attention is drawn to the fact that when analyzing the OGCS it is necessary to take into account not only immediate but also indirect effects of thermal and wind factors on the ocean surface. In conclusion, it is noted that, in the end, by the uneven flow of heat to the surface of the ocean can be explained the nature of both external and almost all internal factors, in one way or another contributing to the excitation of the general, or climatic, ocean circulation.

scholarly journals In Situ Generation of Green Hybrid Nanofibrillar Polymer-Polymer Composites—A Novel Approach to the Triple Shape Memory Polymer Formation

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1900
Author(s):  
Ramin Hosseinnezhad ◽  
Iurii Vozniak ◽  
Fahmi Zaïri
Keyword(s):  
Polymer Blends ◽  
Shape Memory ◽  
Shape Memory Polymer ◽  
Cellulose Nanofibers ◽  
Polymeric Materials ◽  
Novel Approach ◽  
Phase Transition Temperatures ◽  
Triple Shape Memory

The paper discusses the possibility of using in situ generated hybrid polymer-polymer nanocomposites as polymeric materials with triple shape memory, which, unlike conventional polymer blends with triple shape memory, are characterized by fully separated phase transition temperatures and strongest bonding between the polymer blends phase interfaces which are critical to the shape fixing and recovery. This was demonstrated using the three-component system polylactide/polybutylene adipateterephthalate/cellulose nanofibers (PLA/PBAT/CNFs). The role of in situ generated PBAT nanofibers and CNFs in the formation of efficient physical crosslinks at PLA-PBAT, PLA-CNF and PBAT-CNF interfaces and the effect of CNFs on the PBAT fibrillation and crystallization processes were elucidated. The in situ generated composites showed drastically higher values of strain recovery ratios, strain fixity ratios, faster recovery rate and better mechanical properties compared to the blend.

scholarly journals T cell–specific STAT3 deficiency abrogates lupus nephritis

Lupus ◽  
2019 ◽  
Vol 28 (12) ◽  
pp. 1468-1472 ◽  
Author(s):  
N Yoshida ◽  
F He ◽  
V C Kyttaris
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lupus Nephritis ◽  
Lupus Erythematosus ◽  
Cell Responses ◽  
Cytokines And Chemokines ◽  
Novel Approach ◽  
Cell Tissue ◽  
External Stimuli

Signal transducer and activator of transcription (STAT) 3 is a regulator of T-cell responses to external stimuli, such as pro-inflammatory cytokines and chemokines. We have previously shown that STAT3 is activated (phosphorylated) at high levels in systemic lupus erythematosus (SLE) T cells and mediates chemokine-induced migration and T:B cell interactions. Stattic, a small molecular STAT3 inhibitor, can partially ameliorate lupus nephritis in mice. To understand the role of STAT3 better in T-cell pathophysiology in lupus nephritis and its potential as a treatment target, we silenced its expression in T cells using a cd4-driven CRE-Flox model. We found that lupus-prone mice that do not express STAT3 in T cells did not develop lymphadenopathy, splenomegaly, or glomerulonephritis. Moreover, the production of anti-dsDNA antibodies was decreased in these mice compared to controls. To dissect the mechanism, we also used a nephrotoxic serum model of nephritis. In this model, T cell–specific silencing of STAT3 resulted in amelioration of nephrotoxic serum-induced kidney damage. Taken together, our results suggest that in mouse models of autoimmune nephritis, T cell–specific silencing of STAT3 can hamper their ability to help B cells to produce autoantibodies and induce cell tissue infiltration. We propose that STAT3 inhibition in T cells represents a novel approach in the treatment of SLE and lupus nephritis in particular.

scholarly journals Petrobactin, a siderophore produced by Alteromonas, mediates community iron acquisition in the global ocean

2021 ◽  
Author(s):  
Lauren E. Manck ◽  
Jiwoon Park ◽  
Benjamin J. Tully ◽  
Alfonso M. Poire ◽  
Randelle M. Bundy ◽  
...  
Keyword(s):  
Biosynthetic Pathway ◽  
Iron Acquisition ◽  
Biogeochemical Cycling ◽  
Iron Bioavailability ◽  
Siderophore Production ◽  
Global Ocean ◽  
The North ◽  
The North Pacific ◽  
Alteromonas Macleodii

AbstractIt is now widely accepted that siderophores play a role in marine iron biogeochemical cycling. However, the mechanisms by which siderophores affect the availability of iron from specific sources and the resulting significance of these processes on iron biogeochemical cycling as a whole have remained largely untested. In this study, we develop a model system for testing the effects of siderophore production on iron bioavailability using the marine copiotroph Alteromonas macleodii ATCC 27126. Through the generation of the knockout cell line ΔasbB::kmr, which lacks siderophore biosynthetic capabilities, we demonstrate that the production of the siderophore petrobactin enables the acquisition of iron from mineral sources and weaker iron-ligand complexes. Notably, the utilization of lithogenic iron, such as that from atmospheric dust, indicates a significant role for siderophores in the incorporation of new iron into marine systems. We have also detected petrobactin, a photoreactive siderophore, directly from seawater in the mid-latitudes of the North Pacific and have identified the biosynthetic pathway for petrobactin in bacterial metagenome-assembled genomes widely distributed across the global ocean. Together, these results improve our mechanistic understanding of the role of siderophore production in iron biogeochemical cycling in the marine environment wherein iron speciation, bioavailability, and residence time can be directly influenced by microbial activities.

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