scholarly journals The acceleration of dissolved cobalt's ecological stoichiometry due to biological uptake, remineralization, and scavenging in the Atlantic Ocean

2017 ◽  
Vol 14 (20) ◽  
pp. 4637-4662 ◽  
Author(s):  
Mak A. Saito ◽  
Abigail E. Noble ◽  
Nicholas Hawco ◽  
Benjamin S. Twining ◽  
Daniel C. Ohnemus ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Water Column ◽  
Ecological Stoichiometry ◽  
Hydrothermal Vents ◽  
Lithium Ion ◽  
Deep Ocean ◽  
Euphotic Zone ◽  
Particulate Phase ◽  
Mn Oxide ◽  
Basin Scale

Abstract. The stoichiometry of biological components and their influence on dissolved distributions have long been of interest in the study of the oceans. Cobalt has the smallest oceanic inventory of inorganic micronutrients and hence is particularly vulnerable to influence by internal oceanic processes including euphotic zone uptake, remineralization, and scavenging. Here we observe not only large variations in dCo : P stoichiometry but also the acceleration of those dCo : P ratios in the upper water column in response to several environmental processes. The ecological stoichiometry of total dissolved cobalt (dCo) was examined using data from a US North Atlantic GEOTRACES transect and from a zonal South Atlantic GEOTRACES-compliant transect (GA03/3_e and GAc01) by Redfieldian analysis of its statistical relationships with the macronutrient phosphate. Trends in the dissolved cobalt to phosphate (dCo : P) stoichiometric relationships were evident in the basin-scale vertical structure of cobalt, with positive dCo : P slopes in the euphotic zone and negative slopes found in the ocean interior and in coastal environments. The euphotic positive slopes were often found to accelerate towards the surface and this was interpreted as being due to the combined influence of depleted phosphate, phosphorus-sparing (conserving) mechanisms, increased alkaline phosphatase metalloenzyme production (a zinc or perhaps cobalt enzyme), and biochemical substitution of Co for depleted Zn. Consistent with this, dissolved Zn (dZn) was found to be drawn down to only 2-fold more than dCo, despite being more than 18-fold more abundant in the ocean interior. Particulate cobalt concentrations increased in abundance from the base of the euphotic zone to become  ∼  10 % of the overall cobalt inventory in the upper euphotic zone with high stoichiometric values of  ∼  400 µmol Co mol−1 P. Metaproteomic results from the Bermuda Atlantic Time-series Study (BATS) station found cyanobacterial isoforms of the alkaline phosphatase enzyme to be prevalent in the upper water column, as well as a sulfolipid biosynthesis protein indicative of P sparing. The negative dCo : P relationships in the ocean interior became increasingly vertical with depth, and were consistent with the sum of scavenging and remineralization processes (as shown by their dCo : P vector sums). Attenuation of the remineralization with depth resulted in the increasingly vertical dCo : P relationships. Analysis of particulate Co with particulate Mn and particulate phosphate also showed positive linear relationships below the euphotic zone, consistent with the presence and increased relative influence of Mn oxide particles involved in scavenging. Visualization of dCo : P slopes across an ocean section revealed hotspots of scavenging and remineralization, such as at the hydrothermal vents and below the oxygen minimum zone (OMZ) region, respectively, while that of an estimate of Co* illustrated stoichiometrically depleted values in the mesopelagic and deep ocean due to scavenging. This study provides insights into the coupling between the dissolved and particulate phase that ultimately creates Redfield stoichiometric ratios, demonstrating that the coupling is not an instantaneous process and is influenced by the element inventory and rate of exchange between phases. Cobalt's small water column inventory and the influence of external factors on its biotic stoichiometry can erode its limited inertia and result in an acceleration of the dissolved stoichiometry towards that of the particulate phase in the upper euphotic zone. As human use of cobalt grows exponentially with widespread adoption of lithium ion batteries, there is a potential to affect the limited biogeochemical inertia of cobalt and its resultant ecology in the oceanic euphotic zone.

scholarly journals The Acceleration of Dissolved Cobalt’s Ecological Stoichiometry due to Biological Uptake, Remineralization, and Scavenging in the Atlantic Ocean

2016 ◽  
Author(s):  
Mak A. Saito ◽  
Abigail Noble ◽  
Nicholas Hawco ◽  
Benjamin S. Twining ◽  
Daniel C. Ohnemus ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Water Column ◽  
Ecological Stoichiometry ◽  
Hydrothermal Vents ◽  
Lithium Ion ◽  
Deep Ocean ◽  
Euphotic Zone ◽  
Particulate Phase ◽  
Mn Oxide ◽  
Basin Scale

Abstract. Cobalt has the smallest oceanic inventory of all known inorganic micronutrients, and hence is particularly vulnerable to influence by internal oceanic processes including euphotic zone uptake, remineralization, and scavenging. Due to its small oceanic inventory, cobalt provides a unique case study for considering the stoichiometric coupling between dissolved and particulate phases in the context of Redfield theory. The ecological stoichiometry of total dissolved cobalt (dCo) was examined using data from a U.S. North Atlantic GEOTRACES transect and from a zonal South Atlantic GEOTRACES-compliant transect (GA03/3_e and GAc01), by Redfieldian analysis of its statistical relationships with the macronutrient phosphate. Trends in the dissolved cobalt to phosphate (dCo:P) stoichiometric relationships were evident in the basin scale vertical structure of cobalt, with positive dCo:P slopes in the euphotic zone and negative slopes found in the ocean interior and in coastal environments. The euphotic positive slopes were often found to accelerate towards the surface and this was interpreted as due to the combined influence of depleted phosphate, phosphorus sparing mechanisms, increased alkaline phosphatase metalloenzyme production (a zinc or perhaps cobalt enzyme), and biochemical substitution of Co for depleted Zn. Consistent with this, dissolved Zn (dZn) was found to be drawn down to only twofold more than dCo, despite being more than 18-fold more abundant in the ocean interior. Particulate cobalt concentrations increased in abundance from the base of the euphotic zone to become ~ 10 % of the overall cobalt inventory in the upper euphotic zone with high stoichiometric values of ~ 400 μmol Co mol−1 P. Metaproteomic results from the Bermuda Atlantic Time-series Study (BATS) station found cyanobacterial isoforms of the alkaline phosphatase enzyme to be prevalent in the upper water column, as well as a sulfolipid biosynthesis protein indicative of P sparing. The negative dCo:P relationships in the ocean interior became increasingly vertical with depth, and were consistent with the sum of scavenging and remineralization processes (as shown by their dCo:P vector sums). Attenuation of the remineralization with depth resulted in the increasingly vertical dCo:P relationships. Analysis of particulate Co with particulate Mn and particulate phosphate also showed positive linear relationships below the euphotic zone, consistent with the presence and increased relative influence of Mn oxide particles involved in scavenging. Visualization of dCo:P slopes across an ocean section revealed hotspots of scavenging and remineralization, such as at the hydrothermal vents and below the OMZ region, respectively, while that of an estimate of Co* illustrated stoichiometrically depleted values in the mesopelagic and deep ocean due to scavenging. This study provides insights into the coupling between the dissolved and particulate phase that ultimately create Redfield stoichiometric ratios, demonstrating that the coupling is not an instantaneous process and is influenced by the element inventory and rate of exchange between phases. Cobalt’s small water column inventory and the influence of external factors on its biotic stoichiometry can erode its limited inertia and result in an acceleration of the dissolved stoichiometry towards that of the particulate phase in the upper euphotic zone. As human use of cobalt grows exponentially with widespread adoption of lithium ion batteries, there is a potential to alter this dynamic biogeochemical cycling and ecology of cobalt in the oceanic euphotic zone.

6. Deep-ocean biology

2020 ◽  
pp. 115-134
Author(s):  
Philip V. Mladenov
Keyword(s):  
Seasonal Variation ◽  
Water Column ◽  
Hydrothermal Vents ◽  
Deep Ocean ◽  
Ocean Bottom ◽  
Extreme Pressure ◽  
Benthic Animals

The deep ocean is currently defined as the water column and ocean bottom greater than 500 metres, which is the depth at which seasonal variation in temperature and salinity and the influence of sunlight is minimal. This habitat encompasses roughly 90 per cent of the ocean’s volume yet this vast region is the least investigated and understood environment on the planet. ‘Deep-ocean biology’ explains that there are many issues for the existence of life in the deep ocean: lack of light, extreme pressure, scarcity of food, and temperature. However, deep-ocean animals have adapted to their surroundings. The diversity of deep-ocean benthic animals is described along with the unique ecosystems found around hydrothermal vents and seamounts.

scholarly journals Evolution of <sup>231</sup>Pa and <sup>230</sup>Th in overflow waters of the North Atlantic

2018 ◽  
Vol 15 (23) ◽  
pp. 7299-7313 ◽  
Author(s):  
Feifei Deng ◽  
Gideon M. Henderson ◽  
Maxi Castrillejo ◽  
Fiz F. Perez ◽  
Reiner Steinfeldt
Keyword(s):  
Water Column ◽  
Ocean Circulation ◽  
North Atlantic ◽  
Water Mass ◽  
Deep Ocean ◽  
Water Age ◽  
Meridional Transport ◽  
The North ◽  
Basin Scale ◽  
The North Atlantic

Abstract. Many palaeoceanographic studies have sought to use the 231Pa∕230Th ratio as a proxy for deep ocean circulation rates in the North Atlantic. As of yet, however, no study has fully assessed the concentration of, or controls on, 230Th and 231Pa in waters immediately following ventilation at the start of Atlantic meridional overturning. To that end, full water-column 231Pa and 230Th concentrations were measured along the GEOVIDE section, sampling a range of young North Atlantic deep waters. 230Th and 231Pa concentrations in the water column are lower than those observed further south in the Atlantic, ranging between 0.06 and 12.01 µBq kg−1 and between 0.37 and 4.80 µBq kg−1, respectively. Both 230Th and 231Pa profiles generally increase with water depth from surface to deep water, followed by decrease near the seafloor, with this feature most pronounced in the Labrador Sea (LA Sea) and Irminger Sea (IR Sea). Assessing this dataset using extended optimum multi-parameter (eOMP) analysis and CFC-based water mass age indicates that the low values of 230Th and 231Pa in water near the seafloor of the LA Sea and IR Sea are related to the young waters present in those regions. The importance of water age is confirmed for 230Th by a strong correlation between 230Th and water mass age (though this relationship with age is less clear for 231Pa and the 231Pa∕230Th ratio). Scavenged 231Pa and 230Th were estimated and compared to their potential concentrations in the water column due to ingrowth. This calculation indicates that more 230Th is scavenged (∼80 %) than 231Pa (∼40 %), consistent with the relatively higher particle reactivity of 230Th. Enhanced scavenging for both nuclides is demonstrated near the seafloor in young overflow waters. Calculation of the meridional transport of 230Th and 231Pa with this new GEOVIDE dataset enables a complete budget for 230Th and 231Pa for the North Atlantic. Results suggest that net transport southward of 230Th and 231Pa across GEOVIDE is smaller than transport further south in the Atlantic, and indicate that the flux to sediment in the North Atlantic is equivalent to 96 % of the production of 230Th and 74 % of the production for 231Pa. This result confirms a significantly higher advective loss of 231Pa to the south relative to 230Th and supports the use of 231Pa∕230Th to assess meridional transport at a basin scale.

scholarly journals Organic matter processing by microbial communities throughout the Atlantic water column as revealed by metaproteomics

2017 ◽  
Vol 115 (3) ◽  
pp. E400-E408 ◽  
Author(s):  
Kristin Bergauer ◽  
Antonio Fernandez-Guerra ◽  
Juan A. L. Garcia ◽  
Richard R. Sprenger ◽  
Ramunas Stepanauskas ◽  
...  
Keyword(s):  
Organic Matter ◽  
Microbial Community ◽  
Microbial Communities ◽  
Water Column ◽  
Compatible Solutes ◽  
Deep Ocean ◽  
Euphotic Zone ◽  
Atlantic Water ◽  
Phylogenetic Composition ◽  
Solute Transporters

The phylogenetic composition of the heterotrophic microbial community is depth stratified in the oceanic water column down to abyssopelagic layers. In the layers below the euphotic zone, it has been suggested that heterotrophic microbes rely largely on solubilized particulate organic matter as a carbon and energy source rather than on dissolved organic matter. To decipher whether changes in the phylogenetic composition with depth are reflected in changes in the bacterial and archaeal transporter proteins, we generated an extensive metaproteomic and metagenomic dataset of microbial communities collected from 100- to 5,000-m depth in the Atlantic Ocean. By identifying which compounds of the organic matter pool are absorbed, transported, and incorporated into microbial cells, intriguing insights into organic matter transformation in the deep ocean emerged. On average, solute transporters accounted for 23% of identified protein sequences in the lower euphotic and ∼39% in the bathypelagic layer, indicating the central role of heterotrophy in the dark ocean. In the bathypelagic layer, substrate affinities of expressed transporters suggest that, in addition to amino acids, peptides and carbohydrates, carboxylic acids and compatible solutes may be essential substrates for the microbial community. Key players with highest expression of solute transporters were Alphaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria, accounting for 40%, 11%, and 10%, respectively, of relative protein abundances. The in situ expression of solute transporters indicates that the heterotrophic prokaryotic community is geared toward the utilization of similar organic compounds throughout the water column, with yet higher abundances of transporters targeting aromatic compounds in the bathypelagic realm.

scholarly journals Evolution of <sup>231</sup>Pa and <sup>230</sup>Th in overflow waters of the North Atlantic

2018 ◽  
Author(s):  
Feifei Deng ◽  
Gideon M. Henderson ◽  
Maxi Castrillejo ◽  
Fiz F. Perez
Keyword(s):  
Water Column ◽  
Ocean Circulation ◽  
North Atlantic ◽  
Water Mass ◽  
Deep Ocean ◽  
Water Age ◽  
Meridional Transport ◽  
The North ◽  
Basin Scale ◽  
The North Atlantic

Abstract. Many paleoceanographic studies have sought to use the 231Pa / 230Th ratio as a proxy for deep ocean circulation rates in the North Atlantic. As yet, however, no study has fully assessed the concentration of, or controls on, 230Th and 231Pa in waters immediately following ventilation at the start of Atlantic meridional overturning. To that end, full water-column 231Pa and 230Th concentrations were measured along the GEOVIDE section, sampling a range of young North Atlantic deep waters. Th-230 and 231Pa concentrations in the water column are lower than those observed further south in the Atlantic, ranging between 0.004 and 0.738 dpm/1000l, and between 0.023 and 0.295 dpm/1000l, respectively. Both 230Th and 231Pa profiles generally increase with water depth from surface to deep water, followed by decrease near the seafloor, with this feature most pronounced in the Labrador Sea (LA Sea) and Irminger Sea (IR Sea). Analyzing this dataset with Extended Optimum Multi-Parameter (eOMP) Analysis and CFC-based water mass age indicates that the low values of 230Th and 231Pa in water near the seafloor of the LA Sea and IR Sea are related to the young waters present in those regions. This importance of water age is confirmed for 230Th by a strong correlation between 230Th and water mass age (though this relationship is less clear, for 231Pa and 231Pa / 230Th ratio). Scavenged 231Pa and 230Th were estimated and compared to their Potential Total concentrations in the water column. The result shows that more 230Th is scavenged (~ 80 %) relative to 231Pa (~ 40 %), consistent with the relatively higher particle-reactivity of 230Th. Enhanced scavenging for both nuclides is demonstrated near the seafloor in young overflow waters. Calculation of meridional transport of 230Th and 231Pa with this new GEOVIDE dataset enables a complete budget for 230Th and 231Pa for the North Atlantic. Results suggest that net transport southward of 230Th and 231Pa across GEOVIDE is smaller than transport further south in the Atlantic, and indicates that the flux to sediment in the North Atlantic is equivalent to 96 % of the production of 230Th, and 77 % of the production for 231Pa. This result confirms a significantly higher advective loss of 231Pa to the south relative to 230Th and supports the use of 231Pa / 230Th to assess meridional transport at a basin scale.

Extracellular enzymatic activities in the aquatic ecosystems of the Danube Delta. 2. Alkaline phosphatase activity

2021 ◽  
Vol 26 (1) ◽  
pp. 2269-2274
Author(s):  
IOAN PĂCEŞILĂ ◽  
EMILIA RADU
Keyword(s):  
Alkaline Phosphatase ◽  
Water Column ◽  
Aquatic Ecosystems ◽  
Temporal Dynamics ◽  
Extracellular Enzyme ◽  
Danube Delta ◽  
Phytoplankton Communities ◽  
Extracellular Enzymatic Activities ◽  
Adjacent Channels ◽  
Hydrolysis Of

Phosphorus is one of the most important inorganic nutrients in aquatic ecosystems, the development and functioning of the phytoplankton communities being often correlated with the degree of availability in assimilable forms of this element. Alkaline phosphatase (AP) is an extracellular enzyme with nonspecific activity that catalyses the hydrolysis of a large variety of organic phosphate esters and release orthophosphates. During 2011-2013, AP Activity (APA) was assessed in the water column and sediments of several aquatic ecosystems from Danube Delta: Roșu Lake, Mândra Lake and their adjacent channels – Roșu-Împuțita and Roșu-Puiu. The intensity of APA widely fluctuated, ranging between 230-2578 nmol p-nitrophenol L-1h-1 in the water column and 2104-15631 nmol p-nitrophenol g-1h-1 in sediment. Along the entire period of the study, APA was the most intense in Roșu-Împuțita channel, for both water and sediment samples. Temporal dynamics revealed its highest values in summer for the water column and in autumn for sediment. Statistical analysis showed significant seasonal diferences of the APA dynamics in spring vs. summer and autumn for the water column, and any relevant diferences for sediment.

From wood to vent: first cocculinid limpet associated with hydrothermal activity discovered in the Weddell Sea

2020 ◽  
Vol 32 (5) ◽  
pp. 354-366
Author(s):  
Chong Chen ◽  
Katrin Linse
Keyword(s):  
Hydrothermal Vents ◽  
Deep Ocean ◽  
First Record ◽  
Hydrothermal Activity ◽  
Integrative Taxonomy ◽  
Weddell Sea ◽  
Anatomical Reconstruction ◽  
Cold Seeps ◽  
Evolutionary Trajectory ◽  
Genetic Sequencing

AbstractLush ‘oases’ of life seen in chemosynthetic ecosystems such as hot vents and cold seeps represent rare, localized exceptions to the generally oligotrophic deep ocean floor. Organic falls, best known from sunken wood and whale carcasses, are additional sources of such oases. Kemp Caldera (59°42'S, 28°20'W) in the Weddell Sea exhibits active hydrothermal vents and a natural whale fall in close proximity, where an undescribed cocculinid limpet was found living in both types of chemosynthetic habitats. This represents the first member of the gastropod order Cocculinida discovered from hot vents, and also the first record from the Southern Ocean. Here, we applied an integrative taxonomy framework incorporating traditional dissection, electron microscopy, genetic sequencing and 3D anatomical reconstruction through synchrotron computed tomography in order to characterize this species. Together, our data revealed an unusual member of the genus Cocculina with a highly modified radula for feeding on bacterial film, described herein as Cocculina enigmadonta n. sp. Its phylogenetically derived position within the largely wood-inhabiting Cocculina indicates that it probably evolved from an ancestor adapted to living on sunken wood, providing a compelling case of the ‘stepping stone’ evolutionary trajectory from organic falls to seeps and vents.

Depth Profiling Investigation of Seawater Using Combined Multi-Optical Spectrometry

2020 ◽  
Vol 74 (5) ◽  
pp. 563-570 ◽  
Author(s):  
Wangquan Ye ◽  
Jinjia Guo ◽  
Nan Li ◽  
Fujun Qi ◽  
Kai Cheng ◽  
...  
Keyword(s):  
Deep Sea ◽  
Depth Profiling ◽  
Deep Ocean ◽  
Euphotic Zone ◽  
Depth Resolution ◽  
Remotely Operated Vehicle ◽  
Sea Trial ◽  
Depth Profiles ◽  
Diving Depth ◽  
Optical Spectrometry

Depth profiling investigation plays an important role in studying the dynamic processes of the ocean. In this paper, a newly developed hyphenated underwater system based on multi-optical spectrometry is introduced and used to measure seawater spectra at different depths with the aid of a remotely operated vehicle (ROV). The hyphenated system consists of two independent compact deep-sea spectral instruments, a deep ocean compact autonomous Raman spectrometer and a compact underwater laser-induced breakdown spectroscopy system for sea applications (LIBSea). The former was used to take both Raman scattering and fluorescence of seawater, and the LIBS signal could be recorded with the LIBSea. The first sea trial of the developed system was taken place in the Bismarck Sea, Papua New Guinea, in June 2015. Over 4000 multi-optical spectra had been captured up to the diving depth about 1800 m at maximum. The depth profiles of some ocean parameters were extracted from the captured joint Raman–fluorescence and LIBS spectra with a depth resolution of 1 m. The concentrations of [Formula: see text] and the water temperatures were measured using Raman spectra. The fluorescence intensities from both colored dissolved organic matter (CDOM) and chlorophyll were found to be varied in the euphotic zone. With LIBS spectra, the depth profiles of metallic elements were also obtained. The normalized intensity of atomic line Ca(I) extracted from LIBS spectra raised around the depth of 1600 m, similar to the depth profile of CDOM. This phenomenon might be caused by the nonbuoyant hydrothermal plumes. It is worth mentioning that this is the first time Raman and LIBS spectroscopy have been applied simultaneously to the deep-sea in situ investigations.

Disposal in the deep sea: analogue of nature or faux ami?

2003 ◽  
Vol 30 (1) ◽  
pp. 26-39 ◽  
Author(s):  
Paul A. Tyler
Keyword(s):  
Carbon Dioxide ◽  
Radioactive Waste ◽  
Deep Sea ◽  
Hydrothermal Vents ◽  
Natural Radionuclides ◽  
Deep Ocean ◽  
Turbidity Currents ◽  
Chemical Contamination ◽  
Seabed Sediment ◽  
Dredge Spoil

The deep sea is the world's largest ecosystem by volume and is assumed to have a high assimilative capacity. Natural events, such as the sinking of surface plant and animal material to the seabed, sediment slides, benthic storms and hydrothermal vents can contribute vast amounts of material, both organic and inorganic, to the deep ocean. In the past the deep sea has been used as a repository for sewage, dredge spoil and radioactive waste. In addition, there has been interest in the disposal of large man-made objects and, more recently, the disposal of industrially-produced carbon dioxide. Some of the materials disposed of in the deep sea may have natural analogues. This review examines natural processes in the deep sea including the vertical flux of organic material, turbidity currents and benthic storms, natural gas emissions, hydrothermal vents, natural radionuclides and rocky substrata, and compares them with anthropogenic input including sewage disposal, dredge spoil, carbon dioxide disposal, chemical contamination and the disposal of radioactive waste, wrecks and rigs. The comparison shows what are true analogues and what are false friends. Knowledge of the deep sea is fragmentary and much more needs to be known about this large, biologically-diverse system before any further consideration is given to its use in the disposal of waste.

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