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  • 1
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    Relative difference between integrated rates measured in tanks D and G as compared to the controls during the three experiments (2021)
    PANGAEA
    Details
    Publikationsdatum: 2023-08-28
    Schlagwort(e): Change; Event label; EXP; Experiment; FAST; Group; Identification; ION; Parameter; Station label; Treatment; TYR
    Materialart: Dataset
    Format: text/tab-separated-values, 648 data points
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    DATA PANGAEA
  • 2
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    Impact of dust addition on the metabolism of Mediterranean plankton communities and carbon export under present and future conditions of pH and temperature (2021)
    PANGAEA
    Details
    Publikationsdatum: 2023-08-28
    Beschreibung: Although atmospheric dust fluxes from arid as well as human-impacted areas represent a significant source of nutrients to surface waters of the Mediterranean Sea, studies focusing on the evolution of the metabolic balance of the plankton community following a dust deposition event are scarce, and none were conducted in the context of projected future levels of temperature and pH. Moreover, most of the experiments took place in coastal areas. In the framework of the PEACETIME project, three dust-addition perturbation experiments were conducted in 300 L tanks filled with surface seawater collected in the Tyrrhenian Sea (TYR), Ionian Sea (ION) and Algerian basin (FAST) on board the R/V Pourquoi Pas? in late spring 2017. For each experiment, six tanks were used to follow the evolution of chemical and biological stocks, biological activity and particle export. The impacts of a dust deposition event simulated at their surface were followed under present environmental conditions and under a realistic climate change scenario for 2100 (ca. +3 ∘C and −0.3 pH units). The tested waters were all typical of stratified oligotrophic conditions encountered in the open Mediterranean Sea at this period of the year, with low rates of primary production and a metabolic balance towards net heterotrophy. The release of nutrients after dust seeding had very contrasting impacts on the metabolism of the communities, depending on the station investigated. At TYR, the release of new nutrients was followed by a negative impact on both particulate and dissolved 14C-based production rates, while heterotrophic bacterial production strongly increased, driving the community to an even more heterotrophic state. At ION and FAST, the efficiency of organic matter export due to mineral/organic aggregation processes was lower than at TYR and likely related to a lower quantity/age of dissolved organic matter present at the time of the seeding and a smaller production of DOM following dust addition. This was also reflected by lower initial concentrations in transparent exopolymer particles (TEPs) and a lower increase in TEP concentrations following the dust addition, as compared to TYR. At ION and FAST, both the autotrophic and heterotrophic community benefited from dust addition, with a stronger relative increase in autotrophic processes observed at FAST. Our study showed that the potential positive impact of dust deposition on primary production depends on the initial composition and metabolic state of the investigated community. This impact is constrained by the quantity of nutrients added in order to sustain both the fast response of heterotrophic prokaryotes and the delayed one of primary producers. Finally, under future environmental conditions, heterotrophic metabolism was overall more impacted than primary production, with the consequence that all integrated net community production rates decreased with no detectable impact on carbon export, therefore reducing the capacity of surface waters to sequester anthropogenic CO2.
    Schlagwort(e): Biomass/Abundance/Elemental composition; Coast and continental shelf; Community composition and diversity; Containers and aquaria (20-1000 L or 〈 1 m**2); Entire community; Laboratory experiment; Mediterranean Sea; OA-ICC; Ocean Acidification International Coordination Centre; Other; Other metabolic rates; Pelagos; Primary production/Photosynthesis; Respiration; Temperate; Temperature
    Materialart: Dataset
    Format: application/zip, 3 datasets
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    DATA PANGAEA
  • 3
    facet.materialart.
    Unbekannt
    Relative difference between integrated rates measured in tank G as compared to tank D during the three experiments (2021)
    PANGAEA
    Details
    Publikationsdatum: 2023-08-28
    Schlagwort(e): Change; Event label; EXP; Experiment; FAST; Group; Identification; ION; Parameter; Station label; Treatment; TYR
    Materialart: Dataset
    Format: text/tab-separated-values, 324 data points
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    DATA PANGAEA
  • 4
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    Unbekannt
    Peacetime minicosm discrete sampling data (2021)
    PANGAEA
    Details
    Publikationsdatum: 2024-03-15
    Schlagwort(e): 19-Butanoyloxyfucoxanthin; 19-Hexanoyloxyfucoxanthin; Alanine; Alkaline phosphatase, Km value; Alkaline phosphatase, Km value, standard deviation; Alkaline phosphatase, maximum hydrolysis velocity; Alkaline phosphatase, maximum hydrolysis velocity, standard deviation; Alkalinity, total; Alkalinity, total, standard deviation; Alloxanthin; Aluminium, dissolved; Amino acid, hydrolysable as carbon; Amino acid, hydrolysable as nitrogen; Amino acids; Ammonium; Annelida; Antheraxanthin; Appendicularia; Arabinose; Arabinose, standard deviation; Aragonite saturation state; Aragonite saturation state, standard error; Arginine; Aspartic acid and Asparagine; Bacterial biomass production of carbon, standard deviation; Bacterial production; Bacteriochlorophyll a; Bicarbonate, standard error; Bicarbonate ion; Calcite saturation state; Calcite saturation state, standard error; Calcium carbonate; Calculated using seacarb; Calculated using seacarb after Nisumaa et al. (2010); Calculated using seacarb after Orr et al. (2018); Carbohydrates, total hydrolyzable; Carbohydrates, total hydrolyzable, standard error; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard error; Carbon, organic, dissolved; Carbon, organic, flux; Carbon, organic, particulate; Carbonate ion; Carbonate ion, standard error; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, standard error; Carotene; Chaetognatha; Chlorophyll a; Chlorophyll a, total; Chlorophyll b; Chlorophyll c1+c2; Chlorophyll c3; Ciliates; Ciliates, heterotrophic; Ciliates, mixotrophic; Cnidaria; Coefficient of variation; Copepoda; Crustacea; Date; Diadinoxanthin; Diatoms; Diatoxanthin; Dinoflagellates; Divinyl chlorophyll a; Event label; EXP; Experiment; Extracellular release; Extracellular release, standard deviation; FAST; Flagellates, autotrophic; Fluorescence, chlorophyll; Fluorescence, chlorophyll, standard deviation; Fluorescence, dissolved organic matter; Fluorescence, dissolved organic matter, standard deviation; Fucose; Fucose, standard deviation; Fucoxanthin; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Galactosamine; Galactosamine, standard deviation; Galactose; Galactose, standard deviation; Galacturonic acid; Galacturonic acid, standard deviation; gamma-Aminobutyric acid; Gluconic acid; Gluconic acid, standard deviation; Glucosamine; Glucosamine, standard deviation; Glucose; Glucose, standard deviation; Glucuronic acid; Glucuronic acid, standard deviation; Glutamic acid; Glycine; Harosa; Identification; Incubation duration; ION; Iron, dissolved; Isoleucine; Leucine; Lithogenic material; Local Time; Lutein; Mannose/Xylose; Mannose/Xylose, standard deviation; Michealis-Menten constant of protease; Michealis-Menten constant of protease, standard deviatione; Mollusca; Muramic acid; Muramic acid, standard deviation; Nanoeukaryotes; Nanoflagellates, heterotrophic; Neoxanthin; Net community production, cumulated; Net community production of oxygen; Net community production of oxygen, standard error; Nitrate; Nitrate and Nitrite; Nitrite; Nitrogen fixation rate; Opal particles; Organic matter; Organic matter, flux; Oxygen; Oxygen, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Partial pressure of carbon dioxide (water) at sea surface temperature (wet air), standard error; Peridinin; pH; pH, standard deviation; Phaeophorbide a; Phaeophytin a; Phenylalanine; Phosphate; Phosphorus, reactive soluble; Photosynthetic production of dissolved organic matter; Photosynthetic production of dissolved organic matter, standard deviation; Photosynthetic production of particulate organic matter; Photosynthetic production of particulate organic matter, standard deviation; Photosynthetic production of total organic matter; Photosynthetic production of total organic matter, standard deviation; Picoeukaryotes; Potentiometric; Potentiometric titration; Prasinoxanthin; Primary production of carbon; Prokaryotes, heterotroph; Protease, maximum hydrolysis velocity; Protease, maximum hydrolysis velocity, standard deviation; Respiration rate, oxygen; Respiration rate, oxygen, standard error; Rhamnose; Rhamnose, standard deviation; Salinity; Serine; Silicate; Suspended particulate matter; Synechococcus; Temperature, water; Threonine; Time point, descriptive; Total sediment, flux; Transparent exopolymer particles; Transparent exopolymer particles per carbon biomass; Treatment; Type; TYR; Tyrosine; Valine; Violaxanthin; Volume; Zeaxanthin; δ13C, dissolved inorganic carbon; δ13C, dissolved organic carbon; δ13C, particulate organic carbon
    Materialart: Dataset
    Format: text/tab-separated-values, 17025 data points
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    DATA PANGAEA
  • 5
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    Spatial patterns of ectoenzymatic kinetics in relation to biogeochemical properties in the Mediterranean Sea and the concentration of the fluorogenic substrate used (2021)
    Copernicus Publications (EGU)
    Details
    Publikationsdatum: 2024-02-07
    Beschreibung: Ectoenzymatic activity, prokaryotic heterotrophic abundances and production were determined in the Mediterranean Sea. Sampling was carried out in the sub-surface, the deep chlorophyll maximum layer (DCM), the core of the Levantine intermediate waters and in the deeper part of the mesopelagic layers. Michaelis–Menten kinetics were assessed using a large range of concentrations of fluorogenic substrates (0.025 to 50 µM). As a consequence, Km (Michaelis–Menten half-saturation constant) and Vm (maximum hydrolysis velocity) parameters were determined for both low- and high-affinity enzymes for alkaline phosphatase, aminopeptidase (LAP) and β-glucosidase (βGLU). Based on the constant derived from the high-LAP-affinity enzyme (0.025–1 µM substrate concentration range), in situ hydrolysis of N proteins contributed 48 % ± 30 % to the heterotrophic bacterial nitrogen demand within the epipelagic layers and 180 % ± 154 % in the Levantine intermediate waters and the upper part of the mesopelagic layers. The LAP hydrolysis rate was higher than bacterial N demand only within the deeper layer and only when considering the high-affinity enzyme. Based on a 10 % bacterial growth efficiency, the cumulative hydrolysis rates of C proteins and C polysaccharides contributed on average 2.5 % ± 1.3  % to the heterotrophic bacterial carbon demand in the epipelagic layers sampled (sub-surface and DCM). This study clearly reveals potential biases in current and past interpretations of the kinetic parameters for the three enzymes tested based on the fluorogenic-substrate concentration used. In particular, the LAP / βGLU enzymatic ratios and some of the depth-related trends differed between the use of high and low concentrations of fluorogenic substrates.
    Materialart: Article , PeerReviewed
    Format: text
    Format: text
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
  • 6
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    Unbekannt
    Dissolved organic matter released by two marine heterotrophic bacterial strains and its bioavailability for natural prokaryotic communities (2021)
    Wiley | Society for Applied Microbiology
    Details
    Publikationsdatum: 2024-02-07
    Beschreibung: Marine heterotrophic prokaryotes (HP) play a key role in organic matter processing in the ocean; however, the view of HP as dissolved organic matter (DOM) sources remains underexplored. In this study, we quantified and optically characterized the DOM produced by two single marine bacterial strains. We then tested the availability of these DOM sources to in situ Mediterranean Sea HP communities. Two bacterial strains were used: Photobacterium angustum (a copiotrophic gammaproteobacterium) and Sphingopyxis alaskensis (an oligotrophic alphaproteobacterium). When cultivated on glucose as the sole carbon source, the two strains released from 7% to 23% of initial glucose as bacterial derived DOM (B-DOM), the quality of which (as enrichment in humic or protein-like substances) differed between strains. B-DOM induced significant growth and carbon consumption of natural HP communities, suggesting that it was partly labile. However, B-DOM consistently promoted lower prokaryotic growth efficiencies than in situ DOM. In addition, B-DOM changed HP exoenzymatic activities, enhancing aminopeptidase activity when degrading P. angustum DOM, and alkaline phosphatase activity when using S. alaskensis DOM, and promoted differences in HP diversity and composition. DOM produced by HP affects in situ prokaryotic metabolism and diversity, thus changing the pathways for DOM cycling (e.g. respiration over biomass production) in the ocean.
    Materialart: Article , PeerReviewed
    Format: text
    Format: text
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
  • 7
    facet.materialart.
    Unbekannt
    Impact of dust addition on the metabolism of Mediterranean plankton communities and carbon export under present and future conditions of pH and temperature (2021)
    Copernicus Publications (EGU)
    Details
    Publikationsdatum: 2024-02-07
    Beschreibung: Although atmospheric dust fluxes from arid as well as human-impacted areas represent a significant source of nutrients to surface waters of the Mediterranean Sea, studies focusing on the evolution of the metabolic balance of the plankton community following a dust deposition event are scarce, and none were conducted in the context of projected future levels of temperature and pH. Moreover, most of the experiments took place in coastal areas. In the framework of the PEACETIME project, three dust-addition perturbation experiments were conducted in 300 L tanks filled with surface seawater collected in the Tyrrhenian Sea (TYR), Ionian Sea (ION) and Algerian basin (FAST) on board the R/V Pourquoi Pas? in late spring 2017. For each experiment, six tanks were used to follow the evolution of chemical and biological stocks, biological activity and particle export. The impacts of a dust deposition event simulated at their surface were followed under present environmental conditions and under a realistic climate change scenario for 2100 (ca. +3 ∘C and −0.3 pH units). The tested waters were all typical of stratified oligotrophic conditions encountered in the open Mediterranean Sea at this period of the year, with low rates of primary production and a metabolic balance towards net heterotrophy. The release of nutrients after dust seeding had very contrasting impacts on the metabolism of the communities, depending on the station investigated. At TYR, the release of new nutrients was followed by a negative impact on both particulate and dissolved 14C-based production rates, while heterotrophic bacterial production strongly increased, driving the community to an even more heterotrophic state. At ION and FAST, the efficiency of organic matter export due to mineral/organic aggregation processes was lower than at TYR and likely related to a lower quantity/age of dissolved organic matter present at the time of the seeding and a smaller production of DOM following dust addition. This was also reflected by lower initial concentrations in transparent exopolymer particles (TEPs) and a lower increase in TEP concentrations following the dust addition, as compared to TYR. At ION and FAST, both the autotrophic and heterotrophic community benefited from dust addition, with a stronger relative increase in autotrophic processes observed at FAST. Our study showed that the potential positive impact of dust deposition on primary production depends on the initial composition and metabolic state of the investigated community. This impact is constrained by the quantity of nutrients added in order to sustain both the fast response of heterotrophic prokaryotes and the delayed one of primary producers. Finally, under future environmental conditions, heterotrophic metabolism was overall more impacted than primary production, with the consequence that all integrated net community production rates decreased with no detectable impact on carbon export, therefore reducing the capacity of surface waters to sequester anthropogenic CO2.
    Materialart: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
    Format: text
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OceanRep: Artikel in einer Fachzeitschrift - begutachtet
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