cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.1594/pangaea.726862
title: Seawater carbonate chemistry and processes during experiments with cyanobacterium Nodularia spumigena, 2009

description: The surface ocean absorbs large quantities of the CO2 emitted to the atmosphere from human activities. As this CO2 dissolves in seawater, it reacts to form carbonic acid. While this phenomenon, called ocean acidification, has been found to adversely affect many calcifying organisms, some photosynthetic organisms appear to benefit from increasing [CO2]. Among these is the cyanobacterium Trichodesmium, a predominant diazotroph (nitrogen-fixing) in large parts of the oligotrophic oceans, which responded with increased carbon and nitrogen fixation at elevated pCO2. With the mechanism underlying this CO2 stimulation still unknown, the question arises whether this is a common response of diazotrophic cyanobacteria. In this study we therefore investigate the physiological response of Nodularia spumigena, a heterocystous bloom-forming diazotroph of the Baltic Sea, to CO2-induced changes in seawater carbonate chemistry. N. spumigena reacted to seawater acidification/carbonation with reduced cell division rates and nitrogen fixation rates, accompanied by significant changes in carbon and phosphorus quota and elemental composition of the formed biomass. Possible explanations for the contrasting physiological responses of Nodularia compared to Trichodesmium may be found in the different ecological strategies of non-heterocystous (Trichodesmium) and heterocystous (Nodularia) cyanobacteria.
description: In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne and Gattuso, 2011) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI).
description: Supplement to: Czerny, Jan; Barcelos e Ramos, Joana; Riebesell, Ulf (2009): Influence of elevated CO2 concentrations on cell division and nitrogen fixation rates in the bloom-forming cyanobacterium Nodularia spumigena. Biogeosciences, 6(9), 1865-1875
DOI: 10.1594/pangaea.733946
title: Seawater carbonate chemistry and biological processes during experiments with four strains of Emiliania huxleyi

description: Four strains of the coccolithophore E. huxleyi (RCC1212, RCC1216, RCC1238, RCC1256) were grown in dilute batch culture at four CO2 levels ranging from ~200 µatm to ~1200 µatm. Growth rate, particulate organic carbon content, and particulate inorganic carbon content were measured, and organic and inorganic carbon production calculated. The four strains did not show a uniform response to carbonate chemistry changes in any of the analysed parameters and none of the four strains displayed a response pattern previously described for this species. We conclude that the sensitivity of different strains of E. huxleyi to acidification differs substantially and that this likely has a genetic basis. We propose that this can explain apparently contradictory results reported in the literature.
description: In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne and Gattuso, 2011) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI).
description: Supplement to: Langer, Gerald; Nehrke, Gernot; Probert, Ian; Ly, J; Ziveri, Patrizia (2009): Strain-specific responses of Emiliania huxleyi to changing seawater carbonate chemistry. Biogeosciences, 6(11), 2637-2646
DOI: 10.1594/pangaea.873376
title: H+-driven increase in CO2 uptake and decrease in HCO3- uptake explain coccolithophores' acclimation responses to ocean acidification

description: Recent ocean acidification (OA) studies revealed that seawater [H+] rather than [CO2] or [ inline image] regulate short-term responses in carbon fluxes of Emiliania huxleyi. Here, we investigated whether acclimation to altered carbonate chemistry modulates this regulation pattern and how the carbon supply for calcification is affected by carbonate chemistry. We acclimated E. huxleyi to present-day (ambient [CO2], [ inline image], and pH) and OA conditions (high [CO2], ambient [ inline image], low pH). To differentiate between the CO2 and pH/H+ effects, we also acclimated cells to carbonation (high [CO2] and [ inline image], ambient pH) and acidification (ambient [CO2], low [ inline image], and pH). Under these conditions, growth, production of particulate inorganic and organic carbon, as well as carbon and oxygen fluxes were measured. Under carbonation, photosynthesis and calcification were stimulated due to additional inline image uptake, whereas growth was unaffected. Such stimulatory effects are not apparent after short-term carbonation, indicating that cells adjusted their carbon acquisition during acclimation. Being driven by [ inline image], these regulations can, however, not explain typical OA effects. Under acidification and OA, photosynthesis stayed constant, whereas calcification and growth decreased. Similar to the short-term responses toward high [H+], CO2 uptake significantly increased, but inline image uptake decreased. This antagonistic regulation in CO2 and inline image uptake can explain why photosynthesis, being able to use CO2 and inline image, often benefits from OA, whereas calcification, being mostly dependent on inline image, often decreases. We identified H+ as prime driver of coccolithophores' acclimation responses toward OA. Acidified conditions seem to put metabolic burdens on the cells that result in decreased growth.
description: In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2016) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation is 2017-03-10.
description: Supplement to: Kottmeier, Dorothee; Rokitta, Sebastian D; Rost, Björn (2016): H+-driven increase in CO2 uptake and decrease in HCO3- uptake explain coccolithophores' acclimation responses to ocean acidification. Limnology and Oceanography, 61(6), 2045-2057
DOI: 10.1594/pangaea.804574
title: GEMS-GLORI world river discharge database

description: The GEMS-GLORI register, circulated by UNEP for review in 1996, lists 555 world major rivers discharging to oceans (Q &gt; 10 km**3/year, or A &gt; 10 000 km**2, or sediment discharge &gt; 5Mt/year, or basin population &gt;5M people). Up to 48 river attributes are listed, including major ions and nutrients (C, N, P) in both dissolved, particulate, organic and inorganic forms. For many rivers, two or three sets of data are provided with relevant periods of records and references. Although half of the selected rivers are not yet documented for water quality, most of the first 40 rivers are well described (Irrawady, Zambezi, Ogooue, Magdalena, are noted exceptions). Altogether about 10 000 individual data from 500 references are listed. The global coverage in terms of river discharge and/or drainage area ranges from 40 to 67% for most major water quality attributes but drops to 25% for some organic and/or particulate forms of N and P. Planned development of the register includes collection of information on particulate chemistry and data on endorheic rivers and selected tributaries.
description: The river discharge database was digitized and archived on request of the EU-project CARBOOCEAN.Values in columns show corresponding number starting with publication year as listed in the Annex XIII "Alphabetical list of references", see hdl:10013/epic.34684.d009.
DOI: 10.1594/pangaea.875577
title: Environmental context of all samples from the Tara Oceans Expedition (2009-2013), about mesoscale features at the sampling location
DOI: 10.1594/pangaea.861157
title: The modulating effect of light intensity on the response of the coccolithophore Gephyrocapsa oceanica to ocean acidification

description: Global change leads to a multitude of simultaneous modifications in the marine realm among which shoaling of the upper mixed layer, leading to enhanced surface layer light intensities, as well as increased carbon dioxide (CO2) concentration are some of the most critical environmental alterations for phytoplankton. In this study, we investigated the responses of growth, photosynthetic carbon fixation and calcification of the coccolithophore Gephyrocapsa oceanica to elevated inline image (51 Pa, 105 Pa, and 152 Pa) (1 Pa ~ 10 µatm) at a variety of light intensities (50-800 µmol photons/m**2/s). By fitting the light response curve, our results showed that rising inline image reduced the maximum rates for growth, photosynthetic carbon fixation and calcification. Increasing light intensity enhanced the sensitivity of these rate responses to inline image, and shifted the inline image optima toward lower levels. Combining the results of this and a previous study (Sett et al. 2014) on the same strain indicates that both limiting low inline image and inhibiting high inline image levels (this study) induce similar responses, reducing growth, carbon fixation and calcification rates of G. oceanica. At limiting low light intensities the inline image optima for maximum growth, carbon fixation and calcification are shifted toward higher levels. Interacting effects of simultaneously occurring environmental changes, such as increasing light intensity and ocean acidification, need to be considered when trying to assess metabolic rates of marine phytoplankton under future ocean scenarios.
description: Supplement to: Zhang, Yong; Bach, Lennart Thomas; Schulz, Kai Georg; Riebesell, Ulf (2015): The modulating effect of light intensity on the response of the coccolithophore Gephyrocapsa oceanica to ocean acidification. Limnology and Oceanography, 60(6), 2145-2157
DOI: 10.1594/pangaea.873567
title: Underway surface water data during the Tara Oceans expedition in 2013

description: The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. During the entire expedition (2009-2013), underway measurements were obtained from a meteorological station (BATOS), a thermosalinograph (TSG, SBE 45), a Fast Repetition Rate Flurometer (FRRF, LIFT-FRR01), and a spectrophotometer (WETLabs AC-S). In 2013 underway measurements were enhanced by adding a Photosynthetically Available Radiation (PAR) sensor (QCP2350, Biospherical Instruments, Inc.), a laser spectrofluorometer (WETLabs ALFA, Chekalyuk et al., 2012) that replaced the FRRF, a spectral backscattering sensor (WETLabs Eco-bb3), a pCO2 sensor (ProOceanus CO2-Pro), a pH sensor (Satlantic, SeaFET) and a particle imaging system triggered by chlorophyll-a fluorescence (a prototype of McLane Research Laboratories' Imaging FlowCytobot, Sosik Lab, WHOI). Discrete measurements of CDOM absorption measurements were made using an Ultrapath (WPI Inc.) to calibrate the in-line AC-S. Hence the AC-S was also used to provide CDOM absorption in addition to particulate matter properties. The present dataset contains surface water data measured during the 2013 campaigns of the Tara Oceans Expedition. Latitude and Longitude were obtained from TSG data. The time stamp of this data set is harmonised with that of other underway data in this collection.
DOI: 10.1594/pangaea.873566
title: Underway surface water data during the Tara Oceans expedition in 2009-2012

description: The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. During the entire expedition (2009-2013), underway measurements were obtained from a meteorological station (BATOS), a thermosalinograph (TSG, SBE 45), a Fast Repetition Rate Flurometer (FRRF, LIFT-FRR01), and a spectrophotometer (WETLabs AC-S). In 2013 underway measurements were enhanced by adding a Photosynthetically Available Radiation (PAR) sensor (QCP2350, Biospherical Instruments, Inc.), a laser spectrofluorometer (WETLabs ALFA, Chekalyuk et al., 2012) that replaced the FRRF, a spectral backscattering sensor (WETLabs Eco-bb3), a pCO2 sensor (ProOceanus CO2-Pro), a pH sensor (Satlantic, SeaFET) and a particle imaging system triggered by chlorophyll-a fluorescence (a prototype of McLane Research Laboratories' Imaging FlowCytobot, Sosik Lab, WHOI). Discrete measurements of CDOM absorption measurements were made using an Ultrapath (WPI Inc.) to calibrate the in-line AC-S. Hence the AC-S was also used to provide CDOM absorption in addition to particulate matter properties. The present dataset contains surface water data measured during the 2009-2012 campaigns of the Tara Oceans Expedition. Latitude and Longitude were obtained from TSG data. The time stamp of this data set is harmonised with that of other underway data in this collection.
DOI: 10.1594/pangaea.861839
title: Differing responses of three Southern Ocean Emiliania huxleyi ecotypes to changing seawater carbonate chemistry

description: The invasion of anthropogenic carbon dioxide into the surface ocean is altering seawater carbonate speciation, a process commonly called ocean acidification. The high latitude waters of the Southern Ocean are one of the primary and most severely affected regions. Coccolithophores are an important phytoplankton group, responsible for the majority of pelagic calcium carbonate production in the world's oceans, with a distribution that ranges from tropical to polar waters. Emiliania huxleyi is numerically the most abundant coccolithophore species and appears in several different ecotypes. We tested the effects of ocean acidification on 3 carefully selected E. huxleyi ecotypes isolated from the Southern Ocean. Their responses were measured in terms of growth, photosynthesis, calcification, cellular geometry, and stoichiometry. The 3 ecotypes exhibited differing sensitivities in regards to seawater carbonate chemistry when cultured at the same temperature (14°C) and continuous light (110 µmol photons/m2/s). Under future ocean acidification scenarios, particulate inorganic to organic carbon ratios (PIC:POC) decreased by 38-44, 47-51 and 71-98% in morphotype A 'over-calcified' (A o/c), A and B/C, respectively. All ecotypes reduced their rate of calcification, but the cold-water adapted ecotype (morphotype B/C) was by far the most sensitive, and almost ceased calcification at partial pressure of carbon dioxide ( pCO2) levels above 1000 µatm. We recommend that future surveys for E. huxleyi cells in the Southern Ocean should include the capability of recognising 'naked cells' by molecular and microscopic tools. The distinct differences in the physiological responses of these 3 dominant Southern Ocean coccolithophore ecotypes are likely to have consequences for future coccolithophore community structures and thereby the Southern Ocean carbon cycle.
description: In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2015) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation is 2016-06-15.
description: Supplement to: Müller, Marius N; Trull, Tom W; Hallegraeff, Gustaaf M (2015): Differing responses of three Southern Ocean Emiliania huxleyi ecotypes to changing seawater carbonate chemistry. Marine Ecology Progress Series, 531, 81-90
DOI: 10.1594/pangaea.833817
title: Trichodesmium's strategies to alleviate phosphorus limitation in the future acidified oceans

description: Global warming may exacerbate inorganic nutrient limitation, including phosphorus (P), in the surface-waters of tropical oceans that are home to extensive blooms of the marine diazotrophic cyanobacterium, Trichodesmium. We examined the combined effects of P limitation and pCO2, forecast under ocean acidification scenarios, on Trichodesmium erythraeum IMS101 cultures. We measured nitrogen acquisition, glutamine synthetase activity, C uptake rates, intracellular Adenosine Triphosphate (ATP) concentration and the pool sizes of related key proteins. Here, we present data supporting the idea that cellular energy re-allocation enables the higher growth and N2 fixation rates detected in Trichodesmium cultured under high pCO2. This is reflected in altered protein abundance and metabolic pools. Also modified are particulate organic carbon and nitrogen production rates, enzymatic activities, and cellular ATP concentrations. We suggest that adjusting these cellular pathways to changing environmental conditions enables Trichodesmium to compensate for low P availability and to thrive in acidified oceans. Moreover, elevated pCO2 could provide Trichodesmium with a competitive dominance that would extend its niche, particularly in P-limited regions of the tropical and subtropical oceans.
description: In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne et al, 2014) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation is 2014-07-07.
description: Supplement to: Spungin, D; Berman-Frank, I; Levitan, Orly (2014): Trichodesmium's strategies to alleviate phosphorus limitation in the future acidified oceans. Environmental Microbiology, 16(6), 1935-1947
DOI: 10.1594/pangaea.847795
title: Ocean acidification decreases the light-use efficiency in an Antarctic diatom under dynamic but not constant light

description: In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2015) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation is 2015-07-03.
DOI: 10.1594/pangaea.834555
title: Diversity of ocean acidification effects on marine N2 fixers

description: Considering the important role of N2 fixation for primary productivity and CO2 sequestration, it is crucial to assess the response of diazotrophs to ocean acidification. Previous studies on the genus Trichodesmium suggested a strong sensitivity towards ocean acidification. In view of the large functional diversity in N2 fixers, the objective of this study was to improve our knowledge of the CO2 responses of other diazotrophs. To this end, the single-celled Cyanothece sp. and two heterocystous species, Nodularia spumigena and the symbiotic Calothrix rhizosoleniae, were acclimated to two pCO2 levels (380 vs. 980 µatm). Growth rates, cellular composition (carbon, nitrogen and chlorophyll a) as well as carbon and N2 fixation rates (14C incorporation, acetylene reduction) were measured and compared to literature data on different N2 fixers. The three species investigated in this study responded differently to elevated pCO2, showing enhanced, decreased as well as unaltered growth and production rates. For instance, Cyanothece increased production rates with pCO2, which is in line with the general view that N2 fixers benefit from ocean acidification. Due to lowered growth and production of Nodularia, nitrogen input to the Baltic Sea might decrease in the future. In Calothrix, no significant changes in growth or production could be observed, even though N2 fixation was stimulated under elevated pCO2. Reviewing literature data confirmed a large variability in CO2 sensitivity across diazotrophs. The contrasting response patterns in our and previous studies were discussed with regard to the carbonate chemistry in the respective natural habitats, the mode of N2 fixation as well as differences in cellular energy limitation between the species. The group-specific CO2 sensitivities will impact differently on future biogeochemical cycles of open-ocean environments and systems like the Baltic Sea and should therefore be considered in models estimating climate feedback effects.
description: In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne et al, 2014) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation is 2014-07-30.
description: Supplement to: Eichner, Meri; Rost, Björn; Kranz, Sven A (2014): Diversity of ocean acidification effects on marine N2 fixers. Journal of Experimental Marine Biology and Ecology, 457, 199-207
DOI: 10.1594/pangaea.868779
title: Physiological responses of coastal and oceanic diatoms to diurnal fluctuations in seawater carbonate chemistry under two CO2 concentrations

description: Diel and seasonal fluctuations in seawater carbonate chemistry are common in coastal waters, while in the open-ocean carbonate chemistry is much less variable. In both of these environments, ongoing ocean acidification is being superimposed on the natural dynamics of the carbonate buffer system to influence the physiology of phytoplankton. Here, we show that a coastal Thalassiosira weissflogii isolate and an oceanic diatom, Thalassiosira oceanica, respond differentially to diurnal fluctuating carbonate chemistry in current and ocean acidification (OA) scenarios. A fluctuating carbonate chemistry regime showed positive or negligible effects on physiological performance of the coastal species. In contrast, the oceanic species was significantly negatively affected. The fluctuating regime reduced photosynthetic oxygen evolution rates and enhanced dark respiration rates of T. oceanica under ambient CO2 concentration, while in the OA scenario the fluctuating regime depressed its growth rate, chlorophyll a content, and elemental production rates. These contrasting physiological performances of coastal and oceanic diatoms indicate that they differ in the ability to cope with dynamic pCO2. We propose that, in addition to the ability to cope with light, nutrient, and predation pressure, the ability to acclimate to dynamic carbonate chemistry may act as one determinant of the spatial distribution of diatom species. Habitat-relevant diurnal changes in seawater carbonate chemistry can interact with OA to differentially affect diatoms in coastal and pelagic waters.
description: In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2016) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation is 2016-11-24.
description: Supplement to: Li, Futian; Wu, YaPing; Hutchins, David A; Fu, Feixue; Gao, Kunshan (2016): Physiological responses of coastal and oceanic diatoms to diurnal fluctuations in seawater carbonate chemistry under two CO2 concentrations. Biogeosciences, 13(22), 6247-6259