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  • 1. Bosak, S.
    et al.
    Ljubesic, Z.
    Supraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Neeley, A.
    Durkin, C. A.
    Estapa, M.
    Omand, M.
    Carlson, K.
    Cetinic, I.
    PHYTOPLANKTON SPECIES COMPOSITION CONTRIBUTING TO CARBON EXPORT - SEA TO SPACE PARTICLE INVESTIGATION2017In: Phycologia, ISSN 0031-8884, E-ISSN 2330-2968, Vol. 56, no 4, p. 23-24Article in journal (Other academic)
  • 2. Bosak, Sunčica
    et al.
    Šupraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Nanjappa, Deepak
    Kooistra, Wiebe H.C.F.
    Sarno, Diana
    Morphology and phylogeny of four species from the genus Bacteriastrum (Bacillariophyta)2015In: Phycologia, Vol. 54, no 2, p. 130-148Article in journal (Refereed)
  • 3. Gerecht, A. C.
    et al.
    Šupraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Edvardsen, B.
    Langer, G.
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Phosphorus availability modifies carbon production in Coccolithus pelagicus (Haptophyta)2015In: Journal of Experimental Marine Biology and Ecology, ISSN 0022-0981, E-ISSN 1879-1697, Vol. 472, p. 24-31Article in journal (Refereed)
    Abstract [en]

    Abstract The coccolithophore Coccolithus pelagicus (Wallich) Schiller fixes CO2 into particulate organic carbon (POC) through photosynthesis and into particulate inorganic carbon (PIC) in the form of calcite. To examine the role of phosphorus (P) availability in the production of POC and PIC, C. pelagicus subsp. braarudii (Gaarder) Geisen et al. was grown in semi-continuous cultures at three initial phosphate concentrations (P-replete, 1, and 0.5 μM [P]). Reduced P-availability (1 and 0.5 μM [P]) decreased POC production, while PIC production only decreased when phosphate concentrations became growth limiting (0.5 μM [P]). This decrease has not been observed previously in batch cultures, highlighting the inadequacy of the batch culture approach with regard to determining carbon production. The reduction in growth rate by 50% at 0.5 μM [P] was accompanied by a doubling in cell volume (and POC). PIC production was halved, resulting in a lowered PIC to POC ratio. The average number of coccoliths per cell (and PIC content) remained the same among treatments, despite the significant change in cell size. Our data suggest that POC production in C. pelagicus is more sensitive towards a moderate reduction in phosphorus availability than PIC production. Once phosphorus availability limits cell division, however, phosphorus resources are invested into POC rather than PIC production. This reduces cell density and sinking rates, indicating that coccoliths do not act as ballast for reaching deeper nutrient-rich layers under nutrient limitation.

  • 4. Gerecht, Andrea
    et al.
    Supraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Edvardsen, Bente
    Probert, Ian
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    High temperature decreases the PIC/POC ratio and increases phosphorus requirements in Coccolithus pelagicus (Haptophyta)2014In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 11, p. 3531-3545Article in journal (Refereed)
    Abstract [en]

    Rising ocean temperatures will likely increase stratification of the water column and reduce nutrient input into the photic zone. This will increase the likelihood of nutrient limitation in marine microalgae, leading to changes in the abundance and composition of phytoplankton communities, which in turn will affect global biogeochemical cycles. Calcifying algae, such as coccolithophores, influence the carbon cycle by fixing CO2 into particulate organic carbon through photosynthesis (POC production) and into particulate inorganic carbon through calcification (PIC production). As calcification produces a net release of CO2, the ratio of PIC to POC production determines whether coccolithophores act as a source (high PIC / POC) or a sink (low PIC / POC) of atmospheric CO2. We studied the effect of phosphorus (P-) limitation and high temperature on the physiology and the PIC / POC ratio of two subspecies of Coccolithus pelagicus. This large and heavily calcified species is a major contributor to calcite export from the photic zone into deep-sea reservoirs. Phosphorus limitation did not influence exponential growth rates in either subspecies, but P-limited cells had significantly lower cellular P-content. One of the subspecies was subjected to a 5 °C temperature increase from 10 °C to 15 °C, which did not affect exponential growth rates either, but nearly doubled cellular P-content under both high and low phosphate availability. This temperature increase reduced the PIC / POC ratio by 40–60%, whereas the PIC / POC ratio did not differ between P-limited and nutrient-replete cultures when the subspecies were grown near their respective isolation temperature. Both P-limitation and elevated temperature significantly increased coccolith malformations. Our results suggest that a temperature increase may intensify P-limitation due to a higher P-requirement to maintain growth and POC production rates, possibly reducing abundances in a warmer ocean. Under such a scenario C. pelagicus may decrease its calcification rate relative to photosynthesis, thus favouring CO2 sequestration over release. It seems unlikely that P-limitation by itself causes changes in the PIC / POC ratio in this species.

  • 5. Gerecht, Andrea
    et al.
    Supraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology. Univ Oslo, Dept Biosci, Sect Aquat Biol & Toxicol, N-0316 Oslo, Norway.
    Langer, Gerald
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology. Univ Oslo, Dept Biosci, Ctr Ecol & Evolutionary Synth, N-0316 Oslo, Norway.
    Phosphorus limitation and heat stress decrease calcification in Emiliania huxleyi2018In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 15, p. 833-845Article in journal (Refereed)
    Abstract [en]

    Calcifying haptophytes (coccolithophores) sequester carbon in the form of organic and inorganic cellular components (coccoliths). We examined the effect of phosphorus (P) limitation and heat stress on particulate organic and inorganic carbon (calcite) production in the coccolithophore Emiliania huxleyi. Both environmental stressors are related to rising CO2 levels and affect carbon production in marine microalgae, which in turn impacts biogeochemical cycling. Using semi-continuous cultures, we show that P-limitation and heat stress decrease the calcification rate in E. huxleyi. This could lessen the ballasting effect of coccoliths and weaken carbon export out of the photic zone. However, using batch cultures, we show that different culturing approaches (batch versus semi-continuous) induce different physiologies. This affects the ratio of inorganic (PIC) to organic (POC) carbon and complicates general predictions on the effect of P-limitation on the PIC / POC ratio. Furthermore, heat stress increases P-requirements in E. huxleyi, possibly leading to lower standing stocks in a warmer ocean, especially if this is linked to lower nutrient input. In summary, the predicted rise in global temperature and resulting decrease in nutrient availability may first of all decrease CO2 sequestration by coccolithophores through lower overall carbon production. Secondly, the export of carbon may be diminished by a decrease in calcification and a weaker coccolith ballasting effect.

  • 6. Gerecht, Andrea
    et al.
    Šupraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Edvardsen, Bente
    Langer, Gerald
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Phosphorus availability modifies carbon production in Coccolithus pelagicus (Haptophyta)2015In: Journal of Experimental Marine Biology and Ecology, ISSN 0022-0981, E-ISSN 1879-1697, Vol. 472, p. 24-31Article in journal (Refereed)
    Abstract [en]

    The coccolithophore Coccolithus pelagicus (Wallich) Schiller fixes CO2 into particulate organic carbon (POC) through photosynthesis and into particulate inorganic carbon (PIC) in the form of calcite. To examine the role of phosphorus (P) availability in the production of POC and PIC, C. pelagicus subsp. braarudii (Gaarder) Geisen et al. was grown in semi-continuous cultures at three initial phosphate concentrations (P-replete, 1, and 0.5 μM [P]). Reduced P-availability (1 and 0.5 μM [P]) decreased POC production, while PIC production only decreased when phosphate concentrations became growth limiting (0.5 μM [P]). This decrease has not been observed previously in batch cultures, highlighting the inadequacy of the batch culture approach with regard to determining carbon production. The reduction in growth rate by 50% at 0.5 μM [P] was accompanied by a doubling in cell volume (and POC). PIC production was halved, resulting in a lowered PIC to POC ratio. The average number of coccoliths per cell (and PIC content) remained the same among treatments, despite the significant change in cell size. Our data suggest that POC production in C. pelagicus is more sensitive towards a moderate reduction in phosphorus availability than PIC production. Once phosphorus availability limits cell division, however, phosphorus resources are invested into POC rather than PIC production. This reduces cell density and sinking rates, indicating that coccoliths do not act as ballast for reaching deeper nutrient-rich layers under nutrient limitation.

  • 7. Gerecht, Andrea
    et al.
    Šupraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Edvardsen, Bente
    Probert, Ian
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Phosphorus limitation does not change the ratio of calcite to organic carbon in Coccolithus pelagicus (Wallich)2013Conference paper (Other academic)
  • 8. Gerecht, Andrea
    et al.
    Šupraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Edvardsen, Bente
    Probert, Ian
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Temperature, but not phosphorus limitation, changes the ratio of calcite to organic carbon in Coccolithus pelagicus2013Conference paper (Other academic)
  • 9. Gran Stadniczenko, Sandra
    et al.
    Šupraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Egge, Elianne
    Edvardsen, Bente
    Comparing high-throughput sequencing and scanning electron microscopy to investigate haptophyte communities in Oslofjorden (Skagerrak)2016Conference paper (Refereed)
  • 10.
    Gran-Stadniczeñko, Sandra
    et al.
    Univ Oslo, Dept Biosci, POB 1066 Blindern, N-0316 Oslo, Norway.
    Supraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Egge, Elianne D.
    Univ Oslo, Dept Biosci, POB 1066 Blindern, N-0316 Oslo, Norway.
    Edvardsen, Bente
    Univ Oslo, Dept Biosci, POB 1066 Blindern, N-0316 Oslo, Norway.
    Haptophyte diversity and vertical distribution explored by 18S and 28S ribosomal RNA gene metabarcoding and scanning electron microscopy2017In: Journal of Eukaryotic Microbiology, ISSN 1066-5234, E-ISSN 1550-7408, Vol. 64, no 4, p. 514-532Article in journal (Refereed)
    Abstract [en]

    Haptophyta encompasses more than 300 species of mostly marine pico- and nanoplanktonic flagellates. Our aims were to investigate the Oslofjorden haptophyte diversity and vertical distribution by metabarcoding, and to improve the approach to study haptophyte community composition, richness and proportional abundance by comparing two rRNA markers and scanning electron microscopy (SEM). Samples were collected in August 2013 at the Outer Oslofjorden, Norway. Total RNA/cDNA was amplified by haptophyte-specific primers targeting the V4 region of the 18S, and the D1-D2 region of the 28S rRNA. Taxonomy was assigned using curated haptophyte reference databases and phylogenetic analyses. Both marker genes showed Chrysochromulinaceae and Prymnesiaceae to be the families with highest number of Operational Taxonomic Units (OTUs), as well as proportional abundance. The 18S rRNA data setalso contained OTUs assigned to eight supported and defined clades consisting of environmental sequences only, possibly representing novel lineages from family to class. We also recorded new species for the area. Comparing coccolithophores by SEM with metabarcoding shows a good correspondence with the 18S rRNA gene proportional abundances. Our results contribute to link morphological and molecular data and 28S to 18S rRNA gene sequences of haptophytes without cultured representatives, and to improve metabarcoding methodology.

  • 11.
    Henderiks, Jorijntje
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Bordiga, Manuela
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Bartol, Milos
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Šupraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Paleolatitudinal gradients in marine phytoplankton composition and cell size2014Conference paper (Other academic)
  • 12.
    Jordan, Richard W.
    et al.
    Yamagata Univ, Fac Sci, Dept Earth & Environm Sci, Yamagata 9908560, Japan.
    Abe, Kent
    Yamagata Univ, Grad Sch Sci & Engn, Yamagata 9908560, Japan.
    Cruz, Jarret
    Florida State Univ, Earth Ocean & Atmospher Sci, Tallahassee, FL 32306 USA.
    Eriksen, Ruth
    Univ Tasmania, Inst Marine & Antarctic Studies, Hobart, Tas 7001, Australia.
    Guerreiro, Catarina
    Univ Bremen, Dept Geosci, D-28359 Bremen, Germany.
    Hagino, Kyoko
    Kochi Univ, Kochi 7808520, Japan.
    Heldal, Mikal
    Dept Biol, N-5020 Bergen, Norway.
    Hernández-Becerril, David U.
    Univ Nacl Autonoma Mexico, Inst Ciencias Mar & Limnol, Mexico City 04510, DF, Mexico.
    Malinverno, Elisa
    Univ Milano Bicocca, Dept Earth & Environm Sci, Milan, Italy.
    Nishida, Shiro
    Nara Univ Educ, Fac Educ, Dept Earth Sci, Nara, Japan.
    Patil, Shramik M.
    NCAOR, Vasco Da Gama 403804, Goa, India.
    Šupraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Thomsen, Helge Abildhauge
    Tech Univ Denmark, Natl Inst Aquat Resources DTU Aqua, DK-2920 Charlottenlund, Denmark.
    Triantaphyllou, Maria V.
    Univ Athens, Dept Hist Geol & Palaeontol, Athens 15784, Greece.
    Young, Jeremy R.
    UCL, Dept Earth Sci, London WC1E 6BT, England.
    Observations on the morphological diversity and distribution of two siliceous nannoplankton genera, Hyalolithus and Petasaria2015In: Micropaleontology, ISSN 0026-2803, E-ISSN 1937-2795, Vol. 61, no 6, p. 439-455Article in journal (Refereed)
    Abstract [en]

    Scale-bearing siliceous nannoplankton are occasionally encountered in surface seawater samples, but are rarely identified or illustrated. In this study, the morphological diversity of the haptophyte Hyalolithus neolepis and the enigmatic Petasaria heterolepis are investigated in scanning and transmission electron microscopes using materials from around the world. Results show that H. neolepis scales exhibit variation in the width of the marginal hyaline area, but intermediate specimens make separation of the two morphologies difficult. Petasaria heterolepis scales also show differences, in the presence of tubercle rows in the hyaline area and degree of hyaline areal coverage, but separation into discrete varieties is difficult at present. However, specimens with scales bearing a protuberance are considered to be distinct enough to warrant the erection of a new species, Petasaria protuberans Jordan,Malinverno, Å upraha, Thomsen et Young sp. nov.

  • 13.
    Korlević, Marino
    et al.
    Rudjer Boskovic Inst, Ctr Marine Res, Rovinj, Croatia.
    Šupraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Ljubešić, Zrinka
    Rudjer Boskovic Inst, Div Marine & Environm Res, Zagreb, Croatia.
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Ciglenečki, Irena
    Rudjer Boskovic Inst, Div Marine & Environm Res, Zagreb, Croatia.
    Dautović, Jelena
    Rudjer Boskovic Inst, Div Marine & Environm Res, Zagreb, Croatia.
    Orlić, Sandi
    Rudjer Boskovic Inst, Div Mat Chem, Zagreb, Croatia.; Ctr Excellence Sci & Technol Integrating Mediterr, Microbial Ecol, Zagreb, Croatia.
    Bacterial diversity across a highly stratified ecosystem: A salt-wedge Mediterranean estuary2016In: Systematic and Applied Microbiology, ISSN 0723-2020, E-ISSN 1618-0984, Vol. 39, no 6, p. 398-408Article in journal (Refereed)
    Abstract [en]

    Highly stratified Mediterranean estuaries are unique environments where the tidal range is low and the tidal currents are almost negligible. The main characteristics of these environments are strong salinity gradients and other environmental parameters. In this study, 454 pyrosequencing of the 16S rRNA gene in combination with catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH) was used to estimate the bacterial diversity across the Krka estuary in February and July 2013. The comparison of the data derived from these two techniques resulted in a significant but weak positive correlation (R = 0.28) indicating a substantial difference in the bacterial community structure, depending on the applied method. The phytoplankton bloom observed in February was identified as one of the main factors shaping the bacterial community structure between the two environmentally contrasting sampling months. Roseobacter, Bacteroidetes and Gammaproteobacteria differed substantially between February and July. Typical freshwater bacterial classes (Actinobacteria and Betaproteobacteria) showed strong vertical distribution patterns depending on the salinity gradient. Cyanobacteria decreased in abundance in February due to competition with phytoplankton, while the SAR11 clade increased its abundance in July as a result of a better adaptation toward more oligotrophic conditions. The results provided the first detailed insight into the bacterial diversity in a highly stratified Mediterranean karstic estuary.

  • 14.
    Mejdandzic, Maja
    et al.
    Univ Zagreb, Dept Biol, Fac Sci, Zagreb 10000, Croatia..
    Mihanovic, Hrvoje
    Inst Oceanog & Fisheries, Phys Oceanog Lab, Split 21000, Croatia..
    Silovic, Tina
    Rudjer Boskovic Inst, Ctr Marine Res, Rovinj 52210, Croatia..
    Henderiks, Jorijntje
    Univ Oslo, Dept Biosci, CEES, N-0316 Oslo, Norway..
    Supraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Polovic, Dorotea
    Univ Zagreb, Dept Biol, Fac Sci, Zagreb 10000, Croatia..
    Bosak, Suncica
    Univ Zagreb, Dept Biol, Fac Sci, Zagreb 10000, Croatia..
    Bosnjak, Ivana
    Univ Zagreb, Dept Biol, Fac Sci, Zagreb 10000, Croatia..
    Cetinic, Ivona
    Univ Maine, Ira C Darling Marine Ctr, Walpole, ME 04573 USA..
    Olujic, Goran
    Hydrog Inst Republ Croatia, Oceanog Dept, Split 21000, Croatia..
    Ljubesic, Zrinka
    Univ Zagreb, Dept Biol, Fac Sci, Zagreb 10000, Croatia..
    Biomarker Pigment Divinyl Chlorophyll a as a Tracer of Water Masses?2015In: European journal of phycology, ISSN 0967-0262, E-ISSN 1469-4433, Vol. 50, no Suppl. 1, p. 162-163Article in journal (Other academic)
  • 15.
    Supraha, Luka
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Phenotypic variation and adaptive strategies in calcifying marine phytoplankton (Coccolithophores)2015Licentiate thesis, comprehensive summary (Other academic)
    List of papers
    1. Eco-physiological adaptation shapes the response of calcifying algae to nutrient limitation
    Open this publication in new window or tab >>Eco-physiological adaptation shapes the response of calcifying algae to nutrient limitation
    2015 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, article id 16499Article in journal (Refereed) Published
    Abstract [en]

    The steady increase in global ocean temperature will most likely lead to nutrient limitation in the photic zone. This will impact the physiology of marine algae, including the globally important calcifying coccolithophores. Understanding their adaptive patterns is essential for modelling carbon production in a low-nutrient ocean. We investigated the physiology of Helicosphaera carteri, a representative of the abundant but under-investigated flagellated functional group of coccolithophores. Two strains isolated from contrasting nutrient regimes (South Atlantic and Mediterranean Sea) were grown in phosphorus-replete and phosphorus-limited batch cultures. While growing exponentially in a phosphorus-replete medium, the Mediterranean strain exhibited on average 24% lower growth rate, 36% larger coccosphere volume and 21% lower particulate inorganic carbon (PIC) production than the Atlantic strain. Under phosphorus limitation, the same strain was capable of reaching a 2.6 times higher cell density than the Atlantic strain due to lower phosphorus requirements. These results suggest that local physiological adaptation can define the performance of this species under nutrient limitation.

    National Category
    Ecology Cell Biology Evolutionary Biology Earth and Related Environmental Sciences
    Identifiers
    urn:nbn:se:uu:diva-253354 (URN)10.1038/srep16499 (DOI)000364487200001 ()26560531 (PubMedID)
    Funder
    Knut and Alice Wallenberg FoundationThe Royal Swedish Academy of Sciences
    Available from: 2015-05-26 Created: 2015-05-26 Last updated: 2017-12-04Bibliographically approved
    2. High temperature decreases the PIC/POC ratio and increases phosphorus requirements in Coccolithus pelagicus (Haptophyta)
    Open this publication in new window or tab >>High temperature decreases the PIC/POC ratio and increases phosphorus requirements in Coccolithus pelagicus (Haptophyta)
    Show others...
    2014 (English)In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 11, p. 3531-3545Article in journal (Refereed) Published
    Abstract [en]

    Rising ocean temperatures will likely increase stratification of the water column and reduce nutrient input into the photic zone. This will increase the likelihood of nutrient limitation in marine microalgae, leading to changes in the abundance and composition of phytoplankton communities, which in turn will affect global biogeochemical cycles. Calcifying algae, such as coccolithophores, influence the carbon cycle by fixing CO2 into particulate organic carbon through photosynthesis (POC production) and into particulate inorganic carbon through calcification (PIC production). As calcification produces a net release of CO2, the ratio of PIC to POC production determines whether coccolithophores act as a source (high PIC / POC) or a sink (low PIC / POC) of atmospheric CO2. We studied the effect of phosphorus (P-) limitation and high temperature on the physiology and the PIC / POC ratio of two subspecies of Coccolithus pelagicus. This large and heavily calcified species is a major contributor to calcite export from the photic zone into deep-sea reservoirs. Phosphorus limitation did not influence exponential growth rates in either subspecies, but P-limited cells had significantly lower cellular P-content. One of the subspecies was subjected to a 5 °C temperature increase from 10 °C to 15 °C, which did not affect exponential growth rates either, but nearly doubled cellular P-content under both high and low phosphate availability. This temperature increase reduced the PIC / POC ratio by 40–60%, whereas the PIC / POC ratio did not differ between P-limited and nutrient-replete cultures when the subspecies were grown near their respective isolation temperature. Both P-limitation and elevated temperature significantly increased coccolith malformations. Our results suggest that a temperature increase may intensify P-limitation due to a higher P-requirement to maintain growth and POC production rates, possibly reducing abundances in a warmer ocean. Under such a scenario C. pelagicus may decrease its calcification rate relative to photosynthesis, thus favouring CO2 sequestration over release. It seems unlikely that P-limitation by itself causes changes in the PIC / POC ratio in this species.

    Keywords
    coccolithophores, culture experiments, phosphate limitation, calcification
    National Category
    Natural Sciences
    Research subject
    Biology; Earth Science with specialization in Environmental Analysis
    Identifiers
    urn:nbn:se:uu:diva-220830 (URN)10.5194/bg-11-3531-2014 (DOI)000339265800008 ()
    Available from: 2014-03-20 Created: 2014-03-20 Last updated: 2017-12-05Bibliographically approved
    3. Observations on the life cycle and ecology of Acanthoica quattrospina Lohmann from a Mediterranean estuary
    Open this publication in new window or tab >>Observations on the life cycle and ecology of Acanthoica quattrospina Lohmann from a Mediterranean estuary
    2014 (English)In: Journal of Nannoplankton Research, ISSN 1210-8049, Vol. 34, no SI, p. 49-56Article in journal (Refereed) Published
    National Category
    Ecology Biological Systematics
    Identifiers
    urn:nbn:se:uu:diva-253353 (URN)
    Conference
    INA Workshop on Extant Coccolithophores research
    Available from: 2015-05-26 Created: 2015-05-26 Last updated: 2016-09-13Bibliographically approved
  • 16.
    Supraha, Luka
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Ljubesic, Zrinka
    Univ Zagreb, Fac Sci, Dept Biol, Rooseveltov Trg 6, Zagreb 10000, Croatia.
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology. Univ Oslo, Dept Biosci, CEES, POB 1066, N-0316 Oslo, Norway.
    Combination coccospheres from the Eastern Adriatic coast: New, verified and possible life-cycle associations2018In: Marine Micropaleontology, ISSN 0377-8398, E-ISSN 1872-6186, Vol. 141, p. 23-30Article in journal (Refereed)
    Abstract [en]

    Coccolithophore life cycles involve the alternation between morphologically distinct life-cycle phases. This often leads to taxonomic issues where the life-cycle phases of the same species are described as distinct taxa. This issue can be resolved by the observation of combination coccospheres, i.e. cells bearing the coccoliths of both life-cycle phases. This study presents new observations on combination coccospheres from the highly diverse and ecologically important coccolithophore order Syracosphaerales and the genus Alisphaera. New life-cycle associations are revealed between Syracosphaera hirsuta and Corisphaera strigilis, and between Alisphaera unicornis and a nannolith-producing Polycrater galapagensis. The life-cycle association of Syracosphaera marginiporata Anthosphaera sp. type B is verified. A possible association between Rhabdosphaera xiphos and an unidentified holococcolith-bearing morphotype is proposed and needs to be verified in future investigations. The appropriate taxonomic revisions are conducted following the taxonomic principle of priority and recommended practices for naming the coccolithophore life-cycle phases.

  • 17.
    Supraha, Luka
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Ljubesic, Zrinka
    Mihanovic, Hrvoje
    Henderiks, Jorijntje
    Universitetet i Oslo.
    Observations on the life cycle and ecology of Acanthoica quattrospina Lohmann from a Mediterranean estuary2014In: Journal of Nannoplankton Research, ISSN 1210-8049, Vol. 34, no SI, p. 49-56Article in journal (Refereed)
  • 18.
    Šupraha, Luka
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Bosak, Sunčica
    Ljubešić, Zrinka
    Mihanović, Hrvoje
    Olujić, Goran
    Mikac, Iva
    Viličić, Damir
    Cryptophyte bloom in a Mediterranean estuary: High abundance of Plagioselmis cf. prolonga in the Krka River estuary (eastern Adriatic Sea)2014In: Scientia Marina, ISSN 0214-8358, E-ISSN 1886-8134, Vol. 78, no 3, p. 329-338Article in journal (Refereed)
    Abstract [en]

    During the June 2010 survey of phytoplankton and physicochemical parameters in the Krka River estuary (eastern Adriatic Sea), a cryptophyte bloom was observed. High abundance of cryptophytes (maximum 7.9x10(6) cells l(-1)) and high concentrations of the class-specific biomarker pigment alloxanthine (maximum 2312 ng l(-1)) were detected in the surface layer and at the halocline in the lower reach of the estuary. Taxonomical analysis revealed that the blooming species was Plagioselmis cf. prolonga. Analysis of the environmental parameters in the estuary suggested that the bloom was supported by the slower river flow as well as the increased orthophosphate and ammonium concentrations. The first record of a cryptophyte bloom in the Krka River estuary may indicate that large-scale changes are taking place in the phytoplankton community. Such changes could have a major impact on the natural ecosystem dynamics and the mariculture production in the area.

  • 19.
    Šupraha, Luka
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Bosak, Sunčica
    Ljubešić, Zrinka
    Olujić, Goran
    Horvat, Lucija
    Viličić, Damir
    The phytoplankton composition and spatial distribution in the north-eastern Adriatic Channel in autumn 20082011In: Acta Adriatica, ISSN 0001-5113, E-ISSN 1846-0453, Vol. 52, no 1Article in journal (Refereed)
  • 20.
    Šupraha, Luka
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Gerecht, Andrea C.
    Probert, Ian
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    The adaptive strategies of coccolithophores and their biogeochemical implications2016Conference paper (Refereed)
  • 21.
    Šupraha, Luka
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Gerecht, Andrea Cornelia
    Probert, Ian
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Eco-physiological adaptation shapes the response of calcifying algae to nutrient limitation2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, article id 16499Article in journal (Refereed)
    Abstract [en]

    The steady increase in global ocean temperature will most likely lead to nutrient limitation in the photic zone. This will impact the physiology of marine algae, including the globally important calcifying coccolithophores. Understanding their adaptive patterns is essential for modelling carbon production in a low-nutrient ocean. We investigated the physiology of Helicosphaera carteri, a representative of the abundant but under-investigated flagellated functional group of coccolithophores. Two strains isolated from contrasting nutrient regimes (South Atlantic and Mediterranean Sea) were grown in phosphorus-replete and phosphorus-limited batch cultures. While growing exponentially in a phosphorus-replete medium, the Mediterranean strain exhibited on average 24% lower growth rate, 36% larger coccosphere volume and 21% lower particulate inorganic carbon (PIC) production than the Atlantic strain. Under phosphorus limitation, the same strain was capable of reaching a 2.6 times higher cell density than the Atlantic strain due to lower phosphorus requirements. These results suggest that local physiological adaptation can define the performance of this species under nutrient limitation.

  • 22.
    Šupraha, Luka
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Gerecht, Andrea
    Edvardsen, Bente
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Is phosphate availability significant to the morphological diversity within Helicosphaera carteri?2013Conference paper (Other academic)
  • 23.
    Šupraha, Luka
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Gerecht, Andrea
    Probert, Ian
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Strain-specific ecophysiological traits define the response to phosphorus limitation in Helicosphaera carteri2015Conference paper (Other academic)
  • 24.
    Šupraha, Luka
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Ljubešić, Zrinka
    Henderiks, Jorijntje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Combination coccospheres from the eastern Adriatic coast (Mediterranean Sea)2015Conference paper (Other academic)
1 - 24 of 24
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