Data Description

Borchard, C; Engel, A (2014): Experiment: Organic matter exudation by Emiliania huxleyi under simulated future ocean conditions. doi:10.1594/PANGAEA.829883,
Supplement to: Borchard, Corinna; Engel, Anja (2012): Organic matter exudation by Emiliania huxleyi under simulated future ocean conditions. Biogeosciences, 9(8), 3405-3423, doi:10.5194/bg-9-3405-2012
Emiliania huxleyi (strain B 92/11) was exposed to different nutrient supply, CO2 and temperature conditions in phosphorus controlled chemostats to investigate effects on organic carbon exudation and partitioning between the pools of particulate organic carbon (POC) and dissolved organic carbon (DOC). 14C incubation measurements for primary production (PP) and extracellular release (ER) were performed. Chemical analysis included the amount and composition of high molecular weight (>1 kDa) dissolved combined carbohydrates (HMW-dCCHO), particulate combined carbohydrates (pCCHO) and the carbon content of transparent exopolymer particles (TEP-C). Applied CO2 and temperature conditions were 300, 550 and 900 µatm pCO2 at 14 °C, and additionally 900 µatm pCO2 at 18 °C simulating a greenhouse ocean scenario.
Enhanced nutrient stress by reducing the dilution rate (D) from D = 0.3 /d to D = 0.1 /d (D = µ) induced the strongest response in E. huxleyi. At µ = 0.3 /d, PP was significantly higher at elevated CO2 and temperature and DO14C production correlated to PO14C production in all treatments, resulting in similar percentages of extracellular release (PER; (DO14C production/PP) × 100) averaging 3.74 ± 0.94%. At µ = 0.1 /d, PO14C production decreased significantly, while exudation of DO14C increased. Thus, indicating a stronger partitioning from the particulate to the dissolved pool. Maximum PER of 16.3 ± 2.3% were observed at µ = 0.1 /d at elevated CO2 and temperature.
While cell densities remained constant within each treatment and throughout the experiment, concentrations of HMW-dCCHO, pCCHO and TEP were generally higher under enhanced nutrient stress. At µ= 0.3 /d, pCCHO concentration increased significantly with elevated CO2 and temperature. At µ = 0.1 /d, the contribution (mol % C) of HMW-dCCHO to DOC was lower at elevated CO2 and temperature while pCCHO and TEP concentrations were higher. This was most pronounced under greenhouse conditions. Our findings suggest a stronger transformation of primary produced DOC into POC by coagulation of exudates under nutrient limitation. Our results further imply that elevated CO2 and temperature will increase exudation by E. huxleyi and may affect organic carbon partitioning in the ocean due to an enhanced transfer of HMW-dCCHO to TEP by aggregation processes.
Further details:
Lavigne, Héloise; Gattuso, Jean-Pierre (2011): seacarb: seawater carbonate chemistry with R. R package version 2.4. *
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). The date of carbonate chemistry calculation by seacarb is 2014-02-11.
#NameShort NameUnitPrincipal InvestigatorMethodComment
1Species *SpeciesBorchard, Corinna *
2Replicate *ReplicateBorchard, Corinna *
3Treatment *TreatmBorchard, Corinna *
4Growth rate *µ1/dayBorchard, Corinna *
5Exudation as determined by 14C DOC production *Exud 14C DOCµmol/l/dayBorchard, Corinna *
6Primary production of POC as determined by 14C POC production *PP 14C POCµmol/l/dayBorchard, Corinna *
7Primary production of carbon per day *PP Cµmol/l/dayBorchard, Corinna *
8Extracellular release *Extrac rel%Borchard, Corinna *
9Carbohydrates, dissolved hydrolyzable *DHCHOµmol/lBorchard, Corinna *
10Carbohydrates, total combined *TCCHOµmol/lBorchard, Corinna *
11Carbohydrates, particulate hydrolyzable *PCCHOµmol/lBorchard, Corinna *
12Fucose *Fucµmol/lBorchard, Corinna *dissolved
13Rhamnose *Rhaµmol/lBorchard, Corinna *dissolved
14Arabinose/galactosamine *Ara/GalNµmol/lBorchard, Corinna *dissolved
15Glucosamine *GlcNµmol/lBorchard, Corinna *dissolved
16Galactose *Galµmol/lBorchard, Corinna *dissolved
17Glucose *Glcµmol/lBorchard, Corinna *dissolved
18Mannose/xylose *Man/Xylµmol/lBorchard, Corinna *dissolved
19Galacturonic acid *GalURAµmol/lBorchard, Corinna *dissolved
20Glucuronic acid *GlcURAµmol/lBorchard, Corinna *dissolved
21Fucose *Fucµmol/lBorchard, Corinna *particulate
22Rhamnose *Rhaµmol/lBorchard, Corinna *particulate
23Arabinose/galactosamine *Ara/GalNµmol/lBorchard, Corinna *particulate
24Glucosamine *GlcNµmol/lBorchard, Corinna *particulate
25Galactose *Galµmol/lBorchard, Corinna *particulate
26Glucose *Glcµmol/lBorchard, Corinna *particulate
27Mannose/xylose *Man/Xylµmol/lBorchard, Corinna *particulate
28Galacturonic acid *GalURAµmol/lBorchard, Corinna *particulate
29Glucuronic acid *GlcURAµmol/lBorchard, Corinna *particulate
30Transparent exopolymer particles *TEPµmol/lBorchard, Corinna *
31Carbon, organic, dissolved *DOCµmol/lBorchard, Corinna *
32Transparent exopolymer particles/particulate organic carbon ratio *TEP/POCBorchard, Corinna *
33Salinity *SalBorchard, Corinna *
34Temperature, water *Temp°CBorchard, Corinna *
35Alkalinity, total *ATµmol/kgBorchard, Corinna *
36pH *pHBorchard, Corinna *NBS scale
37Carbon, inorganic, dissolved *DICµmol/kgBorchard, Corinna *
38Partial pressure of carbon dioxide (water) at sea surface temperature (wet air) *pCO2water_SST_wetµatmBorchard, Corinna *
39Carbon dioxide *CO2µmol/kgBorchard, Corinna *
40Bicarbonate ion *[HCO3]-µmol/kgBorchard, Corinna *
41Carbonate ion *[CO3]2-µmol/kgBorchard, Corinna *
42Calcite saturation state *Omega CalBorchard, Corinna *
43Revelle factor *RBorchard, Corinna *
44Carbonate system computation flag *CSC flagYang, Yan *Calculated using seacarb after Nisumaa et al. (2010) *
45pH *pHYang, Yan *Calculated using seacarb after Nisumaa et al. (2010) *total scale
46Carbon dioxide *CO2µmol/kgYang, Yan *Calculated using seacarb after Nisumaa et al. (2010) *
47Partial pressure of carbon dioxide (water) at sea surface temperature (wet air) *pCO2water_SST_wetµatmYang, Yan *Calculated using seacarb after Nisumaa et al. (2010) *
48Fugacity of carbon dioxide (water) at sea surface temperature (wet air) *fCO2water_SST_wetµatmYang, Yan *Calculated using seacarb after Nisumaa et al. (2010) *
49Bicarbonate ion *[HCO3]-µmol/kgYang, Yan *Calculated using seacarb after Nisumaa et al. (2010) *
50Carbonate ion *[CO3]2-µmol/kgYang, Yan *Calculated using seacarb after Nisumaa et al. (2010) *
51Carbon, inorganic, dissolved *DICµmol/kgYang, Yan *Calculated using seacarb after Nisumaa et al. (2010) *
52Aragonite saturation state *Omega ArgYang, Yan *Calculated using seacarb after Nisumaa et al. (2010) *
53Calcite saturation state *Omega CalYang, Yan *Calculated using seacarb after Nisumaa et al. (2010) *
1269 data points

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