Iron limitation modulates ocean acidification effects on southern ocean phytoplankton communities ...

• Main Authors: Hoppe, Clara Jule Marie, Hassler, Christel S, Payne, Christopher D, Tortell, Philippe Daniel, Rost, Björn, Trimborn, Scarlett
• Format: Dataset
• Language: English
• Published: PANGAEA 2013
• Subjects: Antarctic; Bottles or small containers/Aquaria <20 L; Community composition and diversity; Entire community; Laboratory experiment; Micro-nutrients; Open ocean; Pelagos; Polar; Primary production/Photosynthesis; Table; Figure; Date; Partial pressure of carbon dioxide water at sea surface temperature wet air; Treatment; Identification; Photosynthetic efficiency; Net primary production of carbon per particulate organic carbon; Chlorophyll a/particulate organic carbon ratio; Effective absorbance cross-section of photosystem II; Non photochemical quenching; Electron transport rate, relative; Species; Percentage; Percentage, standard deviation; Iron, dissolved; Iron, dissolved, standard deviation; Salinity; Temperature, water; Phosphate; Silicate; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Alkalinity, total; Alkalinity, total, standard deviation; pH; pH, standard deviation; Partial pressure of carbon dioxide, standard deviation; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Aragonite saturation state; Calcite saturation state; Coulometric titration; Potentiometric titration; Potentiometric; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Southern Ocean; Weddell; Weddell Sea; Antarc*; Antarctica; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.836013; https://doi.pangaea.de/10.1594/PANGAEA.836013

The potential interactive effects of iron (Fe) limitation and Ocean Acidification in the Southern Ocean (SO) are largely unknown. Here we present results of a long-term incubation experiment investigating the combined effects of CO2 and Fe availability on natural phytoplankton assemblages from the Weddell Sea, Antarctica. Active Chl a fluorescence measurements revealed that we successfully cultured phytoplankton under both Fe-depleted and Fe-enriched conditions. Fe treatments had significant effects on photosynthetic efficiency (Fv/Fm; 0.3 for Fe-depleted and 0.5 for Fe-enriched conditions), non-photochemical quenching (NPQ), and relative electron transport rates (rETR). pCO2 treatments significantly affected NPQ and rETR, but had no effect on Fv/Fm. Under Fe limitation, increased pCO2 had no influence on C fixation whereas under Fe enrichment, primary production increased with increasing pCO2 levels. These CO2-dependent changes in productivity under Fe-enriched conditions were accompanied by a pronounced ... : 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 2014-09-16. ...