Seawater carbonate chemistry and processes during experiments with cyanobacterium Nodularia spumigena, 2009

• Main Authors: Czerny, Jan, Barcelos e Ramos, Joana, Riebesell, Ulf
• Format: Dataset
• Language: English
• Published: PANGAEA 2009
• Subjects: Acetylene reduction; Alkalinity; total; Aragonite saturation state; Automated segmented-flow analyzer (Quaatro); Bacteria; Bicarbonate ion; Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria (<20 L); Calcite saturation state; Calculated; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; organic; particulate; production per cell; Carbonate ion; Carbon dioxide; Carbon per cell; Cell division rate; Chlorophyll a; Counting from image; Cyanobacteria; Czerny_etal_09; Duration; number of days; Element analyser CNS; EURO EA; EPOCA; EUR-OCEANS; European network of excellence for Ocean Ecosystems Analysis; European Project on Ocean Acidification; EXP; Experiment; Experimental treatment; Fluorometry; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Laboratory experiment; Laboratory strains; Nitrogen; Nitrogen fixation rate; Carbonic acid; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.726862; https://doi.org/10.1594/PANGAEA.726862

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.