Biotic and abiotic parameters and cynobacteria abundance during an experimental set-up with varying pCO2 conditions ...

• Main Authors: Wannicke, Nicola, Endres, Sonja, Engel, Anja, Grossart, Hans-Peter, Unger, Juliane, Voss, Maren
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2012
• Subjects: Biological Impacts of Ocean Acidification BIOACID; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.792919; https://doi.pangaea.de/10.1594/PANGAEA.792919

Heterocystous cyanobacteria of the genus Nodularia form extensive blooms in the Baltic Sea and contribute substantially to the total annual primary production. Moreover, they dispense a large fraction of new nitrogen to the ecosystem when inorganic nitrogen concentration in summer is low. Thus, it is of ecological importance to know how Nodularia will react to future environmental changes, in particular to increasing carbon dioxide (CO2) concentrations and what consequences there might arise for cycling of organic matter in the Baltic Sea. Here, we determined carbon (C) and dinitrogen (N2) fixation rates, growth, elemental stoichiometry of particulate organic matter and nitrogen turnover in batch cultures of the heterocystous cyanobacterium Nodularia spumigena under low (median 315 µatm), mid (median 353 µatm), and high (median 548 µatm) CO2 concentrations. Our results demonstrate an overall stimulating effect of rising pCO2 on C and N2 fixation, as well as on cell growth. An increase in pCO2 during ... : The experimental set-up was prepared by ageing 1000 l of seawater which had been sampled in the open Baltic Sea (54.22749°N, 12.1748°E, salinity of 9.1 psu) four months before the start of the experiment. ...