Direct effects of increased CO2 concentrations in seawater on the net primary production of charophytes in a shallow, coastal, brackish-water ecosystem

• Main Authors: Pajusalu, Liina, Martin, Georg, Põllumäe, Arno, Torn, Kaire, Paalme, Tiina
• Format: Dataset
• Language: English
• Published: PANGAEA 2015
• Subjects: Alkalinity; total; Aragonite saturation state; Baltic Sea; Benthos; Bicarbonate ion; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Chara aspera; Chara horrida; Chara tomentosa; Charophyta; Coast and continental shelf; EXP; Experiment; Field experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Identification; Macroalgae; Mesocosm or benthocosm; Net primary production of oxygen; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Plantae; Primary production/Photosynthesis; Registration number of species; Salinity; Single species; Species; Temperate; Temperature; water; Treatment; Type; Uniform resource locator/link to reference; Väike_strait; Boreal Environment Research; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.861372; https://doi.org/10.1594/PANGAEA.861372

Charophytes are found in fresh and brackish waters across the globe and play key roles in coastal ecosystems. However, their response to increasing CO2 is not well understood. The aim of the study was to detect the effects of elevated CO2 on the physiology of charophyte species growing in the brackish Baltic Sea by measuring net primary production. Mesocosm experiments were conducted in the Kõiguste Bay (N Gulf of Riga) during the field season of 2012. Separate mesocosms were maintained at different pCO2 levels: 2000, 1000 and 200 µatm. The experiments were carried out with three species of charophytes: Chara aspera, C. tomentosa and C. horrida. The short-term photosynthetic responses of charophytes to different treatments were measured by the oxygen method. The results show that elevated CO2 levels in brackish water may enhance the photosynthetic activity of charophyte species and suggest that increasing CO2 in the Baltic Sea could have implications for interspecific competition and community structure in a future high CO2 world.