Mesozooplankton community development at elevated CO2

• Main Authors: Niehoff, Barbara, Schmithüsen, Tosia, Knüppel, Nadine, Daase, M, Czerny, Jan, Boxhammer, Tim
• Format: Dataset
• Language: English
• Published: PANGAEA 2013
• Subjects: Acartia longiremis; Alkalinity; total; Aragonite saturation state; Arctic; Bicarbonate ion; BIOACID; Biological Impacts of Ocean Acidification; Biological sample; Biomass/Abundance/Elemental composition; BIOS; Bivalvia; Calanus sp.; female; Calanus spp.; c1; c2; c3; c4; c5; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; partial pressure; Cirripedia; cypris; nauplii; Coast and continental shelf; Copepoda; DATE/TIME; Entire community; Euphausiidae; Experiment day; Field experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Gastropoda; Kongsfjorden; Spitsbergen; Kongsfjord*; Ocean acidification; Svalbard; Copepods
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.845541; https://doi.org/10.1594/PANGAEA.845541

The increasing CO2 concentration in the atmosphere caused by burning fossil fuels leads to increasing pCO2 and decreasing pH in the world ocean. These changes may have severe consequences for marine biota, especially in cold-water ecosystems due to higher solubility of CO2. However, studies on the response of mesozooplankton communities to elevated CO2 are still lacking. In order to test whether abundance and taxonomic composition change with pCO2, we have sampled nine mesocosms, which were deployed in Kongsfjorden, an Arctic fjord at Svalbard, and were adjusted to eight CO2 concentrations, initially ranging from 185 µatm to 1420 µatm. Vertical net hauls were taken weekly over about one month with an Apstein net (55 µm mesh size) in all mesocosms and the surrounding fjord. In addition, sediment trap samples, taken every second day in the mesocosms, were analysed to account for losses due to vertical migration and mortality. The taxonomic analysis revealed that meroplanktonic larvae (Cirripedia, Polychaeta, Bivalvia, Gastropoda, and Decapoda) dominated in the mesocosms while copepods (Calanus spp., Oithona similis, Acartia longiremis and Microsetella norvegica) were found in lower abundances. In the fjord copepods prevailed for most of our study. With time, abundance and taxonomic composition developed similarly in all mesocosms and the pCO2 had no significant effect on the overall community structure. Also, we did not find significant relationships between the pCO2 level and the abundance of single taxa. Changes in heterogeneous communities are, however, difficult to detect, and the exposure to elevated pCO2 was relatively short. We therefore suggest that future mesocosm experiments should be run for longer periods.