Publication Date:
2024-03-22
Description:
The oceans' uptake of anthropogenic carbon dioxide (CO2) decreases seawater pH and alters the inorganic carbon speciation – summarized in the term ocean acidification (OA). Already today, coastal regions experience episodic pH events during which surface layer pH drops below values projected for the surface ocean at the end of the century. Future OA is expected to further enhance the intensity of these coastal extreme pH events. To evaluate the influence of such episodic OA events in coastal regions, we deployed eight pelagic mesocosms for 53 days in Raunefjord, Norway, and enclosed 56–61 m**3 of local seawater containing a natural plankton community under nutrient limited post-bloom conditions. Four mesocosms were enriched with CO2 to simulate extreme pCO2 levels of 1978-2069 μatm while the other four served as untreated controls. Here, we present results from multivariate analyses on OA-induced changes in the phyto-, micro-, and mesozooplankton community structure. Pronounced differences in the plankton community emerged early in the experiment, and were amplified by enhanced top-down control throughout the study period. The plankton groups responding most profoundly to high CO2 conditions were cyanobacteria (negative), chlorophyceae (negative), auto- and heterotrophic microzooplankton (negative), and a variety of mesozooplanktonic taxa, including copepoda (mixed), appendicularia (positive), hydrozoa (positive), fish larvae (positive), and gastropoda (negative). The restructuring of the community coincided with significant changes in the concentration and elemental stoichiometry of particulate organic matter. Results imply that extreme CO2 events can lead to a substantial reorganization of the planktonic food web, affecting multiple trophic levels from phytoplankton to primary and secondary consumers.
Keywords:
Alkalinity, total; Alkalinity, total, standard deviation; Ammonium; Aragonite saturation state; Aragonite saturation state, standard deviation; Bicarbonate ion; Bicarbonate ion, standard deviation; Biogenic silica; Biomass/Abundance/Elemental composition; Calcite saturation state; Calcite saturation state, standard deviation; Calculated using seacarb; Calculated using seacarb after Nisumaa et al. (2010); Calculated using seacarb after Orr et al. (2018); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbon, organic, particulate; Carbon, organic, particulate/Nitrogen, organic, particulate ratio; Carbon, organic, particulate/Phosphorus, particulate ratio; Carbon, total, particulate; Carbonate ion; Carbonate ion, standard deviation; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, standard deviation; Chlorophyceae indeterminata, biomass as carbon; Chlorophyll a; Chlorophyll a, standard deviation; Chrysophyceae indeterminata, biomass as carbon; Coast and continental shelf; Community composition and diversity; Cryptophyceae indeterminata, biomass as carbon; Cyanophyceae, biomass as carbon; DATE/TIME; Day of experiment; Diatoms indeterminata, biomass as carbon; Dinophyceae indeterminata, biomass as carbon; Entire community; Event label; Field experiment; Fjord; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Fugacity of carbon dioxide in seawater, standard deviation; KOSMOS_2015; KOSMOS_2015_Mesocosm-M1; KOSMOS_2015_Mesocosm-M2; KOSMOS_2015_Mesocosm-M3; KOSMOS_2015_Mesocosm-M4; KOSMOS_2015_Mesocosm-M5; KOSMOS_2015_Mesocosm-M6; KOSMOS_2015_Mesocosm-M7; KOSMOS_2015_Mesocosm-M8; KOSMOS_2015_Mesocosm-M9; KOSMOS Bergen; MESO; Mesocosm experiment; Mesocosm label; Mesocosm or benthocosm; Nitrate; Nitrate and Nitrite; Nitrite; Nitrogen, organic, particulate; Nitrogen, organic, particulate/Phosphorus, organic, particulate ratio; Nitrogen, total, particulate; North Atlantic; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Particulate inorganic carbon/particulate organic carbon ratio; Pelagos; pH; pH, standard deviation; Phosphate; Phosphate, total, particulate; Potentiometric titration; Prasinophyceae indeterminata, biomass as carbon; Primary production/Photosynthesis; Prymnesiophyceae indeterminata, biomass as carbon; Ratio; Salinity; Salinity, standard deviation; Silicate; Temperate; Temperature, water; Temperature, water, standard deviation; Type
Type:
Dataset
Format:
text/tab-separated-values, 18566 data points
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