Publication Date:
2024-05-22
Description:
Rising atmospheric CO2 concentrations could cause a calcium carbonate subsaturation of Arctic surface waters in the next 20 yr, making these waters corrosive for calcareous organisms. It is presently unknown what effects this will have on Arctic calcifying organisms and the ecosystems of which they are integral components. So far, acidification effects on crustose coralline red algae (CCA) have only been studied in tropical and Mediterranean species. In this work, we investigated calcification rates of the CCA Lithothamnion glaciale collected in northwest Svalbard in laboratory experiments under future atmospheric CO2 concentrations. The algae were exposed to simulated Arctic summer and winter light conditions in 2 separate experiments at optimum growth temperatures. We found a significant negative effect of increased CO2 levels on the net calcification rates of L. glaciale in both experiments. Annual mean net dissolution of L. glaciale was estimated to start at an aragonite saturation state between 1.1 and 0.9 which is projected to occur in parts of the Arctic surface ocean between 2030 and 2050 if emissions follow 'business as usual' scenarios (SRES A2; IPCC 2007). The massive skeleton of CCA, which consist of more than 80% calcium carbonate, is considered crucial to withstanding natural stresses such as water movement, overgrowth or grazing. The observed strong negative response of this Arctic CCA to increased CO2 levels suggests severe threats of the projected ocean acidification for an important habitat provider in the Arctic coastal ocean.
Keywords:
Alkalinity, total; Aragonite saturation state; Arctic; Benthos; Bicarbonate ion; BIOACID; Biological Impacts of Ocean Acidification; Boron; Bottles or small containers/Aquaria (〈20 L); Calcification/Dissolution; Calcification rate; Calcification rate, standard deviation; Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Date; Figure; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Hydroxide ion; Laboratory experiment; Lithothamnion glaciale; Macroalgae; Net calcification rate of calcium carbonate, per individual; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Phosphate; Phosphorus; Plantae; Polar; Potentiometric; Potentiometric titration; Pressure, water; Replicate; Revelle factor; Rhodophyta; Salinity; Season; Silicate; Silicon; Single species; Species; Temperature, water; Treatment; xCO2 (water) at equilibrator temperature (dry air)
Type:
Dataset
Format:
text/tab-separated-values, 8948 data points
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