Effect of acidification on an Arctic phytoplankton community from Disko Bay, West Greenland

• Main Authors: Thoisen, Christina, Riisgaard, Karen, Lundholm, Nina, Nielsen, Torkel Gissel, Hansen, Per Juel
• Format: Dataset
• Language: English
• Published: PANGAEA 2015
• Subjects: Alkalinity; total; Aragonite saturation state; Arctic; Bicarbonate ion; standard deviation; Bottles or small containers/Aquaria (<20 L); 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; Chaetoceros sp.; Coulometric titration; Diameter; Entire community; EXP; Experiment; Figure; Frequency; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Growth/Morphology; Growth rate; Laboratory experiment; Navicula granii; Navicula sp.; Navicula vanhoeffenii; OA-ICC; Ocean Acidification International Coordination Centre; Open ocean; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; Percentage; Disko Bay; Greenland; Ocean acidification; Phytoplankton
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.847228; https://doi.org/10.1594/PANGAEA.847228

Long-term measurements (i.e. months) of in situ pH have not previously been reported from the Arctic; this study shows fluctuations between pH 7.5 and 8.3 during the spring bloom 2012 in a coastal area of Disko Bay, West Greenland. The effect of acidification on phytoplankton from this area was studied at both the community and species level in experimental pH treatments within (pH 8.0, 7.7 and 7.4) and outside (pH 7.1) in situ pH. The growth rate of the phytoplankton community decreased during the experimental acidification from 0.50 ± 0.01/day (SD) at pH 8.0 to 0.22 ± 0.01/day at pH 7.1. Nevertheless, the response to acidification was species-specific and divided into 4 categories: I, least affected; II, affected only at pH 7.1; III, gradually affected and IV, highly affected. In addition, the colony size and chain length of selected species were affected by the acidification. Our findings show that coastal phytoplankton from Disko Bay is naturally exposed to pH fluctuations exceeding the experimental pH range used in most ocean acidification studies. We emphasize that studies on ocean acidification should include in situ pH before assumptions on the effect of acidification on marine organisms can be made.