Seawater carbonate chemistry and species composition, sinking rate of coastal phytoplankton assemblage

• Main Authors: Feng, Yuanyuan, Chai, Fei, Wells, Mark L, Liao, Yan, Li, Pengfei, Cai, Ting, Zhao, Ting, Fu, Feixue, Hutchins, David A
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2021
• Subjects: Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria <20 L; Coast and continental shelf; Community composition and diversity; Entire community; Laboratory experiment; North Pacific; Other studied parameter or process; Pelagos; Temperate; Temperature; Type; Treatment; Abundance; Ratio; Sinking velocity; Carbon, organic, particulate; Nitrogen, organic, particulate; Phosphorus, organic, particulate; Biogenic silica; Carbon/Nitrogen ratio; Carbon/Phosphorus ratio; Nitrogen/Phosphorus ratio; Carbon/Silicon ratio; Salinity; Temperature, water; pH; pH, standard deviation; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Alkalinity, total; Alkalinity, total, standard deviation; Partial pressure of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide, standard deviation; Bicarbonate ion; Bicarbonate ion, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Calcite saturation state; Calcite saturation state, standard deviation; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, standard deviation; Fugacity of carbon dioxide water at sea surface temperature wet air; Fugacity of carbon dioxide in seawater, standard deviation; Aragonite saturation state; Aragonite saturation state, standard deviation; Experiment; Potentiometric; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. 2010; Calculated using seacarb after Orr et al. 2018; Ocean Acidification International Coordination Centre OA-ICC; Pacific; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.930939; https://doi.pangaea.de/10.1594/PANGAEA.930939

In addition to ocean acidification, a significant recent warming trend in Chinese coastal waters has received much attention. However, studies of the combined effects of warming and acidification on natural coastal phytoplankton assemblages here are scarce. We conducted a continuous incubation experiment with a natural spring phytoplankton assemblage collected from the Bohai Sea near Tianjin. Experimental treatments used a full factorial combination of temperature (7 and 11°C) and pCO2 (400 and 800 ppm) treatments. Results suggest that changes in pCO2 and temperature had both individual and interactive effects on phytoplankton species composition and elemental stoichiometry. Warming mainly favored the accumulation of picoplankton and dinoflagellate biomass. Increased pCO2 significantly increased particulate organic carbon to particulate organic phosphorus (C:P) and particulate organic carbon to biogenic silica (C:BSi) ratios, and decreased total diatom abundance; in the meanwhile, higher pCO2 significantly increased the ratio of centric to pennate diatom abundance. Warming and increased pCO2 both greatly decreased the proportion of diatoms to dinoflagellates. The highest chlorophyll a biomass was observed in the high pCO2, high temperature phytoplankton assemblage, which also had the slowest sinking rate of all treatments. Overall, there were significant interactive effects of increased pCO2 and warming on dinoflagellate abundance, pennate diatom abundance, diatom vs. dinoflagellates ratio and the centric vs. pennate ratio. These findings suggest that future ocean acidification and warming trends may individually and cumulatively affect coastal biogeochemistry and carbon fluxes through shifts in phytoplankton species composition and sinking rates. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2021) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2021-04-30.