Seawater carbonate chemistry and phytoplankton and eubacterial community compositions in the northwest subarctic Pacific, supplement to: Endo, H; Yoshimura, T; Kataoka, Takafumi; Suzuki, Koji (2013): Effects of CO2 and iron availability on phytoplankton and eubacterial community compositions in the northwest subarctic Pacific. Journal of Experimental Marine Biology and Ecology, 439, 160-175

• Main Authors: Endo, H, Yoshimura, T, Kataoka, Takafumi, Suzuki, Koji
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2013
• Subjects: Bottles or small containers/Aquaria <20 L; Community composition and diversity; Entire community; Laboratory experiment; Micro-nutrients; North Atlantic; Open ocean; Pelagos; Primary production/Photosynthesis; Temperate; Treatment; Incubation duration; DATE/TIME; DEPTH, water; Salinity; Temperature, water; Alkalinity, total; Carbon, inorganic, dissolved; pH; Partial pressure of carbon dioxide water at sea surface temperature wet air; Carbon dioxide; Bicarbonate ion; Carbonate ion; Nitrate; Phosphate; Silicate; Silicon/Nitrogen uptake ratio; Silicon/Nitrogen uptake ratio, standard deviation; Nitrogen/Phosphorus uptake ratio; Nitrogen/Phosphorus uptake ratio, standard deviation; Chlorophyll a; Chlorophyll a, standard deviation; Maximum photochemical quantum yield of photosystem II; Maximum photochemical quantum yield of photosystem II, standard deviation; Fucoxanthin, growth; Fucoxanthin, growth, standard deviation; 19-hexanoyloxyfucoxanthin, growth; 19-Hexanoyloxyfucoxanthin, growth, standard deviation; Diatoms; Haptophytes; Pelagophytes; Chlorophytes; Prasinophytes; Cryptophytes; Dinophytes; Cyanobacteria; Ultraphytoplankton, eukaryptic; Ultraphytoplankton, eukaryptic, standard deviation; Synechococcus spp.; Synechococcus spp., standard deviation; Bacteria, heterotrophic; Bacteria, heterotrophic, standard deviation; Carbonate system computation flag; Fugacity of carbon dioxide water at sea surface temperature wet air; Aragonite saturation state; Calcite saturation state; Water sample; Potentiometric titration; Coulometric titration; Calculated using CO2SYS; Autoanalyzer; Calculated; Pigments, Turner fluorometer; PAM PhytoPAM, Phyto-ED Walz, PPAA0138; High Performance Liquid Chromatography HPLC; CHEMTAX Lewitus et al., 2005; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Pacific; Ocean acidification; Subarctic
• Online Access: https://dx.doi.org/10.1594/pangaea.820333; https://doi.pangaea.de/10.1594/PANGAEA.820333

On-deck CO2-Fe-manipulated incubation experiments were conducted using surface seawater collected from the Western Subarctic Gyre of the NW Pacific in the summer of 2008 to elucidate the impacts of ocean acidification and Fe enrichment on the abundance and community composition of phytoplankton and eubacteria in the study area. During the incubation, excluding the initial period, the mean partial pressures of CO2 in non-Fe-added bottles were 230, 419, 843, and 1124 µatm, whereas those in Fe-added treatments were 152, 394, 791, and 1008 µatm. Changes in the abundance and community composition of phytoplankton were estimated using HPLC pigment signatures with the program CHEMTAX and flow cytometry. A DGGE fingerprint technique targeting 16S rRNA gene fragments was also used to estimate changes in eubacterial phylotypes during incubation. The Fe addition induced diatom blooms, and subsequently stimulated the growth of heterotrophic bacteria such as Roseobacter, Phaeobacter, and Alteromonas in the post-bloom phase. In both the Fe-limited and Fe-replete treatments, concentrations of 19'-hexanoyloxyfucoxanthin, a haptophyte marker, and the cell abundance of coccolithophores decreased at higher CO2 levels (750 and 1000 ppm), whereas diatoms exhibited little response to the changes in CO2 availability. The abundances of Synechococcus and small eukaryotic phytoplankton (<10 µm) increased at the higher CO2 levels. DGGE band positions revealed that Methylobacterium of Alphaproteobacteria occurred solely at lower CO2 levels (180 and 380 ppm) during the post-bloom phase. These results suggest that increases in CO2 level could affect not only the community composition of phytoplankton but also that of eubacteria. As these microorganisms play critical roles in the biological carbon pump and microbial loop, our results indicate that the progression of ocean acidification can alter the biogeochemical processes in the study area. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne and Gattuso, 2011) 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 2013-10-13.