Seawater carbonate chemistry, pigments and proteins during experiments with phytoplankton, 2010, supplement to: Hopkinson, Brian A; Xu, Yan; Shi, Dalin; McGinn, Patrick J; Morel, Francois M M (2010): The effect of CO2 on the photosynthetic physiology of phytoplankton in the Gulf of Alaska. Limnology and Oceanography, 55(5), 2011-2024

• Main Authors: Hopkinson, Brian A, Xu, Yan, Shi, Dalin, McGinn, Patrick J, Morel, Francois M M
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2010
• Subjects: Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria <20 L; Entire community; Laboratory experiment; Micro-nutrients; North Pacific; Open ocean; Pelagos; Temperate; Experimental treatment; Time, incubation; Salinity; Temperature, water; pH; pH, standard deviation; Carbon, inorganic, dissolved; Nitrate; Phosphate; Silicon; Carbonate system computation flag; Carbon dioxide; Partial pressure of carbon dioxide water at sea surface temperature wet air; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Alkalinity, total; Aragonite saturation state; Calcite saturation state; Chlorophyll a; Chlorophyll a, standard deviation; Fucoxanthin; Fucoxanthin, standard deviation; 19-Butanoyloxyfucoxanthin; 19-Butanoyloxyfucoxanthin, standard deviation; 19-Hexanoyloxyfucoxanthin; 19-Hexanoyloxyfucoxanthin, standard deviation; Chlorophyll b; Chlorophyll b, standard deviation; Photosynthetic protein PsbA; Photosynthetic protein PsbA standard deviation; Photosynthetic protein cytochrome b6f; Photosynthetic protein cytochrome b6f standard deviation; Photosynthetic protein PsbC; Photosynthetic protein PsbC standard deviation; pH meter Oakton; Colorimetry; Calculated using seacarb after Nisumaa et al. 2010; Fluorometry; High Performance Liquid Chromatography HPLC; see references; European network of excellence for Ocean Ecosystems Analysis EUR-OCEANS; European Project on Ocean Acidification EPOCA; Ocean Acidification International Coordination Centre OA-ICC; Gulf of Alaska; Pacific; Ocean acidification; Alaska
• Online Access: https://dx.doi.org/10.1594/pangaea.758071; https://doi.pangaea.de/10.1594/PANGAEA.758071

In the high-nutrient, low-chlorophyll waters of the Gulf of Alaska, microcosm manipulation experiments were used to assess the effect of CO2 on growth and primary production under iron-limited and iron-replete conditions. As expected, iron had a strong effect on growth and photosynthesis. A modest and variable stimulation of growth and biomass production by CO2 (high CO2: 77-122 Pa; low CO2: 11-17 Pa) was observed under both iron-replete and iron-limited conditions, though near the limit of precision of our measurements in slow-growing low-iron experiments. Physiological acclimations responsible for the changes in growth were assessed. Under iron-limited conditions, growth stimulation at high CO2 appeared to result from an increase in photosynthetic efficiency, which we attribute to energy savings from down-regulation of the carbon concentrating mechanisms. In some cases, iron-rich photosynthetic proteins (PsbA, PsaC, and cytochrome b6) were down-regulated at elevated CO2in iron-limited controls. Under iron-replete conditions, there was an increase in growth rate and biomass at high CO2 in some experiments. This increase was unexpectedly supported by reductions in cellular carbon loss, most likely decreased respiration. We speculate that this effect may be due to acclimation to decreased pH rather than high CO2. The variability in responses to CO2 among experiments did not appear to be caused by differences in phytoplankton community structure and may reflect the sensitivity of the net response of phytoplankton to antagonistic effects of the several parameters that co-vary with CO2. : 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).