Enhancement of photosynthetic carbon assimilation efficiency by phytoplankton in the future coastal ocean, supplement to: Kim, Ju Hyoung; Kim, Kwang Young; Kang, Eun Ju; Lee, Kitack; Kim, Ja-Myung; Park, K T; Shin, Kyoungsoon; Hyun, B; Jeong, Hae Jin (2013): Enhancement of photosynthetic carbon assimilation efficiency by phytoplankton in the future coastal ocean. Biogeosciences, 10(11), 7525-7535

• Main Authors: Kim, Ju Hyoung, Kim, Kwang Young, Kang, Eun Ju, Lee, Kitack, Kim, Ja-Myung, Park, K T, Shin, Kyoungsoon, Hyun, B, Jeong, Hae Jin
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2013
• Subjects: Coast and continental shelf; Entire community; Field experiment; Growth/Morphology; Mesocosm or benthocosm; North Pacific; Pelagos; Primary production/Photosynthesis; Temperate; Temperature; Species; Figure; Table; Treatment; Incubation duration; Date; Identification; Chlorophyll a; Nitrate and Nitrite; Phosphate; Silicate; Cell density; Irradiance; Time of day; Effective quantum yield; Electron transport rate, relative; Gross photosynthesis rate, carbon dioxide, per chlorophyll a; Gross community production of carbon dioxide; Gross community production of carbon dioxide, cumulative; Gross community production of carbon dioxide, per chlorophyll a; Maximal electron transport rate, relative; Electron transport rate efficiency; Saturation light intensity; Maximum potential capacity of photosynthesis; Photosynthetic efficiency, carbon production; Grazing rate; Grazing rate, standard deviation; Partial pressure of carbon dioxide water at sea surface temperature wet air; pH; Salinity; Temperature, water; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Carbon, inorganic, dissolved; Alkalinity, total; Aragonite saturation state; Calcite saturation state; Experiment; Fluorometric; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Pacific; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.833260; https://doi.pangaea.de/10.1594/PANGAEA.833260

A mesocosm experiment was conducted to evaluate the effects of future climate conditions on photosynthesis and productivity of coastal phytoplankton. Natural phytoplankton assemblages were incubated in field mesocosms under the ambient condition (present condition: ca. 400 ppmv CO2 and ambient temp.), and two future climate conditions (acidification condition: ca. 900 ppmv CO2 and ambient temp.; greenhouse condition: ca. 900 ppmv CO2 and 3 °C warmer than ambient). Photosynthetic parameters of steady-state light responses curves (LCs; measured by PAM fluorometer) and photosynthesis-irradiance curves (P-I curves; estimated by in situ incorporation of 14C) were compared to three conditions during the experiment period. Under acidification, electron transport efficiency (alpha LC) and photosynthetic 14C assimilation efficiency (alpha) were 10% higher than those of the present condition, but maximum rates of relative electron transport (rETRm,LC) and photosynthetic 14C assimilation (PBmax) were lower than the present condition by about 19% and 7%, respectively. In addition, rETRm,LC and alpha LC were not significantly different between and greenhouse conditions, but PBmax and alpha of greenhouse conditions were higher than those of the present condition by about 9% and 30%, respectively. In particular, the greenhouse condition has drastically higher PBmax and alpha than the present condition more than 60% during the post-bloom period. According to these results, two future ocean conditions have major positive effects on the photosynthesis in terms of energy utilization efficiency for organic carbon fixation through the inorganic carbon assimilation. Despite phytoplankton taking an advantage on photosynthesis, primary production of phytoplankton was not stimulated by future conditions. In particular, biomass of phytoplankton was depressed under both acidification and greenhouse conditions after the the pre-bloom period, and more research is required to suggest that some factors such as grazing activity could be important for regulating phytoplankton bloom in the future ocean. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne et al, 2014) 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 is 2014-06-10.