Seawater carbonate chemistry, chlorophyll a and photosynthetic carbon fixation rate under different light and pCO2 conditions during experiments, 2010
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| Format: | Dataset Open Access |
| Language: | en |
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PANGAEA
2010
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| _version_ | 1867172038466076672 |
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| author | Wu, YaPing Gao, Kunshan |
| author_facet | Wu, YaPing Gao, Kunshan |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | We carried out short term pCO2/pH perturbation experiments in the coastal waters of the South China Sea to evaluate the combined effects of seawater acidification (low pH/high pCO2) and solar UV radiation (UVR, 280–400 nm) on photosynthetic carbon fixation of phytoplankton assemblages. Under photosynthetically active radiation (PAR) alone treatments, reduced pCO2 (190 ppmv) with increased pH resulted in a significant decrease in the photosynthetic carbon fixation rate (about 23%), while enriched pCO2 (700 ppmv) with lowered pH had no significant effect on the photosynthetic performance compared to the ambient level. The apparent photosynthetic efficiency decreased under the reduced pCO2 level, probably due to C-limitation as well as energy being diverged for up-regulation of carbon concentrating mechanisms (CCMs). In the presence of UVR, both UV-A and UV-B caused photosynthetic inhibition, though UV-A appeared to enhance the photosynthetic efficiency under lower PAR levels. UV-B caused less inhibition of photosynthesis under the reduced pCO2 level, probably because of its contribution to the inorganic carbon (Ci)-acquisition processes. Under the seawater acidification conditions (enriched pCO2), both UV-A and UV-B reduced the photosynthetic carbon fixation to higher extents compared to the ambient pCO2 conditions. We conclude that solar UV and seawater acidification could synergistically inhibit photosynthesis. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_758215 |
| institution | PANGAEA |
| language | en |
| publishDate | 2010 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Seawater carbonate chemistry, chlorophyll a and photosynthetic carbon fixation rate under different light and pCO2 conditions during experiments, 2010 Wu, YaPing Gao, Kunshan Alkalinity, total; Aragonite saturation state; Bicarbonate; Bicarbonate ion; Bicarbonate ion, standard deviation; Calcite saturation state; Calculated; Calculated, see reference(s); Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, inorganic, total, standard deviation; Carbon, total; Carbonate ion; Carbonate ion, standard deviation; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, standard deviation; Carbon dioxide, total; Chlorophyll a; Experimental treatment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Julian day; Light saturation point; Light saturation point, standard deviation; Liquid scintillation; Maximum potential photosynthesis; Maximum potential photosynthesis, standard deviation; Measured; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH, NBS scale; pH, standard deviation; pH, total scale; pH meter (Orion); Photochemical efficiency; Photochemical efficiency, standard deviation; Photosynthetic carbon fixation rate; Photosynthetic carbon fixation rate, standard deviation; Radiation, photosynthetically active; Salinity; Spectrophotometry; Temperature, water; Total organic analyzer (TOC 5000A Shimazdu) We carried out short term pCO2/pH perturbation experiments in the coastal waters of the South China Sea to evaluate the combined effects of seawater acidification (low pH/high pCO2) and solar UV radiation (UVR, 280–400 nm) on photosynthetic carbon fixation of phytoplankton assemblages. Under photosynthetically active radiation (PAR) alone treatments, reduced pCO2 (190 ppmv) with increased pH resulted in a significant decrease in the photosynthetic carbon fixation rate (about 23%), while enriched pCO2 (700 ppmv) with lowered pH had no significant effect on the photosynthetic performance compared to the ambient level. The apparent photosynthetic efficiency decreased under the reduced pCO2 level, probably due to C-limitation as well as energy being diverged for up-regulation of carbon concentrating mechanisms (CCMs). In the presence of UVR, both UV-A and UV-B caused photosynthetic inhibition, though UV-A appeared to enhance the photosynthetic efficiency under lower PAR levels. UV-B caused less inhibition of photosynthesis under the reduced pCO2 level, probably because of its contribution to the inorganic carbon (Ci)-acquisition processes. Under the seawater acidification conditions (enriched pCO2), both UV-A and UV-B reduced the photosynthetic carbon fixation to higher extents compared to the ambient pCO2 conditions. We conclude that solar UV and seawater acidification could synergistically inhibit photosynthesis. |
| title | Seawater carbonate chemistry, chlorophyll a and photosynthetic carbon fixation rate under different light and pCO2 conditions during experiments, 2010 |
| topic | Alkalinity, total; Aragonite saturation state; Bicarbonate; Bicarbonate ion; Bicarbonate ion, standard deviation; Calcite saturation state; Calculated; Calculated, see reference(s); Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, inorganic, total, standard deviation; Carbon, total; Carbonate ion; Carbonate ion, standard deviation; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, standard deviation; Carbon dioxide, total; Chlorophyll a; Experimental treatment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Julian day; Light saturation point; Light saturation point, standard deviation; Liquid scintillation; Maximum potential photosynthesis; Maximum potential photosynthesis, standard deviation; Measured; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH, NBS scale; pH, standard deviation; pH, total scale; pH meter (Orion); Photochemical efficiency; Photochemical efficiency, standard deviation; Photosynthetic carbon fixation rate; Photosynthetic carbon fixation rate, standard deviation; Radiation, photosynthetically active; Salinity; Spectrophotometry; Temperature, water; Total organic analyzer (TOC 5000A Shimazdu) |
| url | https://doi.org/10.1594/PANGAEA.758215 |