Publication Date:
2024-03-15
Description:
The ongoing increase in surface seawater CO2 level could potentially impact phytoplankton primary production in coastal waters; however, CO2 sensitivity studies on tropical coastal phytoplankton assemblages are rare. The present study investigated the interactive impacts of variable CO2 level, light and zinc addition on the diatom dominated phytoplankton assemblages from the western coastal Bay of Bengal. Increased CO2supply enhanced particulate organic matter (POC) production; a concomitant depletion in δ13CPOM values at elevated CO2 suggested increased CO2 diffusive influx inside the cell. Trace amount of Zn added under low CO2 level accelerated growth probably by accelerating Zn-Carbonic Anhydrase activity which helps in converting bicarbonate ion to CO2. Almost identical values of delta 13CPOM in the low CO2 treated cells grown with and without Zn indicated a low discrimination between 13C and 12C probably due to bicarbonate uptake. These evidences collectively indicated the existence of the carbon concentration mechanisms (CCMs) at low CO2. A minimum growth rate was observed at low CO2 and light limited condition indicating light dependence of CCMs activity. Upon the increase of light and CO2 level, growth response was maximum. The cells grown in the low CO2 levels showed higher light stress (higher values of both diatoxanthin index and the ratio of photo-protective to light-harvesting pigments) that was alleviated by both increasing CO2 supply and Zn addition (probably by efficient light energy utilization in presence of adequate CO2). This is likely that the diatom dominated phytoplankton communities benefited from the increasing CO2 supply and thus may enhance primary production in response to any further increase in coastal water CO2 levels and can have large biogeochemical consequences in the study area.
Keywords:
Abundance; Alkalinity, total; Alkalinity, total, standard deviation; Aragonite saturation state; Bicarbonate ion; Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria (〈20 L); Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbon, organic, particulate; Carbon/Nitrogen ratio; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Change; Change, standard deviation; Chlorophyll a; Chlorophyll a, standard deviation; Chlorophyll a/particulate organic carbon ratio; Coast and continental shelf; Community composition and diversity; Diatoxanthin index; Diatoxanthin index, standard deviation; Entire community; EXP; Experiment; Experiment duration; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Growth/Morphology; Growth rate; Indian Ocean; Irradiance; Irradiance, standard deviation; Laboratory experiment; Light; Local Time; Micro-nutrients; Nitrogen, inorganic, dissolved; Nitrogen, inorganic, dissolved, standard deviation; Nitrogen, organic, particulate; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; pH; pH, standard deviation; Phosphate; Phosphate, standard deviation; Pigments, light harvesting; Pigments, light harvesting, standard deviation; Pigments, photo-protective; Pigments, photo-protective, standard deviation; Pigments, photo-protective/light harvesting ratio; Pigments, photo-protective/light harvesting ratio, standard deviation; Pigments, total; Pigments, total, standard deviation; Primary production/Photosynthesis; Salinity; Silicate; Silicate, standard deviation; Species; Temperature, water; Time point, descriptive; Treatment; Tropical; Type; Visakhapatnam_coast; δ13C, particulate organic carbon
Type:
Dataset
Format:
text/tab-separated-values, 3913 data points
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