Publication Date:
2024-03-15
Description:
The effect of ocean warming and acidification was investigated on a natural plankton assemblage from an oligotrophic area, the bay of Villefranche (NW Mediterranean Sea). The assemblage was sampled in March 2012 and exposed to the following four treatments for 12 days: control ( 360 µatm, 14°C), elevated pCO2 ( 610 µatm, 14°C), elevated temperature ( 410 µatm, 17°C), and elevated pCO2 and temperature ( 690 µatm, 17°C). Nutrients were already depleted at the beginning of the experiment and the concentrations of chlorophyll a (chl a), heterotrophic prokaryotes and viruses decreased, under all treatments, throughout the experiment. There were no statistically significant effects of ocean warming and acidification, whether in isolation or combined, on the concentrations of nutrients, particulate organic matter, chl a and most of the photosynthetic pigments. Furthermore, 13C labelling showed that the carbon transfer rates from 13C-sodium bicarbonate into particulate organic carbon were not affected by seawater warming nor acidification. Rates of gross primary production followed the general decreasing trend of chl a concentrations and were significantly higher under elevated temperature, an effect exacerbated when combined to elevated pCO2 level. In contrast to the other algal groups, the picophytoplankton population (cyanobacteria, mostly Synechococcus) increased throughout the experiment and was more abundant in the warmer treatment though to a lesser extent when combined to high pCO2 level. These results suggest that under nutrient-depleted conditions in the Mediterranean Sea, ocean acidification has a very limited impact on the plankton community and that small species will benefit from warming with a potential decrease of the export and energy transfer to higher trophic levels.
Keywords:
19-Butanoyloxyfucoxanthin; 19-Hexanoyloxyfucoxanthin; Alkalinity, total; Alloxanthin; Aragonite saturation state; Bacteria; Bicarbonate ion; Biomass/Abundance/Elemental composition; Bottle number; Bottles or small containers/Aquaria (〈20 L); Calcite saturation state; Calculated using seacarb; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, organic, dissolved; Carbon, organic, particulate; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Carotene; Chlorophyll a; Chlorophyll b; Chlorophyll c1+c2; Chlorophyll c3; Coast and continental shelf; Coulometric titration; DATE/TIME; Day of experiment; Diadinoxanthin; Diatoxanthin; Element analyser CHN; Entire community; EXP; Experiment; Flow cytometry; Fucoxanthin; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Gross community production of oxygen; Gross community production of oxygen, standard error; Gross primary production, 18O; High Performance Liquid Chromatography (HPLC); Irradiance; Laboratory experiment; Mediterranean Sea; Mediterranean Sea Acidification in a Changing Climate; MedSeA; Nanoprokaryotes; Neoxanthin; Net community production, carbon dioxide; Net community production of oxygen; Net community production of oxygen, standard error; Nitrogen, inorganic, dissolved; Nitrogen, organic, particulate; OA-ICC; Ocean Acidification International Coordination Centre; Other event; Oxygen; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; Peridinin; pH; Phaeophytin a; Phosphorus, inorganic, dissolved; Picoeukaryotes, autotrophic; Potentiometric titration; Prasinoxanthin; Primary production/Photosynthesis; Prochlorococcus; Respiration; Respiration rate, oxygen; Respiration rate, oxygen, standard error; Salinity; Silicate; Spectrophotometric; Synechococcus; Temperate; Temperature; Temperature, water; Titration, Winkler; Treatment; Villefranche-2012; Violaxanthin; Viral abundance; Virus, high DNA fluorescence; Virus, low DNA fluorescence; Virus, medium DNA fluorescence; Zeaxanthin; Δδ13C; δ13C, dissolved inorganic carbon; δ13C, particulate organic carbon
Type:
Dataset
Format:
text/tab-separated-values, 3443 data points
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