Villefranche sur Mer: multistressors experiment March 2012, supplement to: Maugendre, Laure; Gattuso, Jean-Pierre; Louis, Justine; de Kluijver, Anna; Marro, Sophie; Soetaert, Karline; Gazeau, Frédéric (2014): Effect of ocean warming and acidification on a plankton community in the NW Mediterranean Sea. ICES Journal of Marine Science

• Main Authors: Maugendre, Laure, Gattuso, Jean-Pierre, Louis, Justine, Anna, de Kluijver, Marro, Sophie, Soetaert, Karline, Gazeau, Frédéric, Dufour, Aurélie
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2015
• Subjects: Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria <20 L; Coast and continental shelf; Entire community; Laboratory experiment; Mediterranean Sea; Pelagos; Primary production/Photosynthesis; Respiration; Temperate; Temperature; Other event; Treatment; Day of experiment; DATE/TIME; Bottle number; Temperature, water; Oxygen; Irradiance; Salinity; Carbon, inorganic, dissolved; Alkalinity, total; Carbonate system computation flag; pH; Partial pressure of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Aragonite saturation state; Calcite saturation state; Carbon, organic, dissolved; Nitrogen, inorganic, dissolved; Phosphorus, inorganic, dissolved; Silicate; Nitrogen, organic, particulate; Carbon, organic, particulate; Chlorophyll c3; Chlorophyll c1+c2; Peridinin; 19-Butanoyloxyfucoxanthin; Fucoxanthin; Neoxanthin; Prasinoxanthin; Violaxanthin; 19-Hexanoyloxyfucoxanthin; Diadinoxanthin; Alloxanthin; Diatoxanthin; Zeaxanthin; Chlorophyll b; Chlorophyll a; Phaeophytin a; Carotene; Virus; Virus, low DNA fluorescence; Virus, medium DNA fluorescence; Virus, high DNA fluorescence; Synechococcus; Picoeukaryotes, autotrophic; Bacteria; Prochlorococcus; Nanoprokaryotes; Net community production of oxygen; Net community production of oxygen, standard error; Respiration rate, oxygen; Respiration rate, oxygen, standard error; Gross community production of oxygen; Gross community production of oxygen, standard error; Gross primary production, 18O; Net community production of carbon dioxide; δ13C, dissolved inorganic carbon; Δδ13C; δ13C, particulate organic carbon; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Experiment; Titration, Winkler; Coulometric titration; Potentiometric titration; Calculated using seacarb; Spectrophotometric; Element analyser CHN; High Performance Liquid Chromatography HPLC; Flow cytometry; Calculated using seacarb after Nisumaa et al. 2010; Mediterranean Sea Acidification in a Changing Climate MedSeA; Ocean Acidification International Coordination Centre OA-ICC; Laure; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.834159; https://doi.pangaea.de/10.1594/PANGAEA.834159

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. : 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 2014-07-22.