Impact of ocean acidification and warming on the Mediterranean mussel (Mytilus galloprovincialis), supplement to: Gazeau, Frédéric; Alliouane, Samir; Bock, Christian; Bramanti, Lorenzo; López Correa, Matthias; Gentile, Miriam; Hirse, Timo; Pörtner, Hans-Otto; Ziveri, Patrizia (2014): Impact of ocean acidification and warming on the Mediterranean mussel (Mytilus galloprovincialis). Frontiers in Marine Science, 1, 62

• Main Authors: Gazeau, Frédéric, Alliouane, Samir, Bock, Christian, Bramanti, Lorenzo, López Correa, Matthias, Gentile, Miriam, Hirse, Timo, Pörtner, Hans-Otto, Ziveri, Patrizia
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2014
• Subjects: Acid-base regulation; Animalia; Benthic animals; Benthos; Calcification/Dissolution; Coast and continental shelf; Containers and aquaria 20-1000 L or < 1 m**2; Growth/Morphology; Laboratory experiment; Mediterranean Sea; Mollusca; Mortality/Survival; Mytilus galloprovincialis; Other metabolic rates; Respiration; Single species; Temperate; Temperature; Species; Figure; Treatment; Date; Mortality; Mortality, standard error; Mass; Mass, standard error; Shell length; Shell length, standard error; Shell, mass; Shell, mass, standard error; Respiration rate, oxygen; Respiration rate, oxygen, standard error; Ammonia excretion; Ammonia excretion, standard error; Net calcification rate of calcium carbonate; Net calcification rate of calcium carbonate, standard error; Haemolymph, pH; Haemolymph, pH, standard error; Extrapallial fluid pH; Extrapallial fluid pH, standard error; Haemolymph, partial pressure of carbon dioxide; Haemolymph, partial pressure of carbon dioxide, standard error; Extrapallial fluid partial pressure of carbon dioxide; Extrapallial fluid partial pressure of carbon dioxide, standard error; Incubation duration; Salinity; Salinity, standard deviation; Alkalinity, total; Alkalinity, total, standard deviation; pH; pH, standard deviation; Temperature, water; Temperature, water, standard deviation; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Carbon, inorganic, dissolved; Aragonite saturation state; Calcite saturation state; Experiment; Potentiometric titration; Potentiometric; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Correa; Gentile; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.843969; https://doi.pangaea.de/10.1594/PANGAEA.843969

In order to assess the effects of ocean acidification and warming on the Mediterranean mussel (Mytilus galloprovincialis), specimens were reared in aquarium tanks and exposed to elevated conditions of temperature (+3°C) and acidity (-0.3 pH units) for a period of 10 months. The whole system comprised a factorial experimental design with 4 treatments (3 aquaria per treatment): control, lowered pH, elevated temperature, and lowered pH/elevated temperature. Mortality was estimated on a weekly basis and every 2 months, various biometrical parameters and physiological processes were measured: somatic and shell growth, metabolic rates and body fluid acid-base parameters. Mussels were highly sensitive to warming, with 100% mortality observed under elevated temperature at the end of our experiment in October. Mortality rates increased drastically in summer, when water temperature exceeded 25°C. In contrast, our results suggest that survival of this species will not be affected by a pH decrease of 0.3 in the Mediterranean Sea. Somatic and shell growth did not appear very sensitive to ocean acidification and warming during most of the experiment, but were reduced, after summer, in the lowered pH treatment. This was consistent with measured shell net dissolution and observed loss of periostracum, as well as uncompensated extracellular acidosis in the lowered pH treatment indicating a progressive insufficiency in acid-base regulation capacity. However, based on the present dataset, we cannot elucidate if these decreases in growth and regulation capacities after summer are a consequence of lower pH levels during that period or a consequence of a combined effect of acidification and warming. To summarize, while ocean acidification will potentially contribute to lower growth rates, especially in summer when mussels are exposed to sub-optimal conditions, ocean warming will likely pose more serious threats to Mediterranean mussels in this region in the coming decades. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2015) 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 2015-03-11.