Seawater carbonate chemistry and processes during experiments with marine mussel, Mytilus galloprovincialis, 2005, supplement to: Michaelidis, Basile; Ouzounis, Christos; Paleras, Andreas; Pörtner, Hans-Otto (2005): Effects of long-term moderate hypercapnia on acid–base balance and growth rate in marine mussels Mytilus galloprovincialis. Marine Ecology Progress Series, 293, 109-118

• Main Authors: Michaelidis, Basile, Ouzounis, Christos, Paleras, Andreas, Pörtner, Hans-Otto
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2005
• Subjects: Acid-base regulation; Animalia; Benthic animals; Benthos; Coast and continental shelf; Containers and aquaria 20-1000 L or < 1 m**2; Growth/Morphology; Laboratory experiment; Mediterranean Sea; Mollusca; Mytilus galloprovincialis; Other metabolic rates; Respiration; Single species; Temperate; Experimental treatment; Experiment day; Salinity; Temperature, water; pH; Partial pressure of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Calcium; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Carbonate ion; Carbon, inorganic, dissolved; Alkalinity, total; Aragonite saturation state; Calcite saturation state; Shell length; Oxygen consumption; Ammonia release; Experiment; Calculated; Calculated using seacarb after Nisumaa et al. 2010; Calculated, see references; Calculated using CO2SYS; Measured; Homogenate method developed by Pörtner et al 1990; pH, Electrode; European network of excellence for Ocean Ecosystems Analysis EUR-OCEANS; European Project on Ocean Acidification EPOCA; Ocean Acidification International Coordination Centre OA-ICC; Andreas; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.727746; https://doi.pangaea.de/10.1594/PANGAEA.727746

In the context of future scenarios of progressive accumulation of anthropogenic CO2 in marine surface waters, the present study addresses the effects of long-term hypercapnia on a Mediterranean bivalve, Mytilus galloprovincialis. Sea-water pH was lowered to a value of 7.3 by equilibration with elevated CO2 levels. This is close to the maximum pH drop expected in marine surface waters during atmosextracellular pHric CO2 accumulation. Intra- and extracellular acid-base parameters as well as changes in metabolic rate and growth were studied under both normocapnia and hypercapnia. Long-term hypercapnia caused a permanent reduction in haemolymph pH. To limit the degree of acidosis, mussels increased haemolymph bicarbonate levels, which are derived mainly from the dissolution of shell CaCO3. Intracellular pH in various tissues was at least partly compensated; no deviation from control values occurred during long-term measurements in whole soft-body tissues. The rate of oxygen consumption fell significantly, indicating a lower metabolic rate. In line with previous reports, a close correlation became evident between the reduction in extracellular pH and the reduction in metabolic rate of mussels during hypercapnia. Analysis of frequency histograms of growth rate revealed that hypercapnia caused a slowing of growth, possibly related to the reduction in metabolic rate and the dissolution of shell CaCO3 as a result of extracellular acidosis. In addition, increased nitrogen excretion by hypercapnic mussels indicates the net degradation of protein, thereby contributing to growth reduction. The results obtained in the present study strongly indicate that a reduction in sea-water pH to 7.3 may be fatal for the mussels. They also confirm previous observations that a reduction in sea-water pH below 7.5 is harmful for shelled molluscs. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne and Gattuso, 2011) 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).