Ocean Acidification

Baltic Mytilus edulis were kept in a flow through system for 3 month at six different CO2 concentrations ranging from 380 ppm to 4,000 ppm. During the experimental period calcification rates were determined using alkalinity anomaly (δTA) technique after Smith and Key 1975 [1] and shell growth was measured. Calcification rates showed that mussels start to dissolve at values higher than 2,400 ppm. This stands in contrast to Gazeau et al. 2007 [2] who found that mussels dissolved at values higher than ~1800ppm.
At the end of the experiment hemolymph and extrapallial fluid were taken and pH, pCO2 and elemental ratios were measured. Shell composition will be investigated via microprobe and LA-ICP-MS. Further, the dry weight of tissue and lipofuscin accumulation will be determined as an indicator for stress. A second experiment was designed to investigate the combined effects of different CO2 levels (380, 840 and 1,400 ppm) and temperatures (5, 10, 15, 20, 25°C).



Heinemann A, Fietzke J, Hiebenthal C, Thomsen J & Melzner F, 2009. Acidification-sensitivity of M. edulis. Awards Ceremony Speeches and Abstracts of the 19th Annual V.M. Goldschmidt Conference, V.M. Goldschmidt Conference. Geochimica et Cosmochimica Acta 73(13)-1:A514. Supplement.