Limacina helicina shell dissolution due to ocean acidification in the California Current Ecosystem from 2011-08-11 to 2013-08-29 (NCEI Accession 0155173)

Pteropod shell dissolution was determined on shells collected from 16 stations for the 2011 cruise and 20 stations during the 2013 cruise. The samples were stored in 90% buffered ethanol. Between 15 to 30 pteropods of Limacina helicina were picked from samples selected randomly. Following the methods described in Bednarsek et al. (2012), shells were repeatedly washed with distilled water before being subjected to chemical shell dehydration, followed by a plasma etching procedure for periostracum removal. All treated shells were analyzed for shell dissolution using a scanning electron microscope (SEM) and identified for the presence of dissolution patterns and the type of more severe types of shell dissolution (Type II and Type III). Following the categorization scheme outlined in Bednarsek et al. (2012), Type II dissolution indicates deeper penetrating dissolution that precedes Type III, which affects large parts of shell crystalline structure, making shells less compact and more fragile. The data files show the percentage of individuals with Type II or Type III shell dissolution in relation to integrated omega saturation state in the upper100 m for each sampled station. For 2011, we also have data on the abundance of pteropods (ind m-2) in relation to integrated omega saturation state.