Lithothamnion glaciale mesocosm and field data Each worksheet holds a separate data set: Growth data is a change in mass of individuals kept in mesocosms for 153 (May-September 2016) PAM data (rapid light curves) were collected over 8 months to ensure that individuals were alive in mesocosms and to measure photosynthetic efficiency, saturating irradiance and max electron transport rate between PSII and PSI O2 production incubations took place over day, night, and 24 h period with blank samples over 4 months (March-September) SONDE measurements took place across a range of sites in the fjord to marine environment from Kangersunneq-Ameralik near Nuuk, Greenland. Total alkalinity anomaly measurements were used to determine calcification rates of individuals in mesocosms over the day, night, and 24-h periods (March-September). Mesocosms parameters were measured almost daily to ensure that artificial environments were stable.