Elements and Isotopes of cultured Serpulid (Spirorbis spirorbis) calcareous shells in Benthocosm System

S. spirorbis were cultured in a benthocosms facility for subsequent treatments: Ambient pCO2 (380 – 400 µatm) and temperature (‘Control’), 1100 µatm pCO2 (‘+CO2’) or +5°C temperature (‘+T’), and the combination of both elevated pCO2 and temperature (‘+CO2+T’). Each treatment has three replicates. After about 11 weeks of incubation for each seasonal experiment (spring, summer, autumn and winter experiments), we analyzed the bulk carbonate fraction of S. spirorbis samples, element ratios: Mg/Ca, Li/Ca, Sr/Ca, Ba/Ca, and Li/Mg, and stable isotopes: d13C, d18O, d44/40Ca in each treatment, included in this dataset. Water chemistry and element distribution coefficients are also included. Carbon and oxygen stable isotopes measured using bleached and unbleached samples are shown in this dataset.