Compound-specific carbon isotopes of sitosterol and cholesterol in gutless marine annelids and associated seagrass and porewater

The data set contains compound-specific carbon isotope measurements of the lipid biomarkers sitosterol and cholesterol in the gutless annelids Olavius algarvensis and Olavius ilvae, which were collected from the sediment by scuba diving in the Bay of Sant' Andrea on the Island of Elba in Italy. Further, compound-specific carbon isotopes of sitosterol was measured for the seagrass plants Posidonia oceanica, which were collected at the seagrass meadows from the same site where the gutless annelids were collected. For Posidonia oceanica, leaves and rhizomes were measured separately for their compound-specific δ13C values . Finally, porewater samples were collected near the seagrass meadows and filtered porewater samples were measured for the compound-specific δ13C values of cholesterol and sitosterol as well.