Calcification, respiration and photosynthesis of the widespread diatom-bearing Larger benthic foraminifer Operculina ammonoides were measured in laboratory experiments that included manipulation of carbonate chemistry parameters. pH was altered while keeping Dissolved Inorganic Carbon (DIC) constant, and DIC was altered while keeping pH constant. The data set contains alkalinity, pH and oxygen measurements with calculations of calcification, carbonate chemistry parameters, photosynthesis and respiration. excel sheet 1: natural sea water results. excel sheet 2: pH-DIC manipulated water results.