Element ratios of seawater and of aragonite precipitated in vitro from seawater at 25°C over variable pH and seawater saturation state and in the presence and absence of amino acids (aspartic acid, glutamic acid and glycine)

Strontium/calcium, magnesium/calcium, lithium/calcium and boron/calcium ratios of 107 aragonite samples precipitated in vitro using a pH stat titrator using the constant composition technique between August 2020 and April 2022. Measured seawater pH and dissolved inorganic carbon concentrations (DIC) are used to estimate the seawater aragonite saturation state (O) of each precipitation. Aragonite precipitation rates are estimated from the rate of titrant dosing. The trace element contents of the solid produced in the experiment was corrected for the composition of the seed used as a surface for aragonite growth. Seawater [Sr], [Mg], [Li], [B] and [Ca] were also measured and seawater [B(OH)4-] is estimated from total seawater [B] and pH. Data were collected to determine how changes in the calcification fluids of calcareous organisms affect aragonite precipitation. Data were collected by Cristina Castillo Alvarez and Ed Hathorne and interpreted by Cristina Castillo Alvarez, Nicola Allison, Adrian Finch, Kirsty Penkman, Roland Kröger, Ed Hathorne and Matthieu Clog.