Table 2.

Experimental conditions for the three OA treatments (mean ± SD)

Seawater parameter	Ambient CO2	Mid-CO2	High CO2
Temperature, °C	−1.67	−1.68	−1.69
Salinity	30.89 ± 1.41	29.97 ± 0.59	29.38 ± 0.48
DIC, μmol⋅kg−1	2,067.5 ± 2.3	2,183.1 ± 9.7	2,156.2 ± 12.8
TA, μmol⋅kg−1	2,156.4 ± 9.3	2,201.9 ± 3.8	2,122.5 ± 29.9
pH, total	8.04 ± 0.03	7.80 ± 0.05	7.60 ± 0.09
pCO2, μatm	371 ± 26.7	698 ± 76.8	1,092 ± 202.8
Ω Calcite	1.82 ± 0.10	1.08 ± 0.12	0.67 ± 0.14
Ω Aragonite	1.13 ± 0.06	0.67 ± 0.08	0.41 ± 0.09

In situ seawater temperature (°C) was measured in the ice hole, and salinity, DIC, and TA were measured in the header tanks. Measured parameters were used to calculate, using CO₂sys, the additional parameters: pH (total) in situ temperature (°C), pCO₂, and saturation states for calcite (Ω Calcite) and aragonite (Ω Aragonite).