Table 4. Ambient H⁺ concentrations and microenvironmental H⁺ differences (ΔH⁺) of photosymbiotic foraminifera at saturated light conditions (mean±SE).

pCO2 treatment	ambient H+ (nM)	ΔH+(nM)
432 µatm	6.06±0.07	−1.67±0.35
1141 µatm	14.3±0.17	−2.92±0.63
2151 µatm	24.9±0.77	−3.53±0.66