2.3.10—Ocean acidification

More dissolved CO₂ changes carbonate chemistry, lowers pH and can make calcium-carbonate shell or skeleton building harder.

pH is logarithmic, so a small numerical fall represents a meaningful increase in hydrogen-ion concentration. Organism response depends on species and local conditions, but calcification can slow or weaken.

If a reef site shifts from pH 8.2 to 8.1, treat it as a real chemical change, not ‘only 0.1’, then test calcification data.

The change is chemical: carbonate availability and pH alter the reaction conditions even when the water appears normal.

Lower pH means more acidic, not ‘no carbon’; and it does not prove every species responds identically.