Assess students' understanding of the chemical processes driving ocean acidification (CO2 uptake, carbonic acid formation, shifts in pH and carbonate/bicarbonate equilibria, and carbonate saturation states) and the resulting effects on marine ecosystems (reduced calcification in corals and shellfish, physiological stress, altered species interactions and food webs, habitat degradation), including interactions with temperature and nutrients and basic interpretation of pH/alkalinity data; requires explanation and application to real-world scenarios and mitigation/adaptation considerations.