Juvenile Eastern Oysters More Resilient to Extreme Ocean Acidification than Their Mud Crab Predators

Ocean acidification is predicted to impair marine calcifiers' abilities produce shells and skeletons. We conducted laboratory experiments investigating the impacts of CO2-induced ocean (pCO2 = 478–519, 734–835, 8,980–9,567; Ωcalcite 7.3–5.7, 5.6–4.3, 0.6–0.7) on calcification rates two estuarine calcifiers involved in a classic predator-prey model system: adult Panopeus herbstii (Atlantic mud crab) juvenile Crassostrea virginica (eastern oyster). Both oyster crab significantly decreased at highest pCO2 level. Notably, however, oysters maintained positive net treatment that was undersaturated with respect calcite, while crabs exhibited dissolution (i.e., loss shell mass) calcite-undersaturated conditions. Secondary electron imaging revealed minor microstructural alterations moderate-pCO2 treatment, major macrostructural changes (including dissolution, delamination periostracum) high-pCO2 treatment. These results underscore threat poses for organisms calcium carbonate shells, illustrate strong biological control some exert over their shell-building process, shows differentially species this classical system.