As carbon dioxide is blown into the beaker through the straw the pH level lowers. The universal indicator showed that the added carbon dioxide turned the pH level acidic. If the pH level in the ocean drops to acidic marine life can be harmfully affected. Coral bleaching and the weakening of calcium carbonate shells are both affects of the increase of acidic pH levels. When testing how the pH level affected the shells, we knew a reaction was according due to the bubbling of the shells. This reaction is similar to how marine animals with calcium carbonate shells, such as crabs and corals, react to the drop of pH. The shells were made of similar compositions as the shells of marine animals. The shell strength was weakened by the exposure to vinegar