What is the primary consequence of ocean acidification on marine life?

Ocean acidification, which results primarily from increased carbon dioxide (CO2) absorption by seawater, significantly affects marine life by altering the chemical composition of the ocean. The main consequence of this process is the increased concentration of hydrogen ions, which lowers the pH of the water. This shift in acidity impacts organisms that rely on calcium carbonate for their shells and skeletons, such as mollusks (like clams and snails) and certain types of plankton.

A lower pH makes it more challenging for these organisms to extract carbonate ions from the water, which are essential for building their calcium carbonate structures. As a result, the ability to form and maintain these shells or skeletons diminishes, leading to weaker shells and decreased survival rates in susceptible species. This has cascading effects on the entire marine ecosystem, as many fish and marine animals rely on these organisms for food and habitat.

The other options either describe phenomena that do not directly relate to the effects of ocean acidification or contradict the broader understanding of marine ecology in the context of changing ocean chemistry.