What is Ocean Acidification?
Ocean acidification refers to a reduction in the pH of the ocean over an extended period of time, caused primarily by the uptake of carbon dioxide (CO2) from the atmosphere.
Carbonate ions are crucial for building structures like seashells and coral skeletons. Decreases in carbonate ions make it difficult for calcifying organisms such as oysters, clams, sea urchins, shallow water corals, deep-sea corals, and calcareous plankton to build and maintain their calcium carbonate structures.
Impact on Non-Calcifying Organisms
These changes in ocean chemistry can affect the behavior of non-calcifying organisms as well. Certain fish's ability to detect predators is decreased in more acidic waters. When these organisms are at risk, the entire food web may also be at risk.
How is Ocean Acidification Affecting Starfish?
Starfish have calcifying skeletons that can be dissolved in more acidic waters, and therefore can be severely impacted by ocean acidification. Like crustaceans, it is more difficult to grow and maintain calcium carbonate shells with increased acidity.
In short: Ocean acidification amplifies wasting disease by forcing sea stars to redirect energy to skeletal maintenance at the expense of immune function.