Acidificação

Acidificação refers to the process by which the pH of a body of water decreases, making it more acidic. This typically occurs when an excess of carbon dioxide is absorbed by the water. In aquatic environments, this absorption leads to a series of chemical reactions that increase the concentration of hydrogen ions, thereby lowering the pH.

The primary driver of widespread acidificação is the increasing concentration of carbon dioxide in the Earth's atmosphere, largely due to human activities such as the burning of fossil fuels and deforestation. Oceans are particularly susceptible as they absorb a significant portion of this atmospheric carbon dioxide. As CO2 dissolves in seawater, it forms carbonic acid, which then dissociates, releasing hydrogen ions.

This increase in acidity has profound implications for marine ecosystems. Many marine organisms, particularly those with calcium carbonate shells or skeletons such as corals, shellfish, and plankton, find it increasingly difficult to build and maintain these structures in more acidic conditions. The availability of carbonate ions, essential for calcification, is reduced.

Beyond calcifying organisms, acidificação can affect the physiology, behavior, and reproduction of a wide range of marine life, including fish. Changes in water chemistry can disrupt sensory systems, alter metabolic rates, and impact larval development. The long-term consequences for marine biodiversity and the fisheries that depend on them are a significant concern. While naturally occurring acidific events can happen, anthropogenic acidificação is a global phenomenon driven by climate change.