![ocean acidification ocean acidification](https://chelsea.co.uk/wp-content/uploads/2022/08/ocean-acidification-scaled.jpg)
For example, researchers have found that acidification may damage clownfish hearing, affecting their ability to detect predators. While effects such as thinning shells and damaged coral reefs are clear to see, others are more subtle. As well as shell effects, acidification can also reduce immune defence against parasites and pathogens. Shellfish are particularly sensitive to ocean acidification at the larval stage. For example, acidification affects coral’s ability to build and repair its hard structures, which in turn affects the whole ecosystem that depends on reefs for survival. Many marine organisms need carbonate to grow shells or skeletons, so acidification has significant physical effects. Dissolving CO 2 in seawater increases the hydrogen ion concentration, making the water more acidic: CO 2 (aq) + H 2O ⇌ H 2CO 3 -⇌ CO 3 2- + 2H +Īs the pH drops, the concentration of carbonate ions also decreases.
![ocean acidification ocean acidification](https://cdn.britannica.com/82/152182-050-719F9121/state-diagram-carbonates-conditions-oceans-2100.jpg)
The ratio of these species depends on factors such as temperature, pressure and salinity. Carbon dioxide dissolves in seawater and forms ionic and non-ionic species, including carbonic acid (H 2CO 3), bicarbonate (HCO 3 -) and carbonate (CO 3 2-).
![ocean acidification ocean acidification](https://oceanfdn.org/wp-content/uploads/2019/05/OA_FeaturedImage-1024x512.jpg)
Ocean chemistry is finely tuned and affected by any change in acidity. This may not sound dramatic but a decrease of one pH unit marks a tenfold increase in acidity. The surface pH could continue to decrease by around 0.3 units by 2100, it predicts. Open ocean surface pH has declined by up to 0.027 pH units per decade since the late 1980s, according to a 2019 report by the Intergovernmental Panel on Climate Change (IPCC). Seawater has a pH of around 8.1, down from 8.2 in pre-industrial times. Clownfish hearing may be negatively affected by acidification, giving predators an unfair advantage