Acidification

Ocean Acidification

General

Ocean Acidification is defined as the process by which the acidity of ocean water increases, as pH lowers, due to an increase in the burning of fossil fuels by human industrialization. This causes an increase in carbon dioxide in the atmosphere, which is then absorbed by the ocean, leading to an imbalance in the chemistry of ocean water, which results in the pH lowering. This process has severe implications for marine ecosystems.

Mechanism

• Ocean Acidification results as the equilibrium of oceanic chemistry is disrupted. Increasing atmospheric carbon dioxide reduces ocean pH.
  • Carbon dioxide reacts with water to form carbonic acid. The carbonic acid further reacts to create bicarbonate and a hydrogen ion. This increases the acidity of water.
  • The extra hydrogen ions then bond with the carbonate ions that are in the water. This reduces the amount of carbonate available in the ocean.
• It is driven by the burning of fossil fuels by humans that results in an increase in carbon dioxide in the atmosphere.
• About one quarter of the carbon dioxide that we release is absorbed by the ocean, so we are not only affecting the atmosphere but also the ocean.

Where it's happening

• Location based studies on Ocean Acidification
  • 1) Coral Triangle- An evident rise in the disintegration of skeletons of hermatypic corals and shellfish.
  • 2) Florida Reef Tract- Collection of carbonate chemistry data shows an increase in the aragonite saturation values that reduce calcification rates of organisms.
  • 3) Great Barrier Reef- Sampling of Porites coral colonies reveals a decrease in growth of 13% across the reef.
  • 4) Tyyrhenian Sea- Declining variety and absence of organisms previously abundant in the area; evidence of seawater corrosion from rising CO2.