What is the big deal about ocean acidification?

If you have been paying attention to environmental news lately you may have read or heard a little bit about this thing called ocean acidification. But what is ocean acidification and why is it such a big deal?

What is ocean acidification?

Ocean acidification, as the name suggests, is an increase in acidity of the world’s oceans which can be shown by a decrease in pH. This increase in acidity parallels an increase in CO₂ in the earth’s atmosphere. This parallel increase occurs because CO₂ stays balanced between the ocean and the atmosphere, so if the CO₂ increases in the atmosphere, the ocean absorbs more CO₂to stay in equilibrium.

In the ocean, CO₂ is also getting used up through a reaction with water and carbonate (a molecule that occurs naturally in the ocean) that creates bicarbonate and carbonic acid, both of which are acidic and decrease the pH of the ocean. Overall, this reaction causes an increase in acidity, a decrease in carbonate, and a decrease in CO₂ in the ocean, which pulls more CO₂out of the atmosphere to maintain the CO₂ balance. Find out more here.

Why is the increased acidity in the ocean, as well as the removal of carbonate a big deal?

The removal of carbonate from the marine environment affects organisms that use carbonate to build shells and skeletal structures such as crabs, lobsters, clams, oysters, and corals. With less carbonate available, it is harder for these animals to create their hard protective structure.
As CO₂increases and carbonate decrease in the ocean, the acidic environment may even break down calcium carbonate of shells and corals, causing these structures to dissolve! (Image of shells dissolving on the right) This is harmful to adult organisms that have already created these calcium carbonate structures, but it is even worse for young individuals that are just trying to build these hard structures. If young individuals cannot build shells or skeletal structures, then they will not survive!
Organisms that utilize carbonate to build calcium carbonate shells and structures are not the only ones to be affected by ocean acidification. There are thousands of species that depend on the larvae and adults of these species for food and corals provide habitat for thousands of fish and top predators. If these shell and skeleton building species are affected by ocean acidification then all of the species that depend on them, many of which are commercially important, will also be impacted.
Many of these species also provide ecosystem services that are valuable to people. Corals provide a layer of protection to coastal habitats in storms. While, shellfish are filter feeders and can filter entire bay areas, cleaning the water for people as well as other organisms.
Ocean acidification by itself has a big impact on the ocean, but when combined with other stressors such as overfishing, increased temperatures, melting sea ice, and coastal pollution, the effects are amplified!

Ocean acidification is a major issue for our planet and for Marine Conservation Institute. Marine Conservation Institute educates policy makers about the causes and effects of ocean acidification as well the importance of funding science to better understand and deal with the issue. Yesterday, Marine Conservation Institute held two Congressional briefings to educate U.S. Senators and Representatives about ocean acidification and the serious impacts it has not only on our ocean environment, but also on our economy, and our culture.

What can you do to help? Get informed! Learn more about ocean acidification. Tell your friends! Tell your U.S. Senators or Representative that you are worried about the impacts of ocean acidification and that they should be too!

(All Photo Credits NOAA)

Marine Conservation Institute News, 19 September 2012. Article.

Ocean Acidification