Daily Science Dose

If you pay attention to the news, and especially news on the state of the environment, you may have heard of something called “ocean acidification.” This is a very serious issue that is just starting to gain some attention from scientists. The ocean won’t become a bubbling cauldron of acid, steaming and fuming with potential pain and burning, but the water’s pH balance may shift toward the more acidic.

The tips of the shells are slowly dissolving, but how?

The oceans are well-known as a sequester of carbon dioxide. So much so that some have advocated that instead of bothering with cutting carbon emissions, we can just “sink” the carbon in the oceans. And it is true that this has been the Earth’s way of dealing with excess carbon and methane for eons, but lately, it seems that anthropogenic carbon (that means that the source is man-made) is too much for the ocean to take it in without throwing the whole system out of whack. When the ocean absorbs carbon dioxide, or CO2, water’s H2O binds with that CO2 and forms HCO3, and that, my friends, is carbonic acid.

Now, obviously, it would take a LOT of carbon dioxide to turn the seas acidic, or more accurately, less alkaline, as the ocean’s typical pH (potential Hydrogen) is 8.2, or at least was before the Industrial Revolution. And guess what we humans have pumped into the atmosphere — a LOT of carbon dioxide.

Do you ever wonder that perhaps fossil fuels were buried in the first place as “carbon sinks?” And we have simply released all that carbon that nature put under ground so many years ago…

I digress. The problem at hand is now that if the pH of the ocean becomes too acidic (less alkaline) too fast, many marine organisms will not be able to adapt quickly enough to survive. Any creature that builds a shell uses calcium carbonate and aragonite in order to do so. Carbonic acid corrodes the aragonite, and shell formation becomes difficult. Scientists have found that some snails that happen upon carbon vents in the Mediterranean are losing their shells, literally. The carbonic acid is dissolving the shells.

The IPCC (Intergovernmental Panel on Climate Change, you know, the Nobel-prize winning IPCC) has warned that pH may decrease 0.14 to 0.35 by 2100. This could mean that with the decrease of 0.1 experienced since the beginning of the Industrial Rev, we could see oceans of 7.8 pH. Shelled creatures will most likely not be able to keep up with that amount of change in pH, and when we lose the shelled organisms, such as some snails, we can lose a valuable food source for things we like to eat, like salmon. With the oceans already stressed, a decrease in pH may be more that they can handle.

ocean acidification, carbonic acid, pH, carbon sinks, climate change, IPCC, methane, calcium carbonate, shells, aragonite