Welcome to the Speak Up For Blue Blogcast, where we recap Andrew’s daily discussion on ocean conservation issues. Today, we’re discussing the very serious issue of ocean acidification. And while it unfortunately may not be news anymore that the oceans are becoming increasingly acidic, what we want to talk about today is acidification particularly in the Southern Ocean.
Ocean acidification is sometimes called the evil twin of climate change. As atmospheric CO2 rises, the amount of CO2 that is dissolved in the ocean increases as well. This added CO2 intake increases the overall acidity of the ocean while decreasing the amount of available calcium carbonate. This is a problem for many marine crustaceans, since they require calcium carbonate to build their shells. A decrease in available calcium carbonate makes it more difficult for snails, pteropods, and other shell-building creatures to protect themselves. That is why increased crustacean mortality typically follows ocean acidification. And this is exactly what researchers are concerned will happen in the Southern Ocean.
In an article titled “Abrupt onset and prolongation of aragonite undersaturation events in the Southern Ocean,” researchers from the University of Hawaii and the University of Alaska Fairbanks predict that we may see adverse effects of acidification down south pretty soon. In fact, by 2100 they estimate that this acidification will impact approximately 70% of the ocean’s surface waters, which in turn will “likely to decrease the ability of organisms to adapt to a quickly evolving environment.” This is a scientist’s way of saying we’re going to see a lot of organisms die.
This isn’t just bad news for people who love escargot imported from Antarctica, this is bad news for everyone who loves seeing whales and fish not starve. Acidity-related mortality will have enormous impacts on the marine food web. A paper published a few years ago in Progress in Oceanography claims that pteropods play a significant role in Southern Ocean ecosystems. Their death, in addition to being a blow to anyone who likes cool invertebrates, will mean a food shortage for many economically important fish and whale species.
The good news is that there is not much of a delay for atmospheric CO2 concentrations affecting ocean chemistry. This means that if we act to decrease CO2 emissions, we can expect to see corresponding decreases in ocean acidification fairly soon. A significant contributor to greenhouse gas emissions is domestic energy usage. By turning down the heat in your home and putting on a sweater, you can help ensure that future species of pteropods can build homes of their own. You can also cut down on single-use plastics, since manufacturing these plastics uses an incredible amount of energy. Ocean acidification is very much a global problem, but it is not an insurmountable problem. Little changes in your daily life can go a long way towards ensuring the health of our oceans.
Enjoy the Podcast!
Hauri, C., Friedrich, T., & Timmermann, A. (2015). Abrupt onset and prolongation of aragonite undersaturation events in the Southern Ocean. Nature Climate Change, doi:10.1038.
Hunt, B. P. V., Pakhomov, E. A., Hosie, G. W., Siegel, V., Ward, P., & Bernard, K. (2008). Pteropods in southern Ocean ecosystems. Progress in Oceanography, 78(3), 193-221.