A Blue View: Understanding Ocean Acidification
Published May 29, 2013
A Blue View is a weekly perspective on the life aquatic, hosted by National Aquarium CEO John Racanelli.
From the smallest plants and animals invisible to the human eye to entire ecosystems, every living thing depends on and is intricately linked by water.
Tune in to 88.1 WYPR every Tuesday at 5:45 pm as John brings to the surface important issues and fascinating discoveries making waves in the world today.
May 29, 2013: Understanding Ocean Acidification
Click here to listen to John discuss how the changing
global climate is impacting on our oceans.
Say you visit the same spot on the same ocean every year. You take a swim, and it feels pretty much like the last time. The temperature doesn’t seem all that different. You certainly can’t tell that the pH is changing.
Yet just as the global climate is changing, so too is the ocean’s chemistry. Alongside atmospheric climate change, ocean acidification is one of the most serious issues affecting the waters of our planet and all of its inhabitants.
Ocean acidification has only recently entered the public’s consciousness, though scientists have been studying and predicting the phenomenon for some time. Many estimate that the ocean absorbs approximately 30 percent of human-generated carbon dioxide, which reacts with sea water to form carbonic acid. The resultant decrease in pH means the water becomes more acidic, with disastrous effects on animals that depend on their shells and exoskeletons to survive.
Though the media has taken to calling ocean acidification our “new climate threat,” it is not a new problem. Since the dawn of the Industrial Revolution, carbon dioxide has been increasing in our atmosphere and therefore our seawater. Now, over 200 years later, we can no longer ignore the threat. Even conservative estimates suggest that by 2100, global ocean waters will warm nearly 2 degrees Fahrenheit on average and acidity will increase by 150 percent.
So what does this mean for ocean wildlife? Clearly, the sea’s complex food web will be disrupted. Highly mobile animals will be forced to expand their home ranges as they search for more hospitable waters. Sadly, coral reefs as we know them will be forever altered and could even disappear. Animals will struggle to build skeletons and shells in waters that literally dissolve them. And growth and reproductive capabilities of numerous marine animals will be at risk.
Ocean acidification has caused coral bleaching on parts of the Great Barrier Reef. Photo via CS Monitor
The Chesapeake Bay watershed is not immune to these dramatic changes. In fact, according to NOAA’s Chesapeake Bay Office, the Bay is being affected at a faster rate than the global average because land in this region is already subsiding naturally. Bay temperatures have already increased almost 2 degrees Fahrenheit since 1960 and are projected to increase by an additional 3 to 10 degrees by 2100—a tremendous change that will have a profound effect on the nation’s largest estuary. Increased acidification of the Bay will alter its delicate balance in other ways. For example, according to marine geologist Justin Ries of the University of North Carolina Chapel Hill, blue crabs could grow larger, while the creatures they eat, including oysters and clams, could suffer from weaker, slower-growing shells. These bivalves, in addition to being an integral part of the food chain, also contribute to healthier water quality by filtering huge quantities of Bay water. The moral: damage one small species and you affect the entire Chesapeake Bay.
We cannot simply undo the impacts of ocean acidification. The carbon dioxide we are putting into the atmosphere today will continue to accumulate for decades. There is hope, however, and as always, it starts with each of us. Reducing our consumption of fossil fuels and minimizing our collective carbon footprint isn’t just the best way forward, it’s the only way. As Fyodor Dostoevsky said in The Brothers Karamazov, “For all is like an ocean. All flows and connects. Touch it in one place and it echoes at the other end of the world.”