Hello, and my best to you! What is outlined today is a quick overview to be sure, but I wanted you to know “what’s goin’ on!”
Chances are, unless you’ve been living under a rock (not a coral, a rock!) you’ve heard something about climate change and how it is linked to carbon dioxide entering the atmosphere . . . our air. But what you may not have heard is how much this process affects our oceans.
The oceans are a sink for carbon dioxide. Our oceans absorb about 25% of the carbon dioxide that is released into the air. Ocean water and carbon dioxide combine to create carbonic acid. This process is called “ocean acidification,” and it increases the pH levels in the water.
You know the algae that live so beautifully within corals’ tissues, giving them their color? The ones that need the right conditions to be comfortable photosynthesizing in order to Miracle Gro the reefs? That algae cannot live in a coral anymore if the surrounding pH goes up a certain amount. When the pH does go up that high, the algae leave. This process is called “coral bleaching,” because once the algae are gone, the coral’s color is gone, too. The coral turns white and eventually dies due to lack of nutrients.
But there is good news! It has been proven that if the water’s pH goes back down again to comfortable levels within two weeks, the algae can return. “Whew. That’s water under the bridge,” they say--in algae language, of course.
There is another issue to consider, however. Ocean acidification also takes up carbonate that is regularly combined with calcium in the water to create—for one thing—shells. This is a problem for any marine animal that is protected by, lives in, trades, eats something that has, or has friended a shell. You cannot build a strong shell without proper raw materials. Remember last column, when I explained that corals build a limestone skeleton? Well, limestone is primarily calcium carbonate, as well.
That is how (say it with me now) ocean acidification is a problem. The algae leave the coral, so the reefs dwindle. The coral cannot build proper skeletons, which loses the reefs in another way. The shelled organisms are weakened, so you’re out lobster, crab, oysters, scallops, clams, and others (is anyone else getting hungry?), and everything that eats those species, not to mention creating an explosion of anything that is normally regulated by those organisms.
And so Dear Readers, let’s breathe and live deeply, and take a walk together instead of a drive. Kailua is such a lovely place to practice reef mind, wouldn’t you say?
The above column was originally posted in April of 2013, in the online newsletter kailua411.com. It was reprinted here with permission from the publisher. The newsletter is no longer online.