“…we have underestimated the overall risks and that the whole of marine degradation is greater than the sum of its parts, and that degradation is now happening at a faster rate than predicted.” State of the Ocean Report, 6.20.11
Some of the excess carbon dioxide we so heedlessly pump into the atmosphere is absorbed by the ocean. There, it mixes with water and creates carbonic acid. Thus, we acidify the ocean. This means there are more and more hydrogen ions floating around; these easily bind to carbonate ions, which are also, crucially, floating around. These captured carbonate ions are therefore unavailable to all the animals (corals, plankton, mollusks etc.) that depend on calcium carbonate for their lives. Calcium carbonate is one of the keys to the ocean’s entire life web. Holy fucking shit: we’re in the process of sterilizing the ocean! (This in addition to raising its temperature, which is killing the vital corals, and over-exploiting just about everything that swims in it: the state of the oceans is perilous.) April’s National Geographic gives more grim, deadly details on the destroying effects of acidification.
In Carl Safina’s book The View from Lazy Point, which also discusses this crisis, he quotes coral specialist Bob Steneck: “To see where all this is heading, put a clamshell or an egg in vinegar for a day.”
OK, so I did. One organic brown egg in a cocktail glass of aged white wine vinegar (6% acidity) that had gone a little mothery.
After about 30 minutes, the outer layer of the shell could be wiped off, as if was dirt, as if it was exfoliated. It was still hard as an eggshell, though. 
24 hours later, I could squeeze the now-rubbery egg. A genuinely creepy sensation, indeed. The shell residue simply came off on my fingers; I rinsed the rest of it off for the following shot: 
The shell, the calcium, was gone, except for the top, where the egg had floated above the vinegar. That was still eggshell-hard. I didn’t know if it was the outer membrane or the inner, or both, that was left holding the liquid interior together. (Had I created the equivalent of a reptile egg??)
Now, why should we care if the oceans are dying? No, seriously, I was asked this recently in a devil’s-advocate-kind-of-way. My response: you like to breath, don’t you? Life in the oceans produces from 50-85% of the oxygen in the atmosphere. That’s a utilitarian answer, of course. We’ve already forfeited the moral answer.
Backyard and Beyond 
I’ve done this same thing with a chicken bone, though that was merely to fascinate the kids, not to take a grievous moral lesson.
The fact is that until someone can find a way to make a profit saving the earth — a profit that is greater than the one we take from destroying it — the task will remain “dubious” and “comminist”. But once the profit motive is found, it will be “patriotic” and “Merkan”.
A sea-change in ways of thinking (and doing) is needed, to be sure. I wonder if crises — I stress the plural — will bring this about; certainly nothing beforehand will.
Horrifying. Good post – I had missed this one.