Excuse me, but what made you think this wasn't a part of the massive interaction called "global warming"...(which has very little to do with your current weather).
Ocean acidification is caused by CO2 being dissolved in the oceans, and the level of solution is in approximate equilibrium with the level of CO2 in the atmosphere (though you need to figure in lots of lag). While the oceans are relatively cool they can absorb extra CO2, as they warm it becomes more "eager" to get out of solution, but with the atmosphere levels of CO2 being high, instead of being expelled into the atmosphere it "tries" to dissolve things. (CO2 dissolved in water is carbonic acid ... H2CO3. A very weak acid.) When the temperature of the ocean is lower, not only is the CO2 more soluble, but the resulting H2CO3 is more stable, and so less acidic.
What's been happening is that as the amount of CO2 in the atmosphere rose, more was dissolved in the (colder) oceans. As things warmed up the ocean has become more reluctant to hold the CO2 that's already been dissolved. But the oceans have so much more thermal mass than the atmosphere, that they've been warming considerably more slowly. Over the last decade, however, their temperature has been increasing, and they can't emit the dissolved CO2 into the atmosphere faster than it's absorbed, because that level is also increasing, so the oceans have become more acidic.
So this is an expected part of global warming, and anyone who is surprised by it just hasn't been paying attention.