http://www.guardian.co.uk/environment/interactive/2009/dec/10/acidification-oceans-copenhagen?INTCMP=SRCH

This interactive link nicely shows how aragonite concentrations have changed globally and also how this is effecting certain marine species.  The dark orange colours in the Arctic are quite scary as it shows just how much aragonite is thought to have been lost between 1865 and 2095, with some areas seeing a decrease of up to 75%.  I think the impact that ocean acidification is having on Whales and Clown fish is quite surprising, and unlike most other marine animals it is not caused by a reduction in aragonite and calcium carbonate.  Acidic oceans are more 'noisy' as sound can travel further, this is what is causing Whale numbers to fall as they cant communicate or navigate as easily.  The problem for clown fish is that the acidifying oceans are affecting their ability to smell the particular species of anemone that they use as a habitat.  If the pH of oceans continues to fall it is likely that they (and other fish species) will lose their sense of smell altogether.  This proves that ocean acidification is having a more devestating impact on ocean ecosystems than you would initially think.