More news on the science coming in that definitively is pointing to Ocean Acidification being the culprit in hatchery mortality rates here.
The mortality of larval Pacific oysters in Northwest hatcheries has been linked to ocean acidification. Yet the rate of increase in carbon dioxide in the atmosphere and the decrease of pH in near-shore waters have been questioned as being severe enough to cause the die-offs. Now, a new study of Pacific oyster and Mediterranean mussel larvae found that the earliest larval stages are sensitive to saturation state, rather than carbon dioxide (CO2) or pH (acidity) per se. Saturation state is a measure of how corrosive seawater is to the calcium carbonate shells made by bivalve larvae, and how easy it is for larvae to produce their shells. A lower saturation rate is associated with more corrosive seawater. Cheryl Dybas reports. (PHYS.ORG)
http://phys.org/news/2014-12-ocean-acidification-culprit-commercial-shellfish.html
And this article follows on it.
http://phys.org/news/2014-11-tool-west-coast-ocean-acidification.html#inlRlv
For those wanting to understand the science behind “saturation state” you can find the definition down this page. Just “find” saturation state when you get to it. The formula is there.