Reply #7: Ocean Acidification and Corals [View All]

[arachadillo]

Coral reefs are part of the foundation of the ocean food chain. Nearly half the fish the world eats make their homes around them. Hundreds of millions of people worldwide — by some estimates, 1 billion across Asia alone — depend on them for their food and their livelihoods.

If the reefs vanished, experts say, hunger, poverty and political instability could ensue. "Whole nations will be threatened in terms of their existence," said Carl Gustaf Lundin of the International Union for the Conservation of Nature.

Also just making the news:
Shell-shocked: How Different Creatures Deal With an Acidifying Ocean
http://www.earthmagazine.org/earth/article/323-7da-3-a

"a recent set of experiments suggests that the ocean acidification story is more complex than first thought. Whereas some marine calcifiers reared under the elevated carbon dioxide levels responded very negatively, not all of the organisms suffered in the acidified seawater. Some, in fact, appeared to benefit from it."

With respect to coral reefs, The National Academy of Sciences reported:
Ocean acidification causes bleaching and productivity loss in coral reef builders
http://www.pnas.org/content/105/45/17442.abstract

"Overall, acidification impacted more strongly on bleaching and productivity than on calcification. Interestingly, the intermediate, warm CO2 scenario led to a 30% increase in productivity in Acropora, whereas high CO2 lead to zero productivity in both corals. CCA were most sensitive to acidification, with high CO2 leading to negative productivity and high rates of net dissolution. Our findings suggest that sensitive reef-building species such as CCA may be pushed beyond their thresholds for growth and survival within the next few decades whereas corals will show delayed and mixed responses."