Posts Tagged ‘oyster die-off’

The Acidification of Oysters

Monday, April 23rd, 2012

Maybe you read about this recently. It seems to me to be quite amazing.

A die-off of oyster larvae at the Whiskey Creek Shellfish Hatchery on the Oregon coast has been correlated with – and almost certainly caused by – a small increase in the acidity of the sea water the larvae were exposed to in their first 24 hrs.

Oyster larvae need critical levels of CaCO3 for their shells to develop, and these levels drop as CO2 levels in the water increase.

Oyster larvae (

The report was published in April in the journal Limnology and Oceanography by three scientists (Richard Feely, Alan Barton and Burke Hales). Then Jeff Barnard, Environmental Writer for the Associated Press, published a summary of the study, and pretty well everyone took notice. When I Googled ‘oyster larvae dying’, most of the first 300 hits were copies of his article republished by American and global news websites.

Oyster life cycle (

All the reports, not just AP’s, emphasize that this is some of the first solid evidence of the potential impact of ocean acidification on a valuable fishery, though in fact oyster growers have been concerned about the threat of acidification for some years.

Anything that has a calcareous skeleton is sensitive to increased acidity (

The event is worrisome, of course, for ocean acidification will continue for many decades, even once (or if?) we stop the increase in atmospheric CO2. Now we know that a very small change in ocean acidity can have a large impact on a sensitive species.

As atmospheric levels of CO2 increase, so do levels in the ocean, resulting in increasing ocean acidity (

But what’s unexpected is the attention the journal publication and its AP description have received. It should signal to our political leaders in North America that in fact people really are worried about the accelerating effects of global warming.

How much evidence is needed? The death of some oyster larvae won’t change the beliefs of most of the US Congress, but it ought to.

It also won’t effect the politics and business of oil that dominates the Canadian economy, but it should.

They say we get the leaders that we deserve, but we don’t deserve this.

The die-off of the oyster larvae cannot be shrugged off as irrelevant or insignificant.

So we are warned.