Thursday, March 20, 2014

Oceans going down

I see that Oceanography has a special issue out about changes to ocean chemistry, which means in large part it's about ocean acidification.

I think all of the articles are available as .pdfs, so I won't bother linking to individual ones.

But having a look at a couple of them, the take away messages are:

*  the oceans at all parts of the world are showing declining pH dues to increase CO2 in line with predictions

*  coastal oxygen free "dead zones" are increasing and are likely to continue increasing with warming temperatures.  (This has been predicted for some time too.)

I don't do many posts about ocean acidification lately, but looking through the Ocean Acidification blog, there is plenty of research still going on, much of it with worrying results.  It seems to be a frequent theme that both oysters and scallop growing areas in North America are already suffering due to coast water acidification.  Although there is a natural variation to pH in those areas anyway, the slow increase in surface acidification is obviously not helping.

Many studies look at developmental and behavioural changes displayed by various species under decreased pH, but it is obviously very difficult to work out how they will play out in the future oceans.   Some species indicate some adaptive ability, but the big picture is enormously hard to predict.

I still think the pteropods are like the canary in the coal mine on this issue.  A study in 2012, which was looking at pteropods taken in 2008, found that those in aragonite undersaturated waters were showing severe shell erosion already.    A future collapse in this extensive species which feeds many of the sort of fish we like to eat could be dire. 

So, for all of the talk of lower rates of temperature rise and when that will turn around, this is the issue that climate change deniers larger ignore or simply dismiss as another scientific disaster story told to ensure funding. 

They are ignorant and dangerous to the future of humanity.

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