Dissolving Sea Snails!

This story speaks for itself, so I will keep my commentary to a minimum. This text is from Science Daily's First Evidence of Ocean Acidification Affecting Live Marine Creatures in the Southern Ocean.

The shells of marine snails — known as pteropods — living in the seas around Antarctica are being dissolved by ocean acidification according to a new study published this week in the journal Nature Geoscience. These tiny animals are a valuable food source for fish and birds and play an important role in the oceanic carbon cycle.

During a science cruise in 2008, researchers from British Antarctic Survey (BAS) and the University of East Anglia (UEA), in collaboration with colleagues from the US Woods Hole Oceanographic Institution and the National Oceanic and Atmospheric Administration (NOAA), discovered severe dissolution of the shells of living pteropods in Southern Ocean waters.

The team examined an area of upwelling, where winds cause cold water to be pushed upwards from the deep to the surface of the ocean. Upwelled water is usually more corrosive to a particular type of calcium carbonate (aragonite) that pteropods use to build their shells. The team found that as a result of the additional influence of ocean acidification, this corrosive water severely dissolved the shells of pteropods.

Ocean acidification is caused by the uptake of carbon dioxide from the atmosphere emitted as a result of fossil fuel burning. A number of laboratory experiments have demonstrated the potential effect of ocean acidification on marine organisms. However, to date, there has been little evidence of such impacts occurring to live specimens in their natural environment. The finding supports predictions that the impact of ocean acidification on marine ecosystems and food webs may be significant.

In short, what had been previously demonstrated only in the laboratory has now been found in the Southern Ocean. The importance of this finding can not be overstated.

Here's the abstract for the Nature Geoscience paper Extensive dissolution of live pteropods in the Southern Ocean.

The carbonate chemistry of the surface ocean is rapidly changing with ocean acidification, a result of human activities. In the upper layers of the Southern Ocean, aragonite—a metastable form of calcium carbonate with rapid dissolution kinetics—may become undersaturated by 2050.

Aragonite undersaturation is likely to affect aragonite-shelled organisms, which can dominate surface water communities in polar regions. Here we present analyses of specimens of the pteropod Limacina helicina antarctica that were extracted live from the Southern Ocean early in 2008.

We sampled from the top 200 m of the water column, where aragonite saturation levels were around 1, as upwelled deep water is mixed with surface water containing anthropogenic CO₂. Comparing the shell structure with samples from aragonite-supersaturated regions elsewhere under a scanning electron microscope, we found severe levels of shell dissolution in the undersaturated region alone. According to laboratory incubations of intact samples with a range of aragonite saturation levels, eight days of incubation in aragonite saturation levels of 0.94–1.12 produces equivalent levels of dissolution.

As deep-water upwelling and CO₂ absorption by surface waters is likely to increase as a result of human activities, we conclude that upper ocean regions where aragonite-shelled organisms are affected by dissolution are likely to expand.

Related Posts

The "Other" Carbon Problem — Ocean Acidification (August 17, 2010)
Acidifying The World's Oceans (February 23, 2012)
The Coming Mass Extinction In The Oceans (August 24, 2012)
There Go The Coral Reefs (June 11, 2012)
A Mass Extinction In The Oceans (June 22, 2011)

Bonus Video — The Acid Test: The Global Challenge of Ocean Acidification (from NRDC, 21:35)

 

Comments

[Gail]

Erm, check this out:

http://www.smh.com.au/national/at-the-edge-of-disaster-20121127-2a5xe.html#ixzz2DXdKopgS

[Ean Gray]

Thought you might want to take a look at this, as well: http://www.slate.com/articles/health_and_science/coal/2012/11/clean_coal_technology_carbon_capture_and_sequestration_is_trapped_in_a_valley.html. It is a new (probably old, really) argument for "clean coal".

On the other hand, Dave I have to ask: What keeps you motivated to write this blog? Its kind of like a historian writing a history of the Earth right before the Sun is about to explode. I don't mean that as a joke, I truly am amazed at your ability to continue to care enough about this hopeless stuff enough to keep writing about it.

[Dave Cohen]

@Ean

My motivations are complex. I would not say I "care" about this hopeless stuff. In fact, the key to writing this stuff every day is not caring!

If I truly cared, I wouldn't be able to continue. My heart was broken long ago. One adjusts.

I think it is important that somebody tell the humans the truth about themselves and their likely fate. The irony of doing so is that any person who does so will invariably be mostly ignored or marginalized.

On the other hand, that human behavior (the ignoring, the shunning etc.) is predictable, too.

So it goes.

-- Dave

[John D]

Running out of ways to say "we're fucked".

[Dave Cohen]

@John D

There's no need for an agent-less construct -- "we're fucked"

We can know exactly why we are fucked and who is doing the fucking ;-)

-- Dave

[Robin Datta]

The life forms affected by the environmental degradation and ecosystem disruption do not vote, make campaign contributions, sit on boards of directors and in legislative bodies, or have other such levers of political power within their reach. A very few have found themselves useful to humans. If success is measured in numbers, feedlot cattle, monoculture corn wheat and soy, factory-farmed chickens and the like might be counted among the successful, but only as long as humans can subsidise them.

[Robert Colgan]

Mark Twain's quote applies here most appropriately:

"I have been reading the morning paper. I do it every morning--knowing well that I shall find in it the usual depravities and basenesses and hypocrisies and cruelties that make up civilization, and cause me to put in the rest of the day pleading for the damnation of the human race. I cannot seem to get my prayers answered, yet I do not despair."
- (Letter to William Dean Howells, 2 April 1899)

since his prayers seem finally to have found a sympathetic God.

Not much good to say about a species that's clever enough to befoul its own nest to self-extinction and whose response to the travesty will probably be to engage in a large suicidal war.... except that they were ultimately undone by their stupidity.. . .
. ...THAT, can be said with certainty.

[Brian M]

Why is it that I seem to be inured to the constant damage we do to our own species, but continually depressed and saddened by what we do to every other living thing on the planet. :-(

Too. Fucking. Depressing.

[Joy]

I couldn't care less about the decline of any empire, Incan, Cretean, Ottoman, BIS, whatever. But the Decline of the Biosphere is truly tragic, in the sense that the comet that hit Yucatan was tragic - mindless and unavoidable.

[Makati1]

Great article and I even liked the video until it got to the advertisement for the 'Techie Comes to the rescue' magic wand at the end. Dream on if you think that is the answer. By the time all of the carbon energy was used to switch to PV, etc, we would nor be able to swim in the oceans of the world because of the additional acidification the 'cure' created.