The magazine of the european research area European Commission Copenhagen, a missed chance?

In the laboratory: measurements of calcification 

and the migration of metal traces by isotopes.

species, others manage to maintain a normal rate 

of calcification but to the detriment of other vital 

functions such as growth or reproduction,” 

explains Ulf Riebesell, an oceanographer at the 

Leibniz-Institut für Meereswissenschaften at Kiel 

University (DE) and coordinator of BIOACID, 

the German research project on ocean acidifi-

cation launched in September 2009.   

The reaction of certain key calcareous organ-

isms is of particular concern to researchers. 

“In cold seas, the coral communities are found 

at great depth where the carbonate concen-

tration is naturally low,” explains Jean-Pierre 

Gattuso. “The latest results and forecasting 

models show that these waters could start to 

have a corrosive effect on the calcium carbon-

ate. The increase in acidity would then not only 

limit the growth of cold water corals but also 

contribute to the dissolving of their structure.” 

Like tropical corals, these cold water corals 

provide a very special habitat and reproduc-

tion site for marine life. “Many vital species 

for the fishing industry are threatened, in the 

Northern and Southern Hemispheres. The 

socio-economic impact of the disappearance 

of corals would be immense. The safety of 

populations could also be an issue because, in 

tropical regions, coral reefs form natural bar-

riers that protect coastlines from the ravages 

of the sea,” adds Jean-Pierre Gattuso.

 Another source of concern are the ptero-

pods, also known as sea butterflies. “The shell 

of pteropods is made of aragonite, a kind of 

less stable calcium that is therefore more sen-

sitive to acidification,” explains Ulf Riebesell. 

“The pteropods play a major role in the marine 

food chain. The salmon in the North Pacific 

feed almost exclusively on this species during 

a certain stage in their growth, for example. 

We do not know whether the predatory spe-

cies will be able to turn to other prey or if the 

growing scarcity of the pteropods will cause 

populations to collapse.”  

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eu No. 63 | APRIL 2010