Fact: More carbon dioxide (CO2) in the air also acidifies the oceans. It seemed to be the logical conclusion that shellfish and corals will suffer, because chalk formation becomes more difficult in more acidic seawater. But now a group of Dutch and Japanese scientists discovered to their own surprise that some tiny unicellular shellfish make better shells in an acidic environment. This is a completely new insight.
Researchers from the NIOZ (Royal Dutch Institute for Sea Research) and JAMSTEC (Japanese Agency for Marine-Earth Science and Technology) found in their experiments that so-called foraminifera might even make their shells better in more acidic water. These single-celled foraminifera shellfish occur in huge numbers in the oceans. The results of the study are published in the leading scientific journal ‘Nature Communications’.
Fact: More carbon dioxide (CO2) in the air also acidifies the oceans. It seemed to be the logical conclusion that shellfish and corals will suffer, because chalk formation becomes more difficult in more acidic seawater. But now a group of Dutch and Japanese scientists discovered to their own surprise that some tiny unicellular shellfish make better shells in an acidic environment. This is a completely new insight.
Researchers from the NIOZ (Royal Dutch Institute for Sea Research) and JAMSTEC (Japanese Agency for Marine-Earth Science and Technology) found in their experiments that so-called foraminifera might even make their shells better in more acidic water. These single-celled foraminifera shellfish occur in huge numbers in the oceans. The results of the study are published in the leading scientific journal ‘Nature Communications’.
Since 1750 the acidity of the ocean has increased by 30%. According to the prevailing theory and related experiments with calcareous algae and shellfish, limestone (calcium carbonate) dissolves more easily in acidic water. The formation of lime by shellfish and corals is more difficult because less carbonate is available under acidic conditions. The carbonate-ion relates directly to dissolved carbon dioxide via two chemical equilibrium reactions.
Continue reading at NIOZ Royal Netherlands Institute for Sea Research
Image: Microscopic pictures of individual foraminifers.
Left: A foraminifer with a shell containing four chambers of which one is empty. Also note the spines.
Right: Picture of the interior of a foraminifer. The green colour is caused by seawater with an indicator showing that the acidity has changed. The actual size of the foraminifer is about 0.25 millimeter.
Credit: Dr. Lennart de Nooijer / NIOZ
