Mussels are fighting back against the increasing acidity of the ocean by having stronger shells, a new research shows.
A team at the University of Glasgow (UoG) has found that their shells are now producing more amorphous calcium carbonate as a repair mechanism, possibly as their way of adapting to the changes in the sea.
Many marine animals produce protective shells and exoskeletons from calcium carbonate from seawater. But higher concentrations of carbon dioxide absorbed into seawater are making it more acidic and affecting the strength of these shells to protect the creatures against predators, the UoG said in a statement yesterday (Feb 15).
“With growth in global industrialisation, the surface pH of the oceans has declined form pH 8.1 to pH 8.0, meaning the water is less alkaline. Increasing CO2 leads to ocean acidification and scientists expect a further reduction in alkalinity from pH 8.0 to pH 7.7 by the end of the 21st century,” the UoG said.
In its study, led by Dr Susan Fitzer from the School of Geography and Earth Sciences, mussels were found to have reduced growth and altered material properties when grown under future projected ocean acidification conditions. Their shells became harder and less elastic, making them being more prone to fracture in stormy environments and more vulnerable against predation.
Working with scientists at the Diamond Light Source, Dr Susan Fitzer’s team used synchrotron X-ray microscopy to investigate the influence of ocean acidification on amorphous calcium carbonate formation within mussel shells.
Dr Fitzer said: “Research suggests that mussels induce amorphous calcium carbonate as a repair mechanism to combat shell damage under ocean acidification.”
“These phase transitions from amorphous calcium carbonate to a crystalline structure are important to understand how marine organisms such as mussels produce their protective shells. Mussels use amorphous calcium carbonate to transport insoluble materials to crystallisation sites for growth and repair.”
Despite the findings, the mussels’ adaptation may be insufficient, the UoG said. The impact of rising oceanic acidification on the crystallisation of mussel shells still raises concerns for the protective function of shells.
Asia One, 16 February 2016. Article.
This press release has a really poor title. If the material properties are changing and shells are more brittle, saying they’re getting “stronger” is completely the wrong direction to take.