London, Dec 25 (IANS): The numbers of mussels could be threatened by climate change, as it has made oceans increasingly acidic, a team of British researchers has revealed.

In a new paper published in the Royal Society's journal Interface, researchers from the University of Glasgow in Scotland said Wednesday they found mussels' shells have become more brittle when they are formed in more acidic water, Xinhua reported.

According to Susan Fitzer, the lead researcher, this could mean mussels growing in the wild in the future could be more vulnerable to attack from predators, as well as from the effect of ocean forces.

The change in the oceanic water could also have an effect on the yields of mussels available for the fishing industry.

The research team housed common blue mussels in laboratory tanks, and altered the temperature and pH levels of the water to simulate four different types of ocean waters. Those waters, which contained different levels of acidity, are expected to appear in the oceans in the coming decades.

"What we found was that the calcite outer shells of the mussels past a certain threshold of acidity was stiffer and harder, making it more brittle and prone to fracture under pressure, and the aragonite inner shell became softer," Fitzer noted.

The world's oceans are becoming increasingly acidic as they absorb some of the atmospheric carbon dioxide which contributes to climate change. The water reacts with the carbon dioxide to form carbonic acid. Scientists expect the pH of the world's oceans to drop from 8 today to 7.7 by the end of the 21st century.