St Andrews study shows CO ² impact on marine life

RISING CARBON dioxide levels in the atmosphere are having a catastrophic effect on microscopic marine life, according to scientists at St Andrews University.

The academics told an international audience of research scientists that experiments show microscopic organisms, called foraminifera ( forams), suffer the equivalent of tooth decay as seawater becomes more acidic.

The f indings were presented at the third annual meeting of the UK Ocean Acidif ication Research programme hosted by St Andrews University yesterday.

Foraminifera are tiny single-celled organisms that build intricate shells to protect themselves.

They feed on algal cells called diatoms, which they break open using teethlike structures on their shells.

Experiments carried out at St A n d r ew s University suggest that as seawater increases in acidity these teeth are reduced in number and size, with many becoming deformed.

These mutations are likely to make them much less effective at feeding.

Since forams may number 500,000 in a square metre of sediment, other organisms further up the food chain are also likely to be affected by these changes.

Professor David Paterson of the School of Biology said: “The studies of foraminifera are only a small part of the story of ocean acidification impacts.

“But we know that many species were lost from the fossil record the last time that CO² rapidly rose, around 55 million years ago, with other major disruptions to marine.

“The threat of future acidification is very real, and comes at a time when the human population depends more than ever on a healthy and productive marine environment.”

Marine scientists are seriously concerned that these changes will have a significant impact on marine, and human, life, with consequences for shellfish, cold and warmwater corals, as well as many other components of ocean food webs.