Shells slim down with CO2

Aug 09, 2011

Marine algae that turn carbon dissolved in seawater into shell will produce thinner and thinner shells as carbon dioxide levels increase.

The algae, called coccolithophores, have floated in our oceans for over 200 million years Hoovering up carbon and turning it into coccoliths - overlapping plates of .

Predicting how these algae, an important part of the carbon cycle, will react to rising has always been a puzzle. Now a team including Ros Rickaby from Oxford University’s Department of Earth Sciences, has found strong evidence that as CO2 concentration in seawater increases so calcification decreases and coccolith mass declines.

The findings, reported in a recent Nature paper, suggest that entire communities of marine organisms, such as coral, are threatened by rising CO2 and ocean acidification.

The new evidence comes from studies of half a million coccoliths from hundreds of seawater samples and ancient marine sediments cores taken from all over the world.

The research shows much greater variations in coccolith mass than previous lab-based studies, as, in the ocean, rising CO2 causes populations of algae to favour smaller, lightly calcified species over heavily calcified ones.

Further work is now needed to understand how the algae will respond to the changing marine environment and what impact a rise in thinner-shelled species will have on our oceans and the planet.

Explore further: Fish will have to find new habitats or perish if global warming is left unchecked

More information: Nature 476, 80–83 (04 August 2011) doi:10.1038/nature10295

Related Stories

CO2 makes life difficult for algae

May 10, 2011

The acidification of the world's oceans could have major consequences for the marine environment. New research shows that coccoliths, which are an important part of the marine environment, dissolve when seawater acidifies.

Microbes on the menu

Jul 28, 2010

The functioning of marine ecosystems depends on the size and flavor of microbes at the base of the food chain. Changes to the Earth's atmosphere might rearrange that microscopic menu. Microbes that currently ...

Recommended for you

Gimmicks and technology: California learns to save water

1 hour ago

Billboards and TV commercials, living room visits, guess-your-water-use booths, and awards for water stinginess—a wealthy swath of Orange County that once had one of the worst records for water conservation ...

Cities, regions call for 'robust' world climate pact

1 hour ago

Thousands of cities, provinces and states from around the world urged national governments on Thursday to deliver a "robust, binding, equitable and universal" planet-saving climate pact in December.

Will climate change put mussels off the menu?

2 hours ago

Climate change models predict that sea temperatures will rise significantly, including in the tropics. In these areas, rainfall is also predicted to increase, reducing the salt concentration of the surface ...

As nations dither, cities pick up climate slack

13 hours ago

Their national governments hamstrung by domestic politics, stretched budgets and diplomatic inertia, many cities and provinces have taken a leading role—driven by necessity—in efforts to arrest galloping ...

Should we all escape to the country during a heatwave?

17 hours ago

A University of Birmingham research project has highlighted the potential health impacts of heatwaves in urbanised areas. By modelling the 2003 heatwave the researchers were able to identify areas where city centres were ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.