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: Mexico investigates mass fish death in lagoon

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

The underestimated risk of ethanol fireplaces

17 hours ago

Ethanol fireplaces are becoming more and more popular. However, they are not only highly combustible – in the past, severe accents have occurred repeatedly with decorative fireplaces. The devices also pollute ...

New research shows temperatures vary block by block

18 hours ago

This summer has seen the temperature rise above the severe heat mark of 90 degrees just five times, with the latest happening Wednesday afternoon. That's far fewer times than in an average New York summer.

User comments : 0