Tiny plankton could have big impact on climate

Sep 13, 2013
Tiny plankton could have big impact on climate
Researchers check the "mesocosms," eight-meter long floatation frames carrying plastic bags with a capacity of 50 cubic meters, deployed for a five-week long field study on ocean acidification conducted in the Kongsfjord off the Arctic archipelago of Svalbard. The results are published in the EGU open access journal Biogeosciences. Credit: Ulf Riebesell/GEOMAR

As the climate changes and oceans' acidity increases, tiny plankton seem set to succeed. An international team of marine scientists has found that the smallest plankton groups thrive under elevated carbon dioxide (CO2) levels. This could cause an imbalance in the food web as well as decrease ocean CO2 uptake, an important regulator of global climate. The results of the study, conducted off the coast of Svalbard, Norway, in 2010, are now compiled in a special issue published in Biogeosciences, a journal of the European Geosciences Union.

"If the tiny plankton blooms, it consumes the nutrients that are normally also available to larger plankton species," explains Ulf Riebesell, a professor of biological oceanography at the GEOMAR Helmholtz Centre for Ocean Research Kiel in Germany and head of the experimental team. This could mean the larger plankton run short of food.

Large plankton play an important role in carbon export to the deep ocean, but in a system dominated by the so-called pico- and nanoplankton, less carbon is transported out of surface waters. "This may cause the oceans to absorb less CO2 in the future," says Riebesell.

The potential imbalance in the plankton food web may have an even bigger . Large plankton are also important producers of a climate-cooling gas called dimethyl sulphide, which stimulates cloud-formation over the oceans. Less dimethyl sulphide means more sunlight reaches the Earth's surface, adding to the . "These important services of the ocean may thus be significantly affected by acidification."

Ecosystems in the Arctic are some of the most vulnerable to acidification because the cold temperatures here mean that the ocean absorbs more carbon dioxide. "Acidification is faster there than in temperate or ," explains the coordinator of the European Project on Ocean Acidification (EPOCA), Jean-Pierre Gattuso of the Laboratory of Oceanography of Villefranche-sur-Mer of the French National Centre for Scientific Research (CNRS).

The increasing acidity is known to affect some calcifying organisms in the Arctic, including certain sea snails, mussels and other molluscs. But scientists did not know until now how ocean acidification alters both the base of the marine food web and carbon transport in the ocean.

The five-week long field study conducted in the Kongsfjord off the Arctic archipelago of Svalbard, under the EPOCA framework, intended to close this knowledge gap. For the experiment, the scientists deployed nine large 'mesocosms', eight-metre long floatation frames carrying plastic bags with a capacity of 50 cubic metres. These water enclosures, developed at GEOMAR, allow researchers to study plankton communities in their natural environment under controlled conditions, rather than in a beaker in the lab. Few studies have looked at whole communities before.

The scientists gradually added CO2 to the mesocom water so that it reached acidity levels expected in 20, 40, 60, 80 and 100 years, with two bags left as controls. They also added nutrients to simulate a natural plankton bloom, as reported in the Biogeosciences special issue.

The team found that, where CO2 was elevated, pico- and, to a lesser extent, nanoplankton grew, drawing down nutrients so there were less available to larger plankton. "The different responses we observed made it clear that the communities' sensitivity to acidification depends strongly on whether or not nutrients are available," Riebesell summarises.

"Time and [time] again the tiniest benefits from the surplus CO2, they produce more biomass and more organic carbon, and dimethyl sulphide production and export are decreasing," he concludes.

Explore further: Pharmaceuticals and the water-fish-osprey food web

Related Stories

Global change puts plankton under threat

May 04, 2012

Changes in the ocean’s chemistry, as a result of increasing atmospheric carbon dioxide (CO2) levels, threaten marine plankton to a greater extent than previously thought, according to new research.

Coccoliths thrive despite ocean acidification

May 22, 2013

Ocean acidification is damaging some marine species while others thrive, say scientists. An international team studied the effect of ocean acidification on plankton in the North Sea over the past forty years, ...

Recommended for you

Pharmaceuticals and the water-fish-osprey food web

8 hours ago

Ospreys do not carry significant amounts of human pharmaceutical chemicals, despite widespread occurrence of these chemicals in water, a recent U.S. Geological Survey (USGS) and Baylor University study finds. ...

User comments : 5

Adjust slider to filter visible comments by rank

Display comments: newest first

Egleton
not rated yet Sep 13, 2013
Humph. I was hoping for some good news for a change.
NikFromNYC
1 / 5 (11) Sep 13, 2013
Good news is bad news as long as "potential imbalances" influence obscure stuff you couldn't measure and "may cause" oceans to do the *opposite* of what the CO₂ starved current ocean is now *actually* doing which is vastly increasing its overall vitality exactly as human demands on it are finally peaking.

Actual link to full article: http://www.biogeo...2013.pdf

Terrorizing school kids with impending doom outfits whole globe trotting teams for important missions in the world's most exotic locales:
http://s22.postim..._Job.jpg

Compressing a century of CO₂ change into five weeks?

"Never mind, but do enjoy our beaming team photo, that we put into a science paper. A picture of our team. In a science paper. We put ourselves decked out in thousand dollar outfits into our science paper. Notice that our male to female ratio is 1:1 and that few of the females are old like many of us men are! Woot woot! Suckers!!! Doom doom doom."
Neinsense99
2 / 5 (8) Sep 13, 2013
Good news is bad news as long as "potential imbalances" influence obscure stuff you couldn't measure and "may cause" oceans to do the *opposite* of what the CO₂ starved current ocean is now *actually* doing which is vastly increasing its overall vitality exactly as human demands on it are finally peaking.

Actual link to full article: http://www.biogeo...2013.pdf

Compressing a century of CO₂ change into five weeks?

"Never mind, but do enjoy our beaming team photo, that we put into a science paper. A picture of our team. In a science paper. We put ourselves decked out in thousand dollar outfits into our science paper. Notice that our male to female ratio is 1:1 and that few of the females are old like many of us men are! Woot woot! Suckers!!! Doom doom doom."

Lots of smear, not much science.
kevin_buckeye_3
1.4 / 5 (9) Sep 13, 2013
@Nik has the IQ of about 0. Most anti-science Nazis do.
Howhot
3 / 5 (2) Sep 15, 2013
The potential imbalance in the plankton food web may have an even bigger climate impact. Large plankton are also important producers of a climate-cooling gas called dimethyl sulphide, which stimulates cloud-formation over the oceans.


That is an unexpected consequence of the biology of the oceans effecting climate change and then climate change effecting the biology. Who would have expected a feedback loop like that?

Certainly not @Nik anti science bigot of 0 IQ fame.