Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Earth Science News .




FLORA AND FAUNA
Researchers publish results of an iron fertilization experiment
by Staff Writers
Munich, Germany (SPX) Jul 20, 2012


Iron plays an important role in the climate system. It is involved in many biochemical processes such as photosynthesis and is hence an essential element for biological production in the oceans and, therefore, for CO2 absorption from the atmosphere.

An international research team has published the results of an ocean iron fertilization experiment (EIFEX) carried out in 2004 in the current issue of the scientific journal Nature. Unlike the LOHAFEX experiment carried out in 2009, EIFEX has shown that a substantial proportion of carbon from the induced algal bloom sank to the deep sea floor.

These results, which were thoroughly analyzed before being published now, provide a valuable contribution to our better understanding of the global carbon cycle.

An international team on board the research vessel Polarstern fertilized in spring 2004 (i.e. at the end of the summer season in the southern hemisphere) a part of the closed core of a stable marine eddy in the Southern Ocean with dissolved iron, which stimulated the growth of unicellular algae (phytoplankton). The team followed the development of the phytoplankton bloom for five weeks from its start to its decline phase.

The maximum biomass attained by the bloom was with a peak chlorophyll stock of 286 Milligram per square metre higher than that of blooms stimulated by the previous 12 iron fertilization experiments.

According to Prof. Dr. Victor Smetacek and Dr. Christine Klaas from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association, this was all the more remarkable because the EIFEX bloom developed in a 100 metre deep mixed layer which is much deeper than hitherto believed to be the lower limit for bloom development.

The bloom was dominated by diatoms, a group of algae that require dissolved silicon to make their shells and are known to form large, slimy aggregates with high sinking rates at the end of their blooms.

"We were able to prove that over 50 per cent of the plankton bloom sank below 1000 metre depth indicating that their carbon content can be stored in the deep ocean and in the underlying seafloor sediments for time scales of well over a century", says Smetacek.

These results contrast with those of the LOHAFEX experiment carried out in 2009 where diatom growth was limited by different nutrient conditions, especially the absence of dissolved silicon in the chosen eddy. Instead, the plankton bloom consisted of other types of algae which, however, have no protective shell and were eaten more easily by zooplankton.

"This shows how differently communities of organisms can react to the addition of iron in the ocean", says Dr. Christine Klaas. "We expect similarly detailed insights on the transportation of carbon between atmosphere, ocean and sea bottom from the further scientific analysis of the LOHAFEX data", adds Prof. Dr. Wolf-Gladrow, Head of Biosciences at the Alfred Wegener Institute, who is also involved in the Nature study.

Iron plays an important role in the climate system. It is involved in many biochemical processes such as photosynthesis and is hence an essential element for biological production in the oceans and, therefore, for CO2 absorption from the atmosphere.

During past ice ages the air was cooler and drier than it is today and more iron-containing dust was transported from the continents to the ocean by the wind. The iron supply to marine phytoplankton was hence higher during the ice ages. This natural process is simulated in iron fertilisation experiments under controlled conditions.

"Such controlled iron fertilization experiments in the ocean enable us to test hypotheses and quantify processes that cannot be studied in laboratory experiments. The results improve our understanding of processes in the ocean relevant to climate change", says Smetacek.

"The controversy surrounding iron fertilization experiments has led to a thorough evaluation of our results before publication", comments the marine scientist as an explanation for the long delay between the experiment to the current publication in Nature.

Original publication: Victor Smetacek, Christine Klaas et al. (2012): Deep carbon export from a Southern Ocean iron-fertilized diatom bloom. Nature doi:10.1038/nature11229

.


Related Links
Helmholtz Association of German Research Centres
Darwin Today At TerraDaily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





FLORA AND FAUNA
Do dolphins think nonlinearly?
Southampton, UK (SPX) Jul 20, 2012
Research from the University of Southampton, which examines how dolphins might process their sonar signals, could provide a new system for man-made sonar to detect targets, such as sea mines, in bubbly water. When hunting prey, dolphins have been observed to blow 'bubble nets' around schools of fish, which force the fish to cluster together, making them easier for the dolphins to pick off. ... read more


FLORA AND FAUNA
Japan sets compensation for Fukushima evacuees

Japan firm 'told workers to lie about radiation dose'

Raytheon technology to transform commercial cargo ships into cutting-edge humanitarian aid delivery platforms

Two China workers killed in Singapore tunnel accident

FLORA AND FAUNA
New Notre Dame research raises questions about iris recognition systems

PayPal stuffs startup into its smartphone wallet

Heat is Source of 'Pioneer Anomaly'

To Extinguish a Hot Flame, DARPA Studied Cold Plasma

FLORA AND FAUNA
Aquifer could supply water for centuries

How to make global fisheries worth five times more

Sea rise threatens 'paradise' Down Under

Faroe Islands blast threat of EU sanctions in mackerel war

FLORA AND FAUNA
Greenland glacier loses ice

The challenges facing the vulnerable Antarctic

5.5-mile-long landslide spotted in Alaska

Antarctica faces major threats in the 21st century, says Texas A and M researcher

FLORA AND FAUNA
Conflict, hunger, cholera and locusts: Mali's woes mount

Scientists Develop New Carbon Accounting Method to Reduce Farmers' Use of Nitrogen Fertilizer

Enhanced royal jelly produces jumbo queen bee larvae

Refining the tool kit for sustainable fisheries

FLORA AND FAUNA
X-rays illuminate the origin of volcanic hotspots

Heavy rain fears as typhoon menaces Japan

Japan warily eyes typhoon

Typhoon dumps rain on flood-weary Japan

FLORA AND FAUNA
China doubles loans to Africa to $20 billion

Sudan rebels claim Darfur helicopter shoot-down

Nigeria increases defense spending

Afro-Japanese fusion music puzzles traditionalists

FLORA AND FAUNA
Oregon's Paisley Caves as old as Clovis sites - but not Clovis

Unique Neandertal arm morphology due to scraping, not spearing

Neanderthals at El Sidron, Northern Spain, had knowledge of plants' healing qualities

Endangered languages get a Google protection plan




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement