Navigation Links
Nitrogen fixation and phytoplankton blooms in the southwest Indian Ocean
Date:8/14/2009

Observations made by Southampton scientists help understand the massive blooms of microscopic marine algae phytoplankton in the seas around Madagascar and its effect on the biogeochemistry of the southwest Indian Ocean.

The observations were made by researchers based at the National Oceanography Centre, Southampton (NOCS) during a 2005 hydrographic survey south and east of Madagascar while aboard the royal research ship RRS Discovery. The fully analysed results are published in the journal Geophysical Research Letters.

Nitrogen-fixing bacteria convert atmospheric nitrogen into nitrogen compounds that organisms can then use as food. This process is thought to be important in areas of the ocean where nitrogen-based nutrients are otherwise in short supply, and the researchers confirm that this is indeed the case in the region south of Madagascar.

But there were some surprises. Previously, it has been thought that the large-scale autumn bloom that develops in this region is driven by nitrogen-fixing blue-green algae, or cyanobacteria, called Trichodesmium, colonies of which the researchers found to be abundant. However, the 2005 bloom was dominated by a diatom a type of phytoplankton the cells of which play host to another nitrogen-fixing cyanobacterium called Richella intracellularis, with Trichodesmium apparently playing second fiddle.

Diatoms have relatively large cells, and when they die they sink down the water column, carrying with them carbon that is ultimately derived from carbon dioxide drawn from the atmosphere though the process of photosynthesis. "Carbon dioxide is a greenhouse gas, and enhanced export of carbon to the deep ocean in the bodies of diatoms is an important natural mechanism by which the ocean regulates atmospheric carbon dioxide and our climate," says team member Dr Alex Poulton of NOCS.

The researchers believe that their findings will have an impact on modelling and satellite studies of the Madagascar bloom. "Future research will also need to account for the magnitude of carbon export associated with diatoms and their nitrogen-fixing guests in the southwest Indian Ocean, and indeed other subtropical oceanic settings," says Dr Poulton.


'/>"/>

Contact: Dr. Rory Howlett
r.howlett@noc.soton.ac.uk
44-023-805-98490
National Oceanography Centre, Southampton (UK)
Source:Eurekalert

Related biology news :

1. Ozone, nitrogen change the way rising CO2 affects Earths water
2. Nitrogen research shows how some plants invade, take over others
3. UC Davis begins $2.8 million in studies of agricultural nitrogens impacts
4. Illinois Soil Nitrogen Test measures microbial nitrogen
5. Tree species composition influences nitrogen loss from forests
6. Researchers call for nitrogen and phosphorus reductions to combat eutrophication in aquatic systems
7. Cropland diversity reduces nitrogen pollution
8. Lichens function as indicators of nitrogen pollution in forests
9. Nitrogen applied
10. A little nitrogen can go a long way
11. EPA releases science assessment on health effects of nitrogen oxides
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/2/2016)... , Feb. 2, 2016 This ... the bioinformatic market by reviewing the recent advances ... tools that drive the field forward. Includes forecast ... Identify the challenges and opportunities that exist ... and software solution developers, as well as IT ...
(Date:2/1/2016)... -- Rising sales of consumer electronics coupled ... gesture control market size through ... electronics coupled with new technological advancements to drive global ... through 2020   --> Rising ... to drive global touchfree intuitive gesture control market ...
(Date:1/25/2016)... 2016   Unisys Corporation (NYSE: UIS ) today ... (JFK) International Airport, New York City , to ... attempting to enter the United States using ... pilot testing of the system at Dulles last year. ... JFK during January 2016. --> pilot testing of ...
Breaking Biology News(10 mins):
(Date:2/5/2016)... 5, 2016 Australian-US drug discovery and development company, ... appointment of a new Chairman, Mr John O,Connor , ... immediately. James Garner , has also been ... former Acting CEO, Mr Iain Ross , will resume ... --> James Garner , has also been formally appointed ...
(Date:2/4/2016)... , February 4, 2016 - New FDA action ... - New FDA action date of July 22, ... July 22, 2016   - ... in the past decade indicated for the treatment of signs and symptoms of ... has the potential to be the only product approved in the U.S. in ...
(Date:2/4/2016)... ... February 04, 2016 , ... Shimadzu Scientific Instruments ... host live demos and poster sessions, and present on the analysis of mycotoxins ... place March 6 to 10 at the Georgia World Congress Center in Atlanta, ...
(Date:2/4/2016)... -- Beike Biotechnology, the Shenzhen ... in late 2015 to mark their successful combined efforts ... --> --> The signing, ... Therapy" was hosted by the Shenzhen Cell Bank and ... Beike Biotechnology Co., Ltd. Shenzhen,s ...
Breaking Biology Technology: