Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Is the ocean losing oxygen? - Oxygen in tropical oceans is declining

02.05.2008
Marine Scientists have made an alarming new discovery. In some regions of the world oceans, oxygen essential for marine organisms is declining. This process might be caused by environmental changes in the context of global warming.

A new study lead by Dr. Lothar Stramma from the Leibniz Institute of Marine Sciences (IFM-GEOMAR) in Kiel, Germany, now published in „Science“, documents that the oxygen values in tropical oceans at a depth of 300 to 700 metres have declined during the past 50 years. As large marine organisms can either no longer exist in these areas or they would avoid them, the expanding oxygen minimum zones may have substantial biological and economical consequences.

The oxygen distribution in the ocean is not homogenous. At the eastern boundaries of the tropical oceans at depths between 200 and 800 metres, there are areas with reduced oxygen, the so-called oxygen minimum zones (OMZ). Rising CO2 levels are causing a temperature increase of the ocean and a general decline of oxygen solubility in the water.

Furthermore, and even more importantly, a reduction of oxygen-rich deep water production in polar regions leads to a reduced oxygen supply in the deep ocean. The expected impacts on subtropical and subpolar regions are larger than in the Tropics. In higher latitudes, the reduction of oxygen has already been proven by observational data. In the Tropics, this was not possible to date due to the lack of sufficient observational data. An international team of researchers, Dr. Stramma from IFM-GEOMAR, together with Dr. Gregory Johnson NOAA, Seattle, Dr. Janet Sprintall from Scripps Institution of Oceanography in San Diego and Dr. Volker Mohrholz from the Institute for Baltic Sea Research in Warnemünde, Germany selected areas with higher data density to document the decline in oxygen. “We found the largest reduction in a depth of 300-700 m in the tropical northeast Atlantic, whereas the changes in the eastern Indian Ocean were much less pronounced”, explains Dr. Stramma. “Whether or not these observed changes in oxygen can be attributed to global warming alone is still unresolved”, Stramma continues. The reduction in oxygen may also be caused by natural processes on shorter time scales” Nevertheless, the results are consistent with model results which predict a further decline in the future.

If this trend continues, it will be of particular importance for the tropical regions investigated in this study, because the oxygen concentrations are quite low and a further reduction may lead to existential problems for marine organisms and to changing biogeochemical conditions.

The results of this study are an important milestone for the ongoing work of the new Collaborative Research Centre (SFB 754) “Climate – Biogeochemistry Interactions in the Tropical Ocean” funded by the German Research Foundation, which started its first phase in January 2008 in close cooperation with the University of Kiel. The SFB aims to better define the interactions between climate and biogeochemistry on a quantitative basis.

Andreas Villwock | alfa
Further information:
http://www.ifm-geomar.de

More articles from Earth Sciences:

nachricht Large-Mouthed Fish Was Top Predator After Mass Extinction
26.07.2017 | Universität Zürich

nachricht Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds
25.07.2017 | University of Illinois at Urbana-Champaign

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

CCNY physicists master unexplored electron property

26.07.2017 | Physics and Astronomy

Molecular microscopy illuminates molecular motor motion

26.07.2017 | Life Sciences

Large-Mouthed Fish Was Top Predator After Mass Extinction

26.07.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>