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 Novel method for investigating pore geometry in rocks
18.06.2018 | Kyushu University, I2CNER

nachricht Decades of satellite monitoring reveal Antarctic ice loss
14.06.2018 | University of Maryland

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

Im Focus: Water is not the same as water

Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.

From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Novel method for investigating pore geometry in rocks

18.06.2018 | Earth Sciences

Diamond watch components

18.06.2018 | Process Engineering

New type of photosynthesis discovered

18.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>