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
Gas hydrate research: Advanced knowledge and new technologies
23.03.2018 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ
New technologies and computing power to help strengthen population data
22.03.2018 | University of Southampton
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
23.03.2018 | Event News
19.03.2018 | Event News
16.03.2018 | Event News
23.03.2018 | Materials Sciences
23.03.2018 | Agricultural and Forestry Science
23.03.2018 | Physics and Astronomy