The breathing sand
New measurement technique detects oxygen supply to the bottom of the North Sea
2014-10-20
(Press-News.org) A desert at the bottom of the sea? Although the waters of the North Sea exchange about every two to three years, there is evidence of decreasing oxygen content. If lower amounts of this gas are dissolved in seawater, organisms on and in the seabed produce less energy – with implications for larger creatures and the biogeochemical cycling in the marine ecosystem. Since nutrients, carbon and oxygen circulate very well and are processed quickly in the permeable, sandy sediments that make up two-thirds of the North Sea, measurements of metabolic rates are especially difficult here. Using the new Aquatic Eddy Correlation technique, scientists from GEOMAR Helmholtz Centre for Ocean Research Kiel, Leibniz Institute of Freshwater Ecology and Inland Fisheries, the University of Southern Denmark, the University of Koblenz-Landau, the Scottish Marine Institute and Aarhus University were able to demonstrate how oxygen flows at the ground of the North Sea. Their methods and results are presented in the Journal of Geophysical Research: Oceans.
"The so-called 'Eddy Correlation' technique detects the flow of oxygen through these small turbulences over an area of several square meters. It considers both the mixing of sediments by organisms living in it and the hydrodynamics of the water above the rough sea floor", Dr. Peter Linke, a marine biologist at GEOMAR, explains. "Previous methods overlooked only short periods or disregarded important parameters. Now we can create a more realistic picture." The new method also takes into account the fact that even small objects such as shells or ripples shaped by wave action or currents are able to impact the oxygen exchange in permeable sediments.
On the expedition CE0913 with the Irish research vessel CELTIC EXPLORER, scientists used the underwater robot ROV KIEL 6000 to place three different instruments within the "Tommeliten" area belonging to Norway: Two "Eddy Correlation Landers" recorded the strength of oxygen fluxes over three tidal cycles. Information about the distribution of oxygen in the sediment was collected with a "Profiler Lander", a seafloor observatory with oxygen sensors and flow meters. A "Benthic chamber" isolated 314 square centimetres of sediment and took samples from the overlying water over a period of 24 hours to determine the oxygen consumption of the sediment.
"The combination of traditional tools with the 'Eddy Correlation' technique has given us new insights into the dynamics of the exchange of substances between the sea water and the underlying sediment. A variety of factors determine the timing and amount of oxygen available. Currents that provide the sandy sediment with oxygen, but also the small-scale morphology of the seafloor, ensure that small benthic organisms are able to process carbon or other nutrients. The dependencies are so complex that they can be decrypted only by using special methods", Dr. Linke summarizes. Therefore, detailed measurements in the water column and at the boundary to the seafloor as well as model calculations are absolutely necessary to understand basic functions and better estimate future changes in the cycle of materials. "With conventional methods, for example, we would never have been able to find that the loose sandy sediment stores oxygen brought in by the currents for periods of less water movement and less oxygen introduction."
INFORMATION:
Original publication:
McGinnis, D. F., S. Sommer, A. Lorke, R. N. Glud, P. Linke (2014): Quantifying tidally driven benthic oxygen exchange across permeable sediments: An aquatic eddy correlation study. Journal of Geophysical Research: Oceans, doi:10.1002/2014JC010303.
Links:
GEOMAR Helmholtz Centre for Ocean Research Kiel
Eddy correlation information page
Leibniz Institute of Freshwater Ecology and Inland Fisheries, IGB
University of Southern Denmark
University of Koblenz-Landau
Scottish Marine Institute
Aarhus University
Images:
High resolution images can be downloaded at http://www.geomar.de/n2110-e.
Video footage is available on request.
Contact:
Dr. Peter Linke (GEOMAR FB2-MG), Tel. 0431 600-2115, plinke@geomar.de
Maike Nicolai (GEOMAR, Kommunikation & Medien), Tel. 0431 600-2807, mnicolai@geomar.de
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2014-10-20
To make a decision for or against adjuvant chemotherapy, a test to measure the concentrations of the biomarkers uPA and PAI-1 in the tumour tissue is available for breast cancer patients. However, as suitable studies are lacking, it remains unclear for patients with an intermediate risk of recurrence which benefit or harm a treatment strategy based on this test may have for them. This is the result of the final report published by the Institute for Quality and Efficiency in Health Care (IQWiG) on 20 October 2014.
Adjuvant systemic treatments aim to prolong survival
Even ...
2014-10-20
Individuals who are genetically predisposed to obesity may soon have a therapeutic solution to combat their condition. A research team led by scientists from the National University of Singapore (NUS) has identified several potent inhibitors that selectively target FTO, the common fat mass and obesity-associated gene. These FTO-specific inhibitors pave the way for the development of novel anti-obesity drugs and treatments.
The research, led by Assistant Professor Esther Woon from the Department of Pharmacy at the NUS Faculty of Science, along with colleagues from the ...
2014-10-20
In a world of matinee idols and cover girls it's easy to assume that humans want their men to be manly and their women womanly.
But a groundbreaking new study suggests that, rather than being a preference passed down through a long process of social and sexual selection, it's a relatively new habit that has only emerged in modern, urbanised societies.
A team of psychologists, anthropologists and biologists, led by Brunel University London, surveyed 12 populations around the world, from the primitive to the highly developed.
Surprisingly, only in the most industrialised ...
2014-10-20
Iron is the most abundant trace element in humans. As a cofactor of certain proteins, it plays an essential role in oxygen transport and metabolism. Due to the major importance of iron in a wide variety of cellular processes, and the harm caused by its uncontrolled accumulation in the body, its uptake and storage is strictly regulated. In mammals, iron is imported into cells by the membrane transport protein DMT1. Mutations of DMT1, which affect its transport properties, lead to iron-related metabolic disorders such as anemia and the iron storage disease hemochromatosis.
Ines ...
2014-10-20
How did life originate? And can scientists create life? These questions not only occupy the minds of scientists interested in the origin of life, but also researchers working with technology of the future. If we can create artificial living systems, we may not only understand the origin of life - we can also revolutionize the future of technology.
Protocells are the simplest, most primitive living systems, you can think of. The oldest ancestor of life on Earth was a protocell, and when we see, what it eventually managed to evolve into, we understand why science is so fascinated ...
2014-10-20
The drug combination umeclidinium/vilanterol (trade name Anoro) has been approved since May 2014 for adults with chronic obstructive pulmonary disease (COPD). In an early benefit assessment pursuant to the Act on the Reform of the Market for Medicinal Products (AMNOG), the German Institute for Quality and Efficiency in Health Care (IQWiG) examined whether this drug combination offers an added benefit over the appropriate comparator therapy.
According to the findings, an added benefit is not proven: For patients with moderate COPD severity and patients with fewer than ...
2014-10-20
Scientists at Nanyang Technological University (NTU Singapore) have discovered a new molecule which can join together chains of amino acids – the building blocks of protein.
Only three other known molecules have been discovered to be able to perform this function, which is an important process in the development of new drugs. A key difference is that the new molecule is able to do the same process 10,000 times faster than the other three and "cleanly" without leaving any residue behind.
This new molecule, which is a type of catalyst or enzyme, was derived from ...
2014-10-20
Researchers at VTT Technical Research Centre of Finland, the University of Turku and the University of Oslo have discovered a previously unknown molecular-level mechanism that may partly explain the increased growth of cancer cells. The study, published in the British Journal of Cancer, showed that high levels of miRNA-378a-5p molecule cause cell division anomalies. This renders the number of chromosomes in cancer cells abnormal, which is known to promote growth and the spread of cancer. In addition, the researchers discovered that elevated miRNA378a-5p levels in breast ...
2014-10-20
Laser physicists have built a tractor beam that can repel and attract objects, using a hollow laser beam that is bright around the edges and dark in its centre.
It is the first long-distance optical tractor beam and moved particles one fifth of a millimetre in diameter a distance of up to 20 centimetres, around 100 times further than previous experiments.
"Demonstration of a large scale laser beam like this is a kind of holy grail for laser physicists," said Professor Wieslaw Krolikowski, from the Research School of Physics and Engineering at The Australian National ...
2014-10-20
What does a 1980s experimental aircraft have to do with state-of-the art quantum technology? Lots, as shown by new research from the Quantum Control Laboratory at the University of Sydney, and published in Nature Physics today.
Over several years a team of scientists has taken inspiration from aerospace research and development programs to make unusually shaped experimental aircraft fly.
"It always amazed me that the X-29, an American airplane that was designed like a dart being thrown backwards, was able to fly. Achieving this, in 1984, came through major advances ...
LAST 30 PRESS RELEASES:
[Press-News.org] The breathing sand
New measurement technique detects oxygen supply to the bottom of the North Sea
