It is red, it burns and itches: a sunburn on our skin. However, too much sun is not only bad for humans. Many plants react sensitively to an increased dose of ultraviolet radiation, too. Yet they are dependent on sunlight.
With the help of pigments absorbing solar energy and light, plants produce their vitally important building blocks by means of photosynthesis. However, this has its limits: too much sun means an over-abundance of energy and thus the destruction of the sensitive pigments. The result are black spots, pale leaves and rotten parts.
Since algae cannot apply sun lotion like we do, they develop their own strategies to protect from the sun: "A species of red algae, for instance, produces under increased ultraviolet radiation less red light-harvesting proteins, thus decreasing the absorption of radiation. The typical red colour of the alga fades and the plant gets white tips.," explains Prof. Dr. Christian Wiencke, marine biologist at the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association. "The algae additionally produce substances which react similar to melanin in human skins: mycosporin amino acids (MAA)." Melanin absorbs ultraviolet radiation and thus protects the human skin - at the same time, it gives a natural suntan.
The ozone layer usually absorbs the major part of the hard and harmful solar ultraviolet radiation of short wavelength. However, because of stratospheric ozone depletion, these dangerous rays increasingly penetrate to the earth's surface and therefore also to the seawater.
Extensive biological experiments are presently conducted on this complex of problems at the German French Research Base AWIPEV on Spitsbergen. "We examine the harmful effects of ultraviolet radiation on algae and their protective mechanisms," says Wiencke. The ultraviolet radiation particularly harms the algae's photosynthesis and their hereditary material. These organisms usually react with a decreased rate of growth or a reduction of reproductive success.
The spores and germ cells of the algae which drift through the water as unicellular organisms are particularly sensitive. Even small ultraviolet doses are damaging and inhibit their germination. "Our investigations show that the distribution of certain species of brown algae is inhibited by the climate of ultraviolet radiation. The algae are displaced into deeper water layers if ultraviolet radiation increases."
The research conditions on Spitsbergen are optimal for Wiencke and his colleagues: "We want to observe the development of marine coastal ecosystems in the face of global climate change. Not only an increased ultraviolet radiation plays a decisive role, but also the water temperature which has been increased by the greenhouse effect. This increase in temperature can particularly be felt on Spitsbergen, in the Atlantic sector of the Arctic."Notes for Editors
The Alfred Wegener Institute carries out research in the Arctic and Antarctic as well as in the high and mid latitude oceans. The institute coordinates German polar research and makes available to international science important infrastructure, e.g. the research icebreaker "Polarstern" and research stations in the Arctic and Antarctic. AWI is one of 15 research centres within the Helmholtz Association, Germany's largest scientific organization.
Dipl.-Ing. Margarete Pauls | idw
Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide
Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences