Even seaweeds get sunburnedAugust 25, 2008It 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." Helmholtz Association of German Research Centres Science News and Science Current Events Tag Cloud This tag cloud is a visual representation of term frequencies of random science news topics with common terms grouped together and emphasized by their display size. Ear Infections Nanoparticles Bone Marrow Spintronics Contraception Lead Poisoning San Andreas Fault Sleeping Sickness Butterflies Ozone Layer Idiopathic Pulmonary Fibrosis Weight Management DNA damage Genetics Mental Health Pulmonary Fibrosis Bees Genetic Variation Narcolepsy Climate Model Cigarettes HIV Gestational Diabetes Ozone Hole Liver Injury
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Related Ultraviolet Radiation Current Events and Ultraviolet Radiation News Articles New fabricated material changes color instantly in response to external magnetic field A research team led by a chemist at the University of California, Riverside has fabricated microscopic polymer beads that change color instantly and reversibly when external magnetic fields acting upon the microspheres change orientation. How oxidative stress may help prolong life Oxidative stress has been linked to aging, cancer and other diseases in humans. Paradoxically, researchers have suggested that small exposure to oxidative conditions may actually offer protection from acute doses. Lettuce gets a healthy suntan Salad dressing aside, a pile of spinach has more nutritional value than a wedge of iceberg lettuce. That's because darker colors in leafy vegetables are often signs of antioxidants that are thought to have a variety of health benefits. Solar wind tans young asteroids A new study published in Nature this week reveals that asteroid surfaces age and redden much faster than previously thought -- in less than a million years, the blink of an eye for an asteroid. This study has finally confirmed that the solar wind is the most likely cause of very rapid space weathering in asteroids. This fundamental result will help astronomers relate the appearance of an asteroid to its actual history and identify any after effects of a catastrophic impact with another asteroid. Discovered after 40 years: Moon dust hazard influenced by Sun's elevation In the 1960s and 1970s, the Apollo Moon Program struggled with a minuscule, yet formidable enemy: sticky lunar dust. Four decades later, a new study reveals that forces compelling lunar dust to cling to surfaces -- ruining scientific experiments and endangering astronauts' health --change during the lunar day with the elevation of the sun. Climate change and atmospheric circulation will make for uneven ozone recovery Earth's ozone layer should eventually recover from the unintended destruction brought on by the use of chlorofluorocarbons (CFCs) and similar ozone-depleting chemicals in the 20th century. Human impacts on coral reefs of Northwestern Hawaiian islands revealed Results of a new study shed light on how threats to the world's endangered coral reef ecosystems can be more effectively managed. The fragility of the world's coral is revealed through a study of the Northwestern Hawaiian Islands A new study by researchers from UC Santa Barbara's National Center for Ecological Analysis and Synthesis (NCEAS) sheds light on how threats to the world's endangered coral reef ecosystems can be more effectively managed. Rocket launches may need regulation to prevent ozone depletion, says study The global market for rocket launches may require more stringent regulation in order to prevent significant damage to Earth's stratospheric ozone layer in the decades to come, according to a new study by researchers in California and Colorado. Skin cancer study uncovers new tumor suppressor gene National Institutes of Health (NIH) researchers have identified a gene that suppresses tumor growth in melanoma, the deadliest form of skin cancer. More Ultraviolet Radiation Current Events and Ultraviolet Radiation News Articles |
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