Ships bring alien jellyfish invaders to our shoresAugust 16, 2005Marine environments around the world are being threatened by exotic species of the moon jellyfish being dispersed by international shipping, according to new research. Using genetic data and computer simulations of ocean currents and water temperatures, researchers from the University of New South Wales and the University of California, Davis, have revealed that the moon jellyfish could not have migrated naturally, according to a report in today's Proceedings of the National Academy of Sciences journal. By simulating the movement of the jellyfish - of the genus Aurelia - over a 7,000 year period the study provides strong evidence that their world-wide dispersal post-dates European global shipping and trade that began almost 500 hundred years ago. Recent surveys suggest that up to almost one quarter (23 per cent) of all marine species in international harbours are non-indigenous, according to one of the research authors, Dr Mike Dawson of the University of California, Davis. "Marine organisms traverse the globe in ballast water, on ship hulls and through the trade of exotic species such as tropical fish and this has potential to displace local marine species, threaten ecosystems and cause billions of dollars in damage and preventive control," says Dawson who tracked the invading jellyfish in Japan, California, western Europe and the east and west Australian coastlines. Introduced species are believed to cost the United States $122 billion per year. About 3,000 species of marine organisms are believed to travel the world in ships' ballast water each day. Ships take in water for stability before a voyage and despite preventative measures such as mid-ocean exchange/flushing this 'foreign' water and its contents can find their way into bays and harbours at the destination. The computer model used to track jellyfish movements could answer similar questions about the migration and introduction of any suspected non-native marine creatures, according to its developers, UNSW oceanographers, Associate Professor Matthew England and Alex Sen Gupta. "Until now our knowledge of natural and human-assisted dispersal of species has been insufficient to confidently track and predict the spread of non-indigenous marine species," says Professor England. "Now we have a tool that can include data on currents, geography and the biology of an organism to help separate natural dispersal from that which happens through shipping and trad. It's a pretty sophisticated model and we plan to make it available as a research tool on the World Wide Web." Discovery: new species of moon jellyfish The researchers also discovered that there are far more species of moon jellyfish than previously thought. "We identified 16 species of moon jellyfish, revealing that marine biodiversity is actually much higher than was thought previously," Dr Dawson says, "in retrospect it's easy to see how this wasn't noticed until now. "When you examine moon jellyfish from locations from around the world they look very similar; it's only when you analyse their DNA as we did, that it becomes obvious that they're very different. This means that traditional methods that compare physical characteristics can benefit from modern techniques such as DNA analysis,\\\ University of New South Wales |
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| Related Jellyfish Current Events and Jellyfish News Articles Aquatic creatures mix ocean water Understanding mixing in the ocean is of fundamental importance to modeling climate change or predicting the effects of an El Niño on our weather. Modern ocean models primarily incorporate the effects of winds and tides. However, they do not generally take into account the mixing generated by swimming animals. Scientists Unravel Evolution of Highly Toxic Box Jellyfish With thousands of stinging cells that can emit deadly venom from tentacles that can reach ten feet in length, the 50 or so species of box jellyfish have long been of interest to scientists and to the public. Yet little has been known about the evolution of this early branch in the animal tree of life. Vibrations key to efficiency of green fluorescent protein University of California, Berkeley, chemists have discovered the secret to the success of a jellyfish protein whose green glow has made it the darling of biologists and the subject of the 2008 Nobel Prize in Physiology or Medicine. Scientists find 'great Pacific Ocean garbage patch' Scientists have just completed an unprecedented journey into the vast and little-explored "Great Pacific Ocean Garbage Patch." NOAA and partners to survey marine life at USS Monitor wreck site NOAA will participate in a private research expedition to study marine life living on and around the wreck of the USS Monitor. Researchers link jellyfish, other small sea creatures to large-scale ocean mixing The ocean's smallest swimming animals, such as jellyfish, can have a huge impact on large-scale ocean mixing, researchers have discovered. Unusually large family of green fluorescent proteins discovered in marine creature Researchers at Scripps Institution of Oceanography at UC San Diego and the Salk Institute for Biological Studies have discovered a family of green fluorescent proteins (GFPs) in a primitive sea animal, along with new clues about the role of the proteins that has nothing to do with their famous glow. Early family ties: No sponge in the human family tree Since the days of Charles Darwin, researchers are interested in reconstructing the "Tree of Life", and in understanding the development of animal and plant species during their evolutionary history. Scripps Scientists Help Decode Mysterious Green Glow of the Sea Many longtime sailors have been mesmerized by the dazzling displays of green light often seen below the ocean surface in tropical seas. Fireflies and jellyfish help illuminate quest for cause of infertility Genes taken from fireflies and jellyfish are literally shedding light on possible causes of infertility and autoimmune diseases in humans. More Jellyfish Current Events and Jellyfish News Articles |
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