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Every year in April an estimated two million birds take ¯ight from Australian shores and head north to their breeding grounds on the Russian tundra. When breeding is completed in September, they head south again to Australian wetlands and coasts. The routes they travel along are called `¯yways', consisting of chains of important wetlands. Nearly 40 species of migratory shorebird visit Australia each year as they follow the East Asian-Australasian ¯yway, which also includes Eastern and Southeast Asia, New Zealand and the Arctic Circle. With the constant threats to habitats in most of these countries, including Australia, shorebirds face enormous challenges to their continuing existence. However, con- servation eorts will be futile unless all countries along the ¯yway act together to protect their wetland areas. The Project activities include the development of site man- agement plans as well as on-ground rehabilitation works and bird counting programmes to enhance existing data. There will also be education and awareness raising ac- tivities targeted at community groups, local governments and State agencies. PII: S0025-326X01)00228-4 Study Could Reduce Chance of Oshore Oil Leaks Researchers at the University of Missouri-Rolla hope to reduce the occurrence of oshore oil leaks by analyzing current methods for detecting such leaks in the Gulf of Mexico. Electronic sensors are currently used to detect sudden drops in pressure and warn engineers of a potential pro- blem. Whenever the pressure in a pipeline drops below a pre-set amount, the sensors set o an alarm known as a pressure safety low or PSL). This alarm indicates a possible leak or break in the pipe. Pressure monitoring is eective because wall failure of a pipeline under pressure is a sudden event, and the ¯uid loss produces a sudden pressure disturbance within the pipeline. These oshore pipelines operate at designated pressures, which are con- tinuously recorded and monitored as a means of de- termining leaks. However, the current systems, although eective, can give false alarms and even result in some leaks going undetected. Previously the group had carried out research into a better understanding of the behaviour of pipelines. They worked out how often line failures might occur, the probability of a release, and the probable failure rate for the sophisticated systems that monitor oil and gas pres- sure in oshore pipelines. The researchers are now plan- ning to take the matter a step further. In their new study, they will analyze the reliability of PSL alarms in detecting actual pipeline releases, and then submit their re- commendations for improving the monitoring system's reliability. It is hoped that the results will help the oil and gas industry to improve the monitoring of undersea pipeline operations and hence reduce the number of oil leaks that occur. PII: S0025-326X01)00229-6 Red Tides and Dust Storms A remarkable and previously unsuspected connection has been found between red tides in the Gulf of Mexico and giant dust clouds that blow across the Atlantic Ocean from the Sahara Desert. Storm activity in the Sahara Desert region kicks up ®ne particles from the arid topsoil there, generating vast clouds of dust. Easterly trade winds carry the dust across the Atlantic Ocean and into the Gulf of Mexico. NOAA and NASA satellites are able to spot such dust clouds en route from Africa to the Americas. In a study, carried out by University of South Florida's College of Marine Science, the arrival of the clouds was matched with the occurrence of red tides and a pattern emerged. The data revealed that these clouds appear to fertilize the water o the West Florida coast with the element iron. Plant-like bacteria cyanobacteria) such as Trichodesmium use that iron to ®x nitrogen in the water, converting it to a form usable by other marine life. The addition of this biologically usable nitrogen in the water makes the Gulf of Mexico a much more productive en- vironment for toxic algae. These reproduce very quickly in the new fertile environment and a red tide ensues. Red tides, which are blooms of these toxic algae, have in the past killed huge numbers of ®sh, shell®sh, marine mammals, and birds. They can also trigger skin and re- spiratory problems in humans. The study used satellite and ground based measure- ments to track large dust clouds leaving Africa on June 17, 1999. The Saharan dust reached the West Florida shelf around July 1st, increasing iron concentrations in the surface waters by 300%. As a result, Trichodesmium counts shot up to 10 times what they had been prior to this event. This resulted in a massive 300% increase in available nitrogen in these waters. By October, a huge bloom of toxic red algae Karenia brevis) had formed within the study area, an 8,100 square mile region be- tween Tampa Bay and Fort Myers, Florida. Around the Gulf of Mexico, scientists and others have recorded ®sh kills totalling in the millions and manatee deaths in the hundreds resulting from a single red tide bloom. Humans who swim in the Gulf during a red tide can experience respiratory problems by breathing toxins from K. brevis that get in the air. Also, eating shell®sh poisoned by red tides can lead to paralysis and memory problems. Scientists have been working for many years to try and ®nd a reliable method of predicting red tides, and hence prevent many of the physical and economically devastating to a region. By using satellites to monitor dust arrivals, and from their predictions of the Trichodesmium blooms, it should be possible to forecast red tides. This would allow beaches and ®sheries to be closed in advance and prevent many of the eects that always ensue. Marine Pollution Bulletin 796

Red tides and dust storms

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