IT HAPPENS ONLY IN INDIA,
GREAT JOB MR. PARMAR
it is good to eat as many as vegetables and fruits (totally vegetarian), but my aurvedic doctor asked me to stop eating every...
"florida Bay used to be full of sea grasses and corals, but now it is as good as a sewer pond," observes Brian LaPointe, a marine biologist at Harbour Branch Oceanographic Institution in Fort Pierce, Florida. Chemicals from agricultural runoff have brought forth the transformation. LaPointe says that the dirty water has fed an explosion in algal blooms over the past few years and is now killing the region's reefs ( New Scientist, Vol 152, No 2055).
Recently, the us Environmental Protection Agency (epa) was called to study this 'mysterious disease' threatening North America's only living coral reef in Everglades, Florida Bay. The disease is destroying the thin layer of living tissue and leaving behind only the coral's white, calcium carbonate skeleton. LaPointe suggested that high toxic nitrogen levels may be the reason for these poisoned waters. Over the years, farmers have repeatedly doused their soil with fertilisers and churned up the nitrogen-rich peat which settled into a thick black layer in the Everglades.
Nitrogen levels have become so high that even huge patches of turtle grass, which are home to various endangered species, have disappeared. The rotting vegetation probably created a nutrient-rich, oxygen-depleted soup that blocked out sunlight, killing yet more grass and providing perfect conditions for massive algal blooms. To neutralise this high nitrogen level, Florida water managers started pumping in more freshwater into the Bay. But this only made matters worse, says LaPointe, because the freshwater contained six times the normal levels of nitrogen. This fed algal growth and the blooms peaked in early 1993.
Most of the nitrogen is absorbed by a blanket of microscopic algal layer. This slimy layer is found naturally throughout Everglades, on the surface or submerged. But although nitrogen levels in the mid-Everglades are low, they soar again along the brackish fringes of the Bay. Mangroves predominate in this area, says Zieman, and their roots are home to several types of bacteria and algae that fix atmospheric nitrogen. When they die, this is released into the water as dissolved ammonia.
Therefore, a lot of nitrogen is seen floating around the Everglades, either due to agricultural runoffs or acid rain, confirmed estuarine ecologist David Rudnick of the South Florida Water Management District.
Most scientists, however, are not convinced. They accept that high levels of agricultural waste flow into the Everglades, but point out that nutrient levels gradually diminish as the water flows south. The Everglades are so adept at soaking up the waste, says Jay Zieman, an environmental scientist at the University of Virginia, that there is a 160 km stretch of nutrient poor water from the edge of agricultural area to the mangroove lined fringes of Florida Bay and one could even use it as distilled water for experiments. Seeing this, water managers have planned to exploit the Everglades' capacity to absorb nutrients by creating a 16,000 ha artificial wetland around the agricultural zone to clean the water before it enters the Everglades.
Maybe, say experts, all that is needed is a powerful hurricane to flush out the sediment and wipe the water body clean.