Earthfiles

Tonight I have some answers to recent environmental mysteries, including the strange white substance found in water near Whiskeytown, California and and the die off of birds in Louisiana. But first, there is unsettling news this week from New England about a rare virus attacking salmon there. When the first boats from Europe arrived at American shores, there were millions of wild salmon in rivers from Maine to Connecticut. But now there are only a couple of thousand left. That is why this recent outbreak of "swim bladder sarcoma virus"- seen only twice before in salmon - is especially tragic. All the virus-infected fish came from Maine's Pleasant River. Biologists have quarantined hatcheries there and have had to kill hundreds of diseased salmon. Some scientists speculate that the virus has spread from commercial salmon farms along Maine's coast where every year thousands of fish escape from their crowded holding pens. Just as humans crowded together can spread disease more easily, those commercial fish carry diseases to wild salmon that have no immunity. Another disease has been destroying birds on the West Coast. One of the worst outbreaks of Avian cholera in memory has killed more than 50,000 water birds in Northern and Central California -- including the rare and beautiful Aleutian Canada Geese that are already on the federal threatened species list. Fortunately, bird cholera is not typically transmitted to humans or other mammals. Scientists speculate that last month's cold weather caused birds to flock together in tight spaces of open water which may have spread the disease - just like the salmon crowded in those Maine commercial fisheries.