Is a thinning ozone layer causing a decline in the number of frogs?  Well for years, environmentalists have been croaking about just such a connection by stating that increased levels of uv-b radiation caused by a thinning ozone layer are roasting the amphibians eggs in shallow ponds.  But now comes a new report by the University of Washington that challenges that assertion.  The study looked at 136 breeding sites in the Olympic and Cascade mountains and found that levels of organic matter present in the water – matter which absorbs uv-b radiation and shields vulnerable eggs – were sufficiently high to protect 85 percent of the amphibians habitat. So it looks like, once again, environmentalists have leaped to wrong conclusions about ozone and frogs.