field exposure of frog embryos and tadpoles along a pollution gradient in the fox river and green bay ecosystem in wisconsin, usa. | we raised embryos and tadpoles of green frogs (rana clamitans melanota) and leopard frogs (r. pipiens) in situ along a contamination gradient in the fox river/green bay ecosystem (wi, usa). differences in exposure were reflected by significant positive regressions between concentrations in sediment and in frogs of polychlorinated biphenyl (pcb) congeners and some heavy metals (cd, cr, and pb), which could have predictive value for estimating exposure of amphibians to contaminants in this ecosyst ... | 2005 | 15839570 |