When laboratory trout are exposed to these compounds at levels found in the environment, their heads develop abnormally, their yolk sacs swell with fluid, their cardiovascular systems collapse, and they die.
Blood flow makes blood vessels readily apparent.
With support from UW Sea Grant, Warren Heideman and Richard Peterson, toxicologists at UW-Madison, are working to reveal the precise cellular processes that underlie dioxin s pernicious effects on young trout. The team is also studying what dioxin does to cellular mechanisms in zebrafish, a well-studied species that is easier to work with than trout. They re the fruit fly of the vertebrate world, Heideman said. The work will help scientists better understand the risks that dioxin poses to lake trout. It will also provide a framework for assessing those risks to other freshwater fish without having to test tens of thousands of species individually, he said.