Constructed wetlands....part 6

The other day we talked about copper as an environmental contaminant.  We have been researching the effects of copper on amphibian development.  As I've said, 13 species have colonized the wetlands.  So far we've done some studies on southern leopard frogs, southern toads, and eastern narrowmouth toads.  We look at how the eggs develop and hatch under different levels of copper and then how well larvae survive to metamorphosis--such as the southern toad on it's way to terrestrial life with back legs out, but still a tail and no front legs yet.  We do this in a lab facility where we can control everything and just vary copper exposure in the water but then also do experiments in the actual constructed wetlands where they are exposed to copper in the water but also through the food they eat.  In the wetland they also have exposure to elevated zinc and elevated pH.  We have a lot of interesting results and are working to write up some papers, but one of the most important things we've seen is that each species responds very differently to copper with leopard frogs being the most tolerant and the eastern narrowmouth toads the most sensitive.  Really emphasizes how doing an ecotox study on one species isn't good enough for setting regulations.  right now we are setting up a really large study with leopard frogs that will start looking at how the route of exposure (food or water) of copper affects them and how exposure to both copper and zinc interacts.  Crazy time now trying to get it all set up, but will be a fun and hopefully interesting study.