The Idaho State Department of Agriculture is about halfway done with the two-week treatment process for the infestation of invasive Quagga Mussels in the Snake River. One downside of using chemicals to kill Quagga, it also impacts fish. I.S.D.A will finish the treatment this weekend and Idaho Fish and Game will monitor fish populations for the foreseeable future. Fish downstream are safe for human consumption.(Below is the transcript from the broadcast story)The Idaho State Department of Agriculture is about halfway done with the two-week treatment process for the infestation of invasive Quagga Mussels in the Snake River.These efforts are critical to maintain the overall health of the ecosystem and to prevent billions of dollars in potential damage.But, one downside of using these chemicals to kill Quagga, it also impacts fish."It's a chelated copper product called Natrix, it's labeled specifically for this kind of use in flowing water as a molluscicide for Quagga and Zebra Mussels and it can be toxic to fish. Last year we saw some species of fish were more impacted than others, said Lloyd Knight, Deputy Director for the Idaho State Department of Agriculture.The fish species that saw the biggest impact were Carp and Sucker Fish, as well as a significant impact on the Sturgeon population.Related: But so far this year, officials say they're seeing better results."We have not seen much in terms of mortality in the section that was treated last year because the fish that experienced high mortality isn't in the system, and we never went back in there and stocked fish just in case we had to do a second treatment, said Mike Peterson, Regional Fish Manager for the Magic Valley Fish and Game.This year the I.S.D.A is focusing on efforts above the Twin Falls Power Station. This area historically already has very low Sturgeon numbers, but that doesn't mean fish aren't seeing the effects of the chemical."It's different fish habitat, we don't have near the densities at that reservoir, or at least we haven't seen that at this point, and the species that we have observed are basically Suckers and Pike Minnows. I think we've seen a coupe Yellow Perch but there is not much in that reservoir but Smallmouth Bass and some pan-fish, said Peterson.I.S.D.A crews will finish the treatment this weekend and Idaho Fish and Game will monitor fish populations for the foreseeable future.Decisions on stocking efforts will be evaluated, but for the time being, taking care of the Quagga issue is priority number one."When you're dealing with an invasive species at some point, you're going to have to make a choice over whether you let the invasive species take hold and impact the entire ecosystem or if you treat that invasive species knowing you're going to have a short-term loss in that ecosystem of some of those fish populations, said Knight.The Idaho State Department of Agriculture says fishing along the treatment area is strictly prohibited but does say any angler's catch downstream is still acceptable for human consumption. Due to the chemical only collecting in the gills of the fish, not the meat. Meaning, the meat is still good.