Montana Fish, Wildlife and Parks experts are investigating what may have caused the death of thousands of whitefish in the Yellowstone River. FWP Spokesman Bob Gibson says this isn’t the first kill off scientists are aware of in the region.

“The last one was some years back in Idaho in the snake river,” said Gibson. “That one instance, the cause of death was narrowed down to probably a parasite of some kind that was affecting the whitefish. That doesn’t say that this one is parasite caused or that it isn’t.”

There is some concern that this might spread to other fish and possibly other rivers in Montana.

“As the fish health folks determine what it is that is causing the kills then they can determine how it spreads and where it is going and then we can take appropriate measure,” Gibson said. “That may well be that we require people to wash their boats going in and wash their boats going out, wash their waders going in and wash their waders going out on that stretch of river.”

Currently, there are not any restrictions in place, but Gibson hopes to receive the testing results as soon as possible so they can take the proper precautions.