FWP Updates Extent of Parasite Distribution in MT Rivers

Thursday Feb. 2nd, 2017

Montana Fish, Wildlife and Parks released a map today indicating the streams in southwest Montana that have tested positive to date for the presence of Tetracapsuloides bryosalmonae (PKX). PKX is the parasite associated with the large fish kill in 2016 on the Yellowstone River.

The Big Hole River is the latest Montana waterbody to test positive for the presence of PKX. Other rivers already found to test positive include the Jefferson, Madison, East Gallatin, Gallatin, Yellowstone, Shields (at the Yellowstone), Boulder, Stillwater, and Big Horn. Of these rivers, only on the Yellowstone River has there been a documented disease event associated with PKX. Several Yellowstone tributaries (as noted on the map with white circles) were also tested and the parasite was not detected.

“The presence of the parasite alone doesn’t mean disease,” says FWP Fisheries Chief Eileen Ryce. “However, this map gives us a better handle on the extent of its distribution and reinforces the need to ramp up our fight against aquatic invasive species statewide.”

Recent aquatic invasive species findings in Montana include PKX and invasive mussel larvae in late fall of 2016. Ryce emphasized the need for Montana boaters and other recreationists to always employ the Clean. Drain. Dry. protocol to prevent the spread of aquatic invasive species.