HELENA — The science reported Monday described grim conditions affecting trout in storied rivers meandering within the Jefferson River Basin — the Big Hole, the Beaverhead, the Ruby and the Jefferson.
In this file photo from August 2023, Save Wild Trout’s lead scientist Kyle Flynn carries a portable water-quality monitor out of the Big Hole River at Jerry Creek Fishing Access Site. Scientists have been studying the factors that might be driving the declines in trout populations in rivers in the Jefferson Basin.
“What we are looking at is an unprecedented, precipitous decline in wild trout fisheries and trophic shifts in macroinvertebrate communities across the Jefferson subbasin in southwest Montana,” said Guy Alsentzer, executive director of Upper Missouri Waterkeeper.
Aquatic macroinvertebrates can include insect larvae, worms, crayfish and other crustaceans often