A recent article in the newspaper the Missoulian (MT) reported that an annual stream survey of native bull trout in the Swan River drainage reveals a continued decline in reproduction, while the number of spawning trout in the North Fork Flathead Basin also fell below average. Biologists believe the likely culprits are two introduced species.

Tristan Scott in the Missoulian writes, “Lake trout were first planted in Flathead Lake a century ago, and for decades the population remained relatively small, co-existing with native bull trout and westslope cutthroat trout. But in the 1980s, when mysis shrimp were introduced, the historic food web began to unravel.” Read more: http://missoulian.com/news/state-and-regional/bull-trout-biologists-says-shrinking-numbers-in-swan-river-drainage/article_4f5b35fe-188f-11e1-8ea8-001cc4c002e0.html#ixzz1f1Rp1G9K