MISSOULA, Mont. \u2014 Montana Fish, Wildlife and Parks researchers have identified the streams that contribute most to bull trout recovery in the Swan River basin through a new study combining decades of spawning data with advanced otolith, or fish ear bone, analysis.<\/p>\n
The research found that some tributaries produce more surviving bull trout than spawning nest counts alone suggest, while others contribute fewer fish despite similar spawning activity. By analyzing the unique chemical signatures preserved in otoliths, biologists were able to trace adult bull trout in Swan Lake back to the streams where they hatched.<\/p>\n
FWP officials say the findings will help prioritize habitat restoration, monitoring and conservation efforts to support the threatened native species in the Swan River system. The study also complements the agency’s ongoing lake trout suppression program in Swan Lake, which aims to reduce competition from the nonnative predator.<\/p>\n