Fisheries biologists utilize a variety of tools to manage and conserve aquatic resources. In addition to restoring and protecting habitat, fish stocking is an important management tool not only for enhancing recreational fishing opportunities, but also for the conservation of native fish populations. Achieving this latter objective requires maintaining one or more genetically diverse and disease-free broodstocks capable of producing fish that will survive, reproduce, and adapt to changing conditions in the wild.
Initially founded from twelve South Fork Flathead and two Clark Fork tributary populations, Montana Fish, Wildlife, and Parks’ (MFWP) westslope cutthroat trout broodstock plays a key role in the conservation and restoration of this native species. Annual genetic and disease testing allows hatchery managers to monitor the health of this captive brood and assess the need for periodic infusion of genes from wild populations. In summer 2009 fisheries crews sampled streams in the South Fork Flathead drainage and collected close to 800 westslope cutthroat trout from five pathogen-free, genetically pure populations. These wild fish are being held at Sekokini Springs Natural Rearing and Conservation Facility until they can be spawned with westslope cutthroat from the broodstock next spring.
In addition to collecting wild westslope cutthroat trout for genetic infusion into the existing broodstock, fisheries crews also initiated development of an alternative westslope cutthroat brood source to aid in restoration efforts in the South Fork Flathead. Over 250 westslope cutthroat from Danaher Creek were collected and transported alive out of the Bob Marshall Wilderness by packstock. Genetically distinct from the existing broodstock and other westslope cutthroat populations, the Danaher brood will be an important tool for conserving genetic diversity. Fish from this brood will be used to establish populations in certain high mountain lakes in the South Fork drainage once nonnative trout have been removed.