Invasive Species

Hydropower facilities on the Lewis River, WA eliminated historic runs of anadromous species to the headwaters of the Lewis River. As anadromous reintroductions are considered and implemented, there remains considerable uncertainty in the viability of reintroductions in reservoir and tributary systems where large populations of non-native species persist and where spawning and rearing habitat may...

The American bullfrog (Rana catesbeiana) has recently invaded backwater and side-channel habitats of the Yellowstone River, near Billings, Montana. In other regions, bullfrog invasions have been linked to numerous amphibian declines (e.g., Adams and Pearl 2007). Immediate management actions may be able to suppress or eradicate localized populations of bullfrogs because they are present at low...

The proliferation of introduced northern pike in Southcentral Alaska is an urgent fishery management concern because pike are voracious predators that prey heavily on juvenile salmonids. Eradication of pike is not possible in connected freshwater networks, so managers must develop control methods that reduce pike populations to less destructive numbers. We are using field and bioenergetics...

Aquatic invasive species (AIS) are aquatic organisms that move into ecosystems beyond their natural, historic range and cause severe and irreversible damage to the habitats they invade. Most AIS arrive as a direct result of human activity, such as boating and angling. The threat of AIS introduction is especially high in the Greater Yellowstone Area, as humans from all over the world come to see...

There is an urgent need to consider more aggressive and direct interventions for conservation of freshwater fishes threatened by invasive species, habitat loss, and climate change. Conservation introduction - moving species to areas outside their previous range, where conditions are predicted to be more suitable - is one type of translocation strategy that fisheries managers can use to establish...

Salmonids – a group of coldwater adapted fishes of enormous ecological and socio-economic value – historically inhabited a variety of freshwater habitats throughout the Pacific Northwest (PNW). Over the past century, however, populations have dramatically declined due to habitat loss, overharvest, and invasive species. Consequently, many populations are listed as threatened or endangered under the...

After 14,000 years of surviving extreme environmental events, such as floods, fires and glaciations, Glacier’s greatest native trout is at high risk of disappearing from several streams and lakes east and west of the Continental Divide. The decline of westslope cutthroat trout (Oncorhynchus clarkii lewisi; WCT) in Glacier National Park (GNP) has been attributed to the establishment of nonnative...

Invasive species and hybridization (reproduction between different species or subspecies) – among the most serious threats to native species and biodiversity – provide some of the richest opportunities for “natural experiments” in evolutionary biology. New genomic technologies, combined with long-term hybridization studies in natural populations, provide exciting opportunities to advance our...