Are early life-stages limited by interactions between geomorphic and hydrologic factors?
Background/Question/Methods Within the context of invasion ecology and native trout conservation, there is a critical need to identify mechanisms limiting the altitudinal species zonation of brown trout (Salmo trutta), as their expansion into higher elevations due to climate change or anthropogenic habitat alterations could be deleterious to conservation of native fishes. Unlike many native species in the western United States, brown trout spawn in the fall, and their fry emerge during the spring snowmelt period. Recent research suggests that the embryos and emerging fry may be susceptible to streambed scour during this crucial life stage. The Logan River, Utah is a coarse bed high-mountain stream in which brown trout are nearly absent from the highest elevations despite barriers to passage or other physiological limits. Partial entrainment of sediment, whereby smaller than average (D50) sediments move during flood events, is a likely phenomenon. We hypothesized that higher entrainment
