Salmonid biologists use both mental models—simple assumptions—and bioenergetics-based mathematical models to understand and predict effects of temperature regime on growth. Bioenergetics model results, however, sometimes conflict with common assumptions. Previous studies plus “Wisconsin model” bioenergetics simulations lead to four conclusions that conflict with some management assumptions….Read more with free access. Photo: Terra Dressler

Historically, anadromous steelhead Oncorhynchus mykiss and spring-run Chinook Salmon O. tshawytscha used high-elevation rivers in the Sierra Nevada of California but were extirpated in the 20th century by construction of impassable dams. Plans to reintroduce the fish by opening migratory passage across the dams and reservoirs can only succeed if upstream habitats have the capacity to support viable populations of each species….Read more with free access. Photo: Lee Harrison.

Recent declines in abundance of Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri in the upper Blackfoot River drainage in Idaho coincided with establishment of a nearby nesting colony and increased abundance of American white pelicans Pelecanus erythrorhynchos. Published pelican predation rates have been estimated to be as high as 70% on Yellowstone Cutthroat Trout in the Blackfoot River….Read more with free access. Photo: IDFG.