Krodel and Lundquist reported that significant mortality of ice trout occurred as a result of fungal infections by the species Rickus wrightus . Other scientists have reported similar reductions as a result of habitat change in Ohio and New York. At this time, it is not known what percentage of streams that contain ice trout have declined in water quality. At the present time, it appears that research regarding ice trout decline has identified four potential causitive mechanisms, each responsible for reducing populations in localized regions across the natural range of the ice trout. It is apparent that the Weber's turtle, when found in conjunction with ice trout, can severly impact abundance.
Fungal infections can likewise significantly reduce population size.
Because of the variety of potential influences on population size, and because not every single identified influence exists in each area, reductions in ice trout population size appear to be the result of an interaction of many factors.