Myxobolus cerebralis (Hofer) infection risk in native cutthroat trout Oncorhynchus clarkii (Richardson) and its relationships to tributary environments in the Yellowstone Lake Basin

Abstract

Conservation of native species is challenged by the introduction of non-native pathogens and diseases into aquatic and terrestrial environments worldwide. In the Yellowstone Lake basin, Yellowstone National Park, the invasive parasite causing salmonid whirling disease Myxobolus cerebralis (Hofer) has been identified as one factor contributing to population declines of native Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri (Jordan & Gilbert). In 2002 and 2003, we examined relationships between the stream environment and severity of M. cerebralis infection in native trout. Coefficients of variation of environmental features were calculated to examine variability. Ten years later, we reassessed infection levels at 22 tributaries broadly across the system. Results of principal component analysis (PCA) of physical features (2003) were negatively correlated with infection severity, mostly in lower jaw cartilage of cutthroat trout, and PCA of chemical features (and temperature) correlated with infection severity in cranial cartilage. Pelican Creek, where M. cerebralis prevalence and severity was high 2002-2003, remained high in 2012. We did not find evidence that the parasite had dispersed further within the system. Variable environmental features (physiological stress) across short spatiotemporal scales within a stream or season may possibly predispose salmonids to infection in the wild and facilitate parasite establishment.

Yellowstone Lake Ecosystem Restoration: A Case Study for Invasive Fish Management

“…Research identified Lewis Lake or other waters in the upper Snake River system as the source of lake trout introduced to Yellowstone Lake [110,111] and identified the potential impacts the new predatory trophic level could have on the cutthroat trout and the ecology of the lake and tributary spawning streams [79,86,112]. As the cutthroat trout population declined, additional causal factors were investigated including Myxobolus cerebralis Hofer, 1903 (the causative agent of whirling disease), which was discovered in cutthroat trout from Yellowstone Lake in 1998 [113,114] and caused localized losses of cutthroat trout in Pelican Creek and the Yellowstone River downstream (Figure 1) [115][116][117][118]. Environmental factors influencing variation in cutthroat trout year class strength were also investigated.…”

Effect of substrate on the proliferation of Myxobolus cerebralis in the mitochondrial lineages of the Tubifex tubifex host

“…Since the early 1990s, numerous studies have demonstrated that M. cerebralis poses a threat to the persistence of wild trout ( Oncorhynchus spp.) across western North America (Vincent 1996 ; Nehring and Walker 1996 ; Allendorf et al 2001 ; Koel et al 2006 ; Granath et al 2007 ; Murcia et al 2015 ; Nehring et al 2018 ; James et al 2021 ). As shown above, a large body of work has focused on the intricate two-host life cycle of M. cerebralis and a multitude of factors contributing to the establishment of the parasite.…”

Accelerated deactivation of Myxobolus cerebralis myxospores by susceptible and non-susceptible Tubifex tubifex

“…Similarly, the spawning run of YC trout in Bridge Creek dropped from 2363 fish to 1 fish in the 6 yr period from 1999 to 2004 (Koel et al 2005). While some investigators hypothesize that predation by non-native lake trout is the primary factor in the decline of the YC trout population in Yellowstone Lake (Williams et al 2014), other investigators consider WD a major contributor to the de cline (Murcia et al 2015).…”