Lake Trout Discovered in Yellowstone Lake Threaten Native Cutthroat Trout

Kaeding, Lynn R.; Boltz, Glenn D.; Carty, Daniel

doi:10.1577/1548-8446(1996)021<0016:ltdiyl>2.0.co;2

Cited by 54 publications

(38 citation statements)

References 10 publications

(12 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Predaceous lake trout (Salvelinus namaycush) were introduced to Yellowstone Lake, Yellowstone National Park, Wyoming (Kaeding et al 1996) during the mid-1980s (Munro et al 2005). The Yellowstone Lake ecosystem is an ideal location to test the idea that an invasive predator may alter ecosystem processes beyond the invaded habitat, because few other perturbations exist besides the introduction of an apex predator, lake trout and because lake trout focus on one prey, the formerly dominant Yellowstone cutthroat trout (Oncoryhynchus clarki bouvieri ).…”

Section: Introductionmentioning

confidence: 99%

Introduced lake trout alter nitrogen cycling beyond Yellowstone Lake

2015

View full text Add to dashboard Cite

Citation: Tronstad, L. M., R. O. Hall Jr., and T. M. Koel. 2015. Introduced lake trout alter nitrogen cycling beyond Yellowstone Lake. Ecosphere 6(11):224. http://dx.doi.org/10.1890/ES14-00544.1Abstract. Introduced predators can have large effects on the ecosystem in which they were introduced, but how much these effects extend to other ecosystems beyond the invaded one is less known. We compared how lake trout (Salvelinus namaycush) affected nutrient cycling in an invaded and adjacent ecosystem in Yellowstone National Park, Wyoming, USA. Introduced lake trout in Yellowstone Lake caused the native Yellowstone cutthroat trout (Oncoryhynchus clarkii bouvieri ) population to decline. Native cutthroat trout are a dominant animal in the lake and may alter nutrient cycling in both Yellowstone Lake where they reside and in tributary streams used for spawning. We estimated changes in nutrient transport and nutrient uptake in both Yellowstone Lake and Clear Creek, a spawning stream, before and after the invasion of lake trout. Annual area-specific excretion fluxes from cutthroat trout were nine times higher in Clear Creek compared to Yellowstone Lake when cutthroat trout were abundant. However, fluxes within the lake and stream were similar after cutthroat trout declined. In Yellowstone Lake, zooplankton excretion supplied 86% of ammonium (NH 4 þ ) that was taken up, but cutthroat trout only supplied ,0.3% after the introduction of lake trout. Conversely, NH 4 þ excreted by cutthroat trout was likely a major flux in ClearCreek, because NH 4 þ fluxes from cutthroat trout exceeded watershed export of NH 4 þ in years when .3000 cutthroat trout spawned. Furthermore, NH 4 þ excretion fluxes from spawning cutthroat trout in ClearCreek supplied up to 6.1% of the NH 4 þ demanded by microbes after the introduction of lake trout.However, based on modeled past NH 4 þ uptake, we estimated that up to 60% of NH 4 þ excreted by spawning cutthroat trout may have been taken up by stream microbes when cutthroat trout were abundant. Therefore, transported NH 4 þ from spawning cutthroat trout was likely an integral part of N cycling in tributary streams in the past. By comparing the effects of declining cutthroat trout on two ecosystems, we show that lake trout had a larger effect on N cycling within an adjacent stream ecosystem than the invaded lake ecosystem itself, because the migratory behavior of cutthroat trout concentrated them in spawning streams increasing their effect.

show abstract

Section: Introductionmentioning

confidence: 99%

Introduced lake trout alter nitrogen cycling beyond Yellowstone Lake

2015

View full text Add to dashboard Cite

show abstract

“…Since the introduction of non‐native lake trout ( Salvelinus namaycush ) and whirling disease ( Myxobolus cerebralis ) and the occurrence of a persistent drought, the cutthroat trout population of Yellowstone Lake has declined by 90% (Koel et al , ). Lake trout were discovered in Yellowstone Lake in 1994 (Keading et al , Koel et al ). Young lake trout compete with cutthroat trout for macroinvertebrates, and each adult lake trout has the potential to consume 50 to 90 cutthroat trout annually (Gerstung , Elrod and O'Gorman , Donald and Alger , Stapp and Hayward ).…”

mentioning

confidence: 99%

Contrasting past and current numbers of bears visiting Yellowstone cutthroat trout streams

et al. 2014

View full text Add to dashboard Cite

Spawning cutthroat trout (Oncorhynchus clarkii bouvieri) were historically abundant within tributary streams of Yellowstone Lake within Yellowstone National Park and were a highly digestible source of energy and protein for Yellowstone's grizzly bears (Ursus arctos) and black bears (U. americanus). The cutthroat trout population has subsequently declined since the introduction of non‐native lake trout (Salvelinus namaycush), and in response to effects of drought and whirling disease (Myxobolus cerebralis). The trout population, duration of spawning runs, and indices of bear use of spawning streams had declined in some regions of the lake by 1997–2000. We initiated a 3‐year study in 2007 to assess whether numbers of spawning fish, black bears, and grizzly bears within and alongside stream corridors had changed since 1997–2000. We estimated numbers of grizzly bears and black bears by first compiling encounter histories of individual bears visiting 48 hair‐snag sites along 35 historically fished streams. We analyzed DNA encounter histories with Pradel‐recruitment and Jolly‐Seber (POPAN) capture‐mark‐recapture models. When compared to 1997–2000, the current number of spawning cutthroat trout per stream and the number of streams with cutthroat trout has decreased. We estimated that 48 (95% CI = 42–56) male and 23 (95% CI = 21–27) female grizzly bears visited the historically fished tributary streams during our study. In any 1‐year, 46 to 59 independent grizzly bears (8–10% of estimated Greater Yellowstone Ecosystem population) visited these streams. When compared with estimates from the 1997 to 2000 study and adjusted for equal effort, the number of grizzly bears using the stream corridors decreased by 63%. Additionally, the number of black bears decreased between 64% and 84%. We also document an increased proportion of bears of both species visiting front‐country (i.e., near human development) streams. With the recovery of cutthroat trout, we suggest bears that still reside within the Lake basin will readily use this high‐quality food resource. © 2014 The Wildlife Society.

show abstract

“…In fact, numerous avian and terrestrial species use Yellowstone cutthroat trout as an energy source in the Yellowstone Lake ecosystem (Schullery and Varley 1995). Nonnative lake trout Salvelinus namaycush, discovered in 1994 in Yellowstone Lake (Kaeding et al 1996), pose an additional threat; significant declines in native Yellowstone cutthroat trout caused by cumulative impacts of exotic species could have ecosystem-level effects.…”

mentioning

confidence: 99%

Myxobolus cerebralis in Native Cutthroat Trout of the Yellowstone Lake Ecosystem

et al. 2006

View full text Add to dashboard Cite

Abstract.-The exotic parasite Myxobolus cerebralis was first detected in native adult Yellowstone cutthroat trout Oncorhynchus clarkii bouvierii from Yellowstone Lake in 1998, seriously threatening the ecological integrity of this pristine, naturally functioning ecosystem. We immediately began to assess the prevalence and spatial extent of M. cerebralis infection in Yellowstone cutthroat trout within Yellowstone Lake and to determine the infection risk of age-0 Yellowstone cutthroat trout, the relative abundance and actinospore production of tubificid worms, and the basic environmental characteristics of tributaries. During 1999-2001, juvenile and adult Yellowstone cutthroat trout were infected throughout Yellowstone Lake; the highest prevalence (15.3-16.4%) occurred in the northern and central regions. Exposure studies in 13 streams indicated that Pelican and Clear creeks and the Yellowstone River were positive for M. cerebralis; the highest prevalence (100%) and severity was found in Pelican Creek during mid-July. Sexually mature individuals of the oligochaete Tubifex tubifex were most abundant in early summer, were genetically homogenous, and were members of a lineage known to produce moderate to high levels of M. cerebralis triactinomyxons. Only 20 of the 3,037 sampled tubificids produced actinospores after 7 d in culture, and none of the actinospores were M. cerebralis. However, one non-actinospore-producing T. tubifex from Pelican Creek tested positive for M. cerebralis by polymerase chain reaction. Stream temperatures at Pelican Creek, a fourth-order, low-gradient stream, were over 208C during the first exposure period, suggesting that T. tubifex were capable of producing triactinomyxons at elevated temperatures in the wild. Although the infection of otherwise healthy adult Yellowstone cutthroat trout within Yellowstone Lake suggests some resistance, our sentinel cage exposures indicated that this subspecies may be more susceptible to whirling disease than previous laboratory challenges have indicated, and M. cerebralis may be contributing to a significant recent decline in this population.

show abstract

Lake Trout Discovered in Yellowstone Lake Threaten Native Cutthroat Trout

Cited by 54 publications

References 10 publications

Introduced lake trout alter nitrogen cycling beyond Yellowstone Lake

Introduced lake trout alter nitrogen cycling beyond Yellowstone Lake

Contrasting past and current numbers of bears visiting Yellowstone cutthroat trout streams

Myxobolus cerebralis in Native Cutthroat Trout of the Yellowstone Lake Ecosystem

Contact Info

Product

Resources

About