The interactive effects of stream temperature, stream size, and non-native species on Yellowstone cutthroat trout

2021 ◽  
Author(s):  
Robert Al-Chokhachy ◽  
Mike Lien ◽  
Bradley B. Shepard ◽  
Brett High
Keyword(s):  
Native Species ◽  
Cutthroat Trout ◽  
Population Level ◽  
Stream Temperature ◽  
Interactive Effects ◽  
Oncorhynchus Clarkii ◽  
Wide Range ◽  
Yellowstone Cutthroat Trout ◽  
Stream Size ◽  
Native Salmonids

Climate change and non-native species are considered two of the biggest threats to native salmonids in North America. We evaluated how non-native salmonids and stream temperature and discharge were associated with Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) distribution, abundance, and body size, to gain a more complete understanding of the existing threats to native populations. Allopatric Yellowstone cutthroat trout were distributed across a wide range of average August temperatures (3.2 to 17.7ºC), but occurrence significantly declined at colder temperatures (<10 ºC) with increasing numbers of non-natives. At warmer temperatures occurrence remained high, despite sympatry with non-natives. Yellowstone cutthroat trout relative abundance was significantly reduced with increasing abundance of non-natives, with the greatest impacts at colder temperatures. Body sizes of large Yellowstone cutthroat trout (90th percentile) significantly increased with warming temperatures and larger stream size, highlighting the importance of access to these more productive stream segments. Considering multiple population-level attributes demonstrates the complexities of how native salmonids (such as Yellowstone cutthroat trout) are likely to be affected by shifting climates.

Potential future climate effects on mountain hydrology, stream temperature, and native salmonid life history

2014 ◽  
Vol 71 (2) ◽  
pp. 189-202 ◽  
Author(s):  
Ryan J. MacDonald ◽  
Sarah Boon ◽  
James M. Byrne ◽  
Mike D. Robinson ◽  
Joseph B. Rasmussen
Keyword(s):  
Cutthroat Trout ◽  
Stream Temperature ◽  
Climate Impacts ◽  
Future Climate ◽  
Bull Trout ◽  
Westslope Cutthroat Trout ◽  
Environmental Pressures ◽  
Oncorhynchus Clarkii ◽  
Thermal Regimes ◽  
Native Salmonids

Native salmonids of western North America are subject to many environmental pressures, most notably the effects of introduced species and environmental degradation. To better understand how native salmonids on the eastern slopes of the Canadian Rocky Mountains may respond to future changes in climate, we applied a process-based approach to hydrologic and stream temperature modelling. This study demonstrates that stream thermal regimes in western Alberta, Canada, may only warm during the summer period, while colder thermal regimes during spring, fall, and winter could result from response to earlier onset of spring freshet. Model results of future climate impacts on hydrology and stream temperature are corroborated by an intercatchment comparison of stream temperature, air temperature, and hydrological conditions. Earlier fry emergence as a result of altered hydrological and thermal regimes may favour native westslope cutthroat trout (Oncorhynchus clarkii lewisii) in isolated headwater streams. Colder winter stream temperatures could result in longer incubation periods for native bull trout (Salvelinus confluentus) and limit threatened westslope cutthroat trout habitat.

scholarly journals Hybridization of Snake River Cutthroat in the Lower Gros Ventre River

2006 ◽  
Vol 30 ◽  
pp. 110-113
Author(s):  
Ryan Kovach ◽  
Lisa Eby
Keyword(s):  
Exotic Species ◽  
National Park ◽  
Cutthroat Trout ◽  
Snake River ◽  
Oncorhynchus Clarki ◽  
Oncorhynchus Clarkii ◽  
Grand Teton National Park ◽  
Water Diversions ◽  
Yellowstone Cutthroat Trout ◽  
Special Concern

The cutthroat trout Oncorhynchus clarki is Wyoming's only native trout. The Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) is designated as a "species of special concern" by a number of agencies and conservation groups. Although the Yellowstone cutthroat trout has recently avoided federal listing because of robust headwater populations (USFWS 2006), they face continued threats across their range. The fine-spotted Snake River native trout is a morphologically divergent ecotype of the Yellowstone subspecies, although it is not genetically distinguishable (Allendorf and Leary 1988, Novak et al. 2005). The Gros Ventre, an important tributary of the Snake River located partially in Grand Teton National Park, historically supported robust populations of fine­ spotted Snake River cutthroat trout. Principal threats to Gros Ventre native trout, especially in the lower end of the drainage within the park boundaries, include both water diversions (loss of water and fish into irrigation ditches) and presence of exotic species.

Cutthroat Trout: Evolutionary Biology and Taxonomy

2018 ◽  
Keyword(s):  
Evolutionary Biology ◽  
Cutthroat Trout ◽  
Westslope Cutthroat Trout ◽  
Oncorhynchus Clarkii ◽  
Coastal Cutthroat Trout ◽  
Lahontan Cutthroat Trout ◽  
Museum Samples ◽  
Yellowstone Cutthroat Trout ◽  
The 1960S

<em>Abstract</em>.—There has been considerable interest in the systematics and classification of Cutthroat Trout since the 1800s. Cutthroat Trout native to western North America (currently classified as <em>Oncorhynchus clarkii</em>) have historically been grouped or separated using many different classification schemes. Since the 1960s, Robert Behnke has been a leader in these efforts. Introductions of nonnative trout (other forms of Cutthroat Trout, and Rainbow Trout <em>O. mykiss</em>) have obscured some historical patterns of distribution and differentiation. Morphological and meristic analyses have often grouped the various forms of Cutthroat Trout together based on the shared presence of the “cutthroat mark,” high scale counts along the lateral line, and the presence of basibranchial teeth. Spotting patterns and counts of gill rakers and pyloric caeca have in some cases been helpful in differentiation of groups (e.g., Coastal Cutthroat Trout <em>O. c. clarkii</em>, Lahontan Cutthroat Trout <em>O. c. henshawi</em>, and Westslope Cutthroat Trout <em>O. c. lewisi</em>) currently classified as subspecies. The historical genetic methods of allozyme genotyping through protein electrophoresis and chromosome analyses were often helpful in differentiating the various subspecies of Cutthroat Trout. Allozyme genotyping allowed four major groups to be readily recognized (Coastal Cutthroat Trout, Westslope Cutthroat Trout, the Lahontan Cutthroat Trout subspecies complex, and Yellowstone Cutthroat Trout <em>O. c. bouvieri </em>subspecies complex) while chromosome analyses showed similarity between the Lahontan and Yellowstone Cutthroat trout subspecies complex trout (possibly reflecting shared ancestral type) and differentiated the Coastal and Westslope Cutthroat trouts from each other and those two groups. DNA results may yield higher resolution of evolutionary relationships of Cutthroat Trout and allow incorporation of ancient museum samples. Accurate resolution of taxonomic differences among various Cutthroat Trout lineages, and hybridization assessments, requires several approaches and will aid in conservation of these charismatic and increasingly rare native fishes.

Factors influencing coastal cutthroat trout (Oncorhynchus clarkii clarkii) seasonal survival rates: a spatially continuous approach within stream networks

2009 ◽  
Vol 66 (4) ◽  
pp. 613-632 ◽  
Author(s):  
Aaron M. Berger ◽  
Robert E. Gresswell
Keyword(s):  
Survival Rates ◽  
Fork Length ◽  
Cutthroat Trout ◽  
Population Level ◽  
Fish Length ◽  
Watershed Scale ◽  
Stream Networks ◽  
Oncorhynchus Clarkii ◽  
Discharge Temperature ◽  
Coastal Cutthroat Trout

Mark–recapture methods were used to examine watershed-scale survival of coastal cutthroat trout ( Oncorhynchus clarkii clarkii ) from two headwater stream networks. A total of 1725 individuals (≥100 mm, fork length) were individually marked and monitored seasonally over a 3-year period. Differences in survival were compared among spatial (stream segment, subwatershed, and watershed) and temporal (season and year) analytical scales, and the effects of abiotic (discharge, temperature, and cover) and biotic (length, growth, condition, density, movement, and relative fish abundance) factors were evaluated. Seasonal survival was consistently lowest and least variable (years combined) during autumn (16 September – 15 December), and evidence suggested that survival was negatively associated with periods of low stream discharge. In addition, relatively low (–) and high (+) water temperatures, fish length (–), and boulder cover (+) were weakly associated with survival. Seasonal abiotic conditions affected the adult cutthroat trout population in these watersheds, and low-discharge periods (e.g., autumn) were annual survival bottlenecks. Results emphasize the importance of watershed-scale processes to the understanding of population-level survival.

Genetic monitoring of trout movement after culvert remediation: family matters

2014 ◽  
Vol 71 (11) ◽  
pp. 1680-1694 ◽  
Author(s):  
Helen M. Neville ◽  
Douglas P. Peterson
Keyword(s):  
Family Structure ◽  
Allelic Richness ◽  
A Priori ◽  
Cutthroat Trout ◽  
Population Level ◽  
Older Individuals ◽  
Management Scenarios ◽  
Genetic Analyses ◽  
Oncorhynchus Clarkii ◽  
Clustering Patterns

We contrasted various genetic analyses to evaluate their utility and constraints for detecting movement of cutthroat trout (Oncorhynchus clarkii) through restored culverts in different field settings: population-level metrics of genetic variability (heterozygosity and allelic richness); Bayesian clustering and assignment of individual genotypes from age 1+ fish; and a novel “sib-split” approach, where movement patterns are extracted from the spatial distribution of young-of-year (YOY) full-sibling groups inferred via pedigree reconstruction. Family structure greatly influenced population-level and individual clustering results in our small headwater populations, even though field sampling was implemented to avoid siblings. Sib-split, which uses family structure to detect movement, uncovered passage of YOY just weeks after emergence. When retrospectively applied to older individuals, it proved essential in interpreting clustering patterns and captured passage in several families of 1- and 2-year-olds. Where family structuring may negatively affect genetic analyses or, alternatively, be prominent enough to allow application of sib-split is difficult to predict a priori; we discuss benefits and limitations of all approaches under different ecological, spatial, and management scenarios.

Competition between native and introduced salmonid fishes: cutthroat trout have lower growth rate in the presence of cutthroat–rainbow trout hybrids

2009 ◽  
Vol 66 (1) ◽  
pp. 133-141 ◽  
Author(s):  
Steven M. Seiler ◽  
Ernest R. Keeley
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Native Species ◽  
Cutthroat Trout ◽  
Stream Channels ◽  
Lower Growth ◽  
Oncorhynchus Clarkii ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Foraging Ability ◽  
Lower Growth Rate

When nonnative species become established within new communities, competition may play a role in determining the persistence of ecologically similar native species. In western North America, many native cutthroat trout ( Oncorhynchus clarkii ) populations have been replaced by nonnative rainbow trout ( Oncorhynchus mykiss ). Superior competitive ability of rainbow trout and cutthroat–rainbow trout hybrids is often cited for this replacement; however, few studies have tested for mechanisms that might allow introduced rainbow trout to out-compete native trout species. Our previous work found individual-based differences in swimming and foraging ability among cutthroat trout, rainbow trout, and their hybrids. In this study, we tested for the presence and strength of competition between cohorts of cutthroat trout, rainbow trout, and their reciprocal hybrids. We assayed the growth rate of juvenile cutthroat trout in allopatry versus cutthroat trout when sympatric with rainbow trout and each hybrid cross. After controlling for size and density of trout, cutthroat trout cohorts in stream channels that contained hybrid genotypes experienced lower growth than cutthroat trout in allopatry. Averaged across heterospecific treatments, cutthroat trout growth was also lower than that of cutthroat trout cohorts in allopatry. Our study suggests that juvenile cutthroat trout experience a growth disadvantage when competing against cutthroat–rainbow hybrids.

Balancing Fisheries Management and Water Uses for Impounded River Systems

2008 ◽  
Keyword(s):  
Brook Trout ◽  
Adult Population ◽  
Stocking Density ◽  
Cutthroat Trout ◽  
Oncorhynchus Clarkii ◽  
Natural Reproduction ◽  
Mean Size ◽  
Yellowstone Cutthroat Trout ◽  
Catch Rates ◽  
Natural Recruitment

<em>Abstract</em>.—The Idaho Department of Fish and Game has stocked fingerling Yellowstone cutthroat trout <em>Oncorhynchus clarkii bouvieri</em>, hybrid trout (rainbow trout <em>O. mykiss</em> × Yellowstone cutthroat trout), and brook trout <em>Salvelinus fontinalis </em>(hereafter referred to collectively as trout) in Henrys Lake since the early 1900s to supplement natural recruitment and increase angler catch rates. Annual stocking rates have varied from 317 to 1,027 fingerling (approximately 75 mm) trout per hectare from 1971 to present. Stocking densities can influence angler catch rates but are limited by production constraints and costs associated with raising and transporting fish. By refining fingerling trout stocking densities, managers can optimize the fishery and minimize hatchery expenditures. To fully understand the effects of stocking density on angler catch rates in a lake with natural reproduction, we estimated the contribution of hatchery fish to the fishery by analyzing 6 years of marked fingerling stockings and found that natural recruitment added little to the adult population. We then explored the relationships among stocking densities, angler catch rates, and size of fish harvested by anglers to determine the optimal stocking density needed to achieve our management objectives of catch rates 0.7 fish per hour and 10% of harvested Yellowstone cutthroat trout exceeding 500 mm. We found increased catch rates following years when stocking densities were high. However, mean size of Yellowstone cutthroat trout harvested decreased following years of higher stocking densities. We estimate that approximately 737 fingerling trout per hectare are needed annually to achieve angler catch rates of 0.7 fish per hour. At this stocking density, we estimated that approximately 3% of harvested Yellowstone cutthroat trout would exceed 500 mm. This fell below our management objective of 10% of harvested Yellowstone cutthroat trout exceeding 500 mm and suggested that our current catch rate objective and size objective may be incompatible. This information should be combined with angler opinion data to formulate attainable goals for the fishery.

Morphological and swimming stamina differences between Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri), rainbow trout (Oncorhynchus mykiss), and their hybrids

2007 ◽  
Vol 64 (1) ◽  
pp. 127-135 ◽  
Author(s):  
Steven M Seiler ◽  
Ernest R Keeley
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Body Shape ◽  
Cutthroat Trout ◽  
Swimming Velocity ◽  
Swimming Ability ◽  
Geometric Morphometric ◽  
Oncorhynchus Clarkii ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Yellowstone Cutthroat Trout

We hypothesized that body shape differences between Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri), rainbow trout (Oncorhynchus mykiss), and their hybrids may influence swimming ability and thus play an important role in the invasion of nonnative rainbow trout and hybrid trout into native cutthroat trout populations. We reared Yellowstone cutthroat trout, rainbow trout, and reciprocal hybrid crosses in a common environment and conducted sustained swimming trials in order to test for genetically based morphological and swimming stamina differences. Linear and geometric morphometric analyses identified differences in body shape, with cutthroat trout having slender bodies and small caudal peduncles and rainbow trout having deep bodies and long caudal peduncles. Hybrid crosses were morphologically intermediate to the parental genotypes, with a considerable maternal effect. Consistent with morphological differences, cutthroat trout had the lowest sustained swimming velocity and rainbow trout had the highest sustained swimming velocity. Sustained swimming ability of hybrid genotypes was not different from that of rainbow trout. Our results suggest that introduced rainbow trout and cutthroat-rainbow trout hybrids potentially out-compete native Yellowstone cutthroat trout through higher sustained swimming ability.

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