Bioinvasive species and the preservation of cutthroat trout in the western United States: ecological, social, and economic issues
Introduction
Human activities have greatly altered natural systems causing measurable and substantial declines in many fish species. Declines of birds and mammals resulting from human-induced disturbances have been documented at global and local scales (Master, 1990, Master, 1991, Richter et al., 1997), and imperilment rates for freshwater fishes, crayfishes, and mollusks have been described as eight times higher than those for terrestrial vertebrates (Master, 1990). Moyle and Leidy (1992) estimated that 20% of the world’s freshwater fishes are extinct or in serious decline and over half of the freshwater fishes in the US now receive some form of legal protection in a portion of their range (Johnson, 1987). Most of the federally listed endangered or threatened fish species are concentrated in the western US (Sheldon, 1988). For example, 63% of California’s fish species and subspecies are extinct, endangered, or declining (Moyle and Williams, 1990), and nearly all endemic fish species in the Colorado River system have experienced local extirpations and restricted distributions (Mueller and Marsh, 2002, Minckley et al., 2003). Similarly, many native fish species in the Great Plains and Rocky Mountain regions have experienced substantial population and range reductions (Fausch and Bestgen, 1997, McMahon and Gardner, 2001, Behnke, 2002).
Bioinvasive fish species are a significant problem for the preservation of native fishes in the western US. Most non-native fish species were introduced to enhance recreational fisheries, and widespread habitat alterations and continual reintroductions have facilitated the spread of non-native fishes (Gido and Brown, 1999, Mueller and Marsh, 2002). Non-native fish species are regarded as a primary cause for most fish species declines and the most significant limitation to preservation efforts into the future (Sheldon, 1988, Miller et al., 1989, Minckley and Deacon, 1991, Richter et al., 1997, Wilcove et al., 1998, Sala et al., 2000). In the western US, non-native, bioinvasive fish species are considered the leading threat to preservation of native fishes (Minckley and Deacon, 1991, Richter et al., 1997).
Preserving native fishes is dependent on not only understanding ecological systems, but also social and economic issues. We use cutthroat trout (Oncorhynchus clarki) to illustrate the ecological, social, and economic issues associated with control of bioinvasive fish species in efforts to preserve native fishes in the western US. Cutthroat trout have declined due to introductions of exotic species and provide a model to illustrate issues facing other native fishes. We contend that arguments for conservation of cutthroat trout should be stronger for this species than for other native fishes of the western US because of their comparatively high social and economic values.
While ecological, social, and economic issues form the basis of our discussion, these issues are presented within the context of a conceptual framework (Fig. 1) that illustrates the positive and negative effects of bioinvasive species. We contend that the relative threats of bioinvasive salmonids may be viewed along two gradients: (1) threats to cutthroat trout as a species and (2) threats to ecosystem function. Additionally, economic effects of bioinvasive species may be positive or negative depending on the comparative social values associated with cutthroat trout or bioinvasive species. Thus, net economic effects of bioinvasion are largely independent of effects on cutthroat trout as a species or ecosystem function. Based on this logic, we evaluate the array of issues facing the preservation of cutthroat trout and other native fishes of the western US. Although our model and discussion focus on cutthroat trout, the arguments may be presented for most native species threatened by bioinvasion.
Section snippets
Cutthroat trout
Cutthroat trout had the broadest distribution of any trout species in North America (Behnke, 2002). Behnke (2002) recognized 14 subspecies of cutthroat trout, nearly all of which have been reduced to <5% of their distributions since settlement by Europeans (Kruse et al., 1997, Shepard et al., 1997, Dunham et al., 1999, Horan et al., 2000, Behnke, 2002). Two subspecies of cutthroat trout are extinct, two subspecies are federally listed as threatened, and several subspecies have been petitioned
Social issues
The value placed on preservation of native fishes has increased in importance among natural resource professionals, but public support of such activities generally differs from professionals (Muth et al., 1998). Thus, understanding public values related to cutthroat trout and bioinvasive salmonids is critical for obtaining support for preservation activities. Social values can be divided into four major categories: ethical, aesthetic, historical, and recreational.
Ethical values originate from
Economic issues
Social issues play an important role in the protection of cutthroat trout from non-native, bioinvasive salmonids and are directly related to economic issues. A common method for assessing the economics of natural resources is a supply and demand model, which illustrates that the price of a resource is based on both its supply and the demand by consumers (Mansfield, 1985, Rees, 1985, Tietenberg, 1996). Although a supply and demand framework may be considered an overly simple model, our purpose
Passive approaches
The decline of cutthroat trout has resulted in the widespread adoption of passive approaches to protect remaining cutthroat trout populations. Passive approaches require little or no monetary or labor inputs from management agencies. Passive approaches include changes to harvest regulations or stocking practices, but they have limited effectiveness due to resistance or non-compliance by anglers and the continued spread of naturalized, non-native salmonid species.
Sport fishing regulations have
Conclusions
Bioinvasive, non-native salmonids have had and are having a significant effect on cutthroat trout. Although brown trout and lake trout are a risk to cutthroat trout populations and ecosystem function in a few areas, the most significant threats to cutthroat trout as a species are rainbow trout and brook trout. Despite these threats, there is little or no social or economic justification for control of rainbow trout or brook trout. Because preservation of cutthroat trout becomes a cost to
Acknowledgements
We thank Wendy Stock and John Tschirhart for suggestions regarding the economic models. Discussions with Charles Anderson, Robert Behnke, Patricia Bigelow, Michael Bower, Dirk Miller, Darren Rhea, Hilda Sexauer, and Robert Wiley greatly enhanced our views on issues facing native species conservation. Helpful comments on a previous version of the manuscript were provided by Patricia Bigelow, Jason Dunham, Amy Harig, Daniel Isaak, Frank Rahel, Darren Rhea, and an anonymous reviewer. The Wyoming
Michael C. Quist is a Postdoctoral Research Associate with the Wyoming Cooperative Fish and Wildlife Research Unit and the Department of Zoology and Physiology at the University of Wyoming. He has conducted various studies focusing on the management of native and exotic species in the Great Plains and Rocky Mountains. He received his PhD from Kansas State University.
References (88)
- et al.
Conservation and distribution of genetic variation in a polytypic species, the cutthroat trout
Conserv. Biol.
(1988) - Baxter, G.T., Stone, M.D., 1995. Fishes of Wyoming. Wyoming Game and Fish Department,...
- Behnke, R.J., 2002. Trout and salmon of North America. Free Press, New...
- et al.
Segregation of resident trout in streams as predicted by three habitat dimensions
Can. J. Zool.
(1992) - et al.
Hybridization and introgression in a managed, native population of Yellowstone cutthroat trout: genetic detection and management implications
Trans. Am. Fish. Soc.
(2002) - Cailteux, R.L., DeMong, L., Finlayson, G.J., Horton, W., McClay, W., Schnick, R.A., Thompson, C. (Eds.), 2001. Rotenone...
- et al.
The Lake Tahoe sport fishery
Calif. Fish Game
(1966) - et al.
Influence of water temperature and interactions between juvenile Colorado River cutthroat trout and brook trout in a laboratory stream
Trans. Am. Fish. Soc.
(1994) - et al.
Geographic distribution, species displacement, and niche overlap for lake trout and bull trout in mountain lakes
Can. J. Zool.
(1993) - et al.
Habitat fragmentation and extinction risk of Lahontan cutthroat trout
North Am. J. Fish. Manage.
(1997)
Local and geographic variability in the distribution of stream-living Lahontan cutthroat trout
Trans. Am. Fish. Soc.
Catchability of three strains of cutthroat trout
North Am. J. Fish. Manage.
The value of biodiversity
Ambio
Effect of habitat fragmentation on the extinction threshold: a synthesis
Ecol. Appl.
Do gradient and temperature affect distributions of, and interactions between, brook charr (Salvelinus fontinalis) and other resident salmonids in streams?
Physiol. Ecol. Jpn.
Invasion of North American drainages by alien fish species
Freshwater Biol.
Comparative behavior and habitat utilization of brook trout (Salvelinus fontinalis) and cutthroat trout (Salmo clarki) in small streams in northern Idaho
J. Fish. Res. Board Canada
Minimum habitat requirements for establishing translocated cutthroat trout populations
Ecol. Appl.
Factors influencing success of greenback cutthroat trout translocations
North Am. J. Fish. Manage.
Timing and location of spawning by nonnative wild rainbow trout and native cutthroat trout in the South Fork Snake River, Idaho, with implications for hybridization
North Am. J. Fish. Manage.
Comparative sport fish performance of Bonneville cutthroat trout in three small put-grow-and-take reservoirs
North Am. J. Fish. Manage.
Occurrence of native Colorado River cutthroat trout (Oncorhynchus clarki pleuriticus) in the Escalante River drainage, Utah
Western North Am. Naturalist
Conserving inland cutthroat trout in small streams: how much stream is enough?
North Am. J. Fish. Manage.
Effects of habitat area and complexity on Colorado River cutthroat trout in Uinta Mountain streams
Trans. Am. Fish. Soc.
Temporal variation in abundance of an isolated population of cutthroat trout in western Oregon, 1981–1991
North Am. J. Fish. Manage.
Lake trout discovered in Yellowstone Lake threaten native cutthroat trout
Fisheries
Population, habitat, and genetic characteristics of Colorado River cutthroat trout in wilderness and nonwilderness stream sections in the Uinta Mountains of Utah and Wyoming
North Am. J. Fish. Manage.
The effect of rotenone on zooplankton populations in freshwater lakes
Trans. Am. Fish. Soc.
Geomorphic influences on the distribution of Yellowstone cutthroat trout in the Absaroka Mountains, Wyoming
Trans. Am. Fish. Soc.
Status of Yellowstone cutthroat trout in Wyoming waters
North Am. J. Fish. Manage.
As assessment of headwater isolation as a conservation strategy for cutthroat trout in the Absaroka Mountains of Wyoming
Northwest Sci.
Values, policy, and ecosystem health
BioScience
Influence of differential angling mortality and stream gradient on fish abundance in a trout-sculpin biotope
Trans. Am. Fish. Soc.
Electrophoretic study of cutthroat trout populations in Utah
Great Basin Naturalist
The imperiled status of North American aquatic animals
Biodiversity Network News
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Michael C. Quist is a Postdoctoral Research Associate with the Wyoming Cooperative Fish and Wildlife Research Unit and the Department of Zoology and Physiology at the University of Wyoming. He has conducted various studies focusing on the management of native and exotic species in the Great Plains and Rocky Mountains. He received his PhD from Kansas State University.
Wayne A. Hubert has been the Assistant Leader of the Wyoming Cooperative Fish and Wildlife Research Unit since 1982 and serves as a fisheries biologist on the faculty at the University of Wyoming as a Professor in the Department of Zoology and Physiology. Previously he was Assistant Leader of the Iowa Cooperative Fisheries Research Unit and on the faculty of the Department of Animal Ecology at Iowa State University. He has also been an aquatic biologist with the Tennessee Valley Authority in Alabama and Tennessee. He received his PhD from Virginia Polytechnic Institute and State University.