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persist, severity of environmental forces become very important (Mack et al. 2000). This suggests that the probability of a species establishing in a new environment would increase as the number of attempts increases (Williamson and Fitter 1996). This becomes especially important when dealing with bait bucket introductions, as the numbers of species escaping is often quite small. Predators and pathogens can limit the ability of a susceptible invasive species to inhabit an area (Kotler and Holt 1989, Mathur and Stein 1993, Humphries et al. 1999). Selective predation was cited as one of the factors altering the abundance of two native Notropis species in a lentic environment (Hartman et al. 1992). Pathogens can be cointroduced with the non-indigenous species (Elton 1958, Li and Moyle 1981). Documentation also exists linking introduced fish with the transfer of pathogens to resident amphibians (Kiesecker et al. 2001). Environmental stressors derived from ecological alterations can even impact the effects of parasites within the host community (Lafferty and Kuris 1999). The potential for an introduced species to colonize an area increases with the amount of anthropogenic disturbance (Moyle 1986, Karr 1991, Winston et al. 1991, Angermeier 1995, Mack et al. 2000, Perry et al. 2002). Artificial barriers, such as dams and reservoirs, can alter biotic communities by providing a source of nonindigenous species through stocking and bait-bucket introductions (Winston et al. 1991). Alternatively, the deterioration of natural migratory barriers and the sophistication of transportation will allow increased mixing of species over time (Elton 1958). Consequently, the rate of introductions has increased sharply since the 1960’s (Courtenay and Hensley 1980, Ross 1991, Mooney and Cleland 2001). The effects of ecosystem 15
alteration may reduce the habitat suitability essential for native species (Moyle 1986), especially those sensitive to factors such as turbidity (Gilbert 1969a, Eisenhour 1995). Rapid eutrophication was cited as a factor reducing the abundance of two native Notropis species in a lotic environment (Hartman et al. 1992). Introduced species could capitalize on released niche availability if they can survive in the host environment. Stream turbidity has even been hypothesized to pose problems in mate recognition that may lead to hybridization with congeneric species (Eisenhour 1995). Review of Study Area/Related Studies Available information is summarized concerning the species, watersheds, and similar studies for that which this review was conducted. Although the study discussed in Chapter 2 was designed to observe potential interactions which can occur between native and nonnative species, the focal species were selected from the New River drainage (specifically from the upper Greenbrier Watershed). The New River system contains a relatively large number of endemic and introduced species (Hocutt and Hambrick 1973, Cincotta et al. 1999, Wellman 2004, Hocutt et al. 1978). Draining approximately 17,918 km 2 the New River flows through the states of Virginia, North Carolina, and West Virginia (Stauffer et al. 1995). Parts of the Blue Ridge, Ridge and Valley, and Appalachian Plateau geographical provinces are transected. Several species are endemic to the upper New River system (Hubbs and Trautman 1932, Hocutt et al. 1978, Jenkins and Burkhead 1994). These include the New River shiner (Notropis scabriceps), the Kanawha darter (Etheostoma kanawhae), the Kanawha minnow (Phenacobius teretulus), the Appalachia darter (Percina 16
Page 1 and 2: An Experimental Study of Vertical H
Page 3 and 4: Acknowledgements I would like to th
Page 5 and 6: LIST OF TABLES Table 1. Results of
Page 7 and 8: In order for similar species to avo
Page 9 and 10: species diversity should increase (
Page 11 and 12: noting that the abundance of some s
Page 13 and 14: exhibited by species involved; the
Page 15 and 16: new environment (Dueser and Porter
Page 17 and 18: host environment, proposing that a
Page 19: Hybridization with introduced speci
Page 23 and 24: in the upper Greenbrier River and o
Page 25 and 26: ubiquitous, appearing in all channe
Page 27 and 28: Literature Cited Addair, J. 1944. T
Page 29 and 30: Gibbs, R. H. 1957. Cyprinid fishes
Page 31 and 32: Lobb, M. D., III. 1986. Habitat use
Page 33 and 34: Paybins, K. S., T. Messinger, J. H.
Page 35 and 36: Chapter 2: An Experimental Study of
Page 37 and 38: Introduction Non-native fishes nega
Page 39 and 40: native cyprinids on their native co
Page 41 and 42: enthic, near-benthic, lower-pelagic
Page 43 and 44: N. telescopus had modes in the lowe
Page 45 and 46: native species pairs were partially
Page 47 and 48: interspecific separation of vertica
Page 49 and 50: MacArthur, R. and R. Levins. 1967.
Page 51 and 52: Table 1. Results of Chi square Test
Page 53 and 54: Total Number of Occurrences 160 140
Page 55: Total Number of Occurrences 160 140

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