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j 22 introduced fishes upon native fishes should be qualified by statements like "remain to be proven, are difficult if not impossible to define, still need good documentation, are difficult to validate, and lack corroborative research evidence". Other qualifications included impacts were "likely, probable, possible, and presumed". The responses concerning degree of impact ranged from "severe" to "moderate" to "small" to "any negative impact should be considered a problem". Question 3: Which introduced species do you consider to be presenting a problem? Seventy-seven percent of the respondents listed introduced fish species they considered to be presenting a problem to native fish species. Twenty-eight species were named, and channel catfish, red shiner, northern pike, common carp, green sunfish, and fathead minnow comprised a group considered by 35 % or more of the respondents to be a problem (Table 3). Over half the respondents listed channel catfish and red shiner as problem species and northern pike was listed by 46% of the respondents. Some respondents did not provide species names, but referred to "catfish species", ''bullheads'', "all centrarchids", "all centrarchids and percichthyids", "nonnative salmonids", "Notropis spp.", "topminnows", and "any which compete with or prey upon tbe native species". Salmonid species listed in Table 3 were proposed solely by respondents from New Mexico, or who had experience in New Mexico. A general statement provided here was that probably all nonnative species that exist in the Colorado River Basin and southwestern United States present a problem given the right conditions, certain situations, or create problems in localized areas. One respondent considered this question as too broad and simplistic, and that case by case analysis was required with consideration of related factors besides the presence of a particular species. Another respondent indicated this was a loaded question based on conjecture. Other respondents stated they were "not sure", or that insufficient evidence existed for most introduced species, or those species that had been investigated did not appear to be abundant in the river (i.e. largemouth bass), or only presented a small problem (channel catfish). One respondent also listed Asiatic tapeworm as an introduced species presenting a problem. Question 4: What native fish species do they affect, and what is the nature of the impact(s) (e.g., predation, competition for food or habitat, disease, etc). This question was aimed at identifying specific interactions between introduced and native fish species. Many respondents approached this question from a theoretical perspective. Some respondents indicated all native species existing where nonnatives occur are affected. Depending on species, life stage, and the "right conditions", each introduced species can negatively affect each native species. Predation and competition were considered the primary types of interaction occurring, though some considered predation the primary interaction in effect Most respondents indicated they felt small-bodied introduced