Examining brook trout invasion into bull trout streams of the Canadian Rockies

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Warnock, Will G
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Lethbridge, Alta. : University of Lethbridge, Dept. of Biological Sciences, c2012
Brook trout invasion into bull trout streams is variable, and likely influenced by a suite of biotic and abiotic factors. Field observations revealed that brook trout dominated the fish community over bull trout in warmer sites that had undercut banks; in contrast, bull trout dominated in colder sites that had a high amount of large substrate cover, and where alternate non-native species were present. Laboratory studies of competition between the two species revealed that bull trout use a scramble foraging tactic, whereas brook trout use a territorial tactic. Bull trout outcompeted brook trout when fish density was low and habitat complexity was high, as this scenario reduced the effectiveness of the aggressive territorial foraging strategy of brook trout. Bull trout from a migratory population competed more successfully against brook trout and had higher rates of oxygen consumption than those from a resident population. This combined field-lab study points to some of the abiotic and biotic factors that affect competition between the two species, and may influence the outcome of brook trout invasion into bull trout streams.
xiv, 184 leaves : ill. ; 29 cm
Marine biological invasions -- Rocky Mountains (B.C. and Alta.) , Brook trout -- Rocky Mountains (B.C. and Alta.) -- Research , Brook trout -- Behavior , Bull trout -- Rocky Mountains (B.C. and Alta.) -- Research , Bull trout -- Behavior , Dissertations, Academic