As anthropogenic demands on water resources intensify instream flow needs are becoming an increasingly important area of study, particularly over winter months during which time little is known about the behaviour and physiology of fishes. This thesis addresses the implications of water withdrawal from a small in situ stream on brook trout (Salvelinus fontinalis) during the winter of 2007 and 2008 in the Rocky Mountains. Water was withdrawn from one of two stream enclosures reducing the discharge by 50% and 75%, for 4hrs daily. Behaviour was monitored using radio transmitters that were externally attached to the small trout. Changes in physiology were monitored by measuring stress hormone levels and by measuring predicted body composition parameters using bioelectrical impedance analysis. Trout reacted to water withdrawal by being more active, but this change in behaviour did not elicit detectable changes in physiology. / x, 129 leaves : ill. ; 29 cm. --

A literature review shows that qualitative dichotomies describing interspecific differences in the movement patterns of foraging animals are widely-used and biologically important, but fraught with ambiguity. Consistent use of the terminology from foraging theory and stronger quantification are proposed to increase clarity and facilitate more rigorous tests of hypotheses. Greater consideration of intraspecific variation is also needed. In forest bird and lizard communities, move-frequency distributions are bimodal, supporting a dichotomous view, but there is important variation within the statistical modes. Fish species with more red muscle are more mobile than species with less red muscle, but the frequency distribution of the proportion of red muscle does not match subjective, dichotomous classifications. A quantitative field investigation of foraging young-of-the-year brook charr (Salvelinus fontinalis) reveals significant individual differences in movement patterns that are more strongly related to microhabitat use and diet, than to morphological and environmental parameters thought to influence swimming capability.

The brook trout population in a 4.7 hectare subarctic lake was sampled in 1986 and intensively fished in 1987, 1988 and 1989 in order to study the effect of stock depletion on fish parasite transmission. Population density was originally high, with slow individual growth rates, and small maximum size. Brook trout bore infections of Eubothrium salvelini, Phyllodistomum umblae, Crepidostomum farionis and Diplostomum sp. as well as some rare parasites. After intensive fishing the growth rates and size of the remaining fish increased. In 1987 all parasites increased in abundance. E. salvelini decreased in 1988 whereas the abundance of the other parasites remained high. In 1989 two new parasites, Echinorhynchus lateralis and Philonema sp. appeared. Parasite community changes and improves fish growth were related to trout diets and the pattern of intermediate host consumption. In 1987 zooplankton feeding increased. It then declined in 1988 and 1989 as populations of large benthic invertebrate prey increased. Feeding shifts may also have been mediated in part by intraspecific competition and aggression.

Thesis (Ph.D.)--Pennsylvania State University, 2005. / Mode of access: World Wide Web.

Thesis (M.S.)--University of Tennessee, Knoxville, 2008. / Title from title page screen (viewed on Sept. 24, 2009). Thesis advisor: John S. Schwartz. Vita. Includes bibliographical references.

Thesis (M.Sc.)--Memorial University of Newfoundland, 1997. / Bibliography: leaves 130-148.

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains viii, 132 p. : ill., maps. Vita. Includes abstract. Includes bibliographical references.

Thesis (M.S.)--Northern Michigan University, 2006. / Bibliography: leaves 113-119.

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains ix, 115 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 78-80).

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