| Summary: | While the impacts of hydropower development on diadromous and riverine fish species have received considerable attention, the ecology and behaviour of fish species residing in hydropower reservoirs is not well understood. As a winter-specialist species, commonly found in hydropower impoundments in North America, burbot, Lota lota, provide a useful model species to test hypotheses regarding reservoir resident ecology and behaviour. In this thesis, 3 empirical studies were used to investigate the behavioural ecology of burbot residing in Kinbasket Reservoir, British Columbia, Canada. Hypotheses regarding diel differences in depth use, individual differences in space use, and seasonal and diel differences in thermal habitat selection, were tested using biotelemetry and mixed effects modelling frameworks. In Chapter 2, results indicated adult burbot performed a diel migration into shallow water at night. Further, the size structured nightly depth distributions, seasonal diel differences in thermal habitat use, and elevated nightly activity observed, suggested the adaptive significance of this migration was best explained by a trade-off among foraging opportunity, bionenergetics advantage, and predation avoidance. In Chapter 3, burbot spatial behavioural traits were identified as personality dependent, with significant repeatability detected in home range, movement, site-fidelity, rate of vertical movement and dispersal from release. Further, home range, movement and site fidelity were correlated at the between individual level, indicating a spatial behavioural syndrome. In Chapter 4, results showed nightly selection by burbot for 8-10°C during the pre-spawn period, 0-2°C during the spawning period, and for 12-14°C during the summer, indicating that selection occurs outside the summer period and differs between seasons and diel periods. The results of the three data chapters provided the first empirical documentation of several interesting species-specific behavioural patterns, including; diel migrations, spatial ...
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