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101	Ecology and impacts of nonnative salmonids with special reference to brook trout (<em>Salvelinus fontinalis</em> Mitchill) in North Europe Korsu, K. (Kai) 06 October 2008 (has links) Abstract My main objectives in this thesis were to explore general patterns and mechanisms driving salmonid invasions globally and, more specifically, to examine the invasion dynamics and impacts of the North American brook trout in North European stream systems. Non-native salmonids have often spread extensively and caused many harmful impacts on their native counterparts. Among the three globally introduced salmonids, the European brown trout appeared as the 'worst' alien species (strongest impact on native fish), followed by the North American rainbow trout and brook trout. Brook trout, which is widely established in European streams, was found to be a non-aggressive species. Moreover, the growth of brown trout was unaffected by brook trout, indicating negligible interspecific interactions between the two species. Habitat niche segregation between brook trout and brown trout was evident, with brook trout occupying mainly low-velocity pool habitats, whereas brown trout resided in fast-flowing riffles. At the river-wide scale, brook trout occurred mainly in small, slightly acid headwater streams, whereas brown trout was found primarily in larger downstream river sections. Evidently, North European streams with a very low number of native fish species offer underutilized niche space for tolerant headwater specialists such as brook trout. However, the habitat niche filled by brook trout was not completely vacant, as brown trout co-occurred with brook trout in numerous small and mid-sized (3–16 m wide) streams. In these streams, brown trout reproduction was negligible presumably related to the presence of brook trout. Brook trout had also increased in density relative to brown trout during the 10-yr study period (1994 vs. 2004). Moreover, the growth rate and population densities of brook trout were high and the species had spread extensively towards the upmost headwater streams during the 10-yr study period. Thus, harmful effects on the native brown trout by brook trout are likely to occur in the core habitat of the invader, i.e. headwater streams, leaving populations of the native species unaffected elsewhere. Due to the high conservation value of the potentially impacted populations of brown trout, I strongly caution against further stocking of brook trout in European watersheds. biological invasions brook trout brown trout growth habitat use interspecific competition meta-analysis multi-scale niche segregation salmonids species replacement streams
102	Hydrology And Predictive Model Of Headwater Streams And The Groundwater/Surface Water Interactions Supporting Brook Trout Habitat In Northeast Ohio Amey, Katherine Springer 01 April 2011 (has links) No description available. Aquatic Sciences Ecology Environmental Geology Freshwater Ecology Geology Hydrologic Sciences Hydrology Hydrology Hydrogeology Groundwater Surface Water Interaction Vertical Hydrauic Gradient Precipitation Temperature Study Brook Trout Cold Water Streams Stable Isotopes Benthic Macroinvertebrates Northeast Ohio Predictive Model
103	Scales of Resilience: Community Stability, Population Dynamics, and Molecular Ecology of Brook Trout in a Riverscape after a Large Flood Rodgers, Erin V. January 2014 (has links) No description available. Aquatic Sciences Climate Change Ecology Environmental Science Freshwater Ecology Genetics Natural Resource Management Wildlife Conservation Brook trout Salvelinus fontinalis flood abundance genetic divergence community change resilience
104	Testing and Refining a Unique Approach for Setting Environmental Flow and Water Level Targets for a Southern Ontario Subwatershed Beaton, Andrew 15 August 2012 (has links) In this study Bradford’s (2008) approach for setting ecological flow and water level targets is tested and refined through application within the Lake Simcoe Region Conservation Authority’s (LSRCA) subwatershed of Lover’s Creek. A method for defining subwatershed objectives and identifying habitat specialists through expert input is proposed and tested. The natural regime of each streamflow and wetland site is characterized along with the hydrological alteration at each site. Potential ecological responses to the hydrologic alterations are then hypothesized for the different types of changes calculated at each site. Methods for setting overall ecosystem health and specific ecological objective flow targets are proposed and tested. These targets are integrated into a flow regime for each site and a process for using this information for decision making is suggested. Flow magnitude quantification is attempted using hydraulic modelling and sediment transport equations, however the data used were found to be inadequate for this application. The accuracy of the targets developed using the method presented in this paper is mainly limited by the accuracy of the hydrological model and quantified flow magnitudes. Recommendations for improving these components of the assessment are made. The unique approach and recommendations presented in this paper provide explicit steps for developing flow targets for subwatersheds within the LSRCA. This research contributes toward the advancement of EFA within the LSRCA, which provides opportunity for enhanced protection and restoration of ecosystem health across the watershed. / Lake Simcoe Region Conservation Authority Ecological flows environmental flow instream flow in-stream flow indicators of hydrologic alteration ecological flow components Lovers Creek Lake Simcoe Watershed streamflow wetland hydroperiod MIKE-SHE HEC-RAS HEC-GeoRAS Du Boyes equation Ontario Stream Assessment Protocol OSAP IHA Southern Ontario Ontario LSRCA flow regime decision making Ontario hydrologic model hydraulic model brook trout amphibian swamp Ontario Wetland Evaluation System ecological function hydrological function expert interview Delphi Technique geomorphic framework river stream hydrology cold water fish Andrea Bradford aquatic aquatic habitat aquatic biology groundwater land use change urbanization pool riffle pool-riffle

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