Arif Jan (co-advisor Dr. Ivan Arismendi)
Dissertation topic: Multiscale ecological niche models to predict the distribution of biological invasions in riverscapes.
I am interested in the distribution of invasive fish species in both geographic and environmental (niche) spaces. My research project focuses on developing ecological niche models in the native areas of invasive salmonids and carps and transfer those models cross-continentally to predict the distribution of their invasion in the Indus Basin, east coast of North America and Patagonia. I use different R packages to model the climatic niches of invasive fishes in their native and introduced ecosystems and generate hypotheses about any shift in their realized niches. I also use Geographic Information Systems (GIS) to characterize stream network from high resolution digital elevation models (DEM) which allows to combine vector and raster-based stream variables to develop more robust ecological niche models. I am also interested in the effect of climatic change on niche shift and geographic distribution of invasive fishes.
Logan Breshears (co-advisor Dr. Jonathan Armstrong)
Thesis Topic: Characterizing thermal refuge usage in the Columbia River, and “Overshoot” migration behavior for John Day River adult summer steelhead.
Logan is an ODFW biologist interested in studying the environmental factors driving population dynamics of wild summer steelhead in the John Day Basin. It is estimated that 60% of adult steelhead destined for the John Day River overshoot the mouth of the John Day River upon their initial upstream arrival, and continue migrating up the Columbia River, getting detected at McNary Dam 119km upstream. A proportion of these fish later return to the John Day River to spawn the following spring. Logan will be using a combination of acoustic telemetry and PIT tags to characterize and quantify individual pathways of John Day origin adult summer steelhead throughout the Columbia River Basin. Monitoring areas of emphasis include the John Day River confluence with the Columbia River, and thermal refuge areas downstream of John Day Dam.