| In the Rocky Mountain foothills of Alberta, Canada, activities of the forestry and energy sectors have resulted in the installation of tens of thousands of stream-crossing structures. In fifteen Athabasca River basins I found that culverts impeded upstream movements of non-sportfish species relative to reference bridge sites. Conversely, abundances of Rainbow Trout significantly increased upstream of culverts. I suggest that culverts that exclude Burbot, a voracious predator, or high temperatures above culverts allow for increased productivity of Rainbow Trout. Water quality and substrate composition did not noticeably change upstream and downstream of bridges, while culverts had significantly higher water temperatures and silt/sand upstream. In evaluating the effectiveness and temporal biases of common sampling techniques, I found that backpack electrofishing and angling had the highest Arctic grayling detection probabilities. Angling detected larger juvenile and adult fish (>110 mm), while young-of-the-year were more easily detected using backpack electrofishing in later summer. |
