ABSTRACT
Heightened attention to the sediment budget for the Colorado River systerm in Grand Canyon Arizona, and the importance of the turbid tributaries for delivering sediment has resulted in the clear-water tributaries being overlooked by scientists and managers alike. Existing research suggests that clear-water tributaries are remnant ecosystems, offering unique biotic communities and natural flow patterns. These highly productive environments provide important spawning, rearing and foraging habitat for native fishes. Additionally, clear water tributaries provide both fish and birds with refuge from high flows and turbid conditions in the Colorado River. Current flow management in the Grand Canyon including beach building managed floods and daily flow oscillations targeting the trout population and invasive vegetation has created intense disturbance in the Colorado mainstem. This unprecedented level of disturbance in the mainstem has the potential to disrupt tributary ecology and increase pressures on native fishes. Among the most likely and potentially devastating of these pressures is the colonization of tributaries by predatory non-native species. Through focused conservation and management tributaries could play an important role in the protection of the Grand Canyon’s native fishes.