Investigations of the Effect of Virgin River Water Quality on Native Fishes

Affiliation(s) PI Project period Funded by
DHS Chen, Li 06/21/2011 - 06/30/2012 Washington County Water Conservancy District

Project Description

This study will focus on the water quality impact on native fishes. Through literature review, historical data analysis, field sampling and laboratory analysis, and modeling study, we intend to obtain a holistic picture of water quality impact on native and non-native fishes in Upper Virgin River. Based on the result, we will be able to identify the most critical water quality constituent affecting fishes in this specific stream, quantify the effect of burning on water quality and predict impact of fire severity and post-fire storm intensity on runoff quality and fishes population. The technical approach includes four major components. A thorough literature review will be conducted first to understand the cutting-edge knowledge of water quality impact on fish. Particular attention will be paid to wildfire caused water quality problems. The research team will then collect historical data of water quality and fish population, both from local stakeholders and federal agencies, and conduct statistical analysis to identify and rank critical water quality factors affecting native fishes in the Virgin River. To have a profound understanding of wildfire related water quality issues, post-fire water quality data will be collected through field experiments and sampling effort. A portable rainfall simulator will be used to conduct field rainfall simulation at burned area to collect water quality samples for ash laden flow. In the mean time, the research team will collect water samples in the main stream and tributaries of the Virgin River immediately after post-fire storm events, depending on the occurrence of such events for various parameters important to fisheries. Finally, a modeling study will be conducted to synthesize historical and newly collected data at various special scales to quantitatively estimate stream flow water quality, with a particular attention to post-fire conditions, for different hydrological conditions.