2018 ESA Annual Meeting (August 5 -- 10)

PS 2-19 - Vegetation cover effects on fish presence in the Verde River in Arizona

Monday, August 6, 2018
ESA Exhibit Hall, New Orleans Ernest N. Morial Convention Center
Maria A. Johnson1, Sierra J. Frydenlund1, Larissa N. Lee2, Zachary C. Nemec2 and Scott A. Bonar3, (1)School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, (2)School of Natural Resources and the Environment, University of Arizona, (3)U.S. Geological Survey Arizona Cooperative Fish and Wildlife Research Unit, University Of Arizona, Tucson, AZ
Background/Question/Methods

Riparian canopy has been shown to be beneficial to instream fish habitat because it provides shading and bank stability. Canopy cover allows streams to maintain suitable fish habitats by preventing water temperature fluctuations and improving channel morphology. Certain species of fish may be negatively affected by a lack of vegetation cover because of an increased temperature range. In order to understand the effect of shading from canopy cover on the fish species in the Verde River, we accessed twelve sites along the upper and middle Verde River in central Arizona. Thirty pre-positioned areal electrofishing devices (PAEDs) were randomly placed throughout each site and were used to sample fish. Microhabitat was also measured at each grid, including canopy cover, which was calculated using a spherical densiometer. This data was analyzed using logistic regressions to determine if there is a relationship between canopy cover and water temperature and species of fish.

Results/Conclusions

Preliminary results show that vegetation cover does not have a significant effect on fish presence as a whole. However, when fish are categorized by family, vegetation cover does show to have an effect on cyprinidae. Three of the six families have small sample sizes and conclusions cannot be properly drawn from that data.