2013 Research Catalyst Grantee
Urban stream health: macroinvertebrates and periphyton as indicators
Working with collaborators from University of Utah and Utah Valley University, this iUtah RCG project will attempt to characterize the impacts of urbanization and mining-related contamination on riparian ecosystems. Changes due to urbanization are known to degrade riparian ecosystems through multiple stressors. Examining the physiochemical parameters, coupled with biological measures sure as macroinvertebrates and periphyton, we can develop a comprehensive assessment of riparian ecosystem health over time.
Our recent work indicates that urbanization does negatively impact the streams along the Wasatch Front, as we found that macroinvertebrate biodiversity was greater in non-urban reaches than in urban reaches of the same streams. In addition, the proportion of the macroinvertebrate community that was sensitive to pollution was greater in non-urban reaches of the streams than in their urban counterparts, while the proportion of pollution tolerant species greater in the urban reaches. Preliminary data suggest that periphyton biomass, an indicator of N and P inputs, was 35 times greater in urban reaches when compared to non-urban reaches of the same streams. These findings were correlated with higher temperatures, lower dissolved oxygen, and higher levels of nitrate in urban reaches compared to non-urban reaches of the same streams. Overall, these findings point to urbanization as a potential source of ecosystem degradation in the Salt Lake Valley.
Our findings also suggest that long-term and expanded monitoring is warranted, along with an in-depth investigation into the mechanisms responsible for the degradation. With iUtah RCG funds, we propose to use the tools and expertise of four scientists from three universities to sample macroinvertebrates and periphyton, measure water and nitrogen isotopes, as well as evaluate water and soil samples for As and heavy metals related to mining and other development. This work aims to produce a more comprehensive understanding of the impact of urbanization on riparian ecosystems, and ultimately inform the management of water resources along the Wasatch Front.
Gabriel Bowen, The University of Utah
James Ehleringer, The University of Utah
Steven Emerman, Utah Valley University