Does Stream Restoration Work? A Case Study in Fayetteville, Arkansas
by Amadeo Scott
Water quality of streams in urban areas, such as the university campus, is often severely degraded due to runoff from impervious surfaces such as roads and parking lots. This results in pollutants and other substances entering streams in these places, especially during storms. This lowers the water quality, and the excess stormwater can change the shape of the streambed and erode the banks. To get streams back to a healthier state, we often carry out restoration projects, which might include planting native streambank vegetation to decrease erosion and increase filtration of runoff, or placing rock structures and gravel in the streambeds to restore the original streambed shape. These were both techniques used in a restoration on campus at Mullins Creek in 2012. Unfortunately, most stream restorations are not monitored, so it’s actually rare to know whether a restoration worked. Mullins Creek had qualitative monitoring done after the project, but no quantitative study. I decided to study the water quality in Mullins Creek, 10 years after the stream restoration, hoping to find whether the restoration goals were met and to determine if the methods used were effective. I looked at the physical, chemical, and biological water quality of sites above the restoration, at it, and below it to compare unrestored and restoration site quality. After a year of monitoring and analysis, I determined that 2 out of 3 studied goals of the restoration—increased nutrient uptake and more aeration and pool habitats—had been met. The third goal, decreased erosion and turbidity, was not met, as turbidity was highest at the restoration site. This study has shown that the methods used for the other two goals, which included rock structure and gravel placement, were effective, but that anti-erosion methods should be reevaluated in future restorations. This project helps contribute to our adaptive management of stream restorations, in which researchers constantly test and improve their methods in ecological restoration.
I chose this topic because I have always been interested in aquatic ecosystems, and finding ways to combat the negative effects of urbanization on the world around us is a quickly-growing field. I heard about the Mullins Creek restoration during an environmental science lab and decided to discuss a potential project on the subject with the professor, Dr. Lisa Wood. She suggested looking at water quality, and after I developed my proposal to determine the efficacy of the restoration, she introduced me to Dr. Shannon Speir, who became my project mentor.
During this project, I learned that the results of stream restoration are generally unknown, and that both designing and assessing restorations are confusing topics with no one scientific approach or consensus. Restorations have thousands of factors, and nuance is very important when trying to answer a question that sounds so black-and-white: “Did the restoration work?”. Throughout the year-long project, I was constantly discovering new aspects of stream quality, interactions between the campus environment and the stream, and the layered effects of continuing urbanization on a restoration. A particularly challenging aspect of the project for me was interpreting some of the water chemistry results. The water chemistry could be influenced by anything in the stream’s aboveground or belowground environment, so it was difficult to find specific possible reasons for a certain result. I gathered literature on each parameter I was measuring to find the mechanisms that could be causing my results, and then went through them methodically and reasoned out which could apply to Mullins Creek and which couldn’t. This made the task much easier, and now when a project feels like too much to focus on, I use this method to break it down into smaller parts.
My mentor, Dr. Speir, guided me throughout the project, helping me to design procedures, choose statistical analyses, edit my writing, and much more. Besides directly working with students, she facilitates a collaborative environment within her lab, and so other students in the Speir Lab also helped me, whether through coming on sampling trips, helping me troubleshoot field techniques, or providing feedback on papers and posters. I also had help from Dr. Brad Austin at the AWRC, who worked with me to analyze my water chemistry samples. Finally, of course, I also received crucial suggestions and feedback from my thesis committee.
After I graduate, I am hoping to work as a laboratory or research technician with an aquatic or marine lab for a year or two. I eventually want to get my Master’s in coastal ecology, and hopefully a Ph.D. after that. I am passionate about conserving our species, particularly those that don’t get a lot of attention, such as aquatic invertebrates. I hope that I’ll be able to spend my life researching and protecting our lesser-known animals.
Recent Comments