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As the human population rapidly expands, ecosystems are being severely affected. Human activities have caused a lot of damage, but many scientists are seeking to understand how we can reverse and mitigate this damage.

BIO-WEST’s ecologist, Ryan Dillingham, is one such scientist. He specializes in watershed ecology, restoration ecology, and the conservation of threatened and endangered species. He recently presented his research on active ecosystem restoration during his Master’s thesis defense at Utah State University.

Active ecosystem restoration is a process designed to help nature recover after being damaged by human activities. But restoring an ecosystem can take a lot of time and effort. Sometimes restoration efforts fail, or it can take decades before changes are noticeable. 

Because it can take such a long time to see improvements, Dillingham realized there needed to be a way to measure how an ecosystem responds to restoration efforts on a smaller scale. So for his Master’s degree, he designed methods that can be used to detect and measure those small changes, specifically for lake ecosystems.

Dillingham focused his research on Utah Lake, where ongoing restoration projects provided the ideal environment to measure incremental responses for recovery. In particular, he observed how Utah Lake was responding to the June Sucker Recovery Program’s large-scale, lake-wide carp removal effort, which began in 2010. 

The goal of this effort is to reduce the enormous population of common carp living in Utah Lake, which should in turn encourage the growth of native aquatic plants, improve water quality and clarity, and aid in the recovery of the endangered June Sucker, a native fish that was listed as endangered in 1986.

The question Dillingham asked for his research was “How are carp removal restoration efforts influencing the Utah Lake ecosystem, and how can we detect and measure ecosystem response to restoration in the absence of full recovery?”

Common carp was introduced into Utah Lake in 1883 as a source of food after native resources had been depleted. Since their introduction, however, the lake’s water quality has gotten worse, native plant and animal species have had a harder time finding food, and the lake’s ecosystem as a whole has significantly changed.

The carp removal effort is one of the largest fish removal programs in the world. A full-time crew of commercial fishermen remove approximately 4–5 tons of carp per day. Since 2009, carp control efforts have removed more than 15,000 tons of carp from Utah Lake and by 2016, it’s estimated that carp biomass was reduced by more than 75 percent. 

One of the most interesting things Dillingham said he found was that areas with fewer carp tended to have more species of aquatic plants and predatory aquatic insects than areas that were dominated by carp. And not only were there more species of aquatic insects, they were also larger and more abundant.

In ecology, predators are often used as indicators of an ecosystem’s health. Removing a predator from an ecosystem can have huge cascading effects, and seeing an increase in their size and numbers, like what Dillingham noticed in Utah Lake, can mean there’s more food available for other animals. This in turn implies that the environment is starting to improve. 

Dillingham hopes that the tools he helped develop will be applied to other large-scale restoration projects. He also believes that they could be applied to smaller projects, like ponds with too much algae. 

You can read his thesis here: https://digitalcommons.usu.edu/etd/8434/