Indiana State University Newsroom

Impact of Otter Creek contaminants researched

November 12, 2016

Indiana State University researchers are looking into the importance of Otter Creek, a small tributary near Terre Haute that runs into the Wabash River.

The research was designed to pinpoint locations with the highest concentration of nitrates and ammonium along Otter Creek and help the Ouabache Land Conservancy reduce human impacts on the ecosystem.

Established in 2007 as a land trust to protect natural lands and farmlands from development, the Ouabache Land Conservancy serves west central Indiana, including Clay, Fountain, Montgomery, Owen, Parke, Putnam, Sullivan, Vermillion and Vigo counties.

The Ouabache Land Conservancy initially approached State with the project, which it hopes to expand on to get a large view of what is happening beneath the water.

"The partnership with ISU and the testing that has been done will help Vigo County improve water quality. We now know more about water quality and where are issues are, and how we can address them," said Adam Grossman, a member of the Ouabache Land Conservancy Board of Directors. "Everyone in the community and downstream benefits from cleaning up our watershed, installing and educating about best management practices."

The team analyzed water quality on a weekly basis for approximately one year, using ProDSS, a water-testing probe made to record how the water quality changes with the seasons.

Samples were collected from nine sites surveyed using a water probe and were examined for toxins in the water, such as nitrate and ammonium. Trends in the data show substantial changes in nutrient fluxes occur throughout the year, with the largest influxes occurring in the winter season.

"The main sources of nitrate and ammonium in the water are from fertilizing crops, and it primarily gets into the water through either runoff or through groundwater," said Jeffery Stone, assistant professor in the earth and environmental systems department and faculty sponsor of the research project.

Following the project, the Ouabache Land Conservancy plans to come up with a grant for farmers to promote better nutrient management, as well as the implementation of preventative measures to reduce the amounts of nutrients that are going to the creek.

Courtney Natt, a junior biology major, participated in the project during the Summer Undergraduate Research Experience.

Recent research has shown that the Wabash Valley farmland contributes a substantial amount of nutrients that leads to massive algal blooms downstream in the Gulf of Mexico.

Another study discovered that the Wabash River is one of the biggest contributors to nutrients being carried downstream, the Gulf to be named a "dead zone," Stone said. Because of all the nutrients in the Gulf that have created a large algal bloom, the algae will eat and thrive on the nutrients and then they will die.

The decomposition process consumes oxygen so by the time that the algae are all dead there is not enough nutrients and oxygen in the water to sustain life, according to Stone.

After this, they plan to come up with a grant for farmers to promote better nutrient management as well as the implementation of preventative measures to reduce the amounts of nutrients that are going to the creek, Stone said. Currently, the Ouabache Land Conservancy is trying to get the community involved and informed about conservation.


Writer and media contact: Briana Lofton, media relations assistant, Office of Communications and Marketing, Indiana State University, 812-237-3773 or