Nutrient Enrichment and Harmful Algal Blooms

Bright green waterways and warnings to avoid water contact are a common sight for visitors to the Ohio River Watershed’s lakes and reservoirs. The cause: harmful algal blooms. These harmful algal blooms release toxins into the water, making it unusable for not only humans, but also pets and wildlife. While not all blooms are harmful, the overabundance of any type of algae can cause unpleasant odors, loss of aesthetic value, and a decrease in recreational opportunities in the Ohio River Watershed’s streams and rivers. These blooms are the result of large amounts of nutrients, primarily nitrogen and phosphorus, flowing into the lakes and reservoirs from the surrounding landscape.

The key to reducing the number and frequency of these algal blooms, harmful or not, is to better understand where these nutrients are coming from and how they behave in the streams that ultimately flow into our lakes and reservoirs. To understand nutrient movements, we are looking at the amount and forms of nutrients present in the water, as well as the makeup of the streams and the surrounding landscape. We also collect information on the types of algae, insects, fish, and substrate within the streams and the land use of the surrounding area. For this project, we are comparing nutrient sources in three differing land types within the Ohio River basin: forest, urban, and agriculture.

Although harmful algal blooms are not a new problem, there is no general method available to evaluate the risk posed by interactions of climate, land-use activities, and local conditions. This project aims to add to our understanding of how climate and land-use changes relate to changes in aquatic ecosystem health, as well as improve risk assessment of harmful algal blooms and improve Best Management Practices used throughout watersheds to reduce the occurrence of harmful algal blooms.

Funding for this research is provided by the Ohio Small Grains and Ohio Corn Marketing Programs and USEPA STAR Grant Number RD839269.

Co-PIs: Lauren Pintor and Kaiguang Zhao

Interested in our methods and preliminary results? Find out more here!

Check out the photo gallery below to see our researchers in action!