Environmental engineers improving algae bloom management

Management of harmful algal blooms has traditionally focused on reducing the amount of phosphorus that reaches the watershed, but targeted efforts can be tough when the exact source of phosphorus is unclear.

Civil, Environmental and Geodetic Engineering Assistant Professor Paula Mouser and PhD candidate Michael Brooker are identifying unique signatures for the phosphorus found in the Lake Erie watershed, in hopes of learning its origins.

Research has historically focused on phosphate, an inorganic form of phosphorus commonly used in fertilizers, explained Mouser. Phosphates are the dominant form of phosphorus in natural waters and are easier to identify, making them the standard measurement for routine monitoring. However, organic phosphorus can come in literally hundreds of forms, from multiple sources, making it more difficult to trace and manage.

Mouser and Brooker collected samples from six different sources in the Sandusky River watershed: chicken, dairy and hog farm manure; runoff from farm fields with row crops, and wastewater treatment plant discharge, along with river water from farther downstream. Within each sample, they found between 100 and 300 different organic phosphorus compounds. The analysis will result in a unique signature for each of the samples, showing both similarities and major differences. Once researchers determine which phosphorus compounds come from each source, they can link those compounds to an upstream location.

“Theoretically if we can identify the source of the phosphorus, we can help improve management strategies to reduce phosphorus loading in our watersheds and reduce the outcomes that result from the algal blooms,” said Mouser.

Follow up sampling will occur in spring 2017 to expand the scope of the study.