University of Idaho researchers are trying to get to the bottom of the algae problem on Fernan Lake.

About 25 UI faculty, post-doctoral researchers and students from multiple disciplines are partnering with local stakeholders to study the lake's toxic blue-green algae problem from different angles.

One of the questions the study will try to address is if urban growth is to blame for the problem, which typically draws warnings from the Idaho Department of Environmental Quality each year.

"Acre for acre, Fernan Lake is Idaho's most popular place for recreational fishing," a UI press release states. "But high phosphorus levels in this Coeur d'Alene-area lake cause blooms of toxic blue-green algae that keep residents from enjoying the natural resource in their backyard."

The research is a pilot project for Idaho's newest grant from the National Science Foundation's Experimental Program to Stimulate Competitive Research. The statewide $20 million grant aims to help Idahoans make science-based decisions about natural resources and provide them with a better understanding of the complex relationship between people and the environment.

UI researchers are studying Fernan Lake to understand what causes its algae problem, how the blooms affect local people and how future changes could affect the lake. Work on the project began last fall.

The research has resulted in a "Virtual Fernan" model that allows users to alter the virtual watershed and see what changes could happen in the lake. An early version of the model can be found at www.idahoecosystems.org.

"When it is completed, anyone who uses the visualization could virtually log 200 acres of hillside and see if it causes blue-green algae growth," said project leader Mark Solomon, a research scientist at UI's Idaho Water Resources Research Institute. "The model will allow the community to anticipate what urban growth and climate change means for phosphorus in the lake."

Excess nutrients are a source of blue-green algae blooms in Fernan Lake.

The blooms reduce water clarity and produce unsightly thick, green mats along the shoreline. In addition, some bloom species identified in the lake may produce toxins that are capable of causing illness in humans and animals and death to animals.

In recent years, during warm weather, health advisories have been issued, warning swimmers and others to avoid drinking the water or coming into contact with water containing any blooms.

According to the Centers for Disease Control and Prevention, humans who drink or swim in water that contains high concentrations may experience gastroenteritis, skin irritation, allergic responses or liver damage.

The state has a 20-year plan that limits discharge of total phosphorus (TP) to the lake. Sources of TP include stormwater runoff, construction activities, lawn/garden fertilizers, stormwater injection wells and septic effluent.

The recommended actions seek to bring Fernan Lake into compliance with state water quality standards and restore it to conditions supporting its beneficial uses which include primary contact recreation and aquatic life support.