Blue-Green Algae: Keeping Our Lakes Clean

How can I prevent future algal blooms?

A rocky shoreline

Algal blooms often occur as a result of excess nutrients, such as phosphorus and nitrogen, in the water. Preventing algal blooms poses a significant challenge because once these nutrients are in the watershed they make take years to be flushed out. Nutrient management strategies such as reducing the use of phosphate-containing fertilizers and restoring natural shorelines can help to control nutrient loading in Wisconsin's lakes, rivers, and streams. The Wisconsin Department of Natural Resources has a number of suggestions for lakefront property owners interested in reducing their contribution to nutrient loading.

You can help keep Wisconsin's lakes clean

  • Minimize the use of lawn fertilizers.
  • Do NOT use phosphate-containing fertilizers.
  • Perform routine maintenance on your septic system.
  • Plant natural vegetation around ponds and lakes to help filter runoff.

Glossary

 
Last revised October 21, 2025