What is a harmful algae bloom? What causes it?

Blue green algae (Cyanobacteria) occurs naturally in ponds, lakes, reservoirs, and other still or slow-flowing bodies of water. However, in the summer heat, excess nutrients in the water – like nitrogen and phosphorus - can cause blue-green algae to explode into harmful algae blooms.

How do excess nutrients enter the water?

Nitrogen and phosphorous are the main elements in commercial fertilizers. If farmers, landscapers, and landowners apply excess fertilizers, then during rainstorms the chemical excess runs into and accumulates in bodies of water.

How can I recognize a harmful algae bloom?

During summer, keep a close eye on creeks, ponds, even on slow-moving drainage ditches that wind through parks or along edge of soccer fields. Look for these signs:

• Does the water surface appear different than usual? Do you see slicks of bright green, blue, or red? Is the slick becoming progressively thick and scummy, perhaps with floating chunks? (Not all HABs appear this visibly, however.)

• Does the water seem more cloudy, green, or smelly than usual?

• Are there dead fish and aquatic life floating to the surface? Are there any dead animals at the water’s edge?

If the answer to any of these questions is yes, you could be looking at a harmful algae bloom. The Kansas Department of Health and Environment (KDHE) only tests public lakes for HABs on request. They do not test private waters but you can test your own pond. If you are in doubt about a water body, stay away - and make sure all children and animals do, too. Report your concerns to local health authorities. Your doctor can report any HAB-related illnesses to KDHE.

How can I help prevent a harmful algae bloom?

Improving your stormwater management will help prevent harmful algae blooms. The faster the water runs off your land, the more chemicals and sediments it carries with it. When you slow down stormwater, you help reduce the nutrient supply that harmful algae depend on.

Some techniques you can try:

• Install rain barrels. You slow down stormwater and also harvest rainwater for irrigation.

• Build rain gardens or other diversion areas. These areas can capture and hold water while filtering out sediments.

• Maintain your existing wetlands. If there’s a low spot on your lot, don’t fill it in – allow it to fulfill its natural function of slowing and filtering stormwater.

• Install buffer strips of cover crops and native vegetation where needed to slow the flow of water across your land.