Algae are commonly found in Indiana lakes and streams without concern, however, the concentrated presence of blue-green algae can be linked to some health effects.
 

USGS Photo

USGS Photo

IDEM fact sheet for Blue-Green Algae
IUPUI fact sheet for Blue-Green Algae
 

• Blue-green algae occur throughout area lakes, reservoirs, and streams and have for many years.  There are numerous different species present but recent years have seen both an increase in the dominance of some species and the appearance of other species?
   
• Some blue-green algae are capable of producing toxins that have potentially serious human, animal, and aquatic health effects; but, not all blue-green algae produce toxins?
   
• In recent years, concerns regarding the production and occurrence of blue-green algal toxins has grown in Indiana and nationally.  Reports of potentially-toxic blue-green algae in Indiana include Geist, Morse, and Eagle Creek in Marion County, Ball Lake in Steuben County, Lake Lemon and Monroe Reservoir in Monroe County, and at least 20 other lakes and reservoirs statewide.

Blue-green algae photosynthesize the same as plants, they need:

• Sunlight
• Warm Water Temperature
• Nutrients (fertilizer!)
• Still Water Conditions

• This is very difficult!
• Reduce Nutrient Fertilizer
• Algaecide Treatment
  • Short-term solution
  • Limited effectiveness
  • Only possible before bloom is well developed
  • Not advisable if toxin-producing species present

• Everyone should be aware and use caution when swimming, skiing, or participating in other recreational water activities.  Avoid coming into direct contact with the algae and try to avoid swallowing water.
   
• Direct contact with blue-green algae can cause skin irritations and rashes.  Drinking untreated water, intentional or accidental, may result in gastrointestinal illness and more severe illness may occur with the presence of microcystin toxin.
   
• Take a bath or shower with warm, soapy water after coming in contact with untreated water in ponds and lakes, especially before preparing or consuming food.  Never drink, cook, or shower with untreated water from lakes, ponds, or streams.  Pets and livestock should also not be allowed to swim in or drink untreated water from these sources.