Toxic Algae Fact Sheet and Frequently Asked Questions

Author: Tadd M. Barrow, School of Natural Resources, University of Nebraska-Lincoln

What is Algae?

Algae are defined as simple rootless plants that grow in bodies of water relative to the amount of nutrients available.

Blue-Green Algae or Cyanobacteria:

Although technically not a true algae, toxic blue-green algae refers to certain species of cyanobacteria that have the ability to produce toxins. Some contend because the cell utilizes sunlight for photosynthesis it is a plant and thus blue-green algae. Others maintain because the cell lacks a well defined nucleus, it is a bacteria or cyanobacteria. Regardless of the terminology, cyanobacteria or blue-green algae are both accepted definitions.

Brief History of Toxic Algae:

Freshwater algae toxins (a.k.a. cyanotoxins) in the United States were first implicated in animal deaths in the late 1800's. Beach closings as a result of toxic algae have occurred in the Midwest since the 1950's. Relatively recent advancements in laboratory procedures has made the process of detecting the most common algal toxins more feasible and affordable; as a result Nebraska agencies and public health organizations collaboratively began addressing toxic algae issues in May 2004.

What is Toxic Algae?

Certain species of Blue-green algae (a.k.a. cyanobacteria) have the ability to produce toxins. Toxic blue-green algae can dominate the algal populations of a lake under the right combinations of water temperature, low water depths, and nutrients.

Risks and symptoms:

Pets and livestock have died from drinking water containing toxic blue-green algae. The risks to humans comes from external exposure (prolonged contact with skin) and from swallowing the water. Symptoms from external exposure are skin rashes, lesions and blisters. More severe cases can include mouth ulcers, ulcers inside the nose, eye and/or ear irritation and blistering of the lips. Symptoms from ingestion can include headaches, nausea, muscular pains, central abdominal pain, diarrhea and vomiting. Severe cases could include seizures, liver failure, respiratory arrest-even death, although this is rare. The severity of the illness is related to the amount of water ingested, and the concentrations of the toxins.

Are some people at greater risk?

Yes. Some people will be at greater risk from toxic blue-green algae than the general population. Those at greater risk include:

  • Children-toddlers tend to explore the shoreline of a lake, causing greater opportunity for exposure. Based on body weight, children tend to swallow a higher volume of water than adults, and therefore could be at greater risk.
  • People with liver disease or kidney damage and those with weakened immune systems are also at higher risk.

Tips on what to do and things to avoid:

  • Be aware of areas with thick clumps of algae and keep animals and children away from the water.
  • Do not wade or swim in water containing visible algae. Avoid direct contact with algae.
  • Make sure children are supervised at all times when they are near water. Drowning, not exposure to toxic algae, remains the greatest hazard of water recreation.
  • If you do come in contact with the algae, rinse off with fresh water as soon as possible.
  • Do not boat or water ski through algae blooms.
  • Do not drink the water, and avoid any situation that could lead to swallowing the water.

Is it safe to eat fish from lakes that have toxic algae?

The toxins have been found in the liver, intestines and pancreas of fish. Most information to date indicates that toxins do not accumulate significantly in fish tissue, which is the meat that most people eat. It is likely that the portions of the fish that are normally consumed would not contain these toxins. However, it is ultimately up to the public to decide whether they want to take the risk, even if it is slight. Anglers may want to practice catch and release at lakes containing toxic algae.

Where can I find out more information about lake sampling for toxic algae?

The Nebraska Department of Environmental Quality is conducting weekly and monthly sampling at select public lakes that are either popular recreational lakes, or have historically had toxic algae problems. This information is updated weekly on the DEQ agency Web site.

How do I get private lake water tested?"

Testing of private lakes is at the discretion and expense of the owner.  Several Nebraska laboratories provide water testing services. 

If I think a public lake has a toxic algae bloom, who do I call?

Please contact the Department of Environmental Quality's Surface Water Section at (402) 471-0096, or (402) 471-2186.


If I am experiencing health symptoms, who do I call?

If you experience health symptoms, notify your physician, and also report it to the Nebraska Health and Human Services System at (402) 471-2937. You can also contact the Nebraska Regional Poison Center at 800-222-1222 for more information.