Harmful Algal Blooms

Contact: Gary Kohlhepp 517-284-5540

Harmful Algae Blooms - Lake ErieThis page can be accessed as michigan.gov/habs.

EGLE staff discover or receive reports from lake associations, and the broader public each year about nuisance algal conditions.  The number of such reports, particularly the occurrence of cyanobacteria or blue-green algae blooms and concern over the possible presence of algal toxins such as microcystin, appear to have increased in recent years.  In particular, severe blooms were observed in the western basin of Lake Erie in August 2014, and access to drinking water for hundreds of thousands of people was temporarily interrupted due to elevated levels of an algal toxin associated with the bloom.  This event caused EGLE to re-examine and expedite our efforts related to blue-green algae blooms, including what constitutes a harmful algal bloom (HAB); our monitoring approach; sampling protocols; analytical capabilities and costs; information gaps; and communication with other agencies, stakeholders, and the public on this issue. 

Summer is peak season for the formation of harmful algal blooms (HABs) that can present health hazards to people and pets. In Michigan, algal blooms typically occur during periods of warm temperatures, lots of sun, and high nutrient levels.

It is not possible to determine whether algal blooms contain harmful toxins by looking at them, so it is best to avoid contact with any body of water that is covered with algal mats or significant rafts of algae on the surface.

The Michigan Departments of Environment, Great Lakes, and Energy (EGLE) and Health and Human Services (DHHS) sample for HABs on a limited basis and work with local health departments to protect the public when toxins are discovered; however, some areas affected by HABs may go undetected. Suspicious-looking algae can be reported to EGLE by calling the Environmental Assistance Center at 1-800-662-9278 or sending an e-mail to AlgaeBloom@Michigan.gov.


Frequently Asked Questions (FAQ's)

1. What are Harmful Algal Blooms?
2. What does a harmful algal bloom look like?
3. What causes a bloom?
4. When do algal blooms happen?
5. What are the health effects on people?
6. What are the health effects on pets or livestock?
7. Should residents be concerned about threats to dog health?
8. Can I swim or go boating if HABs are in the water?
9. Can I eat fish if HABs are in the water?
10. What should I do if I think I’ve found a HAB?
11. Who should I contact if I think I’ve found a HAB?
12. What is Michigan doing to protect the public?
13. What can people do to help prevent harmful algal blooms from occurring?

Resources
Reports
Related Links


Frequently Asked Questions (FAQ's)

1. What are Harmful Algal Blooms?

Cyanobacteria (cy·a·no·bac·te·ri·a), also known as blue-green algae, are a natural part of lakes, rivers, and ponds. Unfortunately, some species can produce toxins, called cyanotoxins (cy·a·no·tox·ins), that can make humans and animals sick. When conditions are right, these organisms can rapidly increase to form cyanobacteria blooms, or HABs. These blooms can last a few days, weeks or longer and are considered harmful because they may contain toxins. A bloom can start small and become very large in size and can give off a foul odor.

2. What does a harmful algal bloom look like?

Not all algal blooms contain toxins, but it is difficult to tell by looking at a bloom if it is harmful. Also, the amount of toxins in a bloom can change over time. HABs can be a variety of colors such as blue, green, blue-green, brown, white, purple, or red. HABs can look like scums in the water that may have small flecks, foams, or globs and mats floating in it. The water can also look like it has spilled paint or a green sheen on the surface. When in doubt, keep yourself and pets out.

3. What causes a bloom?

A bloom can occur when the water temperature is warm, conditions are calm, and the water has a high level of nutrients, like phosphorus and nitrogen. Excess nutrients can come from pollution such as lawn and farm fertilizers, animal manure, storm water runoff, sewage treatment plant discharges, and malfunctioning septic tanks. Invasive zebra and quagga mussels help make water conditions right for HABs.

4. When do algal blooms happen?

Blooms typically occur in Michigan from summer to fall. A bloom can last days to a few months. Blooms may disappear but then form again within the same season.

5. What are the health effects on people?

Typically, symptoms of illness from cyanotoxins appear within hours to days in humans. If symptoms do appear, the severity will depend on how long the exposure was, the type of cyanotoxin, and how the person was exposed.

Skin contact with water containing cyanobacteria may cause irritation such as rashes, hives, or skin blisters. It may also cause runny eyes and noses or asthma-like symptoms. Thoroughly rinse off with fresh water if the skin comes into contact with an algal bloom.

Swallowing large amounts of water containing cyanotoxins while swimming, wading, or playing in the water may cause flu-like symptoms, gastrointestinal illness, or neurotoxic symptoms. These may include abdominal pain, vomiting, diarrhea, weakness, numbness, headaches, dizziness, or difficulty breathing. Swallowing large amounts of cyanotoxins can harm the liver or kidneys.

Recreational water sports like boating and jet skiing may create water spray into the air that can produce an aerosolized toxin (from tiny droplets in the air) if HABs are in the water. Breathing in this water may cause skin, eye, nose, or throat irritation.

If you suspect you have had contact with or swallowed water containing cyanotoxins, and experience any of the symptoms listed above, consult your health care provider and/or call Poison Control at 1-800-222-1222.

If symptoms are severe, seek emergency medical attention as soon as possible.

6. What are the health effects on pets or livestock?

If you see a bloom, do not allow your pets or livestock to come into contact with it – especially dogs. Dogs are more likely than humans to drink the water and can swallow a lot of water for their size. When they groom themselves, dogs can potentially swallow cyanotoxins collected in their fur.

Symptoms of illness from cyanotoxins often appear quicker in animals than in humans – sometimes in minutes to a few hours. Symptoms in animals can include vomiting, diarrhea, fatigue, staggered walking, excessive salivation, convulsions, erratic behavior, or physical distress.

Dogs should be thoroughly rinsed off or bathed with fresh water after contact with water that may contain algae, even if it's not toxic algae.

Contact your veterinarian immediately if pets or livestock show signs of illness or if you know or suspect your pet or livestock had contact with a HAB.

7. Should residents be concerned about threats to dog health?

While there have been no confirmed deaths of dogs in Michigan due to exposure to algal blooms, there have been a few dog deaths where exposure to algal blooms may have been a contributing or causal factor, but no definitive cause could be determined.

The blue-green algae causing toxins that may lead to dog deaths are often associated with warm water temperatures and lots of sun. Preventative measures for dogs include avoid surface scums wherever visible. If people have concerns about their dog’s health, they should contact their vet. In assessing individual situations, it’s best to apply the saying: “When in doubt, stay out.”

8. Can I swim or go boating if HABs are in the water?

If a HAB is suspected, do not swim, wade, or touch the water where algae are present. Humans and pets should be rinsed thoroughly in fresh water if there has been any contact with the water.

Humans and pets should avoid the water entirely if there is a large algal bloom spread out across the lake, river, or pond, including water sports like boating.

Algae can cover the surface of the water so densely that you cannot see underneath to tell how deep the water might be or see rocks in the water. Trying to wade or swim through the algae can be dangerous.

9. Can I eat fish if HABs are in the water?

Cyanotoxins may build up in the meat of fish, such as the fillet, and especially in the guts or organs (liver, kidney, etc.). The amount of toxin found in fish depends on a number of factors, including how badly and for how long the cyanobacteria has been blooming in the area where the fish are caught.

Following the Eat Safe Fish waterbody-specific guidelines, or Statewide Safe Fish Guidelines, and eating only the fillets (and not the guts) reduces the danger of eating fish from areas affected by HABs and from other chemicals that are regularly found in them. The guts should be thrown away and fillets should be rinsed with fresh water before cooking.

10. What should I do if I think I’ve found a HAB?

You cannot tell if a bloom is toxic just by looking at it. Stay out of the water and do not let children or pets play in the water or near the shoreline where algae are present.

If advisories, signs, or closings are posted about the possibility of a HAB or the confirmation of a HAB, pay attention to the advisory or warning about the water.

If you see advisories or closings issued for some beaches for coliform bacteria, such as E. coli, pay attention to those warnings. More information on this monitoring can be found at http://www.deq.state.mi.us/beach/.

11. Who should I contact if I think I’ve found a HAB?

Always report suspicious-looking algae to EGLE by calling the Environmental Assistance Center at 1-800-662-9278 or sending an e-mail to AlgaeBloom@Michigan.gov.

Do not try to treat the water to kill the HABs because this may release toxins into the open water. Additionally, treatment of the water for aquatic nuisances requires a permit from EGLE.

12. What is Michigan doing to protect the public?

EGLE and DHHS are conducting some sampling for HABs in lakes, rivers, and ponds across Michigan; however, some areas affected by HABs may go undetected. Learn what HABs look like, be alert, and report suspicious algal blooms.

When possible, EGLE will collect water samples for testing to determine if a HAB is present. EGLE will notify the state and local health departments, and the health departments will work to determine the safety of the water for people and animals.

If it is possible for state and local agencies to detect and respond to a HAB, health departments may issue advisories through posting of signs and sending out notices to the public.

Public health advisories may indicate a need to avoid areas with algae, specific beaches, or the whole waterbody. Look for and follow all advisory notifications.

13. What can people do to help prevent harmful algal blooms from occurring?

Learning about nutrient pollution, such as excess nitrogen and phosphorus, can help to reduce or prevent algal blooms from happening in lakes, rivers, or ponds. Excess nutrients may come from agricultural fertilizer, lawn fertilizer, detergents, sewers, and malfunctioning septic systems. It is also important to learn what HABs look like, be alert, and report suspicious algal blooms.

People can help reduce HABs by taking simple actions that decrease nutrients getting into the water, like:

  • Using phosphate-free detergents.
  • Disposing of pet waste properly.
  • Appling fertilizers only when necessary and at the recommended amount.
  • Volunteering in local watershed protection efforts.

For health-related questions, contact the DHHS at 1-800-648-6942.

 

Resources

Reports

Related Links