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Harmful Algal Blooms

Algal blooms have become more noticeable in Ohio’s lakes, streams and rivers during the last few years. Although most blooms are green algae and not harmful, there are some that are actually a type of cyanobacteria that have the ability to produce toxins – called harmful algal blooms (HABs).

Remember, you can still boat, fish and recreate in Ohio’s lakes, streams and rivers. Just be aware that HABs exist and when in doubt, stay out. We hope the information here will give you a better idea of what HABs can look like and provide you with the information you need to safely enjoy Ohio's waterways.

Report a bloom to the  Ohio EPA by completing the Bloom Report Web form.

Advisories

Be alert for these signs/advisories and changing water conditions.

For more detailed information on advisories, monitoring and guidelines, please view the 
Ohio HAB Response Strategy for Recreational Waters.

General Signs

These signs will be posted at state park beaches and boat ramps. The white sign describes what a harmful algal bloom looks like and advises that people be on the alert and avoid them.

Download General Sign (PDF)

Recreational Caution

A Blue Recreational Caution sign will be added to the white sign when a HAB is visually confirmed. It indicates that an algal bloom has been visually detected, and that samples have been collected and are pending laboratory analysis for cyanotoxins.

Download Recreational Caution Sign (PDF)

 

Recreational Public Health Advisory

A red sign will be added to the white sign when HAB toxin levels are equal to or exceed a Recreational Public Health Advisory threshold. It advises that algal toxins at unsafe levels have been detected and to avoid all contact with the water.

A safety-green caution sign will be added to the white sign at boat ramps when a red sign is posted at a beach. It advises boaters that is a HAB confirmed at a beach and may be present in other areas of the lake.

Download Recreational Public Health Advisory Sign (PDF)

Download Boat Ramp Caution Sign (PDF)

 

For Recreational AdvisoriesCurrent Ohio recreational water body monitoring and advisories can be found at the Ohio Department of Health's BeachGuard website.

For Drinking Water AdvisoriesIf microcystin, anatoxin-a, cylindrospermopsin or saxitoxin is found above drinking water thresholds in the finished water of a public water system, the water system will public notice a drinking water advisory.

Basics

What is a harmful algal bloom (HAB)?

A harmful algal bloom (HAB) is a large growth of bacteria that can produce cyanotoxins. These cyanotoxins may affect the liver, nervous system and/or skin.

What causes HABs to form?

Some factors that can contribute to HABs include sunlight; low-water or low-flow conditions; calm water; warmer temperatures; and excess nutrients (phosphorus or nitrogen). The primary sources of nutrient pollution are runoff of fertilizers, animal manure, sewage treatment plant discharges, storm water runoff, car and power plant emissions and failing septic tanks.

The State of Ohio's nutrient reduction strategy documents ongoing nutrient reduction activities and identify areas where more work is needed. Additionally, the H2Ohio plan includes targeted solutions to help reduce phosphorus runoff and prevent HABs through increased implementation of agricultural best practices and the creation of wetlands.

How dangerous are HABs?

If you touch HABs, swallow water with cyanotoxins or breathe in water droplets, you could get a rash, have an allergic reaction, get a stomach-ache, diarrhea or vomiting, or feel dizzy or light-headed. HABs also are toxic to pets.

Always look for HABs before going in the water. Check Beachguard for recreactional HAB advisories. Ask the park manager if there has been a recent HAB because colorless cyanotoxins can still be in water.

How will I know if there is a HAB?

HABs have different colors and looks. Some colors are green, blue-green, brown, black, white, purple, red and black. They can look like film, crust or puff balls at the surface. They also may look like grass clippings or dots in the water. Some HABs look like spilled paint, pea soup, foam, wool, streaks or green cottage cheese curd.

What should I do if I see a HAB?

  • Stay out of water that may have a HAB.
  • Do not let your children or pets play in HAB debris on the shore.
  • After swimming or wading in lake water, even where no HABs are visible, rinse off with fresh water as soon as possible.
  • Never swallow any lake or river water, whether you see HABs or not.
  • Do not let pets lick HAB material from their fur or eat HAB material.
  • Do not drink or cook with lake water.
  • See a doctor if you or your children might be ill from HAB toxins. If your pet appears ill, contact your veterinarian.
  • Report the bloom to Ohio EPA by completing the Bloom Report Web form or paper form and emailing it to HABmailbox@epa.ohio.gov.

What about fishing and other activities?

If you plan to eat the fish you catch, remove the guts and liver, and rinse fillets in tap water before eating. More information on fish consumption advisories can be found at http://odh.ohio.gov/ohfishadvisory.

Other activities near the water such as camping, picnicking, biking and hiking are safe. If you are picnicking, wash your hands before eating if you have had contact with lake water or shore debris.

Exposure & Health Effects

How can I be exposed to HABs?

  • Ingestion – or the incidental/accidental swallowing of contaminated water such as during water-related recreational activities.
  • Skin Contact – Swimming, skiing, tubing and other recreational activities in HABs contaminated waters. Skin contact can also occur during hand washing, food preparation, and bathing in HAB contaminated water.
  • Inhalation – Breathing aerosolized water droplets (misting) of HABs-contaminated water from recreational activities such as jet-skiing or power boating. Outside of recreational waters, inhalation may occur from sinks and showers.

What are symptoms of HAB exposure?

See a healthcare provider if you experience any of the following symptoms after being exposed to a HAB:

  • Severe diarrhea and vomiting
  • Abdominal pain
  • Kidney damage
  • Weakness Numbness
  • Dizzy/light-headed
  • Difficulty Breathing
  • Rashes/hives
  • Runny nose
  • Sore throat
  • Allergies

How can I prevent exposure to HABs?

  • Be aware and follow any advisories for HABs that may be posted at beaches or boat ramps.
  • Use BeachGuard to view current Ohio advisories at water bodies.
  • Stay out of water that may have a HAB.
  • Do not let your children or pets play in HAB debris on the shore.
  • After swimming or wading in lake water, even where no HABs are visible, rinse off with fresh water as soon as possible.
  • Never swallow any lake or river water, whether you see HABs or not.
  • Do not let pets lick HAB material from their fur or eat HAB material.
  • Do not drink or cook with lake water.

What if I become ill after exposure to a HAB?

Seek immediate medical care or contact your healthcare provider.

Individuals who are concerned that they may be experiencing HABs illness symptoms after exposure to contaminated water should contact their healthcare provider. Healthcare providers who rule out other potential causes of the symptoms and suspect a HABs illness should notify their local health district epidemiologist. The directory of local health districts can be found here. Local health districts should complete forms for reports of human illnesses associated with either recreational or public water system exposure to HABs toxins, which are available here.

For Physicians

HABs are groups of cyanobacteria which can produce cyanotoxins causing illness. Symptoms can include gastrointestinal (nausea), neurologic (dizziness) and skin rashes. Severe disease can result in neuro, nephro- and hepatotoxicity depending on the cyanotoxin. For patients presenting with ill-defined gastrointestinal, neuro or skin symptoms AND a recent history of recreating in a waterway, consider harmful algal bloom and cyanotoxin exposure.

ODH has developed a diagnostic tool and treatment algorithm for harmful algal bloom exposure. Reports of human illness from recreational or drinking water exposure should be reported to the local health district or to the Ohio Department of Health. More information can be found at odh.ohio.gov/wps/portal/gov/odh/know-our-programs/harmful-algal-blooms/Information-for-Physicians/.

Pets and Livestock

How do pets get exposed to HABs?

Pet exposure to cyanotoxins typically occurs after swimming or drinking from contaminated water. Other exposures occur when animals lick their fur after swimming or by eating the surface scum on the beach. The severity of the illness depends on the amount of water and type of algal cells ingested, the animal’s body size, the amount of food in the animal’s stomach, and the sensitivity of the species and individual animal.

How do pets get exposed to HABs?

Pet exposure to cyanotoxins typically occurs after swimming or drinking from contaminated water. Other exposures occur when animals lick their fur after swimming or by eating the surface scum on the beach. The severity of the illness depends on the amount of water and type of algal cells ingested, the animal’s body size, the amount of food in the animal’s stomach, and the sensitivity of the species and individual animal.

What can I do to reduce risk of HAB-related illness in my pet?

  • Use BeachGuard to track HAB advisories in Ohio.
  • Keep people, pets, and livestock out of water with blooms.
  • If your pets enter the water, be sure to rinse them off with clean, fresh, HAB-free water so they do not lick algae off their fur or skin where cyanotoxins may be present.
  • Do not let your pet eat algae off the beach as cyanotoxins may be present.
  • Do not water lawns or gardens with water from HAB-impacted lakes or ponds.
  • Follow posted water body closures announced by state agencies or local authorities.

What should I do if my pets or livestock become ill?

Time can be critical – if your pet is ill and you suspect HAB exposure, seek immediate veterinary attention. Indicate that your animal was in water containing an algal bloom and was drinking the water; eating algae off the beach; or licking algae off its fur/skin while grooming.

What are symptoms of HAB exposure?

  • Depression
  • Incoordination or weakness
  • Loss of appetite
  • Excessive drooling
  • Muscle Twitching
  • Seizure
  • Respiratory failure
  • Diarrhea & vomiting
  • Abdominal tenderness
  • Jaundice
  • Dark Urine
  • Rashes
  • Allergic Reactions
  • Hives

Where should I report HAB-related illnesses?

After immediate treatment, report the animal illness to your local health district or the Ohio Department of Health at BEH@odh.ohio.gov or at (614) 644-1390. Find your LHD using the web tool: odh.ohio.gov/GetMyLHD. Report a HAB-related illness using the form: odh.ohio.gov/HABAnimalForm.

Helpful Links

For Veterinarians

Pets and animals may have an increased exposure risk and sensitivity to cyanotoxins, if allowed access to water bodies with a HAB. The different hepatotoxins, neurotoxins, and dermatoxins can lead to a wide range of symptoms that without veterinary attention may result in serious illness or death. Report animal illness or death related to harmful algal bloom exposure to the local health district or the Ohio Department of Health. Information on diagnosis and treatment of HAB exposure in animals can be found at odh.ohio.gov/wps/portal/gov/odh/know-our-programs/harmful-algal-blooms/Information-for-Veterinarians/.

ODH has developed a quick reference poster for diagnosis and treatment of animals exposed to harmful algal blooms for veterinarians and a fact sheet on pet exposure to harmful algal blooms for pet owners. odh.ohio.gov/wps/portal/gov/odh/know-our-programs/harmful-algal-blooms/Information-for-Veterinarians/

Contact the Ohio Department of Health at BEH@odh.ohio.gov or at 614-644-7464 for a full size copy of the poster.

Reporting  

Report a Bloom 

Report the bloom to Ohio EPA by completing the Bloom Report Web form or paper form and emailing it to HABmailbox@epa.ohio.gov

Report an Illness

Individuals who are concerned that they may be experiencing HABs illness symptoms after exposure to contaminated water should contact their healthcare provider. Healthcare providers who rule out other potential causes of the symptoms and suspect a HABs illness should notify their local health district epidemiologist. The directory of local health districts can be found here. Local health districts should complete forms for reports of human illnesses associated with either recreational or public water system exposure to HABs toxins, which are available here.

Resources

H2Ohio: Ohio's water quality plan to reduce harmful algal blooms, improve wastewater infrastructure, and prevent lead contamination.

U.S. EPA Cyanohab: Federal guidance on cyanobacterial blooms and cyanotoxins including basic information, response tools, management, prevention, and treatment in both drinking and recreational waters.

Ohio Sea Grant Harmful Algal Blooms in Lake Erie

Publications

The Ohio Department of Health (ODH) samples selected public beaches along Lake Erie for E. coli bacteria. When the amount of bacteria in the water exceeds state standards, beaches are posted with signs that advise against swimming. ODH's site will allow you to view current sample results to determine the risks for swimming.

Related External Links