Health Topics

Skip to Content

North Bay Parry Sound District Health Unit Logo North Bay Parry Sound District Health Unit Logo Print

Contact Us
  • Public Health
    Services
    • Breastfeeding Clinic
    • Community Events and Farmers Markets
    • Dental Clinic
    • Flu Shot
    • Food Safety Certification Training
    • Healthy Babies, Healthy Children
    • Infection Prevention and Control Investigations
    • Inspection Results and Enforcement
    • Needle Syringe Program
    • Parenting Workshops
    • Prenatal Classes
    • Private Drinking Water Testing
    • The Sexual Health Clinic
    • Vaccination Clinics
    • Vaccination Records
    • Vision Screening
  • Health
    Topics
    • Air Quality
    • Alcohol
    • Animal Bites
    • Beach, Lake and Pool Water
    • Breastfeeding
    • Cancer Prevention and Screening
    • Climate Change
    • Dental Health
    • Diseases
    • Drinking Water
    • Emergencies and Being Prepared
    • Flu/Influenza
    • Food Poisoning
    • Food Safety
    • Gambling
    • Healthy Aging
    • Healthy Eating
    • Home Health and Safety
    • Housing and Homelessness
    • Injury Prevention
    • Intimate Partner Violence
    • 2SLGBTQ+
    • Mental Health
    • Naloxone
    • Parenting
    • Perfluoroalkylated Substances (PFAS)
    • Physical Activity
    • Preconception and Pregnancy
    • Prenatal Resources
    • Racism
    • Reducing Weight Bias
    • Sexual Health
    • Sharps
    • Smoking, Vaping and Tobacco
    • Substance Use
    • Vaccinations
    • Youth Engagement – IMPACT
  • Health Professionals
    and Partners
    • Camp Providers
    • Child Cares
    • COVID-19 Healthcare Providers, Hospitals and Long-Term Care
    • Designated Officers
    • Emergency Management
    • Group Home and Shelter Administrators
    • Health Care Professionals
    • Health Care Providers COVID-19 Vaccine Information
    • Letter from the Medical Officer of Health
    • Long-Term Care and Retirement Homes
    • Municipal Resources
    • Ontario Naloxone Program (ONP) Distributing Agencies and First Responders
    • Report an Overdose
    • Schools
    • Teaching Kitchen
  • Community Data
    and Reports
    • Chronic Diseases
    • Environmental Health
    • Health Behaviours
    • Housing and Homelessness
    • Indirect Impacts of COVID-19
    • Infectious Diseases
    • Injuries
    • Mortality
    • Nipissing Parry Sound Public Health Atlas
    • Oral Health
    • Population Demographics
    • Reproductive and Child Health
    • Substance Use
    • Well-being and Mental Health
  • About Us
    • About Us
    • Accessibility
    • Board of Health
    • Careers and Placements
    • Contact Us
    • News and Events
    • Personal Health Privacy Policy
    • Programs and Services
    • RFPs and Tenders
Search Button

Back To Top

Harmful Algae Blooms

HomeHealth TopicsBeach, Lake and Pool WaterHarmful Algae Blooms
  • Open new window to share this page via Facebook Facebook
  • Open new window to share this page via Twitter Twitter
  • Open new window to share this page via LinkedIn LinkedIn
  • Email this page Email

Harmful algae blooms (cyanobacteria), also known as blue-green algae or pond scum, form on lakes and can create toxins that are harmful to humans and animals. Climate change is creating conditions that are more favourable to harmful algal blooms. Warmer air and water temperatures, more precipitation events, and droughts can all affect the growth and toxicity of algal blooms.

Residents of a lake with a harmful algae bloom may be affected depending on their closeness to the site of the algae, the size of the lake, wind directions, water flow, and other environmental conditions that cannot be predicted or controlled. Due to the many factors involved, government authorities are unable to determine where and when there are no toxins. Users are recommended to use their judgment. For further details on the location of the algae bloom, contact the Ministry of the Environment, Conservation and Parks - Spills Action Centre at 1-800-268-6060.

 If you reside near where the bloom was detected or are visiting the lake and encounter the algae, follow these safety measures:

  • Do not use the water. This includes: drinking, cooking, bathing, and brushing teeth. Note: Using a private water system or boiling the water will not destroy the toxins.
  • Do not swim and avoid water sports where there is harmful algae.
  • Limit the amount of fish flesh you eat. Some toxins can build up in fish and shellfish. Do not eat the liver, kidneys and other organs. Be careful not to cut the organs when filleting.
  • If skin contact does occur, wash with soap and water or rinse thoroughly with clean water to remove algae.

 More information about cyanobacteria (harmful algae bloom) found here.

                                          Category 1         Category 2                            Category 3                                          

 

 Appearance

The water appears cloudy, but you can still see through it.  

Particle density can vary greatly in the water column.   

The water colour appears changed due to increased number of cyanobacteria.   

Algae may be in cluster or ball or flakes in the water, like a pea puree. 

This is a dense bloom: it may resemble a paint spill. Accumulated cyanobacteria on the surface of the water may form a scum.                                

Algae is easily swept by the wind and deposited
near the shore.

SwimmingPrecautions  Do not swim in any bloom which obscures your view into the water. Even if it is not blue-green algae, it is unsafe to swim or allow children to play in any dense algal bloom, since you cannot see into the water. Wait until the bloom has subsided and the water is clear.   
Health effects are not expected at this stage   Sensitive individuals may develop mild symptoms of skin rash or eye irritation.
Drinking Water Precautions  Health effects are not expected at this stage Ingestion of water in this category may result in a range of health effects.  Ingestion of water in this category will likely
result in a range of health effects. 
  Do not use the water from a Category 2 or 3 bloom for drinking cooking or other consumption.
Be observant of when the water has cleared. If you treat surface water for cooking or consumption, wait at least a week after the bloom has subsided before normal use of
the treated water. The toxin is naturally reduced by dilution, degradation by other bacteria in the water, and sunlight. 

Assess your water supply if you are in an area where there are frequent algae blooms. Since there is no confirmed domestic water treatment available yet, consider a drilled well. 

 *Adapted from Peterborough Public Health. 

Category 2

Blue Green Algae Category 2

Blue Green Algae Category 2

Category 3

blue-green algae category 3

 Harmful Algae Category 2

Harmful Algae Category 3

 Water Advisory Sign

                                              

 

     

When is it safe to swim after a harmful blue-green algae boom advisory has been release?

The advisory does not close the beach, but rather advises swimmers that they need to take caution in the area. Please refer to the three categories in the chart above to determine the safety status of a swimming area. 

When will the public be made aware when an advisory is lifted?

Harmful blue-green algae can come and go throughout the season. The advisory does not close the beach, rather informs swimmers to be aware that there could be a bloom in the area. Therefore, the advisory stays in place all summer, however, this does not mean the bloom will be there all summer. Look for signs of the bloom and if none are present swimming my take place. 

Why are there signs on the beach? 

The sign reminds swimmers and individuals using the area to watch for blooms before using the water. 

Ontario's 12-point plan on harmful algae blooms

Ontario is concerned about the effects of harmful algae blooms in our water.  Ontario has a 12-point plan outlining how we are working with our many partners, to fight algae blooms in the Great Lakes and other lakes and rivers. 

For more information on Ontario's 12-point plan on harmful algae blooms click here.

Canada's drinking water guidelines during harmful algae blooms

Health Canada and the Federal-Provincial-Territorial Committee on Drinking Water are updating advice for parents of young infants when it comes to using tap water to prepare infant formula during harmful algae blooms.

Learn more on  Canada's drinking water guidelines during harmful algae blooms.

Health Topics
    • Air Quality
    • Alcohol
    • Animal Bites
      Toggle Section Animal Bites Menu
      • Rabies
    • Beach, Lake and Pool Water
      Toggle Section Beach, Lake and Pool Water Menu
      • Beaches
      • Public Spas, Pools and Hot Tubs
      • Harmful Algae Blooms
      • Swimmer's Itch
    • Breastfeeding
      Toggle Section Breastfeeding Menu
      • Using a Breastmilk Substitute
    • Cancer Prevention and Screening
      Toggle Section Cancer Prevention and Screening Menu
      • Sun Safety
    • Climate Change
    • Dental Health
      Toggle Section Dental Health Menu
      • Caring for Your Child's Teeth
      • Dental First Aid
      • Early Childhood Tooth Decay
      • School Screening Program
      • Water Fluoridation
    • Diseases
      Toggle Section Diseases Menu
      • Coronavirus (COVID-19)
        Toggle Section Coronavirus (COVID-19) Menu
        • Business and Workplaces
          Toggle Section Business and Workplaces Menu
          • Face Coverings and PPE
          • Signs and Screening Tools
        • COVID-19: What to do if Symptomatic, Positive or Exposed
        • COVID-19 Testing
        • COVID-19 Vaccine
        • Écoles/services de garde d'enfants et la COVID-19
        • Schools/Child Cares and COVID-19
      • Flu/Influenza
        Toggle Section Flu/Influenza Menu
        • About the Flu Shot
      • Hepatitis A
      • iGAS or Invasive Group A Strep
      • Lyme Disease
      • Measles
      • Monkeypox
      • Mumps
      • Shingles
      • Tuberculosis
      • West Nile Virus
      • Whooping Cough (Pertussis)
        Toggle Section Whooping Cough (Pertussis) Menu
        • Coqueluche - Foire aux questions
    • Drinking Water
      Toggle Section Drinking Water Menu
      • Lead
    • Emergencies and Being Prepared
      Toggle Section Emergencies and Being Prepared Menu
      • Cleaning up after a Flood
      • Drinking Water Disinfection Instruction
      • Emergency Kits
      • Food and Water Safety for Power Outages
    • Flu/Influenza
    • Food Poisoning
      Toggle Section Food Poisoning Menu
      • Farm Fresh Eggs Safety
    • Food Safety
    • Gambling
    • Healthy Aging
      Toggle Section Healthy Aging Menu
      • Age-Friendly Communities
      • Call-in and Online Activity Groups for Older Adults
    • Healthy Eating
      Toggle Section Healthy Eating Menu
      • Community Groups & School Programs
      • Cooking and Food Skills
        Toggle Section Cooking and Food Skills Menu
        • Freezing Fruit and Vegetables
      • Find a Registered Dietitian
      • Food and the Environment
      • Food Insecurity
      • Get Cooking
      • Healthy Food for Life
        Toggle Section Healthy Food for Life Menu
        • Nutrition During Pregnancy
        • Feeding Your Baby
        • Feeding Your Preschooler
        • Feeding Your School-Aged Child
        • Nutrition for Older Adults
      • Healthy Recipes
        Toggle Section Healthy Recipes Menu
        • A Cut Above the Roast
      • Northern Fruit and Vegetable Program
    • Home Health and Safety
    • Housing and Homelessness
      Toggle Section Housing and Homelessness Menu
      • Homelessness Factors
      • Housing is a Health Issue and a Human Right
      • Homelessness Prevention
      • Local Services to Address Homelessness
      • Stigma and its Impacts
    • Injury Prevention
      Toggle Section Injury Prevention Menu
      • Concussions
      • Helmets
    • Intimate Partner Violence
    • 2SLGBTQ+
      Toggle Section 2SLGBTQ+ Menu
      • Committing to 2SLGBTQ+ Equity
      • Homophobia
      • Pronouns
      • Sexual Orientation, Gender Identity and Expression
      • When Someone Comes Out
      • Youth and Teens
      • Positive Spaces and Other Training
      • Resources
    • Mental Health
      Toggle Section Mental Health Menu
      • 5 Ways to Well-being
        Toggle Section 5 Ways to Well-being Menu
        • Be Active
        • Connect
        • Give
        • Keep Learning
        • Take Notice
      • Mental Health Services
      • Postpartum Mood Disorders
    • Naloxone
      Toggle Section Naloxone Menu
      • Naloxone Training FAQ
    • Parenting
      Toggle Section Parenting Menu
      • New Parent Resources
      • Parenting During COVID-19
    • Perfluoroalkylated Substances (PFAS)
    • Physical Activity
      Toggle Section Physical Activity Menu
      • Active Transportation
      • Physical Activity Resources
        Toggle Section Physical Activity Resources Menu
        • Exercise Class Schedule
        • Virtual Exercise Classes
    • Preconception and Pregnancy
    • Prenatal Resources
    • Racism
    • Reducing Weight Bias
      Toggle Section Reducing Weight Bias Menu
      • Body Positivity
    • Sexual Health
      Toggle Section Sexual Health Menu
      • Birth Control
      • Men’s Sexual Health (Guys into Guys)
        Toggle Section Men’s Sexual Health (Guys into Guys) Menu
        • Santé sexuelle chez les hommes : pour les hommes qui aiment les hommes
      • Preconception Health
      • Pregnancy Testing and Options
      • PrEP
      • Sex After Having a Baby
      • Sexually Transmitted Infections
      • Sex & COVID-19
    • Sharps
      Toggle Section Sharps Menu
      • Safe Sharps Handling and Disposal
    • Smoking, Vaping and Tobacco
      Toggle Section Smoking, Vaping and Tobacco Menu
      • Quit Smoking
      • Arrêter de fumer ou de vapoter
      • Smoke-Free Spaces and the Law
      • Vaping and E-cigarettes
      • Vapotage et cigarettes électroniques
    • Substance Use
      Toggle Section Substance Use Menu
      • Cannabis
      • Drug-Related Stigma
        Toggle Section Drug-Related Stigma Menu
        • Let's work together to: Stop the shame. Stop the blame. Stop the stigma.
      • Healthy High - Risk-Taking Can Be Healthy
      • Methamphetamine Use
      • Opioids
      • Social Determinants of Health
    • Vaccinations
      Toggle Section Vaccinations Menu
      • Adult Information
      • Child Care Information
        Toggle Section Child Care Information Menu
        • Vaccination Information for Parents
      • COVID-19 Vaccines
        Toggle Section COVID-19 Vaccines Menu
        • COVID-19 Vaccine Appointments
        • COVID-19 Vaccine & Vaccination Frequently Asked Questions
        • COVID-19 Vaccine: Information for Parents and Caregivers
      • Hepatitis B Vaccine Information
        Toggle Section Hepatitis B Vaccine Information Menu
        • Informations sur le vaccin de l'hépatite B
      • Meningococcal Disease Vaccine Information
        Toggle Section Meningococcal Disease Vaccine Information Menu
        • Informations sur le vaccin contre la méningococcie
      • Publicly Funded Immunization Schedule
      • School Information
        Toggle Section School Information Menu
        • Informed Consent
        • Consentement éclairé
      • TB Testing
      • Tetanus, Diphtheria and Whooping Cough Vaccine Information
      • The Law, Exemptions, Suspensions and Exclusions
        Toggle Section The Law, Exemptions, Suspensions and Exclusions Menu
        • Suspension Process
    • Youth Engagement – IMPACT

Contact Us

Subscribe to this page

North Bay Parry Sound District Health Unit Footer Logo

  • Website

    • About Us
    • Employment Opportunities
    • News
  • Links

    • Accessibility
    • Privacy
    • Sitemap
    • Feedback Form
  • Resources

    Increase Contrast

Your lifetime partner in healthy living!

Copyright 2022 North Bay Parry Sound District Health Unit

By GHD Digital

Browser Compatibility Notification

It appears you are trying to access this site using an outdated browser. As a result, parts of the site may not function properly for you. We recommend updating your browser to its most recent version at your earliest convenience.