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July 20, 2017

FAQs About Harmful Algal Blooms

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Harmful Algal Blooms (HABs) are not algae at all, but are actually bacteria. When conditions are favorable (such as calm weather conditions, and an increase in water temperature and nutrients) these bacteria reproduce rapidly; forming a bloom. HABs can occur at any time, but often occur in late summer or early fall.

HABs can be blue, bright green, brown, or red and may look like paint or anti-freeze floating on the water. As the bloom matures, it may look like foam, scum, or mats on the surface of freshwater lakes and ponds.

People and animals can be exposed to HABs by swallowing water and/or touching the water during recreational activities such as swimming, water skiing, and diving.

The most common health effects are skin and eye irritation. Other more severe health effects can be:

  • Difficulty breathing
  • Stomach pain
  • Nausea
  • Vomiting
  • Diarrhea
  • Dizziness
  • Numbness and tingling in lips, fingers, and toes

If contact with a HAB occurs and you or your family experience any symptoms, consult a medical provider immediately.

Pets and livestock exposed to HABs may exhibit symptoms and conditions such as:

  • Weakness
  • Staggering
  • Foaming at the mouth
  • Difficulty breathing
  • Convulsions/seizures

Animals exposed to HABs may die within tens of minutes to hours. If your pet comes into contact with HABs, call a veterinarian right away. When HABs decompose, they can also kill fish that live in the water.

  • Do not go in or near water that has an unusual color. This includes keeping children, pets, and livestock out of the water.
  • Avoid any water sports such as swimming, diving, water skiing, boating, etc. in areas with HABs.
  • Do not use untreated water for drinking, bathing, cleaning, or cooking. Boiling water that has been contaminated by a HAB  will not remove toxins, it may actually cause more toxins to be released.

Use an alternate source of drinking water such as bottled water while the bloom is present.

The toxins will be confined to the organs and fatty tissue of fish living in waters where a bloom is occurring. When you consume fish from a lake with a bloom, take the following steps:

  • Remove the skin, organs, and fatty deposits from the fish
  • Rinse the meat before cooking
  • Cook the fish thoroughly
  • Limit the consumption of these fish to no more than two 8-oz fillets per week

One way you can report a harmful algal bloom is to download the bloomWatch app on your smartphone or tablet. The bloomWatch app teaches you what to look for and allows you to report photos of potential blooms that you find.