Summer is in full swing! Warmer temperatures and extra nutrients in the water can cause blue-green algae to grow rapidly at this time of year, forming floating layers called blooms in local lakes and near beaches. While not all algae blooms are dangerous, some can produce toxins that can make people and pets severely ill.

Avoid Active Blooms

Blooms often look like thick, spilled paint floating on the water and can appear blue-green, brown, or reddish-green.

If you see a visible algae bloom, avoid wading, swimming, paddleboarding, boating, or water-skiing. Keep young children, pets, and livestock well back from the shoreline.

Always bring clean drinking water for yourself and your pets. Never drink untreated lake water, as boiling and standard filters and purifiers do not remove algae toxins. Do not eat or let pets eat fish caught from waters with an active bloom.

Check for advisories online before you go, and look for signs posted at local lakes and beaches before swimming. 

Health Risks and Symptoms

Toxins from algae cause harm when they are swallowed, inhaled in the form of mist or water droplets, or contact the skin. The two main types of dangerous toxins produced by some algae blooms include:

• Nerve toxins cause numbness, tingling, and dizziness in humans. In animals, they trigger weakness, breathing difficulty, seizures, or death.
• Liver toxins cause severe stomach pain, vomiting, diarrhea, and sometimes organ damage in humans, and can lead to severe illness or death in animals.

If you or a family member or pets show any of these symptoms after being in or near the water where algae is present, seek immediate medical or veterinary care. Symptoms usually appear within hours of exposure and resolve within a few days. Children are especially at risk because they spend more time playing in water and are more likely to swallow water. 

Stay Safe at the Beach

Practice good general beach safety by avoiding swimming near stormwater pipes or for 48 hours after heavy rainfall. Always shower soon after swimming and wash your hands before eating, especially after playing in the sand. You should also avoid open water swimming if you have cuts or abrasions.

How to Help Prevent Algae Blooms

Excess phosphorus feeds algae growth. You can help keep local lakes clean by picking up pet waste immediately, using phosphorus-free lawn fertilizer, and maintaining your septic system regularly. Wash your car on the lawn or at a commercial car wash so runoff water does not run into storm drains. Planting native vegetation along shorelines instead of turf grass also stops nutrient runoff.

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