Green Lake, NY: Swimming Not Recommended Due to Toxic Algae

Current Advisory: Avoid Water Contact

As of August 2022, the New York State Department of Health (NYSDOH) has issued a Harmful Algal Bloom (HAB) advisory for Green Lake. Swimming and water contact are not recommended until the advisory is lifted.

What Are Harmful Algal Blooms?

Rapid algae overgrowth (cyanobacteria/blue-green algae) producing toxins (microcystins, anatoxins) that affect:

• Skin: Rashes, irritation, allergic reactions
• GI tract: Nausea, vomiting, diarrhea, liver damage
• Respiratory: Irritation, asthma exacerbation (aerosolized toxins)
• Neurological: Rare, from high exposure
• Pets/livestock: Often more severe—dogs die annually from HAB exposure

Why Green Lake?

• Nutrient loading (phosphorus/nitrogen from runoff, septic)
• Warm, still water—ideal for cyanobacteria
• Climate change: longer warm seasons, intense rain events
• Internal phosphorus recycling from sediments

Monitoring and Updates

• NYSDOH samples regularly during bloom season (summer-fall)
• Check NYSDOH HAB page for current status
• Local health department: Onondaga County Health Dept
• Visual signs: green scum, paint-like streaks, pea-soup water—but toxins invisible

Safe Alternatives

• Green Lakes State Park: hiking, camping, golf, picnic areas
• Nearby: Jamesville Beach Park, Oneida Shores Park (monitored beaches)
• Verify any water body's status before swimming

Bottom Line

When in doubt, stay out. HABs are increasing globally. Green Lake's beauty is real—so are its toxins right now.