Overview
- The Gesundheitsamt Lindau, which issued the warning on July 8, advises people not to bathe in the Kleiner See while laboratory results are pending.
- Observers reported visible clumps of green‑brown slime on the water surface that local officials say are benthic cyanobacteria, a type of blue‑green bacteria that can form slimy mats on stones and plants.
- Health officials say these organisms can produce toxins that cause skin irritation and diarrhea in people and may be life‑threatening for dogs, so samples have been taken to confirm toxin levels and guide any further measures.
- Nearby Silbersee is already under a public warning after blue‑green algae were detected but currently has no formal bathing ban, and authorities say they will tighten restrictions if test results or conditions worsen.
- Warm water (around 26°C), low lake levels and high nutrient loads favor mat growth and detachment, so residents are urged to avoid visibly greenish or turbid water, keep children and pets away, and follow posted warnings for updates.