Living with a Natural Lake

You may have seen a substance on the lake that looks like thick pea soup, and wondered what it was and if it's safe.

Cyanobacteria (also kn own as blue-green algae) have existed for millions of years all over the planet, and are not new to Clear Lake. Water bodies worldwide are experiencing blooms caused by a variety of environmental conditions. Clear Lake is often susceptible to blooms due to its shallow depth, high nutrient levels, and warm temperatures. Blooms tend to grow rapidly in hot weather.

What should you look for? A paint-like scum or thick mat on the surface of the water or in the water column, various-sized white, green, blue, redblue, red, brown, or black floating masses or matter along the shoreline.

What effects does it have? The first thing you may notice is an unpleasant smell and an objectionable appearance on the water. Some blooms are benign, but others may produce toxins which can be harmful if ingested, inhaled, or, in some cases, if contacted. Its health risks are little understood by scientists and cannot be predicted for any particular bloom.

What should I do?
You can enjoy Clear Lake and keep your family, friends, and pets safe and healthy!

  • be informed -- learn to identify cyanobacteria blooms (see photos on website)
  • use common sense: if the water looks inviting, enjoy! If you're suspicious, be cautious
  • keep pets from playing in blooms, and wash them immediately if they've been in contact
  • make sure that any guests using your lakefront property are informed
  • follow safety recommendation on the State Water Resources Control Board website if your water source comes from the lake
  • call for  bloom reports, or if you have any questions or concerns
  • allow children or friends to swim, wade, waterski, or tube in or near an active bloom
  • allow pets to swim or play catch in or near a bloom, or let them lick their fur after contact
  • inhale aerosolized water (spray caused by motor boats, for example) near a bloom
  • use fertilizers or detergents containing phosphates near the lake, as they increase cyanobacteria growth
  • drink untreated lake water (boiling is NOT adequate!)
  • not all blooms are toxic, but contact with toxins can cause illness
  • you cannot tell if a bloom is toxic by looking at it
  • blooms can occur any time of the year, but are most active in hot weather
  • blooms may have an unpleasant odor as they die off, but not always
  • dogs can have more serious symptoms than people
  • swallowing water containing cyano-toxins may cause serious illness

Lakefront property owners should access more details at the contact info above