Algal bloom warning issued at Eagle Lake

Maury Anderson, Lassen County’s Director of Planning and Building Services (which includes the Environmental Health Division), announced an algal bloom has been discovered at Eagle Lake.

According to the Centers for Disease Control, “harmful algal blooms can look like foam, scum, mats or paint on the surface of the water. They can also grow underneath the water, making some harmful algal blooms hard to see.”

Anderson, speaking at the Lassen County Board of Supervisors Tuesday, Aug. 13 meeting, said the county was posting caution signs to alert swimmers and animals of the potential hazard. He also reported a dog that swam in the bloom had perished.

The state waterboard is responsible for testing the water quality at Eagle Lake, not the county, but Anderson said the two agencies are working together.

According to the Lahontan Regional Water Quality Control Board, “cyanobacteria are small microbes or bacteria that live in nearly every habitat on land and in the water. At times they may release toxins that are harmful to humans and animals, and in these cases they are commonly referred to as harmful algal blooms or HABs.

“Cyanobacteria have existed for billions of years as essential components of freshwater ecosystems and form the foundation of most aquatic food chains. When environmental conditions favor the growth of HABs and algae, such as warm temperatures and low or stagnant water flows, and excessive nutrient inputs, they can multiply very rapidly creating nuisance blooms.

“Some HABs can produce toxins that can harm pets, wildlife or people that come into contact with them. Not all HABs produce toxins, but those that do may cause health issues and even death. In California, harmful algal blooms are most common during the warm weather months between late May through October, but they can occur all year.

“Current research suggests that a warming climate is contributing to an increase in HAB growth, so it is important to be aware of what they look like and what steps to take when you encounter them. Sometimes the bloom is easily visible, forming a “scum” or discoloration on the water surface (planktonic bloom). Other times, it is less visible, floating beneath the surface or on the bottom of a water body (benthic bloom). Blooms can appear green, blue, yellow, red, or brown. Several guidance documents are available to help identify algae and HABs (Fact Sheet & Visual Guide). Typically, harmful algae will not have a structure causing it to easily break apart or be hard to pick up where non- harmful algae will have a structure with long hair like filaments. There are several field tests you can perform to determine if the algae have a structure known as the stick test or the gloved hand test. You can find out how to perform these tests on the HAB wiki Field Test Webpage.

“You cannot tell if toxins are present in the HAB by visually looking at the bloom, so it is important to follow healthy water habits when you encounter a bloom.

“HAB Monitoring at Eagle Lake Eagle Lake was sampled for harmful algal blooms prior to Memorial Day, Independence Day, Labor Day, and during a regular monitoring event at Merrill Campground and Christie Day Use area. Cyanobacteria toxins were found in the samples collected in June, July, and August at low levels. A caution advisory was put in place several times during the season due to the visual indication of a harmful algal bloom and due to the low levels of HAB toxins detected in water samples. If you suspect Eagle Lake is experiencing a HAB check the State Incident Report Map, and if no information is displayed on it for Eagle Lake report the bloom through the Bloom Report Form.”