HAYDEN - A health advisory was issued Thursday for Hayden Lake by the Panhandle Health District and the Idaho Department of Environmental Quality.

Water samples confirmed the presence of the blue-green algae on the north end of Hayden Lake. This species can produce potentially dangerous toxins.

Public health officials are asking people to evaluate the water conditions before recreating in or near the lake. In areas where water is an uncharacteristic green color or areas with thick, green mats along shorelines, take extra precaution.

Avoid inhaling, swallowing or direct contact with water containing algae. Drinking water from the lake may be dangerous if toxins are present and they cannot be removed by boiling or filtering the water. According to the Centers for Disease Control and Prevention, symptoms of exposure are not documented in humans. However, in animals, a toxin produced by blue-green algae can cause a rapid progression of neurological symptoms such as muscle spasms, decreased movement, labored breathing, convulsions and death.

The algae is only affecting the northern end of the lake. Honeysuckle Beach is not currently affected by the bloom.

People are encouraged to enjoy other activities near the lake, including camping, hiking, biking, catch-and-release fishing and bird watching. If people choose to eat fish from this area, it is recommended that you remove all fat, skin and organs before cooking since toxins are more likely to collect in those tissues.

At this time, Fernan Lake and Avondale Lake also have active health advisories related to blue-green algae. There are many species that naturally occur in Idaho surface waters and only some species release toxins under certain conditions.

Blue-green algae blooms occur in water conditions of optimal temperature, oxygen, and when nitrogen is unavailable and phosphorus is abundant. The public will be advised when the concern no longer exists.

For environmental questions, contact IDEQ at 769-1422.

For health-related questions, contact Panhandle Health District's Erik Ketner at 415-5224.