The health advisory for Fernan Lake has been expanded by Panhandle Health District and Idaho Department of Environmental Quality. The advisory was initially issued due to high concentrations of blue-green algae on the east side of the lake, which has spread and now affects the entire lake. Public health officials are urging citizens to use caution when recreating in or near the water.
Blue-green algae are naturally-occurring, microscopic bacteria. Harmful algal blooms typically occur during warm summer months, when toxin-producing algae proliferate under certain oxygen and nutrient conditions. The physical appearance of blue-green algal blooms can be unsightly, often causing discolored water, streaks or globs of scum and thick green mats along lakeshores.
Anyone recreating near Fernan Lake is advised to take precautions and prevent people and pets from exposure to lake water appearing to contain blue-green algae. Property owners utilizing the lake as a drinking water source are cautioned that potentially present toxins cannot be removed by boiling or filtering the water. If contact has been made with water containing blue-green algae, it is recommended to wash off with fresh water. Recreational contact with water that is not visibly affected by a blue-green algae bloom is not expected to cause adverse health effects.
If people choose to eat fish from this area, it is recommended they remove all fat, skin and organs before cooking, since toxins are more likely to collect in those tissues.
Symptoms of exposure to algal toxins vary according to exposure. Symptoms include rashes, hives, diarrhea, vomiting, coughing, and/or wheezing. More severe symptoms affecting the liver and nervous system may result from ingestion of water. If symptoms persist, consult a health care provider.
A similar health advisory is also currently active along the northern arm of Hayden Lake in Kootenai County. The public will be advised when the concerns no longer exists. DEQ is working with residents and landowners to implement nutrient reduction projects to improve overall water quality and limit the frequency and duration of these algal blooms.
Updated information on harmful algae blooms in northern Idaho can be found online at http://www.deq.idaho.gov/water-quality/surface-water/blue-green-algae.