A blue-green algae bloom on the east side of Fernan Lake has spread and now affects the entire lake. A health advisory for the entire lake was issued Friday by the Panhandle Health District and Idaho Department of Environmental Quality. People recreating at the small lake near Coeur d'Alene should use precautions to avoid contact with the water, officials say. The blooms, which look like blobs of scum or thick green mats, can contain toxins. Pets, children, the elderly, and people with compromised immune systems are at most risk of harm from contact with the water. Symptoms can include rashes, hives, diarrhea, vomiting, coughing and wheezing. Drinking the water can harm the liver and nervous system. If people eat fish from areas where blooms are present, they should remove all fat, skin and organs before cooking it. A similar health advisory also is in place along the northern arm of Hayden Lake. DEQ is working with local residents and landowners on strategies to improve water quality and limit the frequency and duration of blue-green algae blooms.