FERNAN LAKE - As Larry Castro navigated his boat Wednesday toward the ramp on the west end of Fernan Lake, he had one comment:
"This water reeks."
It more than just smells bad.
A health advisory was issued Wednesday for Fernan Lake by the Panhandle Health District and the Idaho Department of Environmental Quality.
Water samples confirmed the presence of blue-green algae that can produce toxins harmful to humans and animals.
People are urged to stay out of the lake. Don't touch it, don't drink it, don't touch a stick in it and let your dog chase it.
"The density of blue-green algae in Fernan Lake is likely to be associated with potentially harmful toxin concentrations in water according to World Health Organization guidelines," said a press release.
Kristin Keith, Department of Environmental Quality watershed coordinator, said the last health advisory for Fernan Lake was in 2008.
There was a small algae bloom about two years ago, but not enough for a health concern.
A combination of heat, light and nutrients, including phosphorous, brought on the first significant bloom in four years.
Such blooms are usually in late August or September.
"This is uncharacteristically early," Keith said.
DEQ received a phone call Tuesday from a person who spotted condensed mats of algae. Water sample tests found the lake posed a threat. PHD was called, and the public warning was issued Wednesday.
"The physical appearance of blue-green algae blooms can be unsightly, often causing thick green mats along shorelines," according to a PHD press release. "Often excess nutrients associated with algae blooms are caused by pollution from human activities."
Blooms can occur in waters with high levels of nutrients like phosphorus and nitrogen under certain conditions, PHD said. Above average rain in June combined with rapid recent warming of water created favorable bloom conditions.
Keith said runoff from lawn fertilizer, stormwater, septic and sewage can affect the lake's quality.
"The whole Fernan Village is piped to Coeur d'Alene's wastewater treatment, so septic wouldn't be a big issue," she said.
According to the Department of Ecology website, "The total input of nutrients varies through time, depending upon land use and other factors. During the summer, nutrient input may increase due to fertilization of cropland, lawns, and gardens."
According to the Centers for Disease Control and Prevention, humans who drink or swim in water that contains high concentrations of cyanobacteria or cyanobacterial toxins may experience gastroenteritis, skin irritation, allergic responses or liver damage.
Symptoms of exposure in humans are rare and include numbness, tingling, skin irritation and nausea. If symptoms persist or worsen people should seek medical attention. Pets and livestock should also avoid the area.
With proper precautions to avoid water contact, people are encouraged to enjoy other activities near the lake including camping, hiking, biking, catch and release fishing and bird watching.
"I wouldn't want to get in that water," said Steve Saunders as he watched his sons fish off the dock. "It (the algae) doesn't look too deep, but it covers most of the lake."
If people choose to eat fish from this area, it is recommended that they remove all fat, skin and organs before cooking since toxins are most likely to collect in those tissues.
Water quality improvements can be expected to reduce future algae blooms so the Idaho Department of Environmental Quality is working with residents and landowners to implement nutrient reduction projects.
JEROME A. POLLOS/Press Blue-green algae flows between lily pads on the surface of the most western portion of Fernan Lake.
JEROME A. POLLOS/Press Larry Castro navigates his boat back toward the launch Wednesday on Fernan Lake.