TRAIL — State public-health officials Monday issued a voluntary advisory warning people and pets against contact with Lost Creek Lake water after tests showed an outbreak of blue-green algae above levels considered unhealthy.

TRAIL — State public-health officials Monday issued a voluntary advisory warning people and pets against contact with Lost Creek Lake water after tests showed an outbreak of blue-green algae above levels considered unhealthy.

Water samples taken June 14 showed that water at the Catfish Cove day-use area sported levels of the cyanobacteria anabaena flos-aquae at more than seven times World Health Organization thresholds for safety.

However, water sampled at the Takelma boat ramp area at the reservoir's southwest side sported levels of the algae well below unhealthy standards, according to test results from the U.S. Army Corps of Engineers.

Corps officials Monday posted warning signs at lake boat ramps and swimming areas to inform lake-users of the strictly voluntary advisory — the first of the year in Jackson County and only the second so far this year in Oregon.

There has never been a confirmed human illness in Oregon caused by the algae or its related toxins, though two dogs have died, one in each of the past two years, from algae-related toxins consumed from a large, stagnant puddle along the Umpqua River near Elkton.

Dangerous toxin levels have never been found at Lost Creek Lake or any other Oregon lake or reservoir. But illnesses and deaths have been documented world-wide, and public health officials nevertheless report its presence and issue advisories as precaution.

Under the state Human Services guidelines, visitors are advised not to ingest lake water.

Anglers are encouraged to practice catch-and-release fishing.

Toxins cannot be filtered by standard camp filters or by boiling the water. In-home filtering systems cannot cleanse the water, though public treatment plants can reduce algae toxins through filtration and disinfection.

People who eat fish from algae-tainted waters should remove all fat, skin and organs before cooking because toxins can collect there. People should not eat crayfish or freshwater shellfish taken from infested lakes during an advisory.

The blooms typically focus on the surface, but they can move within the water column. During past blooms, water tested from the reservoir's out-flows at Lost Creek dam tested well within safe levels.

Reach reporter Mark Freeman at 541-776-4470, or email at mfreeman@mailtribune.com.