Toxic algae at Willow Lake spurs health advisory

Unhealthy levels of blue-green algae at Willow Lake led public health officials Wednesday to recommend people and pets avoid contact there. It's the earliest known algae outbreak in Oregon since 2004.

This is the first time levels of blue-green algae prompted a public health advisory at Willow Lake, located 24 miles east of Medford.

"This certainly is a surprise for Willow Lake to have a bloom this soon," said Jennifer Ketterman, who runs the Harmful Algae Bloom Surveillance Program for the state Department of Human Services.

"Algae usually likes to thrive off warm temperatures, so it's an interesting case," Ketterman said.

Tests on water sampled Friday showed algae levels 52 times higher than what the World Health Organization considers healthy.

Results of those tests were received Tuesday by Jackson County officials, who joined DHS officials Wednesday in issuing the advisory.

The algae can produce toxins harmful to humans and pets, and the toxins are most commonly released when the algae dies.

The toxins cannot be removed by boiling, filtering or treating the water with camping-style filters.

People and animals should avoid swallowing or inhaling water droplets and skin contact with the water. Health officials also warn people not to eat fish, crayfish or freshwater shellfish taken from Willow Lake while this advisory is in effect.

However, boating and catch-and-release fishing were not part of the advisory.

Steve Lambert, the county's parks program manager, said recreational visits to the lake were low now.

Willow Lake feeds the Eagle Point Irrigation District, which has yet to begin delivering water to its 545 patrons, so they will not be impacted by the advisory, said Hazel Ellefson, the district's manager.

The lake is owned by the Medford Water Commission, which does not draw any water there for domestic use, commission spokeswoman Laura Hodnett said.

No human illnesses have been directly linked to the algae in Oregon since DHS officials began issuing public health advisories in 2004, records show. However, a dog died from algae exposure last summer along the Umpqua River near Elkton.

There was no known cause for the outbreak of an algae called aphanizomenon, one of three bacteria that make up the axis of dangerous algae that plague area reservoirs normally during hot summer months.

The other, more common blue-green algae forms that have triggered public health advisories in Jackson County are called anabaena flos-aquae and microcystis.

Public health advisories normally are issued when water samples show more than 100,000 algae cells per milliliter of water.

Ketterman said tests on Willow Lake water showed levels of 5.2 million cells per milliliter of water.

The advisory will remain in effect until further notice. Typically, public health officials wait for two weeks after the algae dies to give any toxins time to dissipate naturally.

The previous first public health advisory for an algae outbreak for a calendar year came in March 2004 at Ten Mile Lake in Coos County, DHS records show.

For more information on blue-green algae and a list of current and former public health advisories, visit www.oregon.gov/DHS/ph/hab/.

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