The right mix of factors leads to blue-green algae blooms like the one underway at Wickiup Reservoir.

Plenty of nutrients, lots of sunlight and warm, stagnant water all combine to create a bloom, said David Farrer, toxicologist with the Oregon Health Authority. State health officials issued a public health advisory about the toxin-producing bloom Thursday and it will remain in effect until the algae subsides.

The algae at Wickiup is producing microcystin, a liver toxin, Farrer said. Swallowing the toxin may produce symptoms ranging from dizziness to diarrhea; inhaling water droplets laced with the toxin may trigger breathing troubles; and making skin contact with the toxin may cause a rash.

So far, seven health advisories for blue-green algae have been issued around the state, including the warning for Wickiup. Farrer expects more.

“The busy time is late summer, early fall,” he said.

What about the Deschutes?

Wickiup Reservoir, 40 miles southwest of Bend, feeds the Deschutes River. Farrer said water tests show toxins from the algae bloom in the reservoir have not spread into the river. There were two blue-green algae blooms at Wickiup in 2009. The first lasted 19 days, from Aug. 12, 2009, to Aug. 31, 2009, and the second lasted 23 days, from Sept. 2, 2009 until Sept. 25, 2009.

Changes in conditions, particularly weather turning cooler, will typically end a blue-green algae bloom — and the health advisory, Farrer said. It is unclear how long the bloom at Wickiup will last.

“We’ve had some that last for several months,” he said. “So it is pretty variable and hard to predict.”

A blue-green algae bloom earlier this year at Odell Lake, off state Highway 58 in Klamath County, lasted 18 days, from July 21 to Aug. 8.

Kids and dogs

Found regularly in bodies of water, blue-green algae will take over given the right conditions. The explosion of algae means an increase in toxins that pose a risk to people and dogs.

During a trip to a lake, kids and dogs often have more exposure to water than adults and end up swallowing more, so Farrer urged parents and dog owners to take caution. Dogs may even be drawn in by the smell and taste of the algae.

“So they’ll seek out the scum and eat it on purpose,” he said.

Fishing

A blue-green algae health advisory doesn’t stop fishing at a body of water , but people should take extra precautions before eating fish plucked from the waters. Before cooking the fish, people should remove fat, organs and skin, said Erik Moberly, assistant district biologist for the Oregon Department of Fish and Wildlife in Bend.

The cloudy, warm water during a bloom can also make it hard to find and catch fish.

“It will definitely impact the fishing a little bit,” he said.

Identifying algae blooms

The state keeps photos of blue-green algae blooms on its website, healthoregon.org/hab, to help people know how to spot them.

“If you see the scum, you’ll know it,” Farrer said.

Like its name suggests, blue-green algae varies in color from blue to bright green, he said, but it may also be white. The consistency is similar to pea soup or paint. People who spot an algae bloom sometimes report it as a possible paint spill.

“If you see something like, this you shouldn’t go in even if there isn’t an advisory,” Farrer said.

Monitoring efforts focus on water bodies with the most use, so there could be rivers, ponds and lakes with a blue-green algae bloom but without an warning.

— Reporter: 541-617-7812, ddarling@bendbulletin.com