TRAIL — Mike McFall rented a slip at Lost Creek Lake Marina in June, then motored onto the lake for a day of waterskiing, but the soupy green water shortened his day.
Back at the marina, McFall discovered that the lake was overrun by blue-green algae, and a state-issued advisory against water contact was in place.
Public health advisories for blue-green algae are issued by the Oregon Public Health Division and local county health departments based on criteria established by the World Health Organization, and they are voluntary, meaning people can choose to ignore risks of water contact if they choose.
The three most common forms of cyanobacteria that trigger advisories are anabaena flos-aquae, microcystis and aphanizomenon.
WHO thresholds for anabaena flos-aquae and aphanizomenon are exceeded when concentrations exceed 100,000 cells per milliliter of water. Microcystis is considered a potential threat at 40,000 cells per milliliter.
Lost Creek Lake's recent test revealed aphanizomenon cell counts of more than 2.5 million cells per milliliter and anabaena flos-aquae at more than 517,500 cells per milliliter.
The algae may contain toxins that can be dangerous to people and pets. The toxins are released when the algae die and they dissipate naturally within two weeks.
New health division criteria say the advisories can be lifted after tests confirm toxin levels are below potentially unsafe levels.
During advisories, people and pets are advised to avoid all water contact. 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 are advised to remove all fat, skin and organs before cooking because toxins can collect in those tissues. People should not eat crayfish or freshwater shellfish taken from infested lakes during an advisory.
Fish fat is considered safe once the advisory is lifted.
No confirmed human illness has been tied directly to an algae outbreak in Oregon. In 2009 and 2010, however, at least two dogs died from toxins after drinking from a large stagnant puddle near the Umpqua River near Elkton.
— Mark Freeman
"So we asked the guy at the marina, 'Is this dangerous?' " says McFall, of Eagle Point.
Maybe. Maybe not, the dockhand said. Your call.
"I had just paid $500 to moor the boat, then I thought, 'Should we even be out here?' " McFall says. "Is it even safe?"
To date, no one has been able to provide direct answers to McFall and thousands of other visitors at Oregon lakes and reservoirs during potentially toxic blooms of cyanobacteria, commonly referred to as blue-green algae.
Now an Oregon State University professor is studying algae strains at a series of Oregon waterways to determine whether these individual strains can produce toxins capable of sickening and killing people or whether they are nothing more than gross, smelly scums producing no greater public-health danger than swimmer's itch.
"I think there is plenty of evidence that people should be cautious of blooms," OSU microbiologist Theo Dreher says. "I wouldn't dive into a bloom or fish in it. Nobody really likes blooms, but it's not the same concern as if they are toxic.
"These blooms are all over the place and they have important economic impacts," Dreher says.
"We need to establish scientifically what the real threat is from toxins in Oregon."
The results, public-health officials say, could generate a sea-change in how these voluntary advisories against water contact are handled and in the economic chaos they can cause.
"It could eventually give us more answers on which (algae forms) are greater concerns than others," says Jennifer Ketterman, who coordinates the state's Harmful Algae Bloom Surveillance Program which issues these advisories.
As it stands now, the Oregon Public Health Division issues a standard, across-the-board advisory warning visitors of the potential effects of the algae should it produce toxins at levels that have killed or sickened people across the globe.
The advisories are based on the assumption of a worst-case scenario "because we have the populous to protect," Dreher says.
But to date, only two dead dogs that drank algae-laced water from pools in the Umpqua River drainage have been directly linked to the algae. Though some suspected gastrointestinal illnesses have been reported after people swam in waters posted with advisories, none were considered severe, and none could be tied directly to the algae, Ketterman says.
If particular algae strains in particular lakes were known to be genetically incapable of producing dangerous toxins, then the advisories could be tailored to reflect that knowledge, Ketterman says.
"I don't think we're there yet," Ketterman says. "But it could help us make future public-health management decisions."
Lost Creek Lake Marina concessionaire Mike Lewis can't wait to get there.
His lake is under an advisory for a mammoth outbreak of aphanizomenon and anabaena flos-aquae — which, along with microsystis, make up the trio of cyanobacteria blooming in Oregon waterways.
Blooms occur when zooplankton levels in lakes change from any of several factors, such as higher nutrient levels in the water and large numbers of fish that eat it. Zooplankton feed on the cyanobacteria, which create blooms when left to their own devices.
Lost Creek has seen algae blooms each of the past four Septembers, and they've run anywhere from 25 days in 2009 to 134 days in 2008.
The marina's business plummets by 50 to 70 percent during advisories, with the signs alone scaring many away without any solid proof that the lake's conditions are as devilish as described, Lewis says.
The signs say the algae may develop toxins that can harm people or pets, but the toxins have never actually been found in an Oregon lake or reservoir — perhaps because the tests are calibrated to check only for levels at or above the established thresholds.
Lewis says he would never put his lost money ahead of public safety, but he believes the advisories amount to a red herring.
"It's more miscommunication than communication, and it's not right," Lewis says. "It's illegal to yell 'Fire!' in a crowded theater."
But just because they haven't found the toxins doesn't mean they're not there.
Dreher studied the algae in the Klamath River basin's Copco Reservoir and found some blooms produced "very toxic" microsystis, while other blooms were less toxic — including some years when the blooms produced no toxins at all.
"We don't understand those transitions," Dreher says.
He has a $120,000 federal drinking-water protection grant to study blooms this year and next year in three Willamette Valley reservoirs and at four municipal water plants that draw from them.
The idea is to determine their capabilities for producing toxins, trace their progressions and gauge the threat to drinking water there.
Dreher also is stockpiling samples from Lost Creek Reservoir and other water-bodies for future testing should funding become available, he says.
Each water-body needs to be studied individually over a few years because the strains are so variable, Dreher says.
"In each case, it's a study that has to be done from scratch, and there's been very little of that," Dreher says.
"There's a possibility many blooms in Oregon aren't toxic," Dreher says. "We need to establish that. But until we do, we have to assume they're toxic."
McFall says he doesn't know what to assume.
His daughter and a friend experienced "goopey eyes" after recreating at Lost Creek Lake, and they chalked it up to the algae, so he generally avoids the lake during blooms.
Large, thick mats of algae cloaked the marina Wednesday as McFall took his boat out of his rented marina slip for the last time this year.
"Honestly, it's kind of gross," McFall says. "But it's all we got. It's not like they can make us another lake."
"I'll probably come back," he says.
Reach reporter Mark Freeman at 541-776-4470, or email at firstname.lastname@example.org.