It's blue-green algae season in Oregon, but so far this summer no public-health advisories against water contact have been issued, and a new set of public-health protocols could make those unwanted advisories fewer and shorter than in past years.
The Oregon Public Health Division this year is offering water managers a new monitoring approach that looks for the actual toxins associated with blue-green algae and does not rely on bloom sizes to trigger health warnings that can turn crowded lakes into ghost towns.
Public health advisories for cyanobacteria, commonly referred to as blue-green algae, are issued by the Oregon Public Health Division based on criteria established by the World Health Organization.
The three most common forms here are anabaena flos-aquae, microcystis and aphanizomenon.
The algae may produce toxins that can be dangerous to people and pets, but not every bloom includes toxins. When they do, the toxins are released when the algae die and dissipate naturally.
When the blooms subside, public-health rules require a clean bill of health confirmed by tests for algae cell counts and toxins before an advisory is lifted.
During advisories, people and pets are warned to avoid all water contact, but compliance is voluntary. 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.
No confirmed human illness have been tied directly to an algae outbreak in Oregon. However, at least four dogs have died from toxins in water near the Umpqua River near Elkton.
A study of algae and toxins in that area is ongoing.
— Mark Freeman
These different, albeit more expensive, tests will allow some waterbodies to remain advisory-free this year under conditions that heretofore would have triggered the health advisories. And they would remain so until environmental conditions change enough that an actual health risk is present.
"This is looking for actual exposure risk instead of the possible exposure risk," says Curtis Cude, the division's Harmful Algae Bloom Surveillance Program manager. "We're actually looking for the toxins itself, and that's the actual health risk."
The result, Cude says, should reduce the number of advisories and shorten their duration because they would not require the don't-touch-the-water warnings during sometimes long spells in which algae hangs thick in lakes.
The toxin tests, which cost $400 to $600, are now more available from more labs. During a bloom, they likely would be needed every-other week to ensure toxin levels remain below unsafe levels, Cude says.
A new test would be required when algae conditions change, because toxin releases are most commonly associated with algae die-offs, which actually improves water clarity, he says.
"We've always wanted this process to be as sweet as possible and not a blunt instrument," Cude says. "We hope this will be a new, good tool in the tool box for lake managers."
The new approach is being hailed by some resort operators and county parks officials who are tired of these voluntary advisories scaring away visitors and their recreation dollars without being reasonably sure a health risk exists.
A 2010 pre-spring bloom at Willow Lake in eastern Jackson County triggered a public-health advisory that lasted 120 days, causing the county's recreation concessionaire to pull out of running the campground and cabins because of lack of visitors.
County officials have resumed operations there, and the lake has since skirted any repeat public-health advisories.
Jackson County Parks Manager Steve Lambert says he wants to keep it that way, and any protocols that are less draconian are welcomed.
"If we could have an advisory lifted with a $500 test and have people come up to the lake, it definitely would be worth it," says Lambert.
But others are taking a more cautious approach, and not just over test costs and fear of the liabilities of moving away from the more conservative approach that has kept a clean record of no humans sickened from cyanobateria toxins, though four dogs have died from ingesting the toxins.
The Portland District of the U.S. Army Corps of Engineers, for now, is sticking with the old approach of issuing public-health advisories when algae cell counts hit thresholds deemed potentially unhealthful by the World Health Organization and adopted by Oregon public-health officials.
Lost Creek Lake has been hit with multiple algae outbreaks and advisories since 2006, with advisories often occurring when algae levels differed widely throughout the lake.
Sampling would show for sure only what toxin levels are present at the sampling sites and may not be representative of what's happening reservoir-wide, says Scott Clemans, public affairs specialist for the Army Corps.
"We can't definitely say they're not present elsewhere in the lake," Clemans says.
Until Corps officials are convinced they have the time, personnel and money to do the toxins-based approach properly, "we'd rather be conservative" and stick with the cell-counts approach, Clemans says.
Moreover, Corps officials here since 2006 have kept steady on the mantra of telling people to avoid algae-scummed water, says Jim Buck, the Corps' operations manager in the Rogue River basin.
Moving to the toxins-based testing approach would now have the Corps "telling people, 'Well, it might be OK,' " Buck says. "We don't want to change that message. We don't want to go down that path right now."
Cude says he appreciates water managers' concerns of moving away from the traditionally more conservative approach to this public-health issue.
"The last thing they want is to be doing monitoring and someone gets sick anyway," Cude says.
Reach reporter Mark Freeman at 541-776-4470, or email at firstname.lastname@example.org.