Health warnings issued after algae discoveries
State public health officials issued toxic-algae advisories Friday at Diamond Lake and along a stretch of the South Umpqua River in Douglas County where the death of a dog is being blamed on the algae.
A Jack Russell terrier died at a Douglas County veterinary hospital of apparent toxin poisoning July 20 after it played in stagnant water along the South Umpqua, the state Department of Human Services reported.
Water sampled at the site showed levels of the cyanobacteria microcystis at more than twice the level necessary to trigger an advisory against water contact by people and pets, according to Curtis Cude, who manages the DHS's Harmful Algae Bloom Program.
Toxin tests were planned for the dog and the river water, Cude said.
This marked the third straight summer in which a dog died after playing in stagnant water along the Umpqua or South Umpqua rivers.
"It's three years in a row now, and we hope it isn't a pattern," Cude said. "We're always thinking about lakes and reservoirs, not just stagnant water. It comes back to, 'when in doubt, stay out' because it can happen anywhere."
The advisories, which advise people to voluntarily avoid water contact, come in the midst of the summer vacationing season at Diamond Lake off Highway 138 about 80 miles east of Medford.
Water samples taken earlier this week at the north boat ramp near the Diamond Lake Resort showed algae levels at more than three times the state DHS threshold for the advisory, Cude said.
The sampled water was primarily laden with the blue-green algae anabaena, which was tested at 230,000 cells per milliliter of water, Cude said.
The volunteer advisories kick in when anabaena levels reach 100,000 cells per milliliter, a standard set by the World Health Organization.
Umpqua National Forest officials posted warning signs around the lake Wednesday warning of the possibility of an algae bloom while awaiting test results on the water. Those signs were shifted to the standard advisory signs late Friday.
A similar advisory at Diamond Lake in 2010 lasted 19 days and went largely ignored by visitors. Diamond Lake is one of the most popular trout-fishing lakes in the Pacific Northwest.
"People still swam in it and people still fished in it," said Rick Rockholt, the resort's events coordinator. "I'm looking out my window now and kids are swimming in the lake.
"They're not paying attention to it," Rockholt said. "They should, but they're not."
Not every algae bloom generates toxins, and no reported illnesses or deaths have been reported from algae-tainted water in an Oregon lake or reservoir, public-health records show.
State health officials recommend people and animals avoid swallowing or inhaling water droplets and recommends no skin contact with tainted water. The toxins cannot be removed by boiling, filtering or treating the water with camping-style filters.
People who choose to eat fish caught there should remove all fat, skin and organs before cooking because toxins are more likely to collect in those tissues.
Reach reporter Mark Freeman at 541-776-4470, or email at email@example.com.