Officials warn of potentially toxic algae on major Portland river
Date: 18-Sep-14
Country: USA
Author: Courtney Sherwood
Public health officials in Oregon warned recreational boaters and swimmers who on warm days flock to a river that bisects Portland to stay out of the water on Wednesday after detecting what they suspect is a potentially dangerous toxic algae.
Oregon Health Authority officials said they believe the unusual film found at the Willamette River is the result of toxic blue-green algae, which is dangerous to touch, drink or inhale. Filtering the water won't make it safe, and fish from the river could be dangerous to eat.
The algae's oil-slick-like green sheen could be seen shimmering and moving slowly with the river's current through downtown Portland, and test results confirming its toxicity are expected back on Thursday morning
But because of the Willamette's prominence as a site for recreation and commerce, public health officials rushed to issue a warning as soon as the scum was spotted, health authority spokesman Jonathan Modie said.
Volunteers also visited homeless encampments along the river to warn tent-dwellers of the risks, and posted signs in areas frequented by hikers and boaters, he said.
Toxic algae blooms have been a growing problem in the U.S. Pacific Northwest in the past several years, a trend scientists have attributed to warming waters. Modie said that unusually high temperatures in Portland over recent weeks may have been a factor.
According to the U.S. Centers for Disease control, harmful algae blooms can cause digestive distress, eye irritation and breathing difficulties in healthy adults, and eating contaminated fish can worsen the effects.
Conventional treatment methods such as boiling and filtering do not remove toxins from algae-contaminated water, and it could take days, weeks or months for the algae to dissipate, Modie said.
He said toxic algae, unprecedented on the Willamette, is unusual on rivers in general. Of 118 toxic algae bloom advisories issued by Oregon health authorities since 2006, all but eight were for still bodies of water like lakes and ponds.
The Willamette River is home to Portland's harbor and major industrial areas, as well as waterfront homes, marinas and public beaches.
(Editing by Cynthia Johnston and Eric Walsh)
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