With the cool weather at the beginning of summer, we didn't have our first 2012 blue-green algae advisory until mid-July. Although we still have some advisories in place, we can expect to see the last remnants of summer disappear in the next couple of months.

With the change in seasons, exposure to harmful algae blooms declines due in part to the change in our recreational activities. Swimming, water skiing, tubing and other water activites shift to fall and winter fishing, hiking and hunting. if you participate in these activities, especially with your pet, we recommend you continue to be vigilant about potential exposure to waters that look suspicious - foamy, scummy, thick like paint, pea-green, blue-green or brownish red.

This year we had nine advisories, which is about half the number of advisories in recent years. The primary reason for the decrease was the decision by some waterbody managers to perform toxin testing when a bloom was first identified, and throughout the bloom lifecycle. This testing provided 'actual' toxin and exposure data rather than 'potential' for exposure to toxins that may or may not have been present at harmful levels.

When initial toxin data showed that health advisory guidelines for recreational waters were not exceeded and therefore not harmful to human health, no advisory was issued. This allowed the public to enjoy a lake or reservoir even though a bloom was present. When initial toxin testing was not performed, advisories were issued if lab analysis identified blue-green algae cell counts, among potentially toxigenic species, that were over guidelines for recreational waters. Remember, only a fraction of Oregon's waterbodies are monitored, so when in doubt, stay out!   

Details of historical health advisories issued in previous years can be found in the Advisory Archive.

 Join our Listserv

The HABS program has created a listserv to share information with partners, stakeholders and interested people. When an advisory is issued, an email is sent to subscribers that includes the news release and water sample results (algae species and cell counts). Emails are also sent when an advisory is lifted. Other timely information may be periodically shared as well. Join the list.