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The 2012 bloom season extended from July into January, 2013. Nine advisories were issued that were in effect for a total of 601 days (advisory-days). This was the first season toxin based monitoring (TBM) was used by some waterbody managers to determine if an advisory should be issued once a bloom is identified. Initial TBM of a bloom allows managers to avoid advisories on monitored recreational waters if toxins produced by the cyanobacteria are below guideline values. TBM is conducted every other week throughout the life of the bloom to ensure toxins continue to stay below harmful levels. Cell counts and toxin analysis are still required for all advisories to be lifted. Use of TBM reduced the number of advisories from 18 in 2011 to nine in 2012. Get complete details in the 2012 Bloom Season Recap2012 Bloom Season Recap-Final.pdf
This map displays the location of each advisory (in sequence). See the table below for detailed information, including links to the original advisories. Links are displayed by the date an advisory was issued (start date) or lifted (end date).
2012_All Advisories.gif
# Waterbody​ ​Region ​County ​Dominant Species/Toxin ​Cell Count/Level ​Start Date ​End Date ​Duration (days)
1​ ​Jackson Creek  ​Southwest ​Jackson Aphanizomenon flos-aquae​ ​157,850 7/12/2012 7/17/2012 ​5
2​ Walterville Pond​ Willamette​ Lane​ Anabaena flos-aquae​ 800,000​ 7/27/2012​ 8/23/2012​ 27​
3​ Dorena Reservoir​ Willamette​ Lane​ Anabaena sp.​ 171,000​ 7/31/2012​ 10/23/2012​ 84​
4​ Dexter Reservoir​ Willamette​ Lane​ Anabaena sp.​ 231,000​ 8/13/2012​ 11/16/2012​ 95​
5​ Blue Lake​ Willamette​ Multnomah​ Microcystis aeruginosa 397,732​ 8/28/2012 9/14/2012​ 17​
6​ Willow Creek Reservoir​ Northeast​ Morrow​ Anabaena flos-aquae​​ 27,060,000​ 9/14/2012​ 12/27/2012​ 104​
7​ Lost Creek Reservoir​ Southwest​ Jackson​ Anabaena flos-aquae​​ 405,900​ 9/18/2012​ 1/24/2013​ 128​
8​ Big Creek Reservoir​ Northwest​ Lincoln​ Microcystis aeruginosa​ 312,500​ 9/18/2012​ 12/24/2012​ 87​
​9 Fern Ridge Reservoir​ Willamette​ Lane​ Microcystis sp.​ 2,156,000​ 9/21/2012​ 11/14/2012​ 54​