2008 Data from Devils Lake

2008 Season: 

2008 - 11 - 03:  Sample analyses for Microcystin have shown a significant reduction in toxicity.  This follows over two weeks of increased clarity of the water.  This improved water clarity has been associated with a significant reduction of cyanobacteria.  As a result of these improvements to water quality, the Red Health Advisory issued on August 14, 2008 has been lifted.  As the normal time for cyanobacteria to bloom is in the late summer and early fall, the Devils Lake Water Improvement District has suspended its Cyano-Watch program for the year.  No additional testing will be performed for cyanobacteria or cyanotoxins at this time.

2008 - 10 - 16: The Red Health Advisory posted August 14, 2008 remains in effect. However, a significant drop in toxicity has occurred and if samples continue to be low, the advisory may be lifted shortly.  

2008 - 10 - 07:  The Red Health Advisory posted August 14, 2008 remains in effect. Samples were collected from all of the near shore sample sites, and ran at multiple dilutions.  Sample toxicity varied widely and unpredictably with samples ranging from 1 part per billion to nearly 170 ppb of Microcystin. Visual evidence might have suggested a less varied range as all the sample sites contained cyanobacteria at some density.  Analyses of the same samples for a separate toxin, Saxitoxin, were effectively negative with all samples at or below the lower limit of detection.  This is the second analysis for Saxitoxin conducted on Devils Lake.  Previously the samples were also negative for Saxitoxin.  Documented in the all samples were the cyanobacteria Microcystis and Anabaena, both of which are capable of producing the toxin Microcystin. Anabaena is also capable of producing Saxitoxin (samples were negative), as well as Anatoxin-a and Anatoxin-a (s) which were not tested for.   Sampling will continue until the cyanobacteria blooms have dissipate with the next sample date scheduled for Thursday October 16th, 2008.   

2008 - 09 - 24:  The Red Health Advisory posted August 14, 2008 remains in effect. The current situation on Devils Lake has actually gotten significantly worse, and therefore water contact is seriously warned against.  The resurgence of the cyanotoxins is likely due to the increasing presence of different toxigenic strains of cyanobacteria in Devils Lake. Cyanobacteria such as Microcystis and Anabaena have been documented.  These organisms are among the most toxic cyanobacteria known to exist.  As a result, the highest documented concentrations of Microcystin to date have been seen.  An initial screening of samples collected on 2008-09-22 showed that all the samples were greater than 10.0 ppb.  Further analysis of these same samples has shown some sites in excess of 100 ppb (see table below).  The Recreational Water Use Standard for Microcystin is 8 ppb, and thus samples from Devils Lake may be greater than 13 times the Oregon standard.

2008 - 09 - 22:  The Red Health Advisory posted August 14, 2008 remains in effect. Toxicity analysis performed today at 6 shoreline sample sites were all above the Recreational Water Use Standard (8 ppb) for Microcystin.  The diluted samples were all determined to contain greater than 10 ppb of Microcystin.  Follow up testing is scheduled for Wednesday (2008-09-24).  There was minor scum formations at many of the sample sites around the lake (see table below).

2008 - 09 - 16:  The Red Health Advisory posted August 14, 2008 remains in effect. Toxicity analysis of a sample collected from the campground moorage dock proved to be much greater than expected given the previous values.  The undiluted sample was determined to contain greater than 5 ppb of Microcystin, a known liver toxin.  The Recreational Water Use Standard established by Oregon DHS for Microcystin is 8 ppb and thus the sample may actually exceed that value.  However, analysis of samples for a separate, more dangerous toxin, Saxitoxin proved to be undetectable (Limit of Quantification for Saxitoxin is 0.015 ppb) at all sample sites.  This is the first Saxitoxin analysis done on Devils Lake. Resampling and further analysis will be conducted within 1 week.

2008 - 09 - 03:  Toxicity analysis performed today at 5 shoreline and 3 broad lake sample sites were all below the drinking water standard for Microcystin. This is promising news for Devils Lake, however the Red Health Advisory posted August 14, 2008 remains in effect for the reasons described below.  Department of Heath and Human Services protocol states that an advisory should only be lifted if cell counts are below the threshold that triggered the advisory for one (1) full week, that Microcystin levels are less then 8.00 ppb, and Anatoxin-a, another type of cyanotoxin, is undetected.  If toxicity analysis is unavailable DHS protocol suggests a two (2) week waiting period after cell counts have gone below the threshold that triggered the advisory.  While in 2008 the Devils Lake Water Improvement District developed the capacity to test for Microcystin, we are currently unable to conduct our own tests for Anatoxin-a.  This is due to restrictions by the Department of Homeland Security which currently do not allow the distribution of testing supplies specific to Anatoxin-a.  This restriction is currently also true for acquiring testing supplies for a similar cyanotoxin, Anatoxin-a(s).  While some laboratories can analyze Anatoxin-a and Anatoxin-a(s) using sophisticated and expensive gas chromatography, the turn around time to obtain results would generally surpass the additional one (1) week period necessary to lift the advisory without any toxicity analysis.  Therefore, the health advisory shall remain in effect until September 16th, 2008, provided cyanobacteria do not make a resurgence. 

2008 - 09 - 02:  The Red Health Advisory posted August 14, 2008 remains in effect, however the bloom in Devils Lake does appear to have subsided to a large extent. Only very low densities of cyanobacteria were observed today at any of the six shoreline sample sites.  It is important to note though that cyanotoxins produced by cyanobacteria can remain in the water for up to two (2) weeks after a bloom has vanished. Further analysis from last week's sample at Regatta Grounds, which was previously published as greater than 10 ppb of Microcystin, revealed the actual concentration to be 51.40 ppb Microcystin.  This value greatly exceeded the 8 ppb Recreational Water Quality Standard established by Oregon DHS.  Sampling for the cyanotoxin Microcystin will continue with the next sampling date being Wednesday, September 3, 2008.  Results from the day's testing will be available online by 6pm that same day.

2008 - 08 - 26:  The Red Health Advisory posted August 14, 2008 remains in effect.  A survey of the lake this morning demonstrated a heavy scum of cyanobacteria stretching nearly across the lake throughout the middle section of the lake near Regatta Grounds.  This heavy scum is broken up by boat traffic and wind energy as the day progresses generally, but demonstrates the widespread bloom of toxigenic cyanobacteria currently in Devils Lake. The Devils Lake Water Improvement District conducted toxicity monitoring at shoreline sample sites and at sample sites in the broad lake. Analysis reveals that the presence of Microcystin above the recreational water use limit established by the Oregon Department of Health and Human Services at one site tested (Regatta Grounds -- See Table of Recent Data from Devils Lake).  Oregon DHS also recommends posting when visible scum is present as is the case in many points around the lake.   

2008 - 08 -21:  The Red Health Advisory remains in effect.  Toxigenic Cyanobacteria are known to be in Devils Lake and washing ashore.  The concentrations are variable as the cyanobacteria are pushed around by currents and wave action, and thus cyanobacteria blooms and scum formation are often localized and episodic.  Please see the tables below and recent updates posted below for additional information. The next sampling date for cyanotoxin is scheduled for Tuesday August 26, 2008. 

2008 - 08 -14:  The cyanobacteria bloom in Devils Lake has progressed to the point to warrant a Red Health Advisory. This is the highest level alert the Devils Lake Water Improvement District has established in its CYANO-WATCH program and is consistent with Oregon Department of Health and Human Services protocol for cyanobacteria posting. Scum formation of toxicgenic species has been seen at many of the public accesses as a result of the free-floating cyanobacteria washing ashore. Scums from cyanobacteria have not been seen in the broad lake, as typically only the shorelines are affected at this level. Toxicity testing confirms that the highest risk areas are those shoreline areas with scum present, and that the broad lake is of much less of a risk area. Cyanobacteria concentrations where scums were not forming have been well below the advisory thresholds for both toxicity and cell density. However along the shoreline where the wind and wave action has trapped the cyanobacteria into a cove or bay, cell densities and actual toxicity from Microcystin, a known cyano-toxin, have warranted the RED HEALTH ADVISORIES posted today around the lake. This posting will remain in effect until two-weeks after cell densities and toxicity tests are shown to be below the state standards listed below. It is important to note that while concentrations at the shorelines can change rapidly and at certain sites are currently quite high, concentrations of cyanobacteria and cyano-toxins in the well mixed broad lake have not been shown to be anywhere near the threshold that would warrant a posting.

Overall this is a complicated decision making process, but swimming, snorkeling, water skiing, or other high risk activities in areas where the cyanobacteria have accumulated (generally along the shoreline) is not advised. Boating, hiking, wildlife viewing, picnicking, and other low risk activities around the lake are considered safe, as it is only the ingestion or inhalation of water which puts a person or pet at risk. Fish consumption can provide some risk of exposure, but according to the Department of Health and Human Services is greatly decreased if the head, intestines, and skin are removed before cooking. Boiling or heat will not destroy any toxins that may be present, so lake water should not be used for cooking or drinking. Risk from inhalation or ingestion of cyano-toxin are illnesses with symptoms of diarrhea, nausea, dizziness, fainting, numbness, cramps, and tingling. Consult medical or veterinarian attention should you, your family or your pets be suffering from such symptoms. The cyanotoxins attack the liver and neural systems, so in extreme cases paralysis and even death can occur.

In order to better assess actual toxicity, the Devils Lake Water Improvement District embarked this year on Phase III of its CYANO-WATCH Program which includes some toxicity monitoring. Although not comprehensive of all toxins that cyanobacteria can produce, it does focus on one toxin, Microcystin that recreational standards and drinking water standards have been developed for. Sampling conducted today confirms not only the presence of high concentrations of cyanobacteria washing ashore in bays and coves, but that the organisms were in fact producing Microcystin, a known liver toxin. Analysis of samples from Regatta Grounds showed particularly high levels of Microcystin in excess of the 8 ppb (parts per billion) standard established by the Oregon Department of Health and Human Services for recreational water use. Similarly a sample taken from Sand Point showed a result of 7.0 ppb. In contrast, the level of Microcystin at Holmes Road Park today was 0.21ppb, which is 5 times lower than the Drinking Water Standard. Cyanobacteria are less likely to wash ashore at some places because of the prevailing winds and the shoreline morphology. Like much of the broad lake, the sample taken today at Holmes Road Park was relatively clear. A full summary of the standards and data collected are presented above.

2008 - 08 - 04:  Cyanobacteria are blooming in Devils Lake and may be washing ashore in high densities in protected coves and onto shorelines. Scum formation is possible, and as such, extra caution is warranted when recreating on Devils Lake. As a system of emphasizing the potential increased risk associated with cyanobacteria and how people need to be mindful of such potential risk, the Yellow Caution signage has been posted at all sites around the watershed and has been sent out to stakeholders and interested parties.

The public should be aware that some forms of cyanobacteria are capable of producing toxins, which can be hazardous to humans and pets. Care should be taken to not ingest water or inhale droplets which is more likely when swimming, water skiing or with the use of Personal Watercrafts. Recreational boating is of less concern as are other non- or low water contact recreational activities. Fish consumption can provide some risk of exposure, but according to the Department of Health and Human Services is greatly decreased if the head, intestines, and skin are removed before cooking. Boiling or heat will not destroy any toxins that may be present, so lake water should not be used for cooking or drinking.

Having provided some common sense protections for yourself and your family, it is important to remember your pets too. Extra caution should be exhibited to protect animals as they will often drink water from the shorelines or may have swum in bloom affected areas. Exposure is subsequently increased after exiting the water as an animal will typically lick itself clean and effectively be ingesting and absorbing any cyanobacteria or toxins that may have been on the animals’ fur. As a sensible precaution for yourself or your pet if you suspect exposure, be sure to wash thoroughly with clean water. If symptoms of nausea, vomiting, dizziness, diarrhea, numbness, tingling, or fainting develop seek medical or veterinarian attention immediately.

For more information about cyanobacteria and cyanotoxins see the Green Informational flyer and visit the North American Lake Management Society for a comprehensive review of cyanobacteria and the cyanotoxins they can produce. The Devils Lake Water Improvement District will continue to be monitoring the sites around the lake and will provide updates as more information becomes available. Updates will be available though the Cyano-Watch program and on our web site.

Click Here to Learn More about Cyanobacteria!

Click Here to reach Oregon DHS Cyanobacteria Website!!!