In the Klamath Basin blue-green algae blooms typically occur between June and October when temperatures rise and water conditions are favorable for algal growth. Blue-green algae monitoring typically occurs May - November. If river conditions exceed public health standards for toxic algae the area is posted with a health advisory sign.

View the Klamath BGA Tracker Interactive Map

For more information, please check California's HAB Incident Reports Map. 

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Updated Posting Status

  July 30, 2021- Upper Klamath Lake near Eagle Ridge has been posted a recreational use health advisory based on sample results collected on July 27th for microcystin. Other areas of Upper Klamath Lake remain unaffected by this advisory.

 July 21, 2021- Copco Reservoir has been posted at the Danger level based on sample results collected on July 13th for microcystin.  

 June 29, 2021- Copco Reservoir and Iron Gate Reservoir have been posted at the Caution level due to microcystin  

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About the Tracker

The BGA Tracker Map was built to inform the public and research community regarding river conditions. The Tracker utilizes current information to track  and map the blue-green algae blooms throughout the Klamath Basin. The Blue-Green Algae Tracker identifies blue-green algae public health threats  (i.e. exceeds health thresholds identified in the appropriate guidance) by river reaches bounded by public health monitoring locations.

River reaches which exceed applicable criteria for public health are indicated by different colors on the map that vary depending on the number of tiers within each jurisdiction's advisory thresholds. Advisory colors within the map are:                 

Oregon           

California       

Yurok Tribe     

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Blue-green Algae Official Notifications

Other Information

About Blue-green Algae

Blue-green algae (cyanobacteria) are a form of bacteria. Surface scums of blue-green algae are common in the summer months within reservoirs and along the Klamath River. Exposure to blue-green algae can cause rashes, skin and eye irritation, allergic reactions, gastrointestinal upset, and other effects. At high levels, exposure can result in serious illness or death. Small children and dogs are particularly susceptible due to their small body size and their potential to ingest water while recreating.

For a more detailed analysis of previous sampling seasons, please refer to the following document:

Toxigenic Microcystis aeruginosa bloom dynamics and cell
density/chlorophyll a relationships with microcystin toxin in the Klamath River, 2005-2008.

 

Posting Guidelines

Advisory Threshold Guidelines

The Oregon Health Authority (OHA), California State Water Resources Control Board (SWRCB) and the Yurok Tribe each provide their own guidelines for posting advisories in recreation waters. Posting advisory thresholds recommended by the OHA, SWRCB and the Yurok Tribe are summarized in the following table and detailed in links below.

 

• Oregon
  • Public Health Advisory Guidelines: Harmful Algae Blooms in Freshwater Bodies (As of June 2019, the microcystin threshold follows EPA guidelines)

• California
  • CyanoHAB Trigger Levels for Protection of Human Health
  • Decision Tree & Narrative for Posting and De-Posting Health Advisories for CyanoHABs
  • Appendix A- Description of cyanotoxin trigger levels in recreational water bodies
    
    
• Yurok Tribe
  • 2016 Posting Guidelines for Public Health Advisories

De-Posting Criteria

Postings should remain in place until the following criteria are met:

• Oregon
  • If posting occurred due to visible scum – wait two weeks (there should be no visible scum recurrence during this time) before lifting the advisory.
  • If posting occurred due to exceeding a cell count guideline – wait two weeks after cell count falls below the recommended guideline (there should be no visible scum recurrence during this time) before lifting the advisory.
  • If posting occurred due to exceeding a toxin concentration guideline – wait 1 week after the toxin concentration falls below the recommended guideline (there should be no visible scum recurrence during this time) before lifting the advisory.
• California
  • Quantitative samples confirm that all cyanotoxins are below all threshold levels AND declining bloom conditions continue for a minimum of two weeks.
  • If posting was based on a Secondary Trigger, then either the secondary trigger OR primary triggers should no longer be exceeded (cell densities of toxin producers are below 4,000 cells/mL and no scums are visible.
  • All evidence indicates the bloom is ending and favorable conditions are decreasing.
• Yurok Tribe
  • Toxin Analysis- Two consecutive toxin sampling events (minimum of 1 week apart) with results below posting guidelines. (If the blue-green algae present is known to produce microcystin and anatoxin-a, it is recommended that botoxins be tested prior to lifting an advisory).
  • No visible scums present.
  • In some situations there may be reason, such as reported illness, to prolong the advisory beyond the recommended waiting period.

 

Blue-green Algae Public Health Monitoring

Blue-green algae is monitored for potential risk to public health and to establish baseline condtions for Microcystis aeruginosa cell counts and microcystin toxin levels. Public health monitoring is conducted by PacifiCorp, Karuk Tribe, and Yurok Tribe. Public health monitoring occurs within the reservoirs (Copco and Iron Gate) and Klamath River mainstem from May - November.  Copco and Iron Gate reservoirs are monitored once a month in May and twice per month from June through November (omitting August and September).The Klamath River mainstem from below Iron Gate dam to the estuary are monitored twice per month in June, July and October and weekly in August and September. Baseline monitoring is conducted by U.S. Bureau of Reclamation, PacifiCorp, Karuk Tribe, and Yurok Tribe from below Link Dam to the estuary. Baseline monitoring occurs monthly and seasonally from May -  November. The blue-green algae tracker consists of both public health and baseline monitoring data. This monitoring effort is part of the Klamath Hydroelectric Settlement Agreement (KHSA) monitoring funded by PacifiCorp.

(Click on map to enlarge)

 

 

 

 

 

 

 

 

 

 

 

 

 

Statewide Guidance on Harmful Algal Blooms recommends the following

• Avoid wading and swimming in water containing visible blooms or water containing algal scums or mats, which are most often present on the shoreline.
• Take care that pets and livestock do not drink the water or swim through scums or mats, nor lick their fur after going in the water; wash exposed pets in clean drinking water.
• If no algal scums or mats are visible, you should still carefully watch young children and warn them not to swallow the water.
• Do not drink, cook or wash dishes with untreated river water.
• Consume fish only after removing guts and liver, and rinsing fillets in clean drinking water, mussels should not be consumed.
• Get medical treatment right away if you think that you, your pet, or your livestock might have been poisoned by blue green algae toxins. Be sure to alert your doctor or vet to possible contact with blue green algae.
• If your pet exhibits these symptoms, collect and freeze vomit and/or diarrhea in clean plastic bags or containers, to allow for analysis by State authorities.

 

Health Advisory Posters

• PacifiCorp Caution Warning Danger
• US Forest Service
• Humboldt County
• Yurok Tribe (Precautionary)
• Yurok Tribe Caution  Warning  Danger

Microcystin Toxin in Fish and Freshwater Mussels

Background

In an effort to better inform the public and tribal communities regarding potentially toxic algae (cyanobacteria) blooms, and toxins affecting fish and freshwater mussels, the Klamath Basin Monitoring Program has developed an on-line interactive map for tracking blue-green algae and toxins throughout the Klamath Basin. This work is supported by  the Public Health component of the Klamath Hydroelectric Settlement Agreement (KHSA)  funded by PacifiCorp. The public health monitoring region encompasses the mainstem Klamath River from Link Dam in Oregon to the estuary, in California including several mainstem tributaries. The monitoring is part of a multi-agency effort by the Bureau of Reclamation, PacifiCorp, Karuk, and Yurok Tribes to provide data on cyanobacteria and related toxins to support public health decisions.

During the summer months in the Klamath Basin blooms of toxigenic algae (Microcystis aeruginosa) and other related species of algae (Aphanizomenon flos-aquae, Anabaena flos-aquae, and Oscillatoria sp.) are common in Copco and Iron Gate Reservoirs. M. aeruginosaproduces a toxin, microcystin, a hepatotoxin which affects the liver. The toxigenic algae has been documented hundreds of miles downstream and in some years is found near the mouth of the Klamath River. Large blooms of M. aeruginosa create surface scums which may cover the entire surface of a waterbody (For a detailed map of monitoring locations and bloom conditions, please refer to the Blue-green Algae Tracker). Organisms such as fresh water mussels and yellow perch can ingest M. aeruginosa and there is the potential that the toxin can bioaccumulate in the tissue.

Freshwater Mussels

In 2007 and 2009, the Karuk and Yurok Tribes conducted tissue analysis of fresh water mussels collected from the Klamath River mainstem. The results indicated a seasonal pattern of microcystin congeners beginning in July and persisting through December. In 2009 levels of microcystin congeners found in fresh water mussels frequently exceed the lifetime* total daily intake for a child weighing 22 pounds. In some cases, a single meal of fresh water mussels posed an acute* exceedance of toxin. The 2009, study also revealed that, while concentrations of microcystin in the water column were below levels of concern, substantial microcystin bioaccumulation occurred at all study locations. The results of this study, partially funded by the KHSA monitoring, suggest that consumption of freshwater mussels from the Klamath River mainstem should be exercised with extreme caution.  

For more information please refer to the following report:

 

Microcystin Bioaccumulation in Klamath River Freshwater Mussel Tissue: 2009 Results

 

*Acute Total Intake (250 ppb): single exposure event (e.g. week-end fishing trip). Seasonal Total Daily Intake (40 ppb): ongoing, “daily” exposure for several weeks during the cyanobacterial season. Lifetime Total Daily Intake (4 ppb): ongoing “daily” exposure for many months in settings where microcystin-producing cyanobacteria proliferate perennially.

Fish Tissue

In contrast to fresh water mussels, yellow perch sampled in Copco and Iron Gate Reservoirs in 2009 had no detectable levels of microcystin.  However, the results from yellow perch sampled from Copco and Iron Gate Reservoirs have varied for microcystin over the past few years. Sampling conducted in the summer of 2007, found levels of microcystin in yellow perch fish tissue collected from Copco and Iron Gate reservoirs, exceeding the advisory level of 26 nanograms total microcystin/gram tissue. In 2008 PacifiCorp sampled yellow perch and crappie from Iron Gate and Copco Reservoirs, and rainbow trout from the Klamath River before, during, and after the bloom season; all tissue samples were non-detect for microcystin.

The presence of microcystin in fish tissue remains a health concern for the public and tribal communities. 

Related Links

California Harmful Algal Blooms (HABs) portal

Cyanobacteria and Known Toxins Chart

Blue-Green Algae: A Veterinarian Reference

EPA Frequently Asked Questions and Resources for Harmful Algal Blooms and Cyanobacterial Toxins

California CyanoHAB Network (CCHAB)

California Department of Public Health

Office of Environmental Health Hazard Assessment

California State Water Resources Control Board

North Coast Regional Water Quality Control Board & Press Releases

Siskiyou County Public Health Services

Oregon Department of Health Services

US EPA Cyanobacterial Harmful Algal Blooms (CyanoHABs)

EPA Cyanobacteria and Cyanotoxins: Information for Drinking Water Systems

North American Lake Management Society

Center for Disease Control