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.

To get email updates about posting/deposting decisions and other notifications, email This email address is being protected from spambots. You need JavaScript enabled to view it. to join the Klamath Blue Green Algae Workgroup list serve.

Updated Posting Status

 10/7/24- The off-channel pond "P-1" and waters near the Pulikla Tribal office (formerly Resighini Rancheria) were posted at the Caution advisory level.

 7/31/24- Dwinnell Reservoir was posted at the Caution advisory level. 

 8/13/24- Jones Beach on the Scott River was posted at the Caution advisory level.

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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 – lift the posting if cyanotoxin results from the initial sample are below recreational use values (RUV).
    • If posting occurred due to exceeding a toxin concentration guideline – lift the posting if cyanotoxin results are below RUV and either there is a commitment to continue bi-weekly sampling until the bloom is gone or bloom is visibly gone.
  • 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

  May 12th, 2022 North Coast FHAB Monitoring & Response Training Materials (Recording, Captions, Slides)

  California Harmful Algal Blooms (HABs) portal

  Strategies for Preventing and Managing Benthic Harmful Cyanobacterial Blooms

  Strategies for Preventing and Managing Planktonic Harmful Cyanobacterial Blooms

  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

The Yurok Tribe and the U.S. Army Corps of Engineers, San Francisco District (USACE) are partnering to study and develop an ecosystem restoration project in the Klamath Basin. The team will identify opportunities and goals for a healthy Klamath River and its tributaries, within the Upper-Mid Klamath, Scott River, and Shasta River sub-basins in CA, to the CA/OR state line.

More information can be found on the USACE project website. 

Community Engagement Meetings were held in March, 2025. Slides and a recording of the March 4th meeting are available at the links. 

• March 4th @11 am and 6 pm in Yreka
• March 5th at 11 am in Happy Camp
• March 5th at 6 pm in Etna

KBMP Committees - Roles and Responsibilities

KBMP members

KBMP members are encouraged to participate in full group meetings, serve on KBMP committees, implement water quality monitoring plan, submit data to coordinator, provide input when requested, and participate in decisions.

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Steering Committee

Steering Committee membership reflects the diversity in the basin, with the composition of members including, federal, state (Oregon and California), tribal, non-profit, and private enterprises. The Steering Committee facilitates full group meetings; sets meeting agendas; and guides the KBMP as a whole in an effort to keep workflow going outside of full group meetings. The Steering Committee makes decisions regarding external communication and protocols regarding internal policies and procedures. The steering committee works with the various committees and KBMP staff in an effort to implement the mission and the vision of the program. The Steering Committee defines and applies criteria for disbursement of funds, prioritizes program elements, and provides long-term strategies for program success.

The Steering Committee operates through consensus and collaboration. Each member has equal voice. The chair, co-chair and secretary of the committee shall be elected every year. The role of the chair confers no additional powers or privileges; the co-chair may serve as an alternate to the chair. The role of the chair is to facilitate the meetings and uphold the gradients of agreement. The role of the secretary is to take meeting notes and distribute to members and post on the website, if appropriate. The secretary also records meeting notes at the annual member meeting and facilitates the approval process prior to distribution.

Members

Monitoring Plan Committee

The monitoring plan committee is responsible for reviewing, updating and maintaining the QAPrP and the various associated Standard Operating Procedures (SOPs) on an as needed basis.  The monitoring plan committee is responsible for the development of the water quality monitoring program plan.  The monitoring plan committee coordinates with KBMP staff to develop the technical content of the monitoring plan and makes recommendations to the Steering Committee regarding the prioritization of the various components of the monitoring plan.  Please refer to the Monitoring Plan for a more detailed description of the role of the Monitoring Committee (http://www.kbmp.net/documents). 

Strategic Plan/ Funding Committee

The funding / strategic plan committee identifies funding sources in an effort to implement KBMP program elements, special studies and monitoring plan objectives with the direction of the KBMP steering committee and membership.  Please refer to the Strategic Plan for a more detailed description of the role of the Funding / Strategic Plan Committee. (http://www.kbmp.net/documents).

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Blue-green Algae Committee

The blue-green algae committee coordinates BGA monitoring activities, implements protocols for listing and delisting of water bodies, share BGA monitoring data and implements the California / Oregon public health guidance regarding BGA blooms.  Please refer to the KBMP website for a more detailed description of the role of the Blue-green Algae Committee (http://www.kbmp.net/collaboration/klamath-blue-green-algae-workgroup).

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Work Groups

Work groups are comprised of experts in a particular field and advise the steering committee. For example, work groups may include the Klamath Fish Health workgroup and the Tribal Water Quality workgroup.

Klamath Basin Monitoring Program Staff