CLEAR LAKE CYANOTOXIN ISSUES

EPA

The Environmental Protection Department (Big Valley EPA) researches, plans, funds, and implements projects that protect the Tribe’s environment.  Return to Big Valley EPA's page.

The Big Valley Band of Pomo Indians began a cyanobacteria and cyanotoxin monitoring program on Clear Lake in 2014 with another shoreline Tribe, Elem Indian Colony. Together the two Tribes' Environmental Departments have collaborated with equipment, resources and time to test the water for toxins produced by cyanobacteria (AKA “Blue Green Algae”). These toxins are called cyanotoxins and can be neurotoxins, liver toxins and skin toxins. The Tribes began this program because despite the fact that Clear Lake had thick, noxious blooms covering its surface every summer since 2009, there was no regular and active monitoring of these blooms for the cyanotoxins that the California Office of Environmental Health Hazard Assessment (OEHHA) had reviewed and suggested Action Levels for in 2012, and for which the World Health Organization provided guidance regarding exposure in the 1990’s.  OEHHA's Report  

CURRENT RESULTS - 2021 SAMPLING RESULTS/LOCATIONS 

final Results 102621 map .jpg

 UPDATE ON CLEAR LAKE CYANOTOXIN LEVELS:

================

MICROCYSTIN TOXIN LEVEL HAS DECREASED SUBSTANTIALLY, HIGHEST LEVEL ON LAKE FROM 10/26/21 SAMPLING EVENT IS 25.11 µg/L

NO ANATOXIN-A DETECTS ON THE LAKE.

 At our last sampling event on 10/26/21, we collected water samples from 14 sites on  the lake.  Most had no evidence of bloom but some cyanobacteria was visibly present.  
We submitted all of the samples for microcystin qPCR or toxin analysis, and 4 sites for anatoxin-a qPCR or toxin analysis.  

 We conducted microscopy on all samples. A majority of the sites had Microcystis sp. as the dominant genus present but many had Aphanizomenon sp. or Planktothrix sp. present.  For more information on which cyanobacteria can produce which toxins: https://bit.ly/CyanobacteriaToxinsChart

   

 Identified map signage recommending restricted activity is based on CalOEHHA toxin trigger levels. 

CAUTION  / WARNING / DANGER   SIGNAGE

 10/26/21 RESULTS for

Microcystin:

DANGER (Anything above 20):

RED01                       25.11 µg/L

WARNING (Anything above 6):

CLOAKS01              17.61 µg/L

SBMMEL01             12.07

AP01                          9.47

LC01                          9.16

BP                              6.61

 

CAUTION (Anything above 0.8):

JB                                5.58 µg/L

LPTNT                       0.82

BELOW CAUTION:

Toxin producing genes present

at low levels:

CLV7

KP01

BVCL6

LUC01

NO DETECT OF TOXINS OR TOXIN PRODUCING GENES:

KEYS03

SHADY01

SITES NOT SAMPLED DURING THIS SAMPLING EVENT ARE NOT SHOWN ON THE MAP.

Summer sampling of 2x month is occurring.  Next sampling event will be November 16, 2021. 

SITE ID NAME SPREADSHEET.JPG
Kelsey Creek 063021.jpg

EPA STAFF:

Sarah Ryan, Environmental Director (707)263-3924 x132 and (707)349-4040 cell

Alix Tyler, Water Quality Program Manager

​Katherine Schrade, Environmental Specialist

Richard White, Solid Waste Technician