Cyanobacteria Appearing Early This Year ; Samples Confirm Its Presence in Mad River


Blue-green algae

Press release from Humboldt County’s Department of Health and Human Services:

Public Health officials are reminding residents to keep an eye out for cyanobacteria, also known as blue-green algae, while recreating at local rivers and lakes after samples with the toxin were collected at two locations on the Mad River.

The Blue Lake Rancheria Tribe confirmed Thursday that its Environmental Department collected the samples with cyanobacteria at a popular recreational location known as Pump Station 4 and just west of the Blue Lake Rancheria past the sewer ponds. The North Coast Regional Water Quality Control Board sampled Big Lagoon and Stone Lagoon where no cyanobacteria or toxins were detected, and no other locations have been sampled to date.

Typically, cyanobacteria warnings come out between late July and early August, coinciding with low flows and sustained high temperatures in the inland areas which may contribute to cyanobacteria growth in the river. However, this year’s low level of rainfall and low river levels appears to be leading to an early season and increase in algal blooms in some locations.

Cyanobacteria can be present in any fresh water body, and looks like dark green, blue-green, black, orange or brown scum, foam or mats on the riverbed or floating on the water. Cyanobacteria can produce harmful compounds, such as toxins and taste and odor compounds, that cause health risks to humans and animals. Warm water and abundant nutrients can cause cyanobacteria to grow more rapidly than usual causing “blooms.” These blooms are termed “harmful algal blooms.”

In previous years, cyanobacteria was confirmed in some water bodies within Humboldt and surrounding counties, including the Mad River, South Fork Eel River, Van Duzen River, Trinity River, Big Lagoon, Stone Lagoon, Clear Lake and Lake Pillsbury. It is difficult to test and monitor the many lakes and miles of our local rivers. Most blooms in California contain harmless green algae, but it is important to stay safe and avoid contact.

While most cyanobacteria do not affect animals or people, some are capable of producing toxins that can be harmful to animals and humans. Dogs and children are most likely to be affected because of their smaller body size and tendency to stay in the water for longer periods of time.

Officials recommend the following guidelines for recreational users of freshwater areas:

    • Keep children, pets and livestock from swimming in or drinking water containing algal scums or mats.
    • Adults should also avoid wading and swimming in water containing algal blooms. Try not to swallow or inhale water spray in an algal bloom area.
    • If no algal scums or mats are visible, you should still carefully watch young children and warn them not to swallow any water.
    • Fish should be consumed only after removing the guts and liver and rinsing fillets in tap water.
    • Never drink, cook with or wash dishes with water from rivers, streams or lakes.
    • Get medical attention immediately if you think that you, your pet or livestock might have been poisoned by cyanobacteria toxins. Be sure to tell the doctor or veterinarian about possible contact with cyanobacteria or algal blooms.
    • Join or support one of the many watershed and river organizations.

To learn more about cyanobacteria and harmful algal blooms, visit the state of California’s website at

To learn more about cyanobacteria and algae on the South Fork Eel River, visit

To report a bloom, e-mail [email protected] or call 844-729-6466 (toll free). Blooms can also be reported via the “bloomWatch” app which is available for free download on iTunes or Google play.

For information on conditions occurring within Humboldt County, contact the Division of Environmental Health at 707-445-6215 or 800-963-9241. Photos of suspected blooms can also be emailed to [email protected].




  • Pot farms on the river banks really???

    If anyone knows from experience that if you leave pots of soil out from the year before, that you’ll see the build up of growing fungus that it grows from the food and other stuff people put in there dirt for there pot plants, but then you wonder why our water ways are like this when you allow pot farms along are river like the one’s along the highway next to miranda and benbow also piercy that are yards away from our rivers, and you all don’t think that it’s part of the problem well get a brain and realize ur the problem letting this happen, look at the bigger issue why you officials are allowing it just cuz of money?!?!

  • What is the story on the heavy moss in the water and white powdery coating on the banks beneath Fernbridge?

  • it's called farming....

    And it’s happening all over the world. Every last creek and stream is nothing but a vehicle for fertilizers to get to crops. Nothing else.
    And why do so many of my neighbors on RHBB
    think pot farming is different? Haven’t heard of cows shitting directly in creeks?? How about ammonium nitrate?? Only the most toxic and common fertilizer used worldwide.
    All rural areas are currently production zones for commodities sold in global urbanized areas under capitalism. Nothing more than that. No nuance or anything just produce and consume. So yeah, the environment that we are still a part of is almost over for mammals….. and yeah what about the Giants huh?

  • Third World County

    So what did you expect with all of these new pot farms being permitted taking water and returning it with fertilizer runoff. Just because an engineer designed the pot farm and it is signed off doesn’t mean they aren’t still polluting. There is a creek in the King range below a few cannabis farms that has had Algae like that for months.

  • Come on common sense daaa!!!!!!!

    This is a huge problem for a county to ignore but it has major health concerns for our habitat and fish, but our health and we the people should sue our county and the people along the river for letting this happen it’s crazy, take and have someone fly the river and look at the farms along it and tell me that all the chemical foods aren’t leaching into the river like a grow pot does after season and that it’s ok and doesn’t go into our water ways!!!!!!!

    • Northrup Grunman

      Oh they’re flying alright. This was done on 5/28. (click on photo)

      • Northrup Grunman

        Here’s another flight to the south. These flights were conducted simultaneously by two planes. N252GB, N252AC

  • This is an interesting year! Here on the Mad north of Maple Creek there is no Bactria yet…

    In our creek I’ve spotted some healthy salmon spawns swimming about. Hoping the creek runs enough for them to make it out this year. We will see.

    I really hope the fires don’t get too bad this year.

  • All farming can cause this damage, not just pot farming. And the river isnt dry due to pot farming. Its dry due to drought. All over the state, not just here. Lake shasta is dry, mendocino is dry, eel river is dry, russian river is dry. Because we hardly got any rain this year. Pot farming causes problems, but it isnt the only form of farming causing damage. If you think a corn grow 10x bigger than a pot grow and fertilized just as much, if not more, isnt causing the same kind of damage then you need to learn some things. Especially when 40% of the food grown in the united states is wasted, thrown in the garbage. Talk about a waste of resources, time, and money.

  • i dont know about anywhere else , but the creek that goes through my property is BONE DRY — and when it was running a few weeks ago , there was a GREEN MOSSY substance in it and i saw no evidence of any aquatic life — mudbugs ? NO – sticklebacks ? NO – water skimmers ? NO – lamprey ? NO – brookies ? NO – newts ? NO — this creek is directly connected to the PACIFIC OCEAN and historically there was runs of SALMON and STEELHEADS coming up it to at different times of the year – the old farmer across the creek says he has never seen it dry like this and he goes back 50 + years on his farm – my well is drilled next to the creek and is putting out a great flow of SULPHUR smelling water , so there is water down below in the water table — the sulphorous smell is not harmful , its not from VOLCANIC sources either , it from HYDROGEN SULFIDE H2S – its natural and my plants and trees seem to like it a lot – i wont drink it , why should i ? IT STINKS !! – i’m sure i could get rid of the stink with a reverse osmosis system but WHY ? they are very expensive and i’m an old man on a limited income and cant afford stuff like that – plus i have another source of pure , clean water running under my property , its a pipeline of sweet tasting spring water that just happens to traverse my property – i made a deal with municipality who own it and i get all the sweet , ice cold SPRING WATER that i need – i like that !! – of course they do chlorinate it at the source , but i would rather smell a little chlorine than get sick from some rank 1 cell organism ? – so when it comes to H20 , I’M IN LIKE FLINT !! HAHAHA !! AND WHEN THE CREEK IS RUNNING I HAVE 3 SOURCES OF WATER !!! I COULD ALSO COLLECT RAIN WATER FOR A 4TH SOURCE OF WATER ?? BITCHIN BOB !! HAHAHAA !! MAYBE I’LL BOTTLE IT AND SELL IT TO THE TOURISTS ?? BWAHAHAHA !! …PEACE OUT

  • Yep, don’t blame me, I’m doing it right. Fucking greed will kill us ALL!

  • Is moonstone included in this? And is this a current issue?

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