Algae bloom update

By Ashleigh Bartlett
Special to the Sun

Every year, Isabella Lake experiences a turnover as summer arrives and temperatures rise, causing rapid growth of a particular strain of toxin-producing algae. The Sun, along with several other publications – local and nationwide – cover the story when the initial test results are released reporting the presence of cyanobacteria in the lake. However, there are no follow-up stories to cover the test results at later dates discovering the algae is now toxin-free.

This is primarily due to a lack of structured guidelines provided to the Kern County Public Services Health Department regarding testing and re-testing, as well as a freshwater monitoring program still in its infancy in comparison to the saltwater program. Additionally, there are only two private testing labs in California, while the rest are out of state.

“In terms of testing, we have been doing a monthly visual assessment since January. So far, there hasn’t been any algae observed at the lake. We have some plans in place to begin testing when we start seeing the presence of algae during those visual assessments.” Amy Rutledge, Chief Environmental Health Specialist of the Environmental Health Division at Kern County Public Health Services Department explained during a private interview.

“There are multiple points around the lake that we’ll be looking at in terms of what’s there, because in years past we’ve only seen it on one shore and not another. We take care to be certain we only place the cautionary signs at affected areas of the lake. Given that algae can be present and not producing toxins, the signs are placed accordingly only after testing is completed and returned with the levels.”

Once algae has been visually observed, it is tested for toxin production. If it does not contain any toxins, the visual monitoring frequency is increased to weekly to observe the algae for growth. Visual monitoring or expedited testing can occur when a complaint is received, either of illness, increased algae growth, or various other concerns.

Although scientists do not yet understand fully how many harmful algal blooms (HABs) might affect human health, health agencies in the United States and abroad are monitoring HABs and developing guidelines for HAB-related public health action. The CDC says, “Cyanobacteria, also known as blue-green algae, can produce toxins that may taint recreational water. Humans who drink or swim in water that contains high concentrations of cyanobacteria or cyanobacterial toxins may experience gastroenteritis, skin irritation, and allergic responses.”

After algae tests positive for toxin production, it is also monitored visually weekly for bloom size increase or decrease. Depending on those results, the algae will be tested either weekly or monthly to determine if toxin levels are increasing as well. Signs will then be posted accordingly.

There are three levels of signage: Caution, Warning, and Danger. Signs are to change according to levels for accuracy. Testing is supposed to continue throughout the season, known as “Blooming Season,” which runs from about April through October, or until the warm weather subsides.

When asked about signage currently at Isabella Lake, Rutledge said, “There were cautionary/warning/danger stakes at water level, but they’re no longer visible, unfortunately. We knew a lot of signs had been removed, and we acknowledge that we did miss a few. That was pointed out to us by the local Chamber, which was great because we weren’t certain where they were. We did also have some cautionary signs that said that algae could be present at any time, and those were the ones we’d posted at main entrances with the most flow of people. We realized those signs weren’t as clear as initially thought, and those were removed. We have different ideas moving forward.”

However, many signs remained all of the winter season, when algae and cyanobacteria were no longer present.

Rutledge added, “Last year, we received toxicity level test results at the end of June, at the end of August, and visual assessments continued but because of the construction on the dam, many of our testing points became inaccessible to us. The water also receded to a point where algae was no longer observable during visual assessments.”

When asked about the lack of re-testing and frequently requested regularity regarding it, Rutledge [explained] that the freshwater HABs program itself is a relatively new program in California, and the Health Department is working within the guidelines that the State Water Resources Control Board provides. “Physical testing has been an issue in the past because there are very few labs that conduct that particular testing. The testing that we do and have done in the past has been in conjunction with the State Water Resources Control Board. Moving forward, the plan we have in place works in accordance with guidance documents they’ve released regarding test frequency. A lot of it is new to us, in general, and a lot of it is new to the state. We have to adapt year to year as the program changes.”

“We are working hard every year, as Amy said, on honing in and improving this program. On a local level, we care very much – we hear the same complaints and concerns, and we understand,” added Michelle Corson, Public Information Officer for Kern County Health. “We’ve developed a plan to better communicate when the first positive level test is received, and we’ve introduced a website that’s live now for the public to utilize for easier access and understanding of what’s presently active or inactive, minute by minute, at Isabella Lake.”

The Kern County Health website showcases a map of Isabella Lake, with each testing point hoverable to display the current toxicity levels or lack thereof and related comments. Incidentally, at this private meeting, two points around the lake were still marked as dangerous, and not having been tested since October of last year. Two hours after this meeting, the points were updated.

Asked about the possibility of more frequent required or structured testing in terms of follow-up, Rutledge said, “[They’ve] been working on legislation for marine water testing associated with cyanobacteria with salt water for years, mainly due to the inherent dangers in human consumption of affected shellfish, bivalves, crustaceans, etc. That program is more developed, but even that has taken a lot more time to get to where it is. The freshwater program is still fairly new so it’s not a mandate in legislation. There’s a board for each region and they’re actively working together to ascertain the extent the program, the available resources, and the associated cost. Many saltwater programs are facilitated by third party volunteers, and they’re working to determine if that’s a model that could work for freshwater, or how to allocate and dedicate resources to a freshwater program.”

Michelle made certain to note, “I hear what you’re saying: ‘When it goes away, the public should also be informed.’ That’s really great to hear and for us to try to be responsive to that, and we will continue to message that out.”

Harmful algal blooms impact human health, marine environments, and also have a large economic impact. The majority of the economic losses are due to loss of tourism and the closing of fisheries. A recent EPA publication estimates that the impact of harmful algal blooms on the US economy is over $40 million each year.

Isabella Lake is currently algae- and toxin-free. Kern County Health encourages the public to visit to view the live map. For more information on cyanobacteria, visit

Amulya Shahi - April 26, 2019

I think local governments must take action and take care such algae blooms before it starts harming the local. Some govs have already taken began thinking about algae bloom, which is a good step.

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