California's ongoing drought has helped create a rise in the number of toxic algae blooms that are forming in the state's lakes and waterways.
The Associated Press reported that the toxic blue-green algae, known as cyanobacteria, has been found in more than 40 of the state's bodies of water, which is the highest count in the history of the state.
"Warm temperatures, increased nutrients, and low water flows aggravated by drought conditions and climate change are favoring toxin-producing cyanobacteria and algae; and a number of lakes, reservoirs, and river systems are suffering blooms as a result," the California State Water Resources Control Board said in a statement last month.
Beverley Anderson-Abbs, an environmental scientist with the State Water Board, said generally the blooms are seasonal, beginning when waterbodies warm up and days get longer, providing longer periods of sunlight for photosynthesis.
"However, these seasons have been getting longer over the past few years as winters have been relatively warm and water, especially in smaller lakes, has been warming earlier in the year and staying warm later," she said to AccuWeather in an email. "Cyanobacteria tend to outcompete other algae when water temperatures get above about 20 degrees Fahrenheit, and they outcompete most other organisms and persist for long periods of time."
Throughout the summer, reports of the algae have come in from locations such as Lake Elsinore, situated about 70 miles south of Los Angeles to lakes in the San Francisco Bay Area. Additionally, notices were sent out about two reservoirs along the Klamath River in northern California.
Harmful algal blooms are considered potential public health threats in nearly every state in the United States due to their presence in drinking and recreational waters, according to the Woods Hole Oceanographic Institution (WHOI).
Side effects from exposure to the algae include rashes, skin and eye irritation, allergic reactions and other effects, the California Department of Public Health stated. In extreme cases, exposure can result in serious illness or death.
"There have been no known incidents of drinking water in California being affected," said Anderson-Ebbs.
Lake Elsinore, Southern California's largest freshwater natural lake, was closed to recreational activities from July 28 to Aug. 4, as officials monitored toxin levels in the algae.
While the lake eventually reopened to boating and fishing, the city said it continues to monitor the water levels on a weekly basis and urged residents to avoid bodily contact with the algae.
Nicole Dailey, a senior management analyst for the city of Lake Elsinore, told AccuWeather there has been an impact on overall visitors to the lake since the bloom was identified. She also said the city saw a 50 to 60 percent decline in August and September in the number of lake use passes, compared to what they typically sell.
In California's heavily populated East Bay region where around 2.5 million people reside, the East Bay Regional Park District was forced to close several popular lakes, which had a huge impact on recreation opportunities for the public, according to Carolyn Jones, a spokesperson for the park district.
Millions of dollars in revenue were lost when people weren't able to hit their favorite parks for a swim on hot summer days. Temporary staff hired for the season, such as lifeguards and camp counselors, were also impacted.
In addition, several of the lakes are treated twice a week and the treatments can become expensive, she said.
The park district uses an organic chemical called to Pak 27 to control the algae, which is safe for the public and doesn't harm aquatic life. Currently all lakes except Lake Anza in Berkeley have been reopened.
Prior to to 2014, there was never any formation of the algae in the park system, but over the last several years, Jones said it has felt like a constant revolving door of opening and closing lakes to treat the blooms that come and go.
Health departments, water agencies and parks departments are jointly working together to figure out the best polices going forward.
"It's obviously a huge inconvenience," Jones said. "And I think it's all agencies, not just us that are still learning how to deal with this and trying to make sense of it and trying to figure out a really good long-term plan."
With no end to the drought in sight, the total number of lakes and rivers with toxic algae could rise. Even after a bloom has dissipated, some toxins can remain in the water column or sediments for weeks.
"It is very possible that this could get worse in the future as temperatures continue to increase and the possibility of future droughts along with that," Anderson-Ebbs said.