The Brief

Like a priceless painting, the beautiful blue and green swirl in a lake or pond presents a look-don’t-touch kind of situation.

It’s the work of proliferating cyanobacteria, also known as blue-green algae, which produces toxins that are poisonous to humans and other animals, especially when blooms corrupt freshwater supplies. These toxins, which the microbes evolved to deter herbivores, are linked to ALS and Parkinson’s disease, plus muscle paralysis and liver and kidney failure. One of the toxins, anatoxin-a, is known as Very Fast Death Factor, in case you were doubting that toxicity.

It seemed a shame, then, that a highly nutritious fern called Azolla — that green mat ducks eat on ponds — long ago made a pact with a species of cyanobacteria, an “endocyanobiont.” Living inside the fern, the microbes get shelter, and provide the plant with essential nitrogen in return.

Lately, scientists have been campaigning to turn the fast-growing Azolla into a food of the future. Others envision it becoming both a sustainable biofuel and a fertilizer that captures carbon. But these ideas aren’t likely to get very far if the cyanobacteria living within end up being highly toxic.

Azolla as food

A new paper suggests that Azolla may find its way to plates one day: An international team of researchers discovered that endocyanobiont is no typical cyanobacteria. “The cyanobacteria that lives in Azolla doesn’t produce any of these toxins, and it doesn’t even have the genes required to create those toxins,” said Daniel Winstead, a Penn State research technologist and coauthor of the paper. “So that takes one of those barriers away towards its use as food or even livestock feed.”

This is not to say that anyone should find a local pond, skim off the Azolla, and eat it by the handful. Other research groups need to confirm that Azolla is fully nontoxic and safe for consumption before an industry can develop and produce the plant for food. Winstead’s previous research found that while some species of Azolla are high in harmful polyphenols, a species native to the southeastern United States called Carolina Azolla has much lower levels that are further lowered to safe amounts by cooking. Azolla is also high in protein and nutrients like potassium, zinc, iron, and calcium.

Azolla and the cyanobacteria it harbors have co-evolved a mutually beneficial relationship. Floating out in the open, other cyanobacteria species synthesize toxins to ward off hungry fish. “For the cyanobacteria to live within the Azolla, it can’t produce those toxins or it’d also kill the plant,” Winstead said. “So at some point, it didn’t have those genes anymore, and that’s unique among cyanobacteria.”

Azolla has a valuable resource: nitrogen

In return for providing the microbes housing, the Azolla gets an extremely valuable resource: nitrogen. Plants need that element to thrive, but not many species can pull it from the atmosphere themselves. So-called “nitrogen-fixers,” such as beans and clovers, rely on bacteria in their roots to process nitrogen into something the plant can use to grow. The endocyanobiont does the same for Azolla, helping supercharge the growth that allows the plant to double its biomass as quickly as every two days.

Winstead said that some smallholder farmers already use Azolla as fertilizer, and now that the cyanobacteria are confirmed to be nontoxic, perhaps the technique can spread. With that natural source of nitrogen, farmers would be less reliant on synthetic fertilizers, whose production and use spews greenhouse gases and pollutes rivers and lakes. Azolla could also be used as livestock feed, as some farmers are already doing if they can’t afford traditional feed for cattle and poultry.

Back in the 1980s and ‘90s, farmers in China managed to exploit Azolla for both purposes. They grew Azolla in their flooded rice paddies, added fish that fed on the plants, then ate the fish. But it was a difficult process. It was labor-intensive to grow, since farmers needed to separate the fishes before applying herbicides or pesticides. When the fields drained, crews worked the Azolla into the soils as a fertilizer, but that was labor-intensive, too. 

While Azolla can fix its own nitrogen thanks to its cyanobacteria, it needed applications of phosphorus to really get growing in rice paddies. “There is no free lunch,” said Jagdish Ladha, a soil scientist and agronomist at the University of California, Davis, who wasn’t involved in the new paper. Those farmers in China switched to using cheap synthetic fertilizers instead. But the idea behind industrializing the production of Azolla would be to produce the plant at a larger scale, then conveniently package it as fertilizer or livestock feed.

Azolla as biofuel

Beyond its potential in farming, Azolla could also become a biofuel, according to Winstead, much as corn has been used to make biodiesel. That fuel would be close to carbon-neutral: As the plant grows, it sequesters carbon; burning the biofuel would then release that carbon back into the atmosphere. By incorporating Azolla into soils as fertilizer, farmers would put still more carbon into the ground.

Humans might also shape Azolla like they’ve modified other crops like wheat and corn, selectively breeding the most desired traits, such as bigger grains. “There’s a lot of potential for Azolla to go through that process,” Winstead said, “whether it’s creating a variation of Azolla that tastes the best, or it’s a variation of Azolla that has the most vitamins or the most protein, or maybe the best nitrogen-fixing ability.”

The Los Angeles County Board of Supervisors has rejected a proposal that would have let tenants across the county fall behind by about three months' worth of rent and still have local protections from eviction.

Supporters said the rules would have helped immigrants stay housed after losing income because of federal immigration raids.

Only one of the county’s five supervisors supported the expanded eviction protections. With none of the other four willing to second the motion in Tuesday’s meeting, the proposal died before it ever came to a vote.

The proposal failed after an hour of impassioned public comment from both renters and landlords. Onlookers chanted “cowards” as the board cleared the room for closed session.

Would the rules have been challenged in court?

Supervisor Lindsey Horvath, who put forward the proposal, said earlier in the meeting that expanding eviction protections would have been an appropriate way to help the county’s nearly one million undocumented immigrants.

Anticipating potential lawsuits to strike down the proposed ordinance, Horvath said, “I understand there is legal risk. There is in everything we do. Just like the risk undocumented Angelenos take by going outside their homes every day.”

Landlords spoke forcefully against the proposed rules. They said limiting evictions would saddle property owners with the cost of supporting targeted immigrant households.

“This proposed ordinance is legalized theft and will cause financial devastation to small housing providers,” said Julie Markarian with the Apartment Owners Association of California.

Horvath’s proposal would have built on an existing protection for renters in unincorporated parts of L.A. County, such as East L.A., Altadena and City Terrace. Under the current rules, renters can fall behind by up to one month’s worth of “fair market rent” (an amount determined by the U.S. Housing and Urban Development Department) and still be legally protected from eviction.

Protections won’t go countywide

Last week, county leaders voted to explore increasing that threshold to two months. But Horvath wanted to go further by increasing the limit to three months and making it apply countywide, not just in unincorporated areas.

Tenant advocates said family breadwinners have been detained during federal immigration raids, and other immigrants are afraid to go to their workplaces, causing families to scramble to keep up with the region’s high rents.

“Immigrant tenants are experiencing a profound financial crisis,” said Rose Lenehan, an organizer with the L.A. Tenants Union. “This protection is the bare minimum that we need to keep people housed and keep people from having to choose whether to stay in this county with their families and with their communities or self deport or face homelessness.”

A report published this week by the L.A. Economic Development Corporation found that 82% of surveyed small business owners said they’d been negatively affected by federal immigration actions. About a quarter of those surveyed said they had temporarily closed their businesses because of community concerns.

The Los Angeles County Board of Supervisors on Tuesday placed on the June ballot a proposed temporary half-cent sales tax increase to fund the county’s struggling health care system, which has been hit hard by federal funding cuts.

If passed by voters, the increase would bring the county’s tax rate to 10.25%. It is projected to raise one billion dollars annually over five years.

The tax would expire in five years.

The background

County health officials said Tuesday that President Donald Trump’s “One Big Beautiful Bill” will cut $2.4 billion from county health programs over three years, threatening closure of some of the county’s 24 clinics and an array of public health programs.

Supervisor Holly Mitchell, who co-authored the proposal, said the county faced a “federally imposed crisis” that in the absence of state action, could only be addressed by raising taxes on county residents.

“This motion gives the voters a choice, given the stark realities that our county is facing,” Mitchell said.

The vote was 4-1, with Supervisor Kathryn Barger the lone dissenter. Barger is the board’s sole Republican. She worried shoppers would go to Orange County, where the sales tax is 7.75%. She also said the state should take the lead on addressing federal funding cuts to county health care systems.

Public reaction

More than 700 people showed up Tuesday to speak out on the proposal. Health care providers pleaded with the board to place the measure on the ballot, saying federal funding cuts to Medi-Cal had hit them hard.

“This is a crisis,” said Louise McCarthy, president and CEO of the Community Clinic Association of L.A. County. “Medi-Cal accounts for over half of clinic funding. So these changes will lead to clinic closures, longer wait times, overcrowded E.R.’s and higher costs for the county.” 

Others opposed any plan that would increase the sales tax.

“Our city is opposed to the adding of this regressive tax to overtaxed residents and making it even more difficult for cities, especially small cities, to pay for the increasing cost of basic resident services,” said Rolling Hills Mayor Bea Dieringer. “The county needs to tighten its belt further.”

Details on the proposed plan

Under the plan, up to 47% of revenue generated will be used by the Department of Health Services to fund nonprofit health care providers to furnish no-cost or reduced-cost care to low-income residents who do not have health insurance. 

Twenty-two percent would provide financial support to the county’s Department of Health Services to safeguard its public hospital and clinic services. Ten percent would be allocated to the Department of Public Health to support core public health functions and the awarding of grants to support health equity.

The rest would be sprinkled across the health care system, including to support nonprofit safety net hospitals and for school-based health needs and programs.

A last-minute amendment by Supervisor Lindsey Horvath set aside 5% of funding for Planned Parenthood.

The spending would be monitored by a nine-member committee but ultimately would be up to the discretion of the Board of Supervisors.