Connect with us

Science

Contributor: Factory farming of fish is brewing pathogens

Published

on

Contributor: Factory farming of fish is brewing pathogens

The federal government recently released new dietary guidelines aimed at “ending the war on protein” and steering Americans toward “real foods” — those with few ingredients and no additives. Seafood plays a starring role. But the fish that health advocates envision appearing on our plates probably won’t be caught in the crystal blue waters we’d like to imagine.

Over the past few decades, the seafood industry has completely revolutionized how it feeds the world. As many wild fish populations have plummeted, hunted to oblivion by commercial fleets, fish farming has become all the rage, and captive-breeding facilities have continually expanded to satiate humanity’s ravenous appetite. Today, the aquaculture sector is a $300-billion juggernaut, accounting for nearly 60% of aquatic animal products used for direct human consumption.

Proponents of aquaculture argue that it helps feed a growing human population, reduces pressure on wild fish populations, lowers costs for consumers and creates new jobs on land. Much of that may be correct. But there is a hidden crisis brewing beneath the surface: Many aquaculture facilities are breeding grounds for pathogens. They’re also a blind spot for public health authorities.

On dry land, factory farming of cows, pigs and chickens is widely reviled, and for good reason: The unsanitary and inhumane conditions inside these facilities contribute to outbreaks of disease, including some that can leap from animals to humans. In many countries, aquaculture facilities aren’t all that different. Most are situated in marine and coastal areas, where fish can be exposed to a sinister brew of human sewage, industrial waste and agricultural runoff. Fish are kept in close quarters — imagine hundreds of adult salmon stuffed into a backyard swimming pool — and inbreeding compromises immune strength. Thus, when one fish invariably falls ill, pathogens spread far and wide throughout the brood — and potentially to people.

Right now, there are only a handful of known pathogens — mostly bacteria, rather than viruses — that can jump from aquatic species to humans. Every year, these pathogens contribute to the 260,000 illnesses in the United States from contaminated fish; fortunately, these fish-borne illnesses aren’t particularly transmissible between people. It’s far more likely that the next pandemic will come from a bat or chicken than a rainbow trout. But that doesn’t put me at ease. The ocean is a vast, poorly understood and largely unmonitored reservoir of microbial species, most of which remain unknown to science. In the last 15 years, infectious diseases — including ones that we’ve known about for decades such as Ebola and Zika — have routinely caught humanity by surprise. We shouldn’t write off the risks of marine microbes too quickly.

Advertisement

My most immediate concern, the one that really makes me sweat, is the emergence of drug-resistant bacteria among farmed fish. Aquaculturists are well aware that their fish often live in a festering cesspool, and so many growers will mix antibiotics — including ones that the World Health Organization considers medically important for people — into fish feed, or dump them straight into water, to avoid the consequences of crowded conditions and prevent rampant illness. It would be more appropriate to use antibiotics in animals only when they are sick.

Because of this overuse for prevention purposes, more antibiotics are used in seafood raised by aquaculture than are used in humans or for other farmed animals per kilogram. Many of these molecules will end up settling in the water or nearby sediment, where they can linger for weeks. In turn, the 1 million individual bacteria found in every drop of seawater will be put to the evolutionary test, and the most antibiotic-resistant will endure.

Numerous researchers have found that drug-resistant strains of bacteria are alarmingly common in the water surrounding aquaculture facilities. In one study, evidence of antibiotic resistance was found in over 80% of species of bacteria isolated from shrimp sold in multiple countries by multiple brands.

Many drug-resistant strains in aquatic animals won’t be capable of infecting humans, but their genes still pose a threat through a process known as horizontal transfer. Bacteria are genetic hoarders. They collect DNA from their environment and store it away in their own genome. Sometimes, they’ll participate in swap meets, trading genes with other bacteria to expand their collections. Beginning in 1991, for example, a wave of cholera infected nearly a million people across Latin America, exacerbated by a strain that may have picked up drug-resistant adaptations while circulating through shrimp farms in Ecuador.

Today, drug-resistant bacteria kill over a million people every year, more than HIV/AIDS. I’ve seen this with my own eyes as a practicing tuberculosis doctor. I am deeply fearful of a future in which the global supply of fish — a major protein source for billions of people — also becomes a source of untreatable salmonella, campylobacter and vibrio. We need safer seafood, and the solutions are already at our fingertips.

Advertisement

Governments need to lead by cracking down on indiscriminate antibiotic use. It is estimated that 70% of all antibiotics used globally are given to farm animals, and usage could increase by nearly 30% over the next 15 years. Regulation to promote prudent use of antibiotics in animals, however, has proven effective in Europe, and sales of veterinary antibiotics decreased by more than 50% across 25 European countries from 2011 to 2022. In the United States, the use of medically important antibiotics in food animals — including aquatic ones — is already tightly regulated. Most seafood eaten in the U.S., however, is imported and therefore beyond the reach of these rules. Indeed, antibiotic-resistance genes have already been identified in seafood imported into the United States. Addressing this threat should be an area of shared interest between traditional public health voices and the “Make America Healthy Again” movement, which has expressed serious concerns about the health effects of toxins.

Public health institutions also need to build stronger surveillance infrastructure — for both disease and antibiotic use — in potential hotspots. Surveillance is the backbone of public health, because good decision-making is impossible without good data. Unfortunately, many countries — including resource-rich countries — don’t robustly track outbreaks of antibiotic-resistant pathogens in farmed animals, nor do they share data on antibiotic use in farmed animals. By developing early warning systems for detecting antibiotic resistance in aquatic environments, rapid response efforts involving ecologists, veterinarians and epidemiologists can be mobilized as threats arise to avert public health disasters.

Meanwhile, the aquaculture industry should continue to innovate. Genetic technologies and new vaccines can help prevent rampant infections, while also improving growth efficiency that could allow for more humane conditions.

For consumers, the best way to stay healthy is simple: Seek out antibiotic-free seafood at the supermarket, and cook your fish (sorry, sushi lovers).

There’s no doubt that aquaculture is critical for feeding a hungry planet. But it must be done responsibly.

Advertisement

Neil M. Vora is a practicing physician and the executive director of the Preventing Pandemics at the Source Coalition.

Science

Commentary: My toothache led to a painful discovery: The dental care system is full of cavities as you age

Published

on

Commentary: My toothache led to a painful discovery: The dental care system is full of cavities as you age

I had a nagging toothache recently, and it led to an even more painful revelation.

If you X-rayed the state of oral health care in the United States, particularly for people 65 and older, the picture would be full of cavities.

“It’s probably worse than you can even imagine,” said Elizabeth Mertz, a UC San Francisco professor and Healthforce Center researcher who studies barriers to dental care for seniors.

Mertz once referred to the snaggletoothed, gap-filled oral health care system — which isn’t really a system at all — as “a mess.”

But let me get back to my toothache, while I reach for some painkiller. It had been bothering me for a couple of weeks, so I went to see my dentist, hoping for the best and preparing for the worst, having had two extractions in less than two years.

Advertisement

Let’s make it a trifecta.

My dentist said a molar needed to be yanked because of a cellular breakdown called resorption, and a periodontist in his office recommended a bone graft and probably an implant. The whole process would take several months and cost roughly the price of a swell vacation.

I’m lucky to have a great dentist and dental coverage through my employer, but as anyone with a private plan knows, dental insurance can barely be called insurance. It’s fine for cleanings and basic preventive routines. But for more complicated and expensive procedures — which multiply as you age — you can be on the hook for half the cost, if you’re covered at all, with annual payout caps in the $1,500 range.

“The No. 1 reason for delayed dental care,” said Mertz, “is out-of-pocket costs.”

So I wondered if cost-wise, it would be better to dump my medical and dental coverage and switch to a Medicare plan that costs extra — Medicare Advantage — but includes dental care options. Almost in unison, my two dentists advised against that because Medicare supplemental plans can be so limited.

Advertisement

Sorting it all out can be confusing and time-consuming, and nobody warns you in advance that aging itself is a job, the benefits are lousy, and the specialty care you’ll need most — dental, vision, hearing and long-term care — are not covered in the basic package. It’s as if Medicare was designed by pranksters, and we’re paying the price now as the percentage of the 65-and-up population explodes.

So what are people supposed to do as they get older and their teeth get looser?

A retired friend told me that she and her husband don’t have dental insurance because it costs too much and covers too little, and it turns out they’re not alone. By some estimates, half of U.S. residents 65 and older have no dental insurance.

That’s actually not a bad option, said Mertz, given the cost of insurance premiums and co-pays, along with the caps. And even if you’ve got insurance, a lot of dentists don’t accept it because the reimbursements have stagnated as their costs have spiked.

But without insurance, a lot of people simply don’t go to the dentist until they have to, and that can be dangerous.

Advertisement

“Dental problems are very clearly associated with diabetes,” as well as heart problems and other health issues, said Paul Glassman, associate dean of the California Northstate University dentistry school.

There is one other option, and Mertz referred to it as dental tourism, saying that Mexico and Costa Rica are popular destinations for U.S. residents.

“You can get a week’s vacation and dental work and still come out ahead of what you’d be paying in the U.S.,” she said.

Tijuana dentist Dr. Oscar Ceballos told me that roughly 80% of his patients are from north of the border, and come from as far away as Florida, Wisconsin and Alaska. He has patients in their 80s and 90s who have been returning for years because in the U.S. their insurance was expensive, the coverage was limited and out-of-pocket expenses were unaffordable.

“For example, a dental implant in California is around $3,000-$5,000,” Ceballos said. At his office, depending on the specifics, the same service “is like $1,500 to $2,500.” The cost is lower because personnel, office rent and other overhead costs are cheaper than in the U.S., Ceballos said.

Advertisement

As we spoke by phone, Ceballos peeked into his waiting room and said three patients were from the U.S. He handed his cellphone to one of them, San Diegan John Lane, who said he’s been going south of the border for nine years.

“The primary reason is the quality of the care,” said Lane, who told me he refers to himself as 39, “with almost 40 years of additional” time on the clock.

Ceballos is “conscientious and he has facilities that are as clean and sterile and as medically up to date as anything you’d find in the U.S.,” said Lane, who had driven his wife down from San Diego for a new crown.

“The cost is 50% less than what it would be in the U.S.,” said Lane, and sometimes the savings is even greater than that.

Come this summer, Lane may be seeing even more Californians in Ceballos’ waiting room.

Advertisement

“Proposed funding cuts to the Medi-Cal Dental program would have devastating impacts on our state’s most vulnerable residents,” said dentist Robert Hanlon, president of the California Dental Assn.

Dental student Somkene Okwuego smiles after completing her work on patient Jimmy Stewart, 83, who receives affordable dental work at the Ostrow School of Dentistry of USC on the USC campus in Los Angeles on February 26, 2026.

(Genaro Molina / Los Angeles Times)

Under Proposition 56’s tobacco tax in 2016, supplemental reimbursements to dentists have been in place, but those increases could be wiped out under a budget-cutting proposal. Only about 40% of the state’s dentists accept Medi-Cal payments as it is, and Hanlon told me a CDA survey indicates that half would stop accepting Medi-Cal patients and many others will accept fewer patients.

Advertisement

“It’s appalling that when the cost of providing healthcare is at an all-time high, the state is considering cutting program funding back to 1990s levels,” Hanlon said. “These cuts … will force patients to forgo or delay basic dental care, driving completely preventable emergencies into already overcrowded emergency departments.”

Somkene Okwuego, who as a child in South L.A. was occasionally a patient at USC’s Herman Ostrow School of Dentistry clinic, will graduate from the school in just a few months.

I first wrote about Okwuego three years ago, after she got an undergrad degree in gerontology, and she told me a few days ago that many of her dental patients are elderly and have Medi-Cal or no insurance at all. She has also worked at a Skid Row dental clinic, and plans after graduation to work at a clinic where dental care is free or discounted.

Okwuego said “fixing the smiles” of her patients is a privilege and boosts their self-image, which can help “when they’re trying to get jobs.” When I dropped by to see her Thursday, she was with 83-year-old patient Jimmy Stewart.

Stewart, an Army veteran, told me he had trouble getting dental care at the VA and had gone years without seeing a dentist before a friend recommended the Ostrow clinic. He said he’s had extractions and top-quality restorative care at USC, with the work covered by his Medi-Cal insurance.

Advertisement

I told Stewart there could be some Medi-Cal cuts in the works this summer.

“I’d be screwed,” he said.

Him and a lot of other people.

steve.lopez@latimes.com

Advertisement
Continue Reading

Science

Diablo Canyon clears last California permit hurdle to keep running

Published

on

Diablo Canyon clears last California permit hurdle to keep running

Central Coast Water authorities approved waste discharge permits for Diablo Canyon nuclear plant Thursday, making it nearly certain it will remain running through 2030, and potentially through 2045.

The Pacific Gas & Electric-owned plant was originally supposed to shut down in 2025, but lawmakers extended that deadline by five years in 2022, fearing power shortages if a plant that provides about 9 percent the state’s electricity were to shut off.

In December, Diablo Canyon received a key permit from the California Coastal Commission through an agreement that involved PG&E giving up about 12,000 acres of nearby land for conservation in exchange for the loss of marine life caused by the plant’s operations.

Today’s 6-0 vote by the Central Coast Regional Water Board approved PG&E’s plans to limit discharges of pollutants into the water and continue to run its “once-through cooling system.” The cooling technology flushes ocean water through the plant to absorb heat and discharges it, killing what the Coastal Commission estimated to be two billion fish each year.

Advertisement

The board also granted the plant a certification under the Clean Water Act, the last state regulatory hurdle the facility needed to clear before the federal Nuclear Regulatory Commission (NRC) is allowed to renew its permit through 2045.

The new regional water board permit made several changes since the last one was issued in 1990. One was a first-time limit on the chemical tributyltin-10, a toxic, internationally-banned compound added to paint to prevent organisms from growing on ship hulls.

Additional changes stemmed from a 2025 Supreme Court ruling that said if pollutant permits like this one impose specific water quality requirements, they must also specify how to meet them.

The plant’s biggest water quality impact is the heated water it discharges into the ocean, and that part of the permit remains unchanged. Radioactive waste from the plant is regulated not by the state but by the NRC.

California state law only allows the plant to remain open to 2030, but some lawmakers and regulators have already expressed interest in another extension given growing electricity demand and the plant’s role in providing carbon-free power to the grid.

Advertisement

Some board members raised concerns about granting a certification that would allow the NRC to reauthorize the plant’s permits through 2045.

“There’s every reason to think the California entities responsible for making the decision about continuing operation, namely the California [Independent System Operator] and the Energy Commission, all of them are sort of leaning toward continuing to operate this facility,” said boardmember Dominic Roques. “I’d like us to be consistent with state law at least, and imply that we are consistent with ending operation at five years.”

Other board members noted that regulators could revisit the permits in five years or sooner if state and federal laws changes, and the board ultimately approved the permit.

Advertisement
Continue Reading

Science

Deadly bird flu found in California elephant seals for the first time

Published

on

Deadly bird flu found in California elephant seals for the first time

The H5N1 bird flu virus that devastated South American elephant seal populations has been confirmed in seals at California’s Año Nuevo State Park, researchers from UC Davis and UC Santa Cruz announced Wednesday.

The virus has ravaged wild, commercial and domestic animals across the globe and was found last week in seven weaned pups. The confirmation came from the U.S. Department of Agriculture’s National Veterinary Services Laboratory in Ames, Iowa.

“This is exceptionally rapid detection of an outbreak in free-ranging marine mammals,” said Professor Christine Johnson, director of the Institute for Pandemic Insights at UC Davis’ Weill School of Veterinary Medicine. “We have most likely identified the very first cases here because of coordinated teams that have been on high alert with active surveillance for this disease for some time.”

Since last week, when researchers began noticing neurological and respoiratory signs of the disease in some animals, 30 seals have died, said Roxanne Beltran, a professor of ecology and evolutionary biology at UC Santa Cruz. Twenty-nine were weaned pups and the other was an adult male. The team has so far confirmed the virus in only seven of the dead pups.

Infected animals often have tremors convulsions, seizures and muscle weakness, Johnson said.

Advertisement

Beltran said teams from UC Santa Cruz, UC Davis and California State Parks monitor the animals 260 days of the year, “including every day from December 15 to March 1” when the animals typically come ashore to breed, give birth and nurse.

The concerning behavior and deaths were first noticed Feb. 19.

“This is one of the most well-studied elephant seal colonies on the planet,” she said. “We know the seals so well that it’s very obvious to us when something is abnormal. And so my team was out that morning and we observed abnormal behaviors in seals and increased mortality that we had not seen the day before in those exact same locations. So we were very confident that we caught the beginning of this outbreak.”

In late 2022, the virus decimated southern elephant seal populations in South America and several sub-Antarctic Islands. At some colonies in Argentina, 97% of pups died, while on South Georgia Island, researchers reported a 47% decline in breeding females between 2022 and 2024. Researchers believe tens of thousands of animals died.

More than 30,000 sea lions in Peru and Chile died between 2022 and 2024. In Argentina, roughly 1,300 sea lions and fur seals perished.

Advertisement

At the time, researchers were not sure why northern Pacific populations were not infected, but suspected previous or milder strains of the virus conferred some immunity.

The virus is better known in the U.S. for sweeping through the nation’s dairy herds, where it infected dozens of dairy workers, millions of cows and thousands of wild, feral and domestic mammals. It’s also been found in wild birds and killed millions of commercial chickens, geese and ducks.

Two Americans have died from the virus since 2024, and 71 have been infected. The vast majority were dairy or commercial poultry workers. One death was that of a Louisiana man who had underlying conditions and was believed to have been exposed via backyard poultry or wild birds.

Scientists at UC Santa Cruz and UC Davis increased their surveillance of the elephant seals in Año Nuevo in recent years. The catastrophic effect of the disease prompted worry that it would spread to California elephant seals, said Beltran, whose lab leads UC Santa Cruz’s northern elephant seal research program at Año Nuevo.

Johnson, the UC Davis researcher, said the team has been working with stranding networks across the Pacific region for several years — sampling the tissue of birds, elephant seals and other marine mammals. They have not seen the virus in other California marine mammals. Two previous outbreaks of bird flu in U.S. marine mammals occurred in Maine in 2022 and Washington in 2023, affecting gray and harbor seals.

Advertisement

The virus in the animals has not yet been fully sequenced, so it’s unclear how the animals were exposed.

“We think the transmission is actually from dead and dying sea birds” living among the sea lions, Johnson said. “But we’ll certainly be investigating if there’s any mammal-to-mammal transmission.”

Genetic sequencing from southern elephant seal populations in Argentina suggested that version of the virus had acquired mutations that allowed it to pass between mammals.

The H5N1 virus was first detected in geese in China in 1996. Since then it has spread across the globe, reaching North America in 2021. The only continent where it has not been detected is Oceania.

Año Nuevo State Park, just north of Santa Cruz, is home to a colony of some 5,000 elephant seals during the winter breeding season. About 1,350 seals were on the beach when the outbreak began. Other large California colonies are located at Piedras Blancas and Point Reyes National Sea Shore. Most of those animals — roughly 900 — are weaned pups.

Advertisement

It’s “important to keep this in context. So far, avian influenza has affected only a small proportion of the weaned at this time, and there are still thousands of apparently healthy animals in the population,” Beltran said in a press conference.

Public access to the park has been closed and guided elephant seal tours canceled.

Health and wildlife officials urge beachgoers to keep a safe distance from wildlife and keep dogs leashed because the virus is contagious.

Advertisement
Continue Reading
Advertisement

Trending