Scientists are racing to discover the depth of ocean damage sparked by the LA wildfires

LOS ANGELES (AP) — On a recent Sunday, Tracy Quinn drove down the Pacific Coast Highway to assess damage wrought upon the coastline by the Palisades Fire.

The water line was darkened by ash. Burnt remnants of washing machines and dryers and metal appliances were strewn about the shoreline. Sludge carpeted the water's edge. Waves during high tide lapped onto charred homes, pulling debris and potentially toxic ash into the ocean as they receded.

“It was just heartbreaking,” said Quinn, president and CEO of the environmental group Heal the Bay, whose team has reported ash and debris some 25 miles (40 kilometers) south of the Palisades burn area west of Los Angeles.

As crews work to remove potentially hundreds of thousands of tons of hazardous materials from the Los Angeles wildfires, researchers and officials are trying to understand how the fires on land have impacted the sea. The Palisades and Eaton fires scorched thousands of homes, businesses, cars and electronics, turning everyday items into hazardous ash made of pesticides, asbestos, plastics, lead, heavy metals and more.

Since much of it could end up in the Pacific Ocean, there are concerns and many unknowns about how the fires could affect life under the sea.

“We haven't seen a concentration of homes and buildings burned so close to the water," Quinn said.

Fire debris and potentially toxic ash could make the water unsafe for surfers and swimmers, especially after rainfall that can transport chemicals, trash and other hazards into the sea. Longer term, scientists worry if and how charred urban contaminants will affect the food supply.

The atmospheric river and mudslides that pummeled the Los Angeles region last week exacerbated some of those fears.

When the fires broke out in January, one of Mara Dias' first concerns was ocean water contamination. Strong winds were carrying smoke and ash far beyond the blazes before settling at sea, said the water quality manager for the Surfrider Foundation, an environmental nonprofit.

Scientists on board a research vessel during the fires detected ash and waste on the water as far as 100 miles (161 kilometers) offshore, said marine ecologist Julie Dinasquet with the University of California, San Diego’s Scripps Institution of Oceanography. Things like twigs and shard. They described the smell as electronics burning, she recalled, “not like a nice campfire.”

Runoff from rains also are a huge and immediate concern. Rainfall picks up contaminants and trash while flushing toward the sea through a network of drains and rivers. That runoff could contain “a lot of nutrients, nitrogen and phosphate that end up in the ash of the burn material that can get into the water,” said Dias, as well as "heavy metals, something called PAHs, which are given off when you burn different types of fuel.”

Mudslides and debris flows in the Palisades Fire burn zone also can dump more hazardous waste into the ocean. After fires, the soil in burn scars is less able to absorb rainfall and can develop a layer that repels water from the remains of seared organic material. When there is less organic material to hold the soil in place, the risks of mudslides and debris flows increase.

Los Angeles County officials, with help from other agencies, have set thousands of feet of concrete barriers, sandbags, silt socks and more to prevent debris from reaching beaches. The LA County Board of Supervisors also recently passed a motion seeking state and federal help to expand beach clean ups, prepare for storm runoff and test ocean water for potential toxins and chemicals, among other things.

Beyond the usual samples, state water officials and others are testing for total and dissolved metals such as arsenic, lead and aluminum and volatile organic compounds.

They also are sampling for microplastics, polycyclic aromatic hydrocarbons, or PAHs, that are harmful to human and aquatic life, and polychlorinated biphenyls, or PCBs, a group of man-made chemicals shown to cause cancer in animals and other serious health effects. Now banned from being manufactured, they were used in products like pigments, paints and electrical equipment.

County public health officials said chemical tests of water samples last month did not raise health concerns, so they downgraded one beach closure to an ocean water advisory. Beachgoers were still advised to stay out of the water.

Dinasquet and colleagues are working to understand how far potentially toxic ash and debris dispersed across the ocean, how deep and how fast they sunk and, over time, where it ends up.

Forest fires can deposit important nutrients like iron and nitrogen into the ocean ecosystem, boosting the growth of phytoplankton, which can create a positive, cascading effect across the ecosystem. But the potentially toxic ash from urban coastal fires could have dire consequences, Dinasquet said.

“Reports are already showing that there was a lot of lead and asbestos in the ash,” she added. "This is really bad for people so its probably also very bad for the marine organisms."

A huge concern is whether toxic contaminants from the fire will enter the food chain. Researchers plan to take tissue fragments from fish for signs of heavy metals and contaminants. But they say it will take a while to understand how a massive urban fire will affect the larger ecosystem and our food supply.

Dias noted the ocean has long taken in pollution from land, but with fires and other disasters, “everything is compounded and the situation is even more dire.”

The Associated Press receives support from the Walton Family Foundation for coverage of water and environmental policy. The AP is solely responsible for all content. For all of AP’s environmental coverage, visit apnews.com/hub/climate-and-environment.

FILE - Properties damaged by the Palisades Fire are seen from a coastline perspective Friday, Jan. 17, 2025 in Malibu, Calif. (AP Photo/Carolyn Kaster, File)

FILE - Beachfront properties are burned by the Palisades Fire, Sunday, Jan. 12, 2025 in Malibu, Calif. (AP Photo/Mark J. Terrill, File)

FILE - Tony Lai, center, rakes through the remains of his fire-ravaged beachfront property with his wife Everlyn in the aftermath of the Palisades Fire Tuesday, Jan. 28, 2025 in Malibu, Calif. (AP Photo/Jae C. Hong, File)

FILE - An aerial view shows the devastation by the Palisades Fire Thursday, Jan. 16, 2025 in Malibu, Calif. (AP Photo/Jae C. Hong, File)

FILE - An aerial view shows the devastation from the Palisades Fire on beachfront homes Wednesday, Jan. 15, 2025 in Malibu, Calif. (AP Photo/Jae C. Hong, File)

When NBC carried the Kentucky Derby for the first time in 2001, the broadcast lasted only 90 minutes.

On Saturday, when it carries the Run for the Roses for the 25th time, 90 minutes wouldn’t be enough for all the feature stories that will run leading up to post time.

NBC Sports will present 12 1/2 hours of coverage across two days on NBC, USA Network and Peacock. There will be five hours for Friday’s Kentucky Oaks on USA Network and Peacock. Saturday’s coverage begins on USA Network at noon ET before moving to NBC at 2:30 p.m. while Peacock will stream all 7 1/2 hours.

“So much has changed since we first started in 2001. At that time, we thought 90 minutes to cover a two-minute race. How are we going to fill all this time? Now we are still trying to figure out how we’re going to get this story in and that story in because there are so many great stories to tell,” said Donna Brothers, the only member of the broadcast team involved with all 25 Derbys on NBC.

NBC has done five hours of coverage on the main network on Derby Day since 2018. Sam Flood, the executive producer and president of NBC Sports Production, said the true evolution behind adding more hours while making the coverage appeal to a cross-section of viewers began after he produced his first Derby in 2006.

“I remember getting done with the show, which I think was two hours. I kept thinking, we can do so much more,” Flood said. “There are so many assets here that should be showcased, and that’s when we started blowing it out, adding more hours and slowly shifting more and more hours on to NBC and off the cable platforms.”

The expansion has also included the Kentucky Oaks. It started airing on Bravo in 2009 before moving to the NBC Sports Network and then USA Network.

The Derby broadcast has evolved into one of the most diverse sports events that NBC does yearly and is on par with the Olympics, which it carries once every two years, and the Super Bowl, which it has once every four years.

It also might be the only place where a viewer can see fashion, recipes from one of the hosts of Bravo’s “Top Chef,” and race predictions from NBC News chief data analyst Steve Kornacki.

Mike Tirico, the host of NBC’s coverage since 2017, said doing the Derby served as good preparation for hosting the Olympics as well as a stint as a guest host on the “Today” show last week.

“My time doing the Derby helped me to do the ‘Today’ show last week, not vice versa,” he said. “This show is so cool. It goes from speed figures to fascinators. It goes from betting to bourbon. We cover it all in the five hours with a great team of people who dive in and take their space and own it. We all build towards the race. The audience does the same.”

Tirico succeeded Tom Hammond as host. Hammond, a University of Kentucky graduate, was a guiding force around NBC’s early coverage and introducing the sport’s most prominent personalities to viewers.

Lindsay Schanzer, the supervising producer of NBC’s coverage, said one of the advantages of having nearly 4 1/2 hours leading up to post time at 6:57 p.m. ET is the chance to focus on the stories of the 20 horses that will line up in the starting gate.

Among the stories planned are the return of trainer Bob Baffert — who served a three-year suspension after Medina Spirit failed a drug test — 89-year-old trainer D. Wayne Lukas and Michael McCarthy, the trainer of prerace favorite Journalism, whose family was displaced from home in Southern California due to the wildfires.

Because of the many different topics in the broadcast, Schanzer has an interesting approach in how she books the coverage with what she calls a colors document, where each element of coverage has its own color.

“I like to look at it from a broad perspective to make sure there’s not too much of one color in one area, and every color is kind of represented across the show so that if you’re watching it, you’re getting a little bit of a taste of everything,” she said. “One color could be a fashion element, one could be Kornacki’s insights, one could be an interview with a horseman. I try to look at it in a holistic way like that.”

The approach has certainly worked. Last year’s broadcast averaged 16.7 million viewers, the largest Derby audience since 1989. That included an average minute audience of 714,000 streaming on Peacock.

Overall, 11 of the past 15 Derbies held in May have averaged at least 15 million.

“We’ve had all kinds of things happen (since 2001), and that’s what’s so unique about the sport, but specifically about the Derby,” said Jon Miller, NBC Sports president of acquisitions and partnerships. “You have 20 horses that come into that gate and long shots that can pull off the upset. You have favorites, you have great ownership stories, and you have legendary trainers. Who knows who is going to surprise this year? But that’s what’s great about it.”

AP horse racing: https://apnews.com/hub/horse-racing and Derby coverage: https://apnews.com/hub/kentucky-derby

Horses workout at Churchill Downs Wednesday, April 30, 2025, in Louisville, Ky. (AP Photo/Charlie Riedel)