In recent days, Tracy Quinn took a drive along the Pacific Coast Highway to assess the aftermath of the Palisades fire. The normally vibrant waters were clouded with ash, and debris from burnt appliances littered the shoreline. The area looked like a muddy wasteland, with charred homes being battered by high tide that sent toxic remnants swirling into the ocean.
“It was just heartbreaking,” commented Quinn, who leads the environmental group Heal the Bay. Her team has reported ash and debris spreading over 25 miles south of the burned areas in the West Los Angeles region. As cleanup crews tackle what could be hundreds of thousands of tons of hazardous material from the wildfires, researchers are grappling with how these fires have impacted the marine environment.
The Palisades and Eaton fires have obliterated thousands of homes, businesses, and vehicles, turning everyday items into harmful ash laden with pesticides, asbestos, plastics, lead, and other heavy metals. There are rising concerns that much of this could eventually flow into the Pacific Ocean, potentially endangering marine life.
Quinn noted, “We haven’t seen such a concentration of burnt homes and buildings so close to the water before.” The toxic remnants in the water present dangers for surfers and swimmers, particularly after rains that might wash chemicals and debris into the ocean. Scientists are also worried about the long-term impact of urban contaminants on the food chain in the sea.
Recent atmospheric rivers and landslides in the Los Angeles area have only intensified these worries. From the outset of the fires in January, Mara Dias, a manager at the Surfrider Foundation, was concerned about ocean water contamination. Strong winds carried smoke and ash far from the burned zones, and some of these toxic remnants were found as far as 100 miles offshore.
The heavy rainfall poses another immediate threat. Rainwater can carry a mix of pollutants and trash into the ocean via drainage systems and rivers. Dias explained that the runoff could include nutrients, nitrogen, and phosphates derived from the ash of burned materials, along with heavy metals and harmful compounds released during combustion.
Furthermore, the burned landscape is susceptible to landslides and debris flows, which could further pollute the ocean. Burned soil absorbs less rain and may develop a water-repellent crust from the charred remains. With diminished organic material to anchor the soil, the risk of landslides increases.
In response, Los Angeles County officials, with help from other agencies, have erected barriers and sandbags to prevent debris from reaching the beaches. The County Board of Supervisors has recently approved a motion to seek state and federal assistance for beach cleanups, storm runoff preparations, and ocean water testing for potential toxins.
Officials are not only testing the usual pollutants but are also examining levels of total and dissolved metals like arsenic, lead, and aluminum, as well as volatile organic compounds. Studies are underway for microplastics and polycyclic aromatic hydrocarbons (PAHs), which pose risks to both human and marine life. These chemicals, once widely used in products, have been linked to significant health issues, including cancer.
Public health officials have stated that tests conducted on ocean water last month did not indicate immediate health risks, but they still advised beachgoers to steer clear of the water. Researchers are working to determine how far the toxic ash and debris have spread, how quickly they sink, and where they might end up.
While forest fires can introduce important nutrients to the ocean, like iron and nitrogen, which potentially aid phytoplankton growth, the toxic ashes from coastal urban fires could have dire consequences. Dinasquet pointed out, “Reports already indicate significant levels of lead and asbestos in the ash. This is truly harmful to people and likely just as detrimental to marine organisms.”
A major concern remains whether these toxic contaminants will enter the food chain. Researchers plan to examine fish tissue for indications of heavy metals and pollutants, but they acknowledge it will take time to fully understand the impact of such a massive urban fire on the broader ecosystem and our food supply.
Dias emphasized that while the ocean has long been a recipient of land-borne pollution, with disasters like these, “everything becomes more complicated and the situation worsens.”
