Scripps researchers discover what lies within mysterious haloed barrels on the seafloor

[Zorro]

The leaked substance has created an extreme environment where little to no life can survive.



When researchers discovered several eroding barrels on the seafloor off the coast of Southern California with an eerie, white halo encircling them, it wasn’t immediately clear what they held.

The barrels represent just a few of the thousands of barrels and barrel-sized objects that litter the seafloor in the San Pedro Basin, a stretch of ocean between Long Beach and Santa Catalina Island.

The area is significantly polluted with DDT, a chemical used as an insecticide that was banned in 1972. While researchers thought these haloed barrels may have carried DDT waste, they didn’t know for sure.

Until now. New research published Tuesday from UC San Diego’s Scripps Institution of Oceanography found that the barrels with halos contain caustic alkaline waste — a highly corrosive material that has been leaking out of the barrels for decades.

The leaked substance, which will take thousands of years to break down, has created an extreme environment surrounding the barrels where little to no life can survive — similar to deep sea hydrothermal vents, but not naturally found off the California coast.

https://www.sandiegouniontribune.com/2025/09/11/scripps-researchers-discover-what-lies-within-mysterious-haloed-barrels-on-the-seafloor/