Sponsored message
Audience-funded nonprofit news
radio tower icon laist logo
Next Up:
0:00
0:00
Subscribe
  • Listen Now Playing Listen
Climate & Environment

Toxic waste dumped decades ago has drastically altered life on SoCal's sea floor, study finds

A muddy looking cylinder with a white circle around it in brown sand.
A barrel that possibly contained caustic alkaline waste rests on the ocean floor off the coast of Santa Catalina Island. Note the mysterious halo.
(
David Valentine
/
UC Santa Barbara
)

Truth matters. Community matters. Your support makes both possible. LAist is one of the few places where news remains independent and free from political and corporate influence. Stand up for truth and for LAist. Make your year-end tax-deductible gift now.

Listen 0:42
Waste dumped off SoCal coast has drastically altered life on the sea floor, study finds
The waste was likely dumped alongside barrels of DDT discovered in recent years. Its chemical makeup has changed the types of organisms that live on the ocean bottom.

Between the 1930s and 1970s, companies dumped barrels of toxic waste, including DDT, off the coast of Southern California, from Santa Cruz Island south to Mexico.

Listen 0:42
Listen: Researchers find lingering affects of waste dumped from the 1930s through 1970s.

The revelations came to light several years ago, and since then researchers have been investigating the various sites using remotely operated vehicles thousands of feet beneath the surface.

There have long been questions about a specific subset of barrels that looked like they were surrounded by concrete and white halos. On Tuesday, researchers from the Scripps Institution of Oceanography published a paper in the Proceedings of the National Academy of Sciences with a potential explanation.

They believe that the barrels contained caustic waste so alkaline that it changed the chemistry and the microbial makeup of the organisms on the seafloor. What that waste is remains a mystery.

Trending on LAist

Samples taken from around the barrels showed pH levels as high as 12 (normal is 7 to 8) and were dominated by alkalophilic bacteria adapted to high-pH environments, like those around hydrothermal vents. Colonies of bacteria farther from the barrels were far more diverse and consistent with what’s been found in other parts of the area.

Sponsored message

“ We've created these naturally occurring extremophile environments in these little patches in the ocean wherever these barrels landed that had the caustic waste,” said Paul Jensen, professor of microbiology at Scripps and co-author of the study.

A map of the Southern California coast with sites indicating where waste was dumped.
Dumping occurred off the coast of Southern California from Santa Cruz Island to Mexico.
(
Environmental Protection Agency
)

When researchers tested pieces of the concrete-looking stuff, they discovered it was brucite, or magnesium hydroxide, and that the white halos are calcium carbonate, both of which form in high-pH environments.

They estimate it could take thousands of years for these changes to resolve.

You come to LAist because you want independent reporting and trustworthy local information. Our newsroom doesn’t answer to shareholders looking to turn a profit. Instead, we answer to you and our connected community. We are free to tell the full truth, to hold power to account without fear or favor, and to follow facts wherever they lead. Our only loyalty is to our audiences and our mission: to inform, engage, and strengthen our community.

Right now, LAist has lost $1.7M in annual funding due to Congress clawing back money already approved. The support we receive before year-end will determine how fully our newsroom can continue informing, serving, and strengthening Southern California.

If this story helped you today, please become a monthly member today to help sustain this mission. It just takes 1 minute to donate below.

Your tax-deductible donation keeps LAist independent and accessible to everyone.
Senior Vice President News, Editor in Chief

Make your tax-deductible year-end gift today

A row of graphics payment types: Visa, MasterCard, Apple Pay and PayPal, and  below a lock with Secure Payment text to the right