by It’s not just toxic chemical waste and mysterious barrels that litter the seabed off the coast of Los Angeles. Oceanographers have now discovered what appears to be a huge military munitions dumping ground.
As part of an unprecedented effort to map and better understand the history of ocean dumping in the region, scientists have discovered dozens of discarded munitions boxes, smoke floats and depth charges lurking 3,000 feet underwater. Most appear to be from the Second World War era, and it remains unclear what risk they may pose to the environment.
“We started finding the same things by the dozens, if not hundreds, consistently… It took a few days to really understand what we were seeing on the sea floor,” said Eric Terrill, who led the deep-ocean survey with Sophia Merrifield at UC San Diego’s Scripps Institution of Oceanography. “Who knew that right in our backyard, the more you look, the more you find.”
Among the munitions weapons documented were the Hedgehog and Mark 9 depth charges – explosives typically dropped from warships to attack submarines. Researchers also identified Mark 1 smoke floats — chemical smoke munitions released by ships to mark locations or conceal their movements.
These results, published on Friday, build on a stunning 2021 sonar survey that identified thousands of barrel-like objects between Los Angeles and Catalina Island. Merrifield and Terrill’s research team, aided by a rare partnership with the US Navy Lifeguards, launched again last year – this time with even more advanced sonar technology, as well as a high-definition deep-sea camera that sought visual identification. as many things as possible.
Dumping military waste at sea is not uncommon in recent years, but this forgotten history of ocean dumping continues to affect our environment today. (Actually a practice bomb from World War II, which was landed last week in Santa Cruz County after a very high tide.)
The US Navy has confirmed that what the Scripps team found “was likely the result of World War II-era disposal practices” and noted in a statement that “disposal of munitions at sea was permitted at this location at that time to ensure safe disposal when naval vessels returned to a US port.” Officials are now reviewing the latest Scripps findings and “determining the best path forward to ensure that the health risk is addressed to manage people and the environment appropriately.”
Public interest in the legacy of the Southern California ocean dump has grown since the Los Angeles Times reported that up to half a million barrels of DDT acid waste were unaccounted for in the deep ocean, according to old shipping logs and UC Santa. Barbara’s study provided the first real insight into how the Los Angeles coast became an industrial dumping ground.
Dozens of marine scientists and ecotoxicologists have since met regularly to discuss the data gaps in our understanding of DDT, a pesticide (banned in 1972) produced mostly in Los Angeles and so powerful it poisoned birds and fish . Congress — at the urging of US Senator Alex Padilla (D-Calif.) and the late Senator Dianne Feinstein (D-Calif.) — allocated more than $11 million to work on the issue, and Gov. Gavin Newsom also further boosted research with an additional $5.6 million.
In another recent plot twist, an exhaustive historical investigation by the US Environmental Protection Agency concluded that the pesticide waste was not actually in barrels—instead, the chemicals were poured directly into the ocean from giant tank barges. In the process of digging up old records, the EPA also discovered that 13 other areas off the coast of Southern California had been approved from the 1930s to the 1970s to dump military explosives, radioactive waste and various refinery byproducts—including 3 million. metric tons of petroleum waste.
Read more: History of DDT ocean dumping off LA coast is even worse than thought, EPA says
“When the team at UC Santa Barbara first revealed the deep-water dump in detail, the reaction was, ‘Oh my god, this is the tip of the iceberg.’ And now we see how big this iceberg is – we don’t know how big it is yet,” said Mark Gold, an environmental scientist at the Natural Resources Defense Council who has worked on the problem. DDT since the 1990s.
“What’s scary – as if we needed it to be more scary – is that we have up to 100 square miles of contamination from this dump site, with high concentrations of DDT at depths that no one has even looked before, and we are now. looking at all the other stuff that was dumped as well,” he said. “And it’s just what we see, in terms of large munitions, other than: How do we know that other chemicals weren’t dumped at the Department of Defense?”
David Valentine, the UC Santa Barbara scientist whose marine research team first came across the many eerie-looking barrels, also argued that the less visible pollution is a bigger concern. The legacy of DDT contamination still haunts sea lions and dolphins in mysterious ways, and concentrations of the chemical have been traced all the way up the seafood food chain to critically endangered condoms by other researchers.
Read more: Scientists uncover alarming concentrations of pure DDT along the ocean floor off the coast of LA
“We can’t get a glimpse of the 500-pound gorilla down there, which is the enormous amount of chemical waste that was dumped and spread all over the place,” said Valentine, who noted that the contents of the barrels found his team is still there. a mystery.
“Now that we know that the army was doing its thing, and that the chemical dumping was actually being dumped, it really begs the question: so what else could possibly be necessary to be in the barrels this?” he said.
Valentine, who has also been working with several scientists to piece together how DDT might be remobilizing from the ocean floor, said the latest high-resolution imaging from Scripps is critical to helping the entire research community understand what the bottom of the sea looks like.
In fact, the deepest parts of the ocean floor between Los Angeles and Catalina Island had not been mapped in this way. Distinctive features across such a wide range of seabeds were compared to searching for the smallest needles in the largest haystack.
On the most recent trip, a crew of nine Scripps researchers and ten Navy Salvage Specialists scoured the seabed for more than 300 hours – capturing as many images as possible with high-resolution technology not normally available to scientists.
Patterns began to emerge. Object after object appeared, and the scientists found themselves processing and interpreting vast amounts of data in real time.
Terrill, an oceanographer who also specializes in deep-sea scavenging for downed military aircraft as co-founder of the nonprofit Project Recover, tapped an underwater archaeologist on his team to help identify the vintage military debris.
Another surprise for researchers was scores of whale skeletons and carcasses, known as whale falls. Advanced sonar readings indicated that there could be more than 60 whale falls, and the researchers were able to visually confirm seven with their camera system.
Craig Smith, an emeritus professor of oceanography at the University of Hawaii who has spent much of his life studying whale falls, said this finding is groundbreaking in his field. In the entire world, only about 50 naturally occurring whale falls have ever been identified, so locating 60 more off the coast of Los Angeles alone would essentially double the number of known whale falls.
Many questions remain as to why there appears to be such a high concentration of slowly decomposing dead whales off the coast of Southern California. Smith and his colleagues are keen to study this further.
“When we do calculations at the population level, we estimate that there could be about 600,000 or more whales in the global ocean. But they fall more or less randomly, so it is difficult to find them,” said Smith, who noted. those whale falls become extremely interesting ecosystems but undiscoverable for deep-sea criteria.
Merrifield, the physical oceanographer who co-led the Scripps expedition, noted that there is still a lot of new data to sift through and analyze. Her team was able to capture high-resolution images of the different textures of the seabed, for example, as well as mounds that could represent small burrowing animals that could stir up any half-buried chemicals in the sediment.
“New technologies are dramatically changing the way we look at the seabed, and there are interdisciplinary problems from microbiology and remediation, to chemistry, geology, physical oceanography and behavior that require all kinds of specialists to come together,” she said. “I hope the takeaway here is that maybe we didn’t find what we thought we were going to find, but we found a lot of really important things and insights that will hopefully lead to really good scientific results for the public. “
This story originally appeared in the Los Angeles Times.
