World War II ammunition found dumped off the coast of Los Angeles
When marine scientists sent an underwater camera to the seabed off the coast of Southern California, they expected to find the remains of barrels used decades ago to dump chemical waste.
Instead, they found hundreds of World War II-era munitions, including anti-submarine explosives and smoke devices, scattered across the ocean floor in rough lines stretching for more than a mile.
Eric Terrill and Sophia Merrifield, scientists at the University of California San Diego Scripps Institution of Oceanography, announced on Friday the findings of their underwater research project, which was carried out in April last year.
The seabed south of Los Angeles was an industrial dumping ground from the 1930s to the 1970s. Previous studies had shown that there were tens of thousands of barrel-shaped objects in the area, which scientists believed could contain the chemical waste, including the banned pesticide DDT.
“It was a big surprise to us,” Mr. Terrill said in an interview. “Our expectations were that we would find fragments of barrels along all these rubble lines, and we came across objects that were not barrels.”
“Not knowing what is happening on the seabed near coastlines is worrying,” Ms Merrifield said.
Over three weeks, the researchers used sonar to map a 130-square-mile (210-square-kilometer) stretch of the ocean floor between Catalina Island and Long Beach, capturing 300 hours of high-definition video of the ocean floor. Through a partnership with the US Navy Supervisor of Salvage, they used military technology normally used to find downed aircraft to widely and clearly map the ocean floor.
They found boxes of Hedgehog and Mark 9 ammunition and depth charges, which were carried on warships and dropped into the ocean to deter submarines. They also found Mark 1 smoke floats, a type of pyrotechnics used to disguise ships during battle.
Some ammunition was similar in shape and size to barrels used elsewhere to dispose of industrial waste. Only by using video footage, with the help of an expert specialized in underwater archaeology, were the scientists able to confirm that the objects were ammunition.
Mr. Terrill and Ms. Merrifield said they believed the munitions were linked to the Long Beach Naval Shipyard, where warships were maintained and repaired during World War II and the Korean War before being shut down in the 1990s.
The U.S. Navy confirmed in a statement that the munitions were “likely the result of World War II disposal practices,” and that the dumping of munitions at that location was approved at the time to “ensure safe disposal when Navy ships returned to the US.” ports.”
The Navy would “review the findings and determine the best path forward to ensure the risk to human health and the environment is appropriately managed,” the statement added.
Recent media attention has renewed public concern about the impact of past industrial dumping off the coast of Southern California. Adult sea lions in the area have a high cancer rate, which scientists have linked to the presence of DDT.
DDT, or dichlorodiphenyltrichloroethane, was used as a pesticide starting in the 1940s. But it was banned in 1972 after mounting evidence of damage to ecosystems.
The seabed off the coast of California was long known as a dumping ground for DDT waste products and other types of industrial waste during the 1930s to the 1970s. Scientists are still evaluating the extent of the dumping and its lingering effects on marine ecosystems.