The Ocean Scientist Calls
Extent of DDT Dumping in Pacific
‘Staggering’ #2021
Hi Friends,
You can see about of Southern California’s Catalina Island is a popular destination for nature lovers. It is reachable by boat from Los Angeles and San Diego. With just one city, most of the small island is a government-protected wild area.
But, a report last October in the Los Angeles Times newspaper raised public concern about the water surrounding Catalina.
➥ The newspaper discovered that industrial companies for years had been dumping the insect poison DDT into the ocean near Catalina. The practice began in the 1940s and ended in the 1970s.
➥ The newspaper report led to a search and study of the area by scientists at the Scripps Institution of Oceanography at the University of California San Diego (UCSD).
➥ The research team discovered about 25,000 large containers, or barrels, below the surface of the Pacific Ocean. The scientists suspect the barrels hold DDT, and other chemicals used to make the poison.
➥ Eric Terrill leads the Scripps program that worked on the project. He said the barrels were spread over a very large area. That finding was a “surprise,” Terrill said.
➥ The Scripps examination also showed the companies responsible for the chemical dump disobeyed rules about where to place the barrels.
“These results also raise questions about the continued exposure and potential impacts on marine mammal health, especially in light of how DDT has been shown to have multi-generational impacts in humans,” said Aluwihare, who was not part of the survey expedition. Diana Aga, a chemistry professor at University at Buffalo who is not affiliated with the study, said the findings were shocking if the barrels are proven to contain the toxic chemical. “That's a lot of DDT at the bottom of the ocean," she said. If the barrels haven't leaked, they could be moved to a place where disposal is safer, Aga said. If they leaked, scientists could take samples from the water, sediment and other marine life to gauge the damage.
➥ The researchers mapped about 15,000 hectares of ocean floor where past studies had shown evidence of poisonous chemicals. The area lies between coastal Los Angeles and Catalina.
➥ The long-term effect on ocean life and humans is still unknown, said Scripps chemical oceanographer and professor of earth sciences Lihini Aluwihare. She was not connected to the study. But, in 2015, she co-wrote another study that found high amounts of DDT and other chemicals in the blubber, or fat, of bottlenose dolphins.
➥ Aluwihare said some studies among humans show that DDT-linked health problems have been passed from parents to children. So she said, it is possible than non-human animals will do the same.
➥ Eric Terrill briefed lawmakers on the findings last week. California Senator Dianne Feinstein wants the companies responsible to be punished.
“Simply put,” she said, “this is one of the biggest environmental threats on the West Coast.” She noted that the problem is made especially complex because the barrels are so deep in the ocean and there are few records about the dumps. The lawmaker also noted that the Scripps team’s findings may represent only a small part of the total dumped material.
➥ DDT was widely used around the world to kill insects that hurt crops and carry disease.
➥ But the U.S. government banned the chemical in 1972 after it was found to be harmful to humans. Most other countries did the same.
➥ DDT has been found in several ocean animals off the Southern California coast. Earlier research shows the poison causes cancer in sea lions.
“It really was a surprise to everybody who's worked with the data and who sailed at sea,” Terrill told reporters Monday. The survey provides “a wide-area map” of where the barrels are resting, though it will be up to others to confirm through sediment sampling that the containers hold DDT, Terrill said. It's estimated between 350 and 700 tons of DDT were dumped in the area, 12 miles (20 kilometers) from Los Angeles, and 8 miles (12 kilometers) from Catalina Island. The long-term impact on marine life and humans is still unknown, said Scripps chemical oceanographer and professor of geosciences Lihini Aluwihare, who in 2015 co-authored a study that found high amounts of DDT and other man-made chemicals in the blubber of bottlenose dolphins that died of natural causes.
Now, the scientists will further study some of the barrels and the bottom of the ocean where they were found.
➥ Diana Aga is a chemistry professor at the University of Buffalo. If the barrels are leaking, she said, the amount of the chemical in the area would be “shocking.”
➥ "There's a lot of DDT at the bottom of the ocean,” Aga said. But, she said if the barrels have not leaked, they could be moved to a safer area.
➥ The Scripps Institution of Oceanography study took place from March 10 to March 24. The researchers said they did the study as a way to aid clean-up efforts.
Historical shipping logs show that industrial companies in Southern California used the basin as a dumping ground until 1972, when the Marine Protection, Research and Sanctuaries Act, also known as the Ocean Dumping Act, was enacted. Disposing of industrial, military, nuclear and other hazardous waste was a pervasive global practice in the 20th century, according to researchers. Resting deep in the ocean, the exact location and extent of the dumping was not known until now. The territory covered was “staggering,” said Eric Terrill, chief scientist of the expedition and director of the Marine Physical Laboratory at Scripps Institution of Oceanography.Underwater drones using sonar technology captured the images of barrels resting 3,000 feet (900 meters) below the surface all along the steep seafloor that was surveyed.
