Ocean scientists use robotic submarines to discover barrels of toxic chemicals under the sea.
Thousands of barrels of DDT and other substances are believed to have been submerged in the Pacific near Los Angeles, but authorities aren’t sure where or how many.
To get a picture, researchers have launched two “underwater roombas,” Remote Environmental Monitoring Units (REMUS) that can operate in waters from 80 feet to around 20,000 feet.
It takes 12 hours to charge the vehicles. While one of them scans the sea floor with his sonar, the other switches on and passes on his results.
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Marine researchers use “underwater roombas” to search the ocean floor for barrels of toxic chemicals, including the banned pesticide DDT. Thousands of barrels were discovered in the waters off the Santa Catalina Islands last year
DDT was developed as an insecticide and became an effective way of limiting the spread of typhoid and malaria during World War II.
After the war, it declined as both an agricultural and household pesticide.
In 1959 alone, nearly 80 million pounds of DDT were released on US soil, according to the US Fish and Wildlife Service.
In the 1960s, environmentalists pointed out that this posed a threat to both animal life and humans.
DDT was banned in 1972 and has been linked to devastating effects on marine life and other animals. According to the Los Angeles Times, up to half a million barrels could still be underwater
In 1972, the EPA banned DDT in the United States and classified it as a likely human carcinogen.
Almost half a century later, in October 2020, thousands of barrels of DDT were discovered in the waters off Santa Catalina Island, the Los Angeles Times reported.
Montrose Chemical Corp, once the leading manufacturer of DDT, was based in Los Angeles.
For nearly 40 years, the company reportedly filled a ship with barrels of toxic waste, including DDT, and sank it in the Pacific every month, the Times reported.
Up to half a million of these barrels could still be thousands of feet under the water.
“These barrels are full of toxic chemicals that can cause disease in marine wildlife and even humans,” California Senator Dianne Feinstein told the newspaper. “Ignoring it or saying it’s just too difficult to deal with is not an option.”
The researchers at the Scripps Institution of Oceanography at UC San Diego have shortened the planning for two weeks to a few months and set off on a two-week mission aboard the R / V Sally Ride on Wednesday (picture).
The first step was to determine the extent of the problem, and researchers came up with a unique solution: two robots scanned nearly 50,000 acres of the seabed of the San Pedro Basin for these toxic tubs.
“We want to provide a common base map of the ocean floor with a sufficiently high resolution,” Eric Terrill, marine researcher at UC San Diego’s Scripps Institution of Oceanography, told the L.A. Times.
The sub-like remote environmental monitoring units (REMUS) can operate in waters from 80 feet to about 20,000 feet, or 3.73 miles.
Terrill calls them “underwater roombas,” even though instead of vacuum cleaners they are equipped with sonar technology that gathers data from the ocean floor.
Pictured: Marine researcher Eric Terrill prepares Remote Environmental Monitoring UnitS (REMUS). The robotic submarines are equipped with sonar technology that collects data from the ocean floor
He has previously used the technique to find crashed World War II planes.
Each robot can run underwater for around 12 to 16 hours before it needs to be recharged. This process can take half a day.
While one is scanning the ocean floor, the other is uploading and downloading his results.
Terrill had already worked with the National Oceanic and Atmospheric Administration (NOAA) to test the robots, but it was decided to skip the prep and send them on a mission.
With a planning period of two years in just a few months, they sailed Wednesday on a two-week mission aboard the R / V Sally Ride, an oceanographic research vessel for the Navy on loan to Scripps.
There is a sense of urgency: DDT has been linked to cancer growth in sea lions, shorter lifespans for shrimp, and numerous other problems for marine life.
It also caused a decline in bald eagles, peregrine falcons and other birds: the pesticide caused their eggshells to thin and break open prematurely.
According to CDC. The health effects of DDT at low environmental doses are unknown.
“The rediscovery of the massive DDT landfill off Southern California is certainly a disaster in need of context. How did DDT, spilled from thousands of sunken drums, get into the parts of the food chain that Californians rely on?” Brice Semmens, a marine biologist at Scripps, told the Times.
With the help of the data from the twin scanners, the authorities can determine how big the problem is and which areas are most at risk. However, in order to reverse the environmental degradation that has lasted for decades, separate solutions are required.
Montrose Chemical closed in 1982, a decade after the US banned DDT.
The former plant was declared a high priority Superfund site in 1989, but is still awaiting renovation.
According to the EPA, Montrose poured over 1,700 tons of DDT into the Pacific via its sewer system between the late 1950s and early 1970s.