In a startling discovery, marine researchers announced on Friday that underwater dump sites off the Los Angeles coast contain a vast number of World War II-era munitions, including anti-submarine weapons and smoke devices. The Scripps Institution of Oceanography at the University of California, San Diego, which led the survey, explained that the munitions were first found through a survey of the areas using deep-water vehicles equipped with sonar and video cameras back in April.

The region off the Los Angeles coast was notorious for being a government-approved dumping ground for industrial and chemical waste from the 1930s until the enactment of the Marine Protection, Research and Sanctuaries Act, also known as the Ocean Dumping Act, in 1972. It was during a recent sonar survey using underwater drones in 2021 that over 25,000 "barrel-like objects" were located on the sea floor near Catalina Island.

These objects are suspected to contain DDT, an insecticide that was banned in 1972, as well as other toxic chemicals. The presence of these chemicals has been previously found in marine mammals in the region and has been linked to cancer in sea lions. The discovery has raised concerns about the potential risk to human health and the environment.

The Navy has announced that they will conduct a review to determine the best course of action to manage the risk appropriately. It is believed that the munitions were dumped into the sea during the World War II era as ships returned to port, as it was considered a safe and government-approved disposal method at the time.

The survey conducted in April concluded that most of the objects found thousands of feet below the surface were "multiple types of discarded military munitions and pyrotechnics." Among the findings were anti-submarine depth charges and smoke floats used to provide cover for warships. The presence of these munitions highlights the historical significance of the dump sites and provides a glimpse into the past.

However, further research, including from the U.S. Environmental Protection Agency, has suggested that much of the contamination in the region may have come from acid waste containing DDT that was stored in above-ground tanks and then dumped into the sea in bulk from barges, rather than in barrels. This raises questions about the extent to which the munitions themselves are responsible for the presence of toxic chemicals in the area.

The discovery of these World War II-era munitions is a reminder of the long-lasting impact of human activities on the marine environment. The findings underscore the need for continued research and monitoring to understand the potential risks and develop appropriate strategies for managing and mitigating them.