Over fifty years ago, thousands of steel drums containing industrial waste were dumped off the coast of Southern California by chemical companies. The barrels, which are peppered across 14 sites along the coastline from San Diego to Santa Monica, were largely forgotten until 2020, when new images of the ghostly barrels brought the issue back to surface.
It’s still not entirely clear what is in these barrels sitting 3,000 feet deep on the ocean bed—it’s been so long that historical records on the drums appear to be lost and their contents dispersed. But a new study funded by the National Oceanographic and Atmospheric Administration and University of Southern California Sea Grant sheds light on the mystery behind these containers.
Using remotely operated vehicles, the scientists collected samples around five barrels at a dumping site between Catalina Island and the Palos Verdes Peninsula. It turns out that the barrels surrounded by a white halo are leaking alkaline waste, a byproduct of industrial production, that is pushing the pH of the water around the barrels to as high as 12—much higher than the ocean’s average 8.1 pH. The alkalinity of the sediment around the tanks has formed a ring of mineral build up of brucite and killed all but the bacteria known as extremophiles that are usually found near deep-sea hydrothermal vents.
“It is a fairly localized effect that is just in the surrounding of those barrels,” said Johanna Gutleben, a post-doctoral researcher and marine microbiologist at UC San Diego’s Scripps Institution of Oceanography. “Just three meters away…we find fairly regular microbial communities that are extremely diverse.”…