Decades-old toxic waste leaks reshape the deep-sea floor

Decades after the U.S. dumped thousands of barrels of toxic waste into the Pacific, new findings show leaks are still altering the San Pedro Basin’s deep-sea sediment chemistry and microbial life. A 58-square-mile survey identified around 74,000 debris targets, including ~27,000 barrels, with halos of hardened minerals indicating alkaline leakage. The resulting high pH and altered microbial communities could affect deep-sea ecosystems for thousands of years, complicating cleanup and policy decisions; the study appears in PNAS Nexus.