By some estimates, more than 300,000 barrels were discarded in the San Pedro Basin. In essence, leaking alkaline waste has transformed parts of the San Pedro Basin into miniature versions of natural deep-sea vents. one-third of the steel barrels visually identified to date on the San Pedro Basin seafloor,” the study notes. Rather than dispersing into the vastness of the ocean, the alkaline waste persists in solid mineral form, leaching slowly into surrounding sediments. Additionally, scientists caution that the San Pedro Basin may hold more surprises.