Second Seafloor Survey of Dumpsite Off Coast of Southern California Completed

As part of ongoing efforts to understand the scale of the environmental impact of industrial waste dumping off the coast of Southern California, researchers from UC San Diego’s Scripps Institution of Oceanography revisited two industrial undersea dumpsites in April 2023 to identify objects discarded on the seafloor. Led by Scripps oceanographers Sophia Merrifield and Eric Terrill, the 2023 survey used a deep water autonomous underwater vehicle (AUV) with state-of-art synthetic aperture sonar and a remotely-operated vehicle (ROV) with a high definition video camera, both capable of working up to full ocean depth of 6,000 meters (19,600 feet). The expedition took place with support from the U.S. Navy’s Supervisor of Salvage and the Office of Naval Research. Between the 1930s and 1970s, the site was a known location for industrial dumping, including byproducts from the manufacturing of the pesticide DDT. It was initially surveyed using robotic vehicles by the same team in April 2021. The second survey aimed to extend seafloor maps using higher resolution acoustic sonar imaging techniques, applying video imaging systems to classify objects in a previously mapped debris field and collecting observations of deep-sea ocean currents. The 2023 survey mapped 350 square kilometers (135 square miles) and recorded more than...