California Academy of Sciences Team Retrieves Decade-Old Deep Reef Structures in Palau

In May, a team of scientists led by Luiz Rocha, a zoologist and curator at the California Academy of Sciences, retrieved autonomous reef monitoring structures (ARMS) from the deep reefs of Palau, marking a key step in a decade-long study of mesophotic coral ecosystems. The ARMS, deployed between 2016 and 2018 at depths of 10, 50, and 100 meters, were also placed in Guam, the Marshall Islands, and French Polynesia. After retrieval, the structures were transported to the Palau International Coral Reef Center, where researchers including Smithsonian's Chris Meyer and Sarah Tweedt, and Cal Academy's Terry Goslinger and Susanne Bähr, began processing nearly 3,000 specimens. Early analysis revealed that only 3% of samples have been identified to species level, with less than 20 assigned to a genus. The project aims to answer fundamental questions about energy sources, food webs, and climate change impacts on deep reefs, which remain largely unexplored due to the challenges of technical diving. Rocha emphasized that while the puzzle won't be solved in their lifetimes, the work will provide crucial pieces for future generations.