South China Sea experiment uses carcass to study deep-sea sharks

Chinese scientists conducted a deep-sea experiment in the South China Sea, southeast of Hainan Island, to study how deep-sea creatures react to large food sources. To simulate a “whale fall”—a natural phenomenon where a deceased whale sinks to the ocean floor and provides long-term energy for marine life—researchers lowered a cow carcass to a depth of 1,629 meters.

Using underwater cameras, the team observed Pacific sleeper sharks (Somniosus pacificus) interacting with the bait. The footage revealed behavioral differences based on size: sharks longer than 2.7 meters attacked the carcass aggressively, while smaller individuals circled the body cautiously, appearing to wait for an opportunity to approach. Researchers suggest this behavior may indicate a predatory hierarchy among the species.