Direct observations of the causes of injuries to cetaceans are rare events. For very small and declining populations, such events may be even less likely to be observed because of the few individuals that remain. A long-term monitoring program using photographic identification of individuals resulted in the documentation of an individual Taiwanese humpback dolphin Sousa chinensis taiwanensis that survived a harmful interaction with fishing gear. An adult female that was accompanied by a young calf sustained massive damage to several tissue types on her dorsal surface. From the injuries, it is clear that the animal had suffered intense trauma that likely caused pain for several months as the fishing gear sliced through its dorsal hump and fin. Given the incredible mutilation, the animal is likely compromised at some level and probably continues to experience ongoing pain. This case, along with observations of other individuals in this population bearing serious injuries or being entangled in fishing gear, is direct evidence that the impacts of local fisheries on this subspecies are almost certainly unsustainable.
Keywords: Conservation; Critically Endangered; Entanglement; Fisheries impact; Humpback dolphin; Injuries; Taiwan.