Indo-Pacific humpback dolphins are at risk from factors that also threaten all other cetaceans, such as entanglement in fishing nets, pollution and the depletion of fish stocks worldwide (6). These coastal dolphins are also threatened by boat traffic, a factor that is especially pertinent in Hong Kong where this dolphin's habitat is also the busiest harbour in the world. In South Africa, shark nets may be an important cause of mortality but more data on this potential threat is required (8).