Wild dolphins usually travel together in close-knit family groups called pods. During a dolphin drive, fishermen will surround a pod of dolphins in their boats, often banging metal sticks underwater to confuse the dolphins’ echolocation. The dolphins are then surrounded by nets which are tightened, pulling them into a more and more confined area. During the ensuing chaos, some dolphins have their throats slit or are stabbed with spears. Others are caught on hooks and lifted out of the water by winch, to be slaughtered nearby. Some die of shock, whilst others become tangled in the nets and suffocate. In their panic, many crash into boats, harbour walls and each other. The sea turns red with blood whilst many dolphins thrash about, taking several minutes to lose consciousness and die. This process can last for days, and estimates of the number of dolphins killed in this way every year vary between 16,000 and 20,000.
Japanese proponents of the dolphin drives defend them as an important tradition, contributing to the local cuisine as well as the livelihoods of those involved. An increasing proportion of the dolphins captured in drive hunts are now being sold into captivity rather than slaughtered for food. In the past, it seemed that drive hunts were becoming a dying practice, but the lucrative support of the billion-dollar dolphin industry has provided an incentive for poorly paid fishermen to supplement their income by trading in live dolphins.