A humpback whale with no fluke has been spotted in the waters around Kaikoura, New Zealand. Photographed by Fiona Wardle, a guide for Dolphin Encounter Kaikoura, the whale appears to be doing fine even without its tail fins, showing no signs of reduced mobility or general distress.
Speaking to BBC News, local Department of Conservation ranger Mike Morrissey said he was “bewildered” as to how the whale lost its fluke, but suggests that the deformity may be the result of the animal becoming entangled in fishing nets.
Whales’ flukes consist of two boneless lobes made up largely of fibrous tissue and blood vessels, and are often used by researchers to identify individual whales, since no two are exactly alike. They are used for a number of functions, such as providing propulsion and directing food toward the mouth. Expansion and contraction of the blood vessels in the fluke also helps to regulate body temperature.
According to Morrissey, the whale is probably between two and three years old, and is likely to have been carrying the injury for some time, judging by the extent to which the severed tail has healed up. Importantly, it does not seem to be affected by the loss of its fluke, and was seen “swimming well and breaching, diving and rolling, as humpback whales typically do.”
While the apparent good health of this particular whale comes as a great relief, the fact that it has suffered such a drastic injury draws attention to the impact that human activities can have on marine wildlife. Even though the cause of the wound has not been confirmed, whales becoming injured or killed by fishing nets is not unheard of, while Wardle has also suggested that the disfigurement may have been brought about by a boat propeller.