Dolphins being pushed to extinction twice as fast from being fed by tourists, experts reveal

Dolphins in Western Australia – and across the country – could be pushed toward extinction twice as fast as would otherwise have been the case due to being fed by tourists, a new study has revealed.

A Queensland University team focused on Indo-Pacific bottlenose dolphins in Bunbury as part of an international study into how dolphin population are impacted by human interaction.

Honing in on Bunbury’s population of about 350 Indo-Pacific bottlenose dolphins, scientists discovered that number could fall to just eight within the next century, with the lead author of the study, Dr Valeria Senigaglia, warning the scale of the fallout caused by human interaction would be significant.

“Feeding dolphins has been correlated with high levels of begging behaviour, (such as) approaching vessels for handouts, which leads to inappropriate food or injury, and the removal of bait from fishing gear that could lead to entanglement,” Dr Senigaglia began.

It could also lower reproduction success and offspring survival, with Dr Senigaglia explaining: “This is because the dolphins face many other stressors from climate change, recreational watercraft, disease outbreaks and possible algae blooms, oil spills and habitat degradation.”

Feeding wild dolphins is illegal in Australia but four locations – including two in WA – have permission from state regulators to provide limited amounts of food for tourism.

Using 10 years of data, researchers modelled how the Bunbury population could fare over the next century under a range of scenarios to examine the differences between fed and non-fed dolphins, alongside the potential impacts of human-linked calf deaths, major oil spills, and outbreaks of morbillivirus – a highly contagious pathogen often described as the marine equivalent of measles.

While feeding was not the only contributor to the projected decline, with a morbillivirus outbreak posing an even greater threat, the study concluded it would compound the decline and double the probability of extinction.

“Stopping this practice might increase dolphins’ resilience and ability to withstand other, more severe, stressors,” Dr Senigaglia concluded.

The research team also looked into the potential impact of Bunbury adopting conservation measures similar to those used in Scotland’s Moray Firth, where protection efforts halved calf mortality and doubled local dolphin fertility by cutting out food handouts, establishing protective zones, and dialling back recreational and industrial water activity.

Researchers found that by adopting similar measures, the Bunbury dolphin population would likely increase.