A new study by Murdoch University PhD student Valeria Senigaglia and colleagues from the University of Hawaii and Aarhus University in Denmark reveals the downside of feeding wild dolphins.

The peer-reviewed study, involving more than 10 years of systematic data collection, has found that feeding dolphins decreases their reproductive success and hinders calf survival, even when it is conducted under State-issued permits.

While feeding wild dolphins is illegal, permits have been issued to allow routine feeding in certain locations, such as Bunbury in Western Australia.

The study of Bunbury’s local population of bottlenose dolphins shows that, from 63 dolphins including 8 who were provided with food. Only one out of three calves from provisioned mothers survive to weaning age (three years old) compared to 74 per cent survival rate of calves from non-provisioned females.

The results from this research add to those of previous studies showing that the local population is in decline and facing additional pressures of port expansion and increased boat traffic. 

Ms Senigaglia said the findings showed that the seemingly harmless action of giving a fish to a dolphin could have detrimental consequences.

The article was published in Scientific Reports.

Further information on this population of dolphin and a complete comparison between Bunbury and Monkey Mia provisioning program can be found in the Aquatic Megafauna Research Unit research program and the Animal Science Database.