Dolphins are being put at risk of serious injury and even death by fisherman who feed them illegally in Cockburn Sound, according to researchers from Murdoch University.
In a decade-long study by the Murdoch University Catacean Research Group and the Conservation Medicine Program, which was recently published in the London journal of Animal Conservation, researchers found the number of bottlenose dolphins which begged recreational fisherman for food increased from one to at least 14 – representing 20 per cent of the 75 adult dolphins which live in the popular Perth waterway.
CMC Marine Biologist Bec Donaldson said dolphins which swam up to boats in search of food were at much higher risk of being hit by a boat or becoming entangled in discarded fishing line.
“There are examples of dolphins that became beggars at Cockburn Sound, which are swimming around without fins after they were cut off by propellers and other dolphins with huge propeller scars across their backs,” Ms Donaldson said.
“You could imagine a calf being injured like that – it probably wouldn’t survive.”
During the course of the study, Ms Donaldson was alarmed and surprised to find dolphins were learning from each other to beg and she saw evidence of a young calf learning to beg from her mother.
“It’s so unusual to see animals learning harmful behaviours from each other.”
“If people do not feed dolphins, they will not get the opportunity to learn this damaging and dangerous behaviour from each other.”
Ms Donaldson said feeding the mammals could put them at a greater risk of shark attacks and have an adverse affect on the mammals’ reproductive success as they become separated from their group in their obsessive quest to get handouts from boats.
“How will male dolphins have time for finding mates when they’re so obsessed with boats?”
“It’s also concerning because in winter when there are less boats around and they can’t get enough fish from fisherman they haven’t necessarily learnt all the complicated skills to do with catching their own fish.”
Ms Donaldson said humans who fed the dolphins were also putting themselves in danger of being bitten.It is illegal to feed dolphins under state and federal law and offenders can be hit with fines of up to $10,000.