"Most wildlife, including penguins and other seabirds, is absolutely protected under the Wildlife Act 1953, making it illegal for people to kill or have in their possession any protected species without a permit. The penguin colony and many other rehabilitation centres or researchers have permits to carry out the work they do, but the public are not permitted to pick up or disturb protected species."
The issue was not unique to Oamaru, as yellow-eyed penguins had also been disturbed on North Otago's beaches, including Moeraki, she said.
Dr Agnew was concerned the behaviour had the potential to impact on the breeding success of penguins.
She said the colony had taken steps to combat poor behaviour, but admitted it was difficult to control at times.
"We obviously have very strict controls within the colony and we have staff working at Bushy Beach and the boat ramp on Waterfront Rd each night to protect the penguins. Our staff cannot be everywhere at once, of course, so it may be that members of the public should point out to others if they see this kind of behaviour occurring."
The public could also notify the Department of Conservation if they were concerned about the welfare of penguins.
Dr Agnew advised those who viewed birds coming ashore to give them space, not to block pathways to nests and not to take photographs that used a flash.
"People also need to be aware when they are walking their dogs that there may be penguins present," she said.
In December a dog being walked off its leash at the harbour attacked and killed a penguin Under the council's dog control bylaw, all dogs being walked at the harbour coastal area between sunrise and sunset must be on a lead.