The injured penguin, thought to be a Snares Island Crested penguin, prompted a call to the Department of Conservation (DOC) hotline after it was spotted on Monday night.
DOC biodiversity ranger Steve Harraway checked on the penguin on Tuesday morning and said he would be keeping an eye on him in the coming days.
"He's feisty enough .. he tried to take off on me.
"I shifted him over into the retaining wall to give him some protection," he said.
The wound, likely to have been inflicted by a barracuda, had already started healing, however Harraway said he was concerned the penguin's coat might not be waterproof around the wound which could leave him feeling a bit cold.
"I will keep an eye on him."
If it was deemed necessary, the penguin would be taken to Oamaru for rehabilitation, he said.
The arrival of the injured penguin has prompted a warning to beach users, especially those walking dogs, along the South Canterbury and North Otago coastline to beware of penguins coming ashore to moult over the next two months.
Department of Conservation media advisor Fiona Oliphant said it was not uncommon for a variety of penguin species to arrive at this time of year.
"Penguins will be coming ashore to moult and will potentially be on the beachline for two to three weeks," she said.
While ashore the penguins would shed and replace all their feathers which could leave them looking bedraggled, she said.
"Generally it's best to observe them from afar and let them get on with their moulting."
In recent years Blue penguins, Fiordland crested penguins and Yellow-eyed penguins had all visited the area to moult.
"The key thing is the public need to be aware there are penguins on the beach ... particularly with any dog owners, they need to keep dogs under control."
In the past, moulting penguins had prompted several calls to the DOC hotline from concerned residents, however Oliphant said it was a natural process and not uncommon along the Southern coastline.
However, anyone with concerns about injured penguins or any loose dogs near penguins should report those to the hotline, she said.