A bottlenose dolphin, known to marine researchers as TM007, was showing the survival instinct of a James Bond when it was seen swimming gamely in the Hauraki Gulf with a 20cm-wide gash on its back and two smaller cuts on its tail.
"It was a severe wound ... pretty horrific to see," said Sarah Dwyer, a Massey University PhD student, who photographed the dolphin last Wednesday from a research boat.
"It was swimming with its presumed mother TM009, but very slowly."
Ms Dwyer said the three wounds were consistent with the dolphin having been struck by the fast revolving propeller of a boat.
"It was seen alive and well four weeks ago off Whangaparapara, Great Barrier Island, and at the latest sighting it was injured."
Asked by the Herald about the dolphin's chances of survival, Ms Dwyer said: "We don't know, we can only hope for the best."
"But it's one of the most severe cases I'm aware of where the animal has survived for at least a short period of time."
"I was surprised by the distances it could swim given the severity of its injuries.
"Dolphins do have quite an amazing ability to heal."
The dolphin and its mother had been observed since May 2010, always together, in the waters of Great Barrier Island and the inner gulf.
Ms Dwyer said she feared TM007 had suffered damage to its spinal process.
In a 2009 Australian case of a dolphin being bitten on the back by a shark, the dolphin made a recovery from the injury.
However, its spine was not affected.
Last year a common dolphin died in the Hauraki Gulf as a result of receiving spinal injuries after being struck by a jetski.
Ms Dwyer said the injured dolphin and its companion were aware of the research craft but she maintained a safe distance to avoid further stress to the animal.
Department of Conservation Warkworth and Great Barrier Area Manager Tim Brandenburg said the injured dolphin's plight highlighted the need for boat operators to take care around the dolphins, which were in the marine park throughout the year.