Experts are blaming recreational set net fishing for a dead Hector's dolphin found in Akaroa Harbour.
A tourism operator reported the dead dolphin to the Department of Conservation.
Professors Steve Dawson and Elizabeth Slooten examined the 1.23m male and say it had marks indicating it had died in a set net.
It was found in Petit Carenage Bay about 11 kilometres from the harbour entrance.
Despite Banks Peninsula's status as a Marine Mammal Sanctuary, recreational setnets for flatfish in the inner parts of Akaroa Harbour are legal from April 1 to September 30.
Professor Dawson said there's no doubt about how this dolphin died.
"There were clear indented lines across the dolphin's snout, multiple sharp cuts in the flippers and tail flukes, and a fresh nick out of its dorsal fin," he said.
Professor Dawson said the dolphin was probably 4-5 years old. He said it was in good condition, apparently healthy, and would have reached maturity within the next couple of years.
"This capture shows that these setnets pose a very real risk. It just should not be permitted," Professor Dawson said.
"It's ridiculous to have a marine reserve at one end of the harbour, a very active and lucrative tourist industry based on the dolphins, and yet allow use of fishing methods that kill those same dolphins."
Hector's dolphins are among the smallest marine dolphins and can live to about 20 years old. There are about 7500 left, and are an endangered species.
Seafood NZ represents the Commercial Fishing Industry. Spokesman Tim Pankhurst said commercial fishermen are not allowed to fish in the harbour.
He pointed out that the critically endangered Maui's dolphin (a subspecies of the Hector's dolphin), of which it is estimated there are only 55 left in the world, is only found in the North Island.
This was a Hector's dolphin, with substantially more animals in its population.
"We don't want to see any dolphin death, but it's not as if it's a critically endangered species," he said.