The stranding of nine orca in Southland is only the third such mass stranding of the species recorded in New Zealand, a specialist researcher says.
Orca Research Trust founder and principal scientist Ingrid Visser said nine of the creatures, including a calf, its mother and at least one adult male, died after stranding themselves early today.
Dr Visser said it was hard to determine what had caused the stranding without visiting the site. She was on her way and planned to be there by tomorrow morning.
"In terms of orca strandings, there's only been two other strandings of this magnitude in New Zealand.
"One was in 1955 [when] 17 animals stranded at Paraparaumu near Wellington, we don't know what caused that.
"And then there was 12 animals that stranded in the 1980s in the Chatham Islands and they all died before they were found. We have no idea what caused that either.''
When small groups or single orca strandings occurred, it was often related to them hunting for rays but it was impossible at this stage to say whether that was the reason for this stranding, Dr Visser said.
"They don't generally strand and when they do strand they don't mass strand like this. This is a very unusual situation.''
The Department of Conservation described the latest stranding as a blow to New Zealand's small orca population.
The whales were seen swimming in shallow water at Te Waewae bay near Tuatapere yesterday evening and by midnight had beached at Blue Cliffs beach, DoC spokesman Reuben Williams said.
When DoC staff arrived at 1am, the eight adults and one juvenile whale had died, he said.
"In terms of endangered species, there's only 200 in the local population. Nine out of 200 - it's a bit of an impact on the population and it's unfortunate.''
DoC had consulted local iwi before removing one of the whale carcasses and taking DNA samples for research purposes, Mr Williams said.
No other whales had been seen swimming in the area.
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