An attempt to refloat the whales on Tuesday. Photo: Facebook / Project Jonah screenshot
Some of the whales that were refloated at Farewell Spit in Golden Bay today have already become stranded again.
Nearly 40 pilot whales were stranded on Monday - the surviving 24 were refloated around midday Tuesday.
Department of Conservation operations manager Ross Trotter said the whales had re-stranded as the tide headed out.
He said they would not be able to be refloated until high tide on Wednesday.
"The ones who have stranded, we'll just be looking after their welfare now and trying to keep them as comfortable as we can until we get another opportunity when the tide comes back."
But with the rest of the pod also milling around, more whales could become stranded yet.
A dozen whales dead after stranding Farewell Spit
Marine biologist Ingrid Visser told Checkpoint every whale rescue after a stranding was a complex operation because each scenario differed.
"We do know that Golden Bay is a hot spot for whale strandings just unfortunately we don't know what's driving the whales to come into these hot spots."
A decade or so ago there were some very high success rates in terms of refloating whales after they had stranded, but more recently the numbers of whales able to be saved were lower, she said.
"It depends on each event and the animals themselves, what actually triggered the stranding.
"Sometimes you'll get a female that is having a breach birth and she will come into shallow water, so that if the calf is born and is alive then the calf won't sink very deep, it's also a way for her to avoid deep water predators, then all of the rest of the group come in with her. Then if you get a place like Golden Bay where the tide drops very very fast then the animals can get stuck."
It was very important that the animals were set upright as quickly as possible because they became very disoriented when they remained on their sides, she said.
"They basically swim in a semi-circle when you release them and then they'll come back on the shore."
There was also a rock and roll technique used, but it was important to know what you were doing so as not to hurt the animal, she said.
"It helps restore their balance, we actually learned how to do that from watching them help each other at strandings back in the '80s and '90s we watched this happening and we learnt from the whales themselves."
Humans had done so much to damage whales' environment and it was vital that they helped them, she said.
"We absolutely do need to help them and it is just a matter of doing it the right way and as humanely as possible and in some instances unfortunately individuals do have to be euthanised."
Visser said she was not on site at Golden Bay, but she suspected that the whales may have split into different groups there as a result of social bonds.
"So it may be a mother and daughter sub-group, it may be that it is young males that are looking for their mums, it could be anything like that, but usually it's driven by the social structure in the group itself."
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