Scientists to study euthanised dolphins

A joint effort managed to refloat a pod of false killer whales at Māhia only for the pod to restrand themselves at another spot where several died and others were highly distressed, leading to the decision to euthanise them. Facebook images

The remains of a pod of 45 dolphins euthanised in Hawke’s Bay will be studied to try to learn more about their stranding.

The pod of 44 false killer whales and one bottlenose dolphin stranded at Taylor’s Bay near Māhia on Sunday, then stranded again at an inaccessible reef point not long after being refloated.

Department of Conservation (DoC) operations manager Matt Tong said the samples were important because not a lot was known about false killer whales.

“False killer whales, we don’t know a huge amount about them and that’s why we’ve got a big team on site taking measurements and samples to try to understand more about these strandings.

“There’s a team from Auckland University, alongside our own ranger team,” Tong said.

False killer whales are a dolphin that looks like a pilot whale but with a more slender and tapering head without grey or white colouring on their sides or top.

Mana whenua, DoC and members of the scientific community went to the site yesterday to take samples and measurements.

Tong said the decision made to euthanise the mammals was distressing for the community.

“Their chances of survival were very slim. Where they restranded themselves, it was a really rocky situation. A number of them were high and dry and in a really bad state — really scratched up and in a lot of distress,” Mr Tong said.

“Our next potential opportunity to refloat them would have been 4pm this afternoon (Monday) and the health and safety considerations of having a team down there overnight took priority, so we made the decision to put them out of their misery.”

A volunteer who has helped with beached whales said it was unusual for false killer whales to strand in a big pod.

Darren Grover, of marine mammal trust Project Jonah, said conditions for the whales were grim.

“When the whales were then discovered by DoC rangers, some of the whales had already died and they were seeing whales highly distressed,” he said.

“One of the responses to stress they have is thrashing their bodies around, and being helpless, stuck up on the rocks, they were thrashing themselves around. They were injuring themselves,” Mr Grover said.

There were a number of reasons the dolphins would come close to the shoreline, he said.

“Chasing food in the shallows. There could be illness or injury among the pod, which causes them to slow down and come closer to shore. Māhia itself is a bit of a hot spot in New Zealand whale stranding. There’s an ocean current that runs along that coast and this hook of land does tend to catch them out.”

Mr Grover said the last false killer whale stranding happened eight years ago but involved just two animals on Christchurch’s New Brighton beach. — RNZ