Over 200 whates die in strandings in New Zealand and Australia

What makes over 200 whales die in strandings over several days?

As many as 145 pilot whales dead after mass stranding on Stewart Island

NZ Herald,

26 November, 2018

As many as 145 pilot whales have died after a mass stranding in Mason Bay on Stewart Island.

A hiker reportedly spotted the whales on Saturday and notified Department of Conservation staff at 10.30pm.

There were two pods stranded at the southern end of Mason Bay, approximately 2km apart.

DoC Rakiura operations manager Ren Leppens said half of the whales had already died by the time they were found and due to the condition of the remaining whales and the remote, difficult to access location, the decision was made to euthanise the remainder.

"Sadly, the likelihood of being able to successfully refloat the remaining whales was extremely low. The remote location, lack of nearby personnel and the whales' deteriorating condition meant the most humane thing to do was to euthanise."

"However, it's always a heart-breaking decision to make."

Marine mammal strandings are a relatively common occurrence on New Zealand shores, with DoC responding to an average 85 incidents a year – mostly of single animals.

On Sunday 10 pygmy killer whales stranded at Ninety Mile Beach. Two have since died and attempts were being made to refloat the others.

It was the second stranding in the Far North in three days after a 15m sperm whale died on Tokeroa Beach on Saturday, after washing ashore on Friday.

The strandings are unlikely to be related

More than 50 whales dead after another mass stranding

TVNZ,

30 November, 2018

Fifty pilot whales have been found dead after a mass stranding in the Chatham Islands.

Initially, up to 80 whales were found beached at the southern end of Hanson Bay near Owenga township yesterday evening, but it was too late in the day to help the animals, the Department of Conservation said today.

When staff showed up at the beach this morning, they were relieved to find that about 30 or 40 of the whales had re-floated themselves without human intervention. However, another 51 whales remained - all of them dead except for one.

The remaining whale was euthanised by DOC staff.

"It was the most humane thing to do," said DOC Chatham Islands Operations Manager Dave Carlton. "This is always an awful decision to have to make."

The stranding comes only days after 145 pilot whales died on the shore of Stewart Island on Monday..

And eight pygmy whales beached themselves on Ninety Mile Beach in Northland last Sunday.

Twenty-eight whales dead in 'inexplicable' beaching in Victoria

9News.com,

28 November, 2018

Wildlife authorities have said it’s unclear what caused twenty-eight whales to become stranded at a remote beach in Far East Gippsland.

The mass beaching at the Croajingolong National Park between Petrel Point and Rame Head was first spotted by aircraft pilot Grant Shorland senior yesterday about 4pm.

Three wildlife experts that were flown in by helicopter found one dead humpback whale and 23 dead pilot whales.

Four of the pilot whales were earlier in a critical condition, but died this afternoon; two were euthanised, while the remaining two died of natural causes.

Pilot Grant Shorland said he was shocked and saddened by the mass stranding, which is the state’s worst in more than 30 years.

“I’ve never seen whales like that before. We see a lot of other stuff on the beach, but not a big pod of whales like that.”

The cause of the beaching remains unclear, but marine mammal expert Dr Kate Charlton-Robb said seismic activity of illness may have been a factor.

Incident Controller with the Department of Environment, Land, Water and Planning (DELWP), Michael Turner, earlier told 9News.com.au this morning he’d never seen a beaching of this scale in 32 years with the department.

“The whales are in a very remote part of the national park that’s only really accessible on foot,” Mr Turne said.

"I recently responded to a beaching in Point Hicks, but that was only one whale.

“We encourage people to steer clear of the area for safety reasons and to ensure the efforts of crews are not impacted,” he said.

Sharks may be more active in the area.

Wildlife officers will remain in the area over the coming days, and will take samples for research to better understand why they beached themselves and how it can be prevented in the future.

The mass beaching comes just days after two massive pods of up to 145 pilot whales washed ashore on a beach in southern New Zealand.

Many died before help arrived, while the rest were euthanised by conservation workers.

New Zealand's Department of Conservation has released heartbreaking footage showing dozens of pilot whales sprawled helplessly in Mason Bay on the west coast of Stewart Island.