Tasmanian/NZ Stranding Event
On Sunday afternoon (28 Nov'04), rescuers scrambled to reach a mass stranding of at least 55 pilot whales and 25 bottle-nosed dolphins at a remote beach at Sea Elephant Bay, on King Island, north-west of Tasmania.
On Monday (29 Nov'04), just as it was confirmed a further 17 pilot whales had also died on King Island, the alarm was raised on the other side of the state. A further pod of more than 40 pilot whales was reported stranded on the beach at Darlington Bay on the former penal colony of Maria Island, off the southeast coast.
Stranding date approx. 13th November.
King Island is above the north-west tip of Tasmania and only 45 minutes by air from Melbourne.
Scientists to investigate Tas whale, dolphin strandings
KING Is., 29 November, 2004 - Tasmanian scientists are today hoping to determine why more than 100 whales and dolphins beached themselves on King Island off Tasmania yesterday.
About 150 pilot whales and dolphins were found at Sea Elephant Beach, eight kilometres north of Naracoopa yesterday afternoon.
The strandings were first noticed mid-afternoon by locals who immediately launched a rescue attempt.
However Mike Greenwood from the Department of Environment says more than 72 pilot whales and 30 bottlenose dolphins were already dead.
King Island's park ranger, Nigel Burgess, says the stranding is the biggest he has seen on Sea Elephant Beach.
"I have had pilot whales strand on this beach and I have had dolphins stranded on this beach, but they have been independent of each other," he said.
A rescue team travelled to the Island last night to help locals in their attempts to save another 40 to 50 whales and dolphins stranded 250 metres offshore.
Mr Burgess, says the first locals at the scene managed to pull six whales back into the sea, but it is not known whether they survived.
"It was quite a difficult operation because it is a very shallow shelving beach and they had been there for quite some time," he said.
"I don't think there was a lot of hope of keeping them alive because they were half buried in sand by the receding tide."
More than 50 dead whales will be buried today after a mass stranding at a Coromandel Beach.
by Juliet Rowan
30 November, 2004 - Seventy-three pilot whales came ashore at Opoutere beach on Sunday night. By late last night, only 21 were alive. Eleven of those had been refloated but little hope was held of saving the remaining 10.
A local resident discovered the stranded whales at the north end of the 4.5km beach about 10am yesterday and immediately alerted the Department of Conservation.
Twenty DoC staff raced to the beach, where 50 volunteers helped them to try to refloat the whales, which ranged in size from 4m to 6m.
DoC Hauraki area manager John Gaukrodger said the rescue effort was hampered by the fact the whales had been out of the water for hours.
The stranding was not noticed earlier because several hundred metres of dunes separate the beach from houses.
He said late last night the 10 remaining whales had been out of the water for close to 24 hours. "It could be a bit much to expect they will be salvaged."
A digger was used to help to channel water around the whales. It also dug a channel to float them out to sea.
Today, the machine would dig graves for the whales that did not survive.
"With that number, we'll be burying them right on site," Mr Gaukrodger said.
Mr Gaukrodger said the stranding had been an emotional ordeal for some of the volunteers, who included members of local iwi, residents and members of Project Jonah, who are trained in whale rescues.
It was the biggest whale stranding in the area in over a decade. Most strandings in the Coromandel have involved individual whales.
Mass strandings round the New Zealand coast are not uncommon, though the reasons remain unclear. Whale experts say sometimes a herd may follow a sick leader or a young whale may strand by accident and the rest try to rescue it.
Mr Gaukrodger could not say whether the whales that were successfully refloated were out of danger. They were moved into the seabound channel with flotation equipment. The main task before they could be moved was to keep them wet.
The DOC staff and volunteers covered the whales in water throughout the day.
Showery conditions and a rising tide made the job easier in the evening. But while the high tide at 10.30pm helped the whales, the rescue team struggled to stay warm.
An emergency call was put out to local residents for wetsuits. The team also needed food and hot drinks.
Mr Gaukrodger said Opoutere's remote location, on the east coast of Coromandel Peninsula 17km north of Whangamata, made it particularly difficult.
Getting people and vehicles to the stranding required crossing private properties and large tracts of sand.
DOC would compile a report on the effort to ensure lessons were learned for future whale strandings.
Male pilot whales can weigh up to 2.3 tonnes and females up to 1.3 tonnes. They are usually found in pods of 20 to 100, but groups of more than 1000 long-finned pilot whales have been reported.
The last big stranding of pilot whales in New Zealand was at Stewart Island in January last year.
The pod of 159 stranded 5km from the Half Moon Bay settlement of Oban on January 8. Just 39 were refloated.
The stranding came within a day of two mass strandings in Tasmanian waters within 24 hours.
Fifty-three long-finned pilot whales ran ashore at Darlington Bay on Maria Island yesterday morning.
Parks and Wildlife Service district manager Shane Hunniford said 18 of the whales had died, but 22 had been carried back to the water and every effort was being made to save the 13 still alive onshore.
The stranding was the second in Tasmanian waters in just 24 hours -- a mass beaching of whales and dolphins on King Island, in Bass Strait on Sunday resulted in the deaths of 98 animals.
Hopes for the survival of an offshore pod of 17 whales were dashed yesterday with the discovery that all had died.
The mixed group of long-finned pilot whales and bottlenose dolphins beached on the remote Sea Elephant Beach, north of Naracoopa, on Sunday.
The final death toll was 73 whales and 25 dolphins and there were no further survivors in the area, Mr Brennan said.
King Island ranger Nigel Burgess said the scene of the mass stranding was bleak.
"They're all dead and they're starting to wash out on the tide and wind. It's not particularly bright," he said.
He said that wildlife officers had taken tissue samples from the carcasses for further analysis.
More than three quarters of Australia's whale strandings occur in Tasmania. The most common species to come ashore are the common dolphin, the sperm whale, the long-finned pilot whale and the bottlenose dolphin.
University of Tasmania associate professor Mark Hindell carried out research which found a 10 to 12 year cycle of strandings which would peak around this summer.
He said that while the frequency of strandings followed a somewhat predicable pattern, the causes were unknown.
"That's still one of the great mysteries really, what causes particular animals to strand, or particular groups to strand," associate professor Hindell said.
"There's probably as many different causes as there are strandings.
"I don't think there's any question it's a naturally-occurring phenomenon, it's been happening forever." A combination of oceanographic factors combined to bring large numbers of whales into Tasmanian coastal waters, leading to an increase in the number of strandings at certain times, he said.
"I think it's remarkable that they're so close together but we know that we're in a period of particularly high strandings at the moment - - there's been a lot of strandings happening for the past 12 months or so.
"I expect it might continue for a little while, and then hopefully, it will drop away again over the next few years."
- additional reports by AAP
Then 73 pilot whales were found yesterday (30 Nov'04) stranded on a New Zealand beach. Even Tasmanian whale experts, used to a stranding on average every 12 days on the island state, were reeling.
Many accept the broad theory put forward by Tasmanian zoologist Mark Hindell. He believes a peak of strandings is occurring as part of a cycle of atmospheric conditions which bring sub-Antarctic waters closer than normal to Tasmania every 10 to 12 years.
These cooler waters are teeming with food, luring whales closer to land than in other years. In the case of the recent strandings, Hindell believes the pilot whales were too close to land when seeking the abundant squid. It only takes one whale to beach for an entire pod to respond to its distress signal and also become stranded.
Hindell's findings help provide a backdrop to explain the larger number of strandings in some years, but do not answer the question of how whales become beached. Yesterday, fingers of blame for the three strandings in 48 hours were also being pointed at oil company exploration in Bass Strait, taking place as late as Friday.
Conservation groups and the Australian Greens called for the exploration to be suspended until after the whale migration season, pointing to evidence that dynamite charges used to generate seismic "sound-bombing" of the ocean floor can disrupt whale and dolphin sonar Ð which they use to navigate. Government-paid researchers are careful about discussing this theory in public but believe it should be further investigated.
"It's important to have an open mind," says Rosemary Gales, who has spent 20 years researching whale strandings.
A senior marine biologist at Tasmania's Nature Conservation Branch, Gales was among those who rushed to King Island on Sunday afternoon, only to realise the alarm had been raised too late to save those whales stranded. On Monday, she was sent scrambling to Maria Island on the other side of the state. While 23 whales were successfully returned to the water and appear to have safely found open sea, Gales now has the grisly task of conducting autopsies on the 19 whales that died.
As usual in these cases, sections of the inner ear from some of the dead whales will be examined for the presence of infections that can cause strandings by disrupting the whales' sonar. Locals on King Island reported seeing shark bites in some of the dead whales on Sunday, suggesting they may have been corralled into danger and shallow water by sharks. This was also suspected at Maria, but a fly- over of the area by the National Parks and Wildlife Service failed to spot sharks. And several experts have discounted it as a cause in either of the Tasmanian strandings.
Sometimes the seabed contour can impair whale navigation because their sonar signals are disrupted, but experts say this is unlikely to have been a factor in either of this week's Tasmanian strandings because of the nature of the beach landscape.
Instead, a far more intriguing and potentially sinister line of inquiry has emerged from the latest strandings Ð cold-blooded murder of long-finned pilot whales by bottle-nosed dolphins. At Maria Island, a pod of about 50 of the dolphins could be seen just metres offshore. Experts are puzzled that the dolphins would not leave and were behaving aggressively, despite none of their own number being stranded.
"Locals on King Island were adamant they observed similar behaviour in the dolphins," Gales says. "Locals and police trying to deter the animals from stranding observed the dolphins herding the whales ashore and stopping them from going to the open sea."
Another whale stranding expert with 20 years' experience in Tasmania, David Pemberton, believes the dolphins are capable of corralling whales into danger and death. "I believe they could Ð yesterday at Maria they were behaving very bolshie and aggressive and we are for the first time looking at whether the dolphins are part of the problem or whether they are just hanging around," he says. "We will now be looking very closely through the data to understand the relationship between the dolphins and the pilot whales in past strandings."
Gales and other researchers will also take skin samples for DNA profiling to examine whether the three pods of pilot whales stranded in recent days are related. "Skin genetics will tell us if they are related to other stranded whales and allow us to look at the relatedness between the King Island, Maria Island and New Zealand strandings," she says.
"We are just looking at DNA profiling and over time we will be able to build up a genetic picture of whales that are stranded in Tasmania and compare those with samples from overseas."
As to the wider search for answers, researchers such as Peter Gill, a doctoral student at Deakin University in Geelong, say the effort is complicated by each event having unique factors. "It's a case by case thing," says Gill.
While the zonal westerly winds theory posed by Hindell's group may be part of the answer to the present cycle of strandings, a host of other explanations have been suggested by teams elsewhere. Gill ticks them off, beginning with "geomagnetic anomalies" Ð the natural but abrupt change of the Earth's magnetic field Ð along a coastline that could confuse migrating animals. As well, he says researchers have linked noise produced by humans to the problem. For example, military tests of an acoustic system for detecting submarines was implicated in a series of mass strandings of Cuvier's beaked whale between 1991 to 1997 in the East Ionian Sea.
And just three years ago, US Navy experts concluded that strandings of beaked whales in the Bahamas in 2000 were caused by an unusual combination of factors including nearby military exercises, sea- bottom contour and water conditions that may have channelled and magnified the navy's sonar pings.
Some of the stranded animals even had bleeding ears, probably produced by the mighty pinging sounds. According to Gill, some researchers suggest that on occasion whales may strand due to a type of decompression sickness Ð a whale version of the bends suffered by human divers Ð triggered by exposure to sonar.
Thousands of years since Aristotle's observation, we may be starting to ask the right questions, if not yet finding the answers, to an age- old mystery.
Leigh Dayton is The Australian's science writer. Matthew Denholm is The Australian's Tasmanian correspondent.