Dolphins found dead off Cornish coast 'committed suicide', wildlife expert claims

Dolphins found dead off Cornish coast 'committed suicide', wildlife expert claims

ByDaily Mail Reporter
Last updated at 4:14 PM on 11th June 2008

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A leading scientist has compared the deaths of 26 dolphins in Cornwall to a "mass suicide" - a natural phenomenon found in the species.

Veterinary wildlife pathologist Vic Simpson, who has examined the bodies, says the animals died after they inhaled debris and mud that clogged their insides.

He said the scenes in the River Percuil, where 26 dolphin carcasses were washed up on Monday, looked like "some sort of mass suicide".

Post mortem: Scientists have so far failed to explain why 26 common dolphins died after beaching themselves

Experts say dolphins have been known to take their own lives whilst living in captivity after becoming distressed and confused at their conditions.

In several cases the creatures repeatedly slammed their head against sides of a pool - or simply stopped coming up for air.

The largest known cases of dolphin suicide was in September and October last year when 152 striped dolphins washed up on the coast of southern Iran.

Locals who battled to save them by taking them back out to sea were distraught when the dolphins refused and persistently re-beached themselves to die.

Grim task: The recent heatwave caused a massive bloom of algae in shallow waters which attracts bait fish, but the dolphins may have become confused in rivers and shallow estuaries

The best known case of dolphin suicide is that of a dolphin named Cathy, one of the bottle nose dolphins that performed in the television series Flipper.

She is said to have died of self induced asphyxiation in the presence of her trainer Richard O'Barry.

Mr Simpson, who founded the Wildlife Veterinary Investigation Centre in Truro, is still working at the scene on behalf of the Zoological Society in London.

He said: "On the face of it, it looks like some sort of mass suicide - but the question is why?

"The dolphins had swallowed and inhaled big chunks of mud from the estuary. Their lungs and stomachs were full of it. That is very bizarre indeed.

"We have seen strandings on beaches, sometimes with five to seven dolphins - but never on a scale like this.

"It could be a bacteria or viral infection that we're dealing with. Some algae produce toxins that can prove fatal. But it is really far too early to say." 

Despite the efforts of marine experts, volunteers, fire crews and coastguards, 26 common dolphins died in the worst incident of its kind in the UK for 30 years.

Tests have so far revealed the mammals were well-fed and that there were no obvious signs of disease or poisoning - causing experts to consider other possibilities.

British Divers Marine Life Rescue (BDMLR) said many of the dolphins had no fish in their stomach, which adds weight to the theory that they were panicked by an underwater disturbance.

A common reason for the animals being stranded is when they are chasing fish - but if they were feeding, there would be clear evidence of it, a BDMLR spokesman said.

The Royal Navy has admitted it was carrying out a live exercise in Falmouth Bay prior to the stranding but has denied it would have affected the dolphins because it was a short-range device.

Experts continued to examine the dolphins

An MoD spokesman said: "A survey vessel was conducting trials using a high definition, short-range side scan sonar for sea bed mapping trials approximately 12 nautical miles off the coast of Falmouth at the time of the incident.

"It is considered extremely unlikely that this operation could have affected the mammals in any way." 

Officials also denied reports that the Navy was carrying out gunnery practice at the time of Monday's mass beaching in the Falmouth Bay area. Several residents reported hearing loud explosions late on Sunday.

Other theories are that the dolphins died chasing fish or escaping a natural predator, possibly a killer whale.

Possible theory: Killer whales could be to blame for the shocking deaths

In all, more than 100 deep-sea-dwelling common dolphins strayed into Falmouth Bay. More than 30 became stranded and dozens more became distressed in shallow water, in one of the worst scenes to confront coastguards and animal rescue groups for years.Although many dolphins were saved, 24 died and two were put down.

Enlarge 

Some dolphins did survive on the Percuil river in Cornwall yesterday

The creatures' innate sense of family could have made the situation worse. Gill Bell, of the Marine Conservation Society, said: 'If one of them was sick and stranded itself after getting disorientated, they would have gone after it to try to assist.'

 

More...

• Dolphin disaster: What we must learn from this before it's too late

Alan Knight, chairman of the British Divers Marine Life Rescue organisation, said: 'We can find no conclusive evidence as to why the stranding took place or why they stranded in such numbers at different locations.

'My personal conclusion is that there was some sort of disturbance that has caused the animals to panic.'

Disruption: Some experts have blamed the Royal Navy, who were carrying out live firing exercises involving a submarine, for the deaths (file picture)

Factfile: Possible causes of the dolphin tragedy

• They committed suicide
  
• Sonar signals scrambled the dolphins' echo-location system
• Killer whales scared the dolphin pod into the shallows
  
• An explosion frightened them into shallow water
• They fled to the cost to escape predation by a killer whale
• They were swimming to the aid of an injured pod mate
• They were chasing fish feeding on algae thriving in the warm water