Dame Joanna Lumley hosts an explosive demonstration as part of her 'Stop Sea Blasts' campaign

Dame Joanna Lumley is today (Thurs) hosting an explosive demonstration as part of her 'Stop Sea Blasts' campaign - to stop the MoD blasting the sea bed to clear military ordnance.

Ab Fab star Lumley, 75, has called for a change in the way the sea floor is cleared of over 500,000 bombs and mines to make way for wind farms.

They are traditionally just 'blown up' which the actress says has an ''incredibly damaging'' effect on the auditory systems of whales and dolphins.

Her campaign resulted in Defra changing its guidance last November on the way that unexploded ordnance is cleared from the sea floor.

Today Lumley and Secretary of State for Environment, Food and Rural Affairs, George Eustice met at a quarry for a demonstration.

Her 'Stop Sea Blasts' campaign calls for a technique known as low order deflagration, which burns out the explosive rather than blows it up, and is proven to be several hundred times quieter.

During the visit they witnessed a comparison between the two explosions at Broadmead Quarry, in Somerset.

Unexploded ordnance (UXO) is any kind of explosive ordnance or military ammunition - usually leftover from military operations in the First and Second World Wars - which has failed to function as it was intended.

Evidence suggests that each explosion has the potential to cause up to 60 hearing loss events in marine mammals, and up to 3000 for the 50 clearance explosions that take place every year in the UK.

Because these marine mammals need their hearing systems for navigation and communication, they can be very vulnerable to high levels of noise - damage can lead to harm and, in extreme cases, death.

Lumley said: "The [detonation] technique can lead to mass-stranding events, such as at the Kyle of Durness in Scotland in 2011, where thirty-nine pilot whales were stranded following a nearby munitions disposal. Nineteen of these precious creatures lost their lives.

"I think we owe it to our marine life to do all that we can to prevent such a situation ever happening again - both on our beaches and many miles out at sea."

Liz Sandeman, from the conservation charity Marine Connection, added:

"It is inhumane to continue to detonate these weapons of war in our waters when we have this viable alternative available, setting off shells and mines is nothing less than vandalism of the sea.

''Our oceans and their inhabitants, including whales, dolphins and porpoises (cetaceans), are under extreme pressure from other threats such as climate change, therefore whilst disposal of these weapons when found in our waters is vital, we must do this without harming the very natural environment and cetaceans that we are fighting to save.

''We are so grateful that so many members of the public have seen the obvious solution to this problem.

''We hope that the Prime Minister, and Ms. Symonds, are able to recognise this too, so that we can safeguard our marine life from continued desecration."

Dame Joanna argues that 'low order deflagration' is just as effective as detonation but causes the contents of an explosive to 'burn out' from within. The technique is also no more expensive and is already used in over fifteen navies across the world.

In a remote special force and ammunition center in Somerset, George Eustice and Dame Joanna Lumley head down into the depths of a quarry where both explosives - the low order deflagration and the high order - are set off.

The pair are placed in a metal bunker, also known as a 'Sangar' made in Northern Ireland, used by the British army when fighting in Afghanistan.

There were two IBC's in the center of the quarry that 'acted' as UXOs.

An IBC is an Intermediate Bulk industrial-grade Container, essentially an industrial-grade white box, used so easy visual comparisons could be made between the two explosions to see their effects.

The high order explosion went off first - a very loud burst and explosive that reached almost the top of the quarry.

The IBC completely blew up and disappeared.

After a short break, the low order deflagration, that burns the explosive faster than it can ignite, was then set off.

It still gave off an explosion, though much less overwhelming and made more of a 'pop' sound, significantly quieter in volume than the High Order explosive.

Rolland, CEO of Alford Technologies in charge of the operation, said the Low Order Deflagration "essentially works like a pump and a football - if you keep pumping air into it, it eventually pops open.

"With the low order explosion, the IBC, acting as a UXO, bursts and peels open. Whereas with the high order, everything completely disappears.

"This helps us vision the shock waves that soar through the ocean with huge energy, that then hits the mammals.

Mr. Alford stated that we are currently "at a tipping point."

He said: "With the implementation of massive off-shore wind farms, we need to be deploying low order deflagration now, not in 6 months, not in a year, but now.

"There is now no circumstances where High Order should be used to destroy UXOs anywhere."

George Eustice, Defra Secretary, described the event as "a fascinating demonstration."

He said: "This is an incredibly important issue. We are in the process of building lots of wind farms that are planted on the sea floor.

"This means we have got to develop and deploy environmentally friendly ways to deal with UXOs, that won't destroy the ocean wildlife.

When asked whether the deployment of High Order will now be halted completely, the Minister said: "There will still be instances where HO will be used depending on the bomb, but it will be less."

Dame Joanna also described the event as "fascinating" but said that the use of High Order is now "inexcusable" and "unjustifiable."

She said: "A lot of things in life we have to see first-hand to be able to understand ourselves.

"I was very happy to be able to experience this demonstration with the Minister. He's a very progressive man and I have faith that we are going to see positive results from this project."

When asked about the immediacy of the implementation of the Low Order Deflagration, Dame Joanna crossed her fingers in hope.

She explained: "The time for action is now. We need to push low order deflagration immediately because it is the only way forward for our environment and beautiful wildlife.

"The destructive impact of High Order explosives on animals is unbearable and must come to an immediate end."