Part of the contract was to protect migrating Atlantic Salmon from acoustic trauma and possible death on their journey through the River Tyne.

John F Hunt faced restricted hours for piling work during creation of five new river walls and dock closure structures which would have added extra time and costs to the job.

Instead they turned to a novel method which protects passing fish from site noise with the installation of a “bubble curtain” in the water which blocks potentially harmful sounds.

David McLaren, Site Manager at John F Hunt Regeneration said: “A 90m long vertical curtain of bubbles was created from a perforated, weighted tube laying on the riverbed, through which compressed air was forced.

“The uniform wall of bubbles reduced our sound impact in the river by an amazing 20dB, to an approved level, effectively satisfying the Marine license condition to allow us unrestricted continuous working.

“This was the first time this had ever been granted in the UK.  It is also the first time the Bubble Curtain system, which originated in Canada, has been tested as an acoustic barrier in Europe, although it has been used in several other countries around the world.”