Measures unveiled to curb underwater noise from offshore wind development

As part of the government’s Plan for Change, the measures will reduce harmful noise levels in the sea to allow offshore wind projects to continue to be built at pace, particularly in sensitive areas. The measures will be followed by a public consultation on setting a future noise limit for offshore wind construction.  

The government partnered with The Crown Estate’s Offshore Wind Evidence and Change programme and representatives from the explosives and offshore wind industries to test and develop new, quieter technologies for bomb clearance, and pilot proposed noise limits during offshore wind construction.

More than 300,000 pieces of unexploded ordnance from the First and Second World Wars sit on the UK seabed and, if encountered, must be cleared during the construction of offshore wind projects. Currently, operators are expected to use low-noise disposal methods to clear such ordnance by default, with noisy high-order detonations considered a last resort and restricted to extraordinary circumstances only.   

Developers will also now be required to demonstrate they have made clear efforts to reduce underwater noise during the installation of offshore wind turbines. 

As well as minimising the harmful effects of explosions and pile driving on vulnerable marine species and commercially valuable fish stocks, the measures will prevent construction delays caused by breaches in noise thresholds, accelerating the building of offshore wind projects planned for 2025 onwards.

Marine Minister Emma Hardy said, “As we expand offshore wind to make Britain a clean energy superpower through our Plan for Change, we need to protect the vulnerable animals of our seas.   

“These new measures support the construction of offshore wind that the UK needs, while making sensible changes to stop needless harm to underwater life.”

Marine Planning Officer at The Wildlife Trusts Christina Platt said, “While many people are aware of the harmful impacts pollutants like plastic and sewage can have on marine wildlife, underwater noise tends to get a lot less airtime. But the reality is that human activities at sea can often emit noise at levels which can negatively impact wildlife, from causing changes in their behaviour, to injuries and even in some cases death.   

“As UK seas get busier, it’s only right that all efforts are taken to limit unnecessary harmful underwater noise pollution. That’s why for many years The Wildlife Trusts have worked closely with government and statutory nature advisors, alongside regulators and industry, to find practical solutions to reduce the impact of this pollution on marine life. Not only do we welcome Defra’s new policy on underwater noise, but see the new approach as vital given the increasing pressures our marine wildlife faces.”

ScottishPower Renewables managing director offshore Ross Ovens said collaboration between government and industry is key to accelerating the building of offshore clean energy projects. “Through the learning from the construction of our East Anglia THREE windfarm and the pilot project, we welcome the opportunity to play our part in shaping the policy landscape that will allow developers like us to deliver the projects that will support investment, growth and a clean energy future for us all.”

One of the companies pioneering the use of low noise technology, EODEX Group said, “We are thrilled by the government announcement mandating the use of quieter, environmentally friendly techniques for clearing unexploded subsea munitions in all but the most exceptional cases.

“This milestone reflects years of hard work and our unwavering commitment to protecting marine ecosystems. With so many unexploded munitions – such as bombs, mines, torpedoes and depth charges in UK waters – and the growing demand for marine infrastructure, this change ensures safer, greener practices for the future.”