Thank you for contacting me about the impact of unexploded ordnance (UXO) clearances on vulnerable marine species, as part of the Stop Sea Blasts campaign.

I recognise ocean noise is one of the many serious manmade threats faced by whales, dolphins and other marine animals.

Although increased renewable energy sources are necessary and offshore wind farms are one of the best ways to achieve that, I believe it should not come at the cost of threatening our marine life or causing irreparable damage to the seabed. We should not have to tolerate any more manmade tragedies, such as that at Kyle of Durness in 2011.

The location and size of many offshore wind farm developments and cable connector projects mean there is a high likelihood of encountering UXO during construction. This is particularly so where there is overlap with World War I and World War II conflict areas, military training areas and munitions disposal sites.

Using high-order detonation methods to remove munitions from the seabed is causing undue harm, and yet it remains the most common method of clearing UXO. I believe an up-to-date assessment of this harm on our vulnerable marine life is well overdue. We must establish the damage caused by recent detonations so we can understand the scale of the problem today.

Two phases of a UK Government-funded project to characterise and contrast the acoustic fields generated by UXO clearance using high-order detonation and low-order deflagration have been completed and reported on. It was found that the deflagration method offers a substantial reduction in acoustic output over traditional high-order methods, with the peak being typically more than 20 dB lower.

I understand that, following an almost complete third phase to further improve the information base for the clearance options, the Government will undertake a fourth during summer and autumn 2021, reporting in the first half of 2022. This is to determine if low-order deflagration techniques are transferable to offshore marine settings where partially-buried and decades-old explosives can pose greater challenges for successful clearance operations.

In the face of declining marine biodiversity it is critical to properly protect UK waters and the species that live there.

I can assure you I will continue to press for the Government to take urgent action to protect our marine life.