They are some of the country’s greatest untouched treasures, having lain undisturbed on the seabed, in some cases for centuries. But now these archaeological riches are being destroyed at an unprecedented rate before scientists or historians can get their hands on them.

That is the stark situation described by marine archaeologist Sean Kingsley, who says fishing boats that use heavyweight bottom-trawling and shellfish-dredging equipment are annihilating precious artefacts and sunken ships. Our desire for fresh scallops is putting our heritage at risk.

Once shipwrecks have been struck by fishing gear, they – and their contents – are obliterated for ever Sean Kingsley, Wreck Watch International

“We know what damage can be done by these bulldozers of the deep – trawlers that drag hundreds of tonnes of gear over the seabed,” says Kingsley, who is director of Wreck Watch International. “They are destroying great swaths of the marine environment and are turning habitats rich in coral, sponge and sea fan into monotonous expanses of gravel and mud.

“But fauna and flora can regenerate. The problem for marine archaeology is that once shipwrecks have been struck by fishing gear, they – and their contents – are obliterated for ever.”

That represents a tremendous loss to society, he argues. Intriguing archaeological artefacts have been brought up from the sea floor over decades, ranging from stone age axes to second world war planes. One wreck yielded a 17th-century golf club.

“We don’t really know fully what is down there,” says Kingsley. “And at this rate we will never find out.”

Among the sites worst affected by trawlers is Doggerland, a vast area that was inhabited during the Mesolithic period 8,000 years ago, but has since been inundated by the waters of the North Sea. Hundreds of stone tools have been dredged up from it over the centuries. Today, it is being “bulldozed” by trawlers. Similarly endangered is the wreck of the 73-gun Dutch warship Eendracht, which was sunk in 1665 in the Battle of Lowestoft during the second Anglo-Dutch war.

Nor is the problem confined to Britain. Many other marine sites around the world are at risk, says Kingsley. These include the seabed off Takashima Island, Japan, where the Mongol fleet of Kublai Khan was destroyed by a hurricane in 1281. Weapons, statues and pottery have since been dragged up, but again the area is risk from bottom-dredging, says Kingsley.

These and many other sites around the globe and in British waters are being pulverised by fishing boats that use huge, 30-tonne nets that have metal doors and chains to hold them down and which are dragged across the seabed, over and over again. It is the equivalent of allowing a fleet of tractors to drag 30 tonnes of gear over a 150-metre wide swath of land for most days of the year. The effect on the habitat – and the treasures it contains – is catastrophic. “This is not a business in which treasures are being surgically removed. They are being obliterated on a widespread scale,” says Kingsley.

But what can be done to halt this desecration is less obvious. “We need to fish to help feed the planet. I accept that. But we have to do something to save our archaeological treasures.” Kingsley suggests a “red list” of key sites. Fishing boats would have keep clear of them or, in some cases, they could be protected by surrounding them with concrete pillars on the seabed. “In the end, we are only going to be able to save a fraction of our most important sites and only if we act as a matter of urgency.”

Fishing and Shipwreck Heritage: Marine Archaeology’s Greatest Threat by Sean Kingsley is published by Bloomsbury (£45)