They are teeming with rare wildlife and are nurseries for much of the country’s fish stocks which drive much of the rural economy.

But illegal dredging from scallop boats can destroy the fragile ecosystems in sea lochs and recent reports of alleged illegal dredging have prompted industry groups, charities, and politicians to call for urgent government action.

The Scottish White Fish Producers Association (SWFPA) are calling on ministers to introduce electronic monitoring of all scallop boats in the country in a bid to stop illegal dredging.

It follows an investigation carried out in part by Scottish marine charity Open Seas into dredging in Loch Gairloch. They found from underwater footage that the seabed had signs of disturbance within the protected area, which is illegal.

Scallops are usually caught by dredging boats, which drag heavy equipment, often weighing more than 2 tonnes, along the sea bed. This plows the ocean floor like a field collecting scallops but often destroying rare reefs and wildlife in the process.

This is illegal in certain protected areas across Scotland including Marine Protected Areas, set up by the Scottish Government in 2014.

The investigation into Loch Gailoch was done independently of the Scottish Government, since Open Seas said that it "doesn't hold particularly high hopes’ for a conclusive Marine Scotland investigation.

Now Mike Park, CEO of the SWFPA, has written to the Cabinet Secretaries for Rural Economy and the Environment, Fergus Ewing and Roseanna Cunningham, calling for further action to stop illegal dredging.

In the letter, Mr Park said: “We are committed to maintaining the integrity of the Scallop sector, a commitment that leaves no place for illegal fishing as was reported by Open Seas very recently within Loch Gairloch.

“We are now calling on the Scottish Government to introduce such measures on board every vessel dredging for scallops, irrespective of size.

“We recognise the commitment the Scottish Government has made to broaden the requirement for vessel monitoring and understand that planning is now underway for the introduction of appropriate monitoring technology for the inshore fleet from 2020.

“We ask you to consider as a priority the introduction of a licence condition which makes it illegal to dredge for scallops without a secure onboard vessel monitoring system.”

The latest evidence comes after Loch Carron near Plockton was subject to dredging last year.

Damage to the rare flame-shell reef, thought to be the largest in the world, caused speculation that it could take decades to recover.

Earlier this year a team of divers also claimed to have uncovered evidence of illegal scallop dredging in the protected area around the Firth of Lorn.

MPAs have been set up all over Scotlish waters in order to protect rare wildlife such as the common skate which has been critically endangered since 2006.

Scottish Greens Rural & Island Communities spokesman John Finnie MSP said: “The Scottish Greens believe that robust, tamper-proof tagging of vessels is a vital step in protecting our marine environment.

"These tags should be able to identify individual boats and their location to allow authorities to prosecute those who fish illegally.

"Currently Scotland only has three enforcement vessels to patrol Scotland’s coastline and tagging dredgers would afford some extra protection to vulnerable areas such as MPAs. I raised this issue with the First Minister in Parliament last week, and I’m expecting a detailed response from the Cabinet Secretary soon.”

Scottish wildlife charities are determined that this kind of illegal activity should not be allowed to continue. Dr Sam Collin, Marine Planning Manager for Scottish Wildlife Trust said: “There is a clear link between sustainable fishing and the health of our seas. In fragile areas dredging can cause catastrophic damage to complex habitats which may never fully recover.

“We support the use of new technology to provide better monitoring and help ensure that all fishing boats operate within the law. Recent reports of illegal activity indicate that this needs to be introduced as soon as possible so that we can maintain the integrity of Scotland’s Marine Protected Areas.”

Calum Duncan, Head of Conservation Scotland for the Marine Conservation Society said: "We support vessel monitoring on all boats in order to understand what fishing is happening where and to ensure a sustainable and legal fishery going forward.

“Extending monitoring to smaller vessels is one vital part of what is needed."
However, for some these measures do not go far enough. Phil Taylor, head of Policy at Open Seas, said in response to this latest incident: “What we have seen in Gairloch are the actions of a few greedy fishermen, for whom 95% of it is not enough. These scallopers have decided to decimate one of the few small areas protected from this damaging form of fishing.

“The blame in this instance lands firmly with Scottish Ministers. The current regulation of scallop dredging is pitifully inadequate.

“This Government is failing to protect our natural heritage by allowing one of the only places where herring are still spawning to be destroyed in this way.”

A Scottish Government spokesman said: “Enhanced electronic monitoring for higher risk vessels operating near sensitive areas, such as Marine Protected Areas, will come in next year and tracking of vessels under 12m will be introduced from 2020. We will review what further measures, including possible licence conditions, as work progresses.”