Until last month razor clams could only be legally harvested in Scotland by hand, by divers or by different types of dredges.
But under new rules electrofishing is the sole method allowed to catch the shellfish commercially, while individuals may hand-gather up to 30 for personal consumption.
Electrofishing has been prohibited across the European Union since 1998, except for scientific research.
However, it had become the most commonly used technique due to its efficiency and accuracy, and a burgeoning demand from overseas has seen a major rise in the number of boats operating illegally around Scotland.
It is a problem the Scottish Government has admitted it cannot effectively police due to the difficulty of catching criminals “in the act”.
The trial has sparked criticism from fishing crews and sustainable fisheries organisations, who fear it could result in devastation of razor clam stocks and put people out of work.
They back the need for such an investigation but claim the methodology is flawed and the study is merely a way of legitimising an industry that has spiralled out of control.
Nick Underdown, head of campaigns for green fisheries group Open Seas, claims the plans are “grossly irresponsible”.
He fears they could result in overfishing and will fail to accurately assess the impacts of electrofishing on other marine life.
“To deal with criminal fishing activity the Scottish Government has legalised this potentially damaging fishery by the back door,” he said.
“We support a controlled trial in principle, and it could provide some useful lessons for other inshore fisheries. However, in sustainability terms, this trial is grossly irresponsible.
“The Scottish Government openly admits it doesn’t know current stock levels of razor clams and yet has opened up huge areas of razor beds to electrofishing.
“Without baseline surveys to inform stock control measures the trial could easily backfire, damaging Scotland’s reputation for high quality and responsibly sourced shellfish.”
Skipper Alasdair Hughson, who owns shellfish firm Keltic Seafare, believes any trial should be restricted and thorough.
He said: “What I would like to see done here is a focused, purely scientific study to show us whether or not this method of fishing is benign in the environment or otherwise.
“We need to have confidence that the results of this trial will stand up to scrutiny.”
Electrofishing involves probes being pulled slowly over the seabed from a fishing vessel.
The electric field stuns the shellfish, causing them to emerge from their burrows.
Divers follow behind, collecting the live clams.
Official figures show the value has increased from below £500,000 in 2006 to £2.3 million in 2016, when 460 tonnes were landed.
A high of 915 tonnes were caught in 2013, worth £3.1 million.
The decision to launch a trial came following a report from national fisheries agency Marine Scotland and an official consultation.
It technique is widely considered to be less environmentally destructive than traditional methods such as dredging.
However, there is little evidence to back up the theory, and most respondents to the consultation called for further research to establish the full impact on ecosystems.
Critics in the fishing community believe the trial is too large and lacks scientific credentials, while also excluding skippers who have invested considerable sums in methods that were legal until 1 February.
One fisherman, who didn’t want to be named, has been fishing Scotland inshore waters for more than 30 years and recently sunk around £40,000 into developing a legal non-electric method of razor fishing.
But he cannot make use of it under current rules.
He says there is evidence many Scottish fishing grounds have already been seriously depleted and is alarmed that opening such a widespread area to electrofishing without proper monitoring could see the same happen around the country.
“Places are being cleaned out,” he said.
“I’m not against the method, but it could damage the razor clam population for years to come if it’s allowed to go on.
“It could cause environmental devastation and has the potential to destroy local industry.
“There is currently no understanding of stocks and no idea of the potential impacts.
“To be a legitimate scientific study there should be independent experts aboard each vessel to report the findings.”
A Scottish Statutory Instrument has been lodged with the EU, which grants a derogation to allow electrofishing for scientific research.
A total of 10 sites have been earmarked for the trial, covering almost the entirety of currently harvested razor clam grounds around Scotland.
Surveys to establish razor populations have so far been carried out in only two areas, but the results are yet to be published.
Ministers have granted 26 licences to electrofishing vessels, with a catch limit of 450kg per boat and a maximum 110 days at sea.
Four of the chosen operators have previously received convictions relating to illegal electrofishing.
No end date for the experiment has been set.
Marine biologist Alex Watson Crook, projects manager for the Sustainable Inshore Fisheries Trust (Sift), says the organisation was “initially delighted” to support the trial as a means to “rigorously test the environmental and economic benefits of the fishery”.
However, members are now concerned financial interests are being given precedence over scientific evaluation.
“Sift is now convinced that the current razor clam elecrofishing trial excludes environmental and scientific rigour,” she said.
“Furthermore, the minister has allowed this trial to proceed in such a way that effectively legitimises the previously illegal razor clam fishery over 90 per cent of the previous razor clam grounds in the Scottish inshore. We question how this can possibly constitute an area of ground consistent with the concept of a trial.
“This trial has been designed to legitimise an illegal fishery which Marine Scotland Compliance agreed they could not successfully enforce.”
Rural economy secretary Fergus Ewing did not address the accusations.
He said: “These scientific trials will help us understand the potential economic impact of the industry, will provide useful evidence on how this fishery can be managed effectively and sustainably and contribute to Scotland’s reputation for quality seafood.
“We believe there is significant potential for economic benefit to coastal communities from an appropriately managed electro-fishery for razor clams.
“Given the growth in demand for this product, particularly in the Far East, it is vital that its harvesting is regulated properly and that the effects on stocks are monitored.”