A “SUSTAINABLE” shellfish farm overrun with disease had to destroy stocks of the prawns it imported from the US, documents reveal.

In June, Great British Prawns launched what it claimed was the world’s first sustainable, land-based, clean water prawn farm from its site in Stirlingshire.

The Balfron facility uses tanks capable of holding 300 tonnes of water to grow up to one million fresh shellfish and company chairman James McEuen said it offers a greener alternative to the imported prawns commonly served to UK consumers.

While wild prawns are found in Scottish waters, most diners eat varieties flown in frozen from Asia and Central America.

Launching its new farm, Great British Prawns said its specially developed technology would produce warm water king prawns – also known as Pacific whiteleg shrimp – in the UK for the first time.

Hotels and restaurants within a two hour radius of the site were to be targeted in a sales drive designed to capitalise on growing demand for local produce.

As many as 350,000 crustaceans were imported from the US as operations began. But in a blow to the business, it has had to cull shrimp on site as a result of disease.

Just one month after the launch, there were only 43,000 left on site. More than half of the shellfish died while being imported into Scotland and more had to be culled when the illness was detected.

Details were revealed in inspection and tests results published by a Scottish Government body last week.

Great British Prawns imported the captive-bred animals from Texas in April, placing them in a hatchery at Balfron before moving them into the production site.

They had been expected to grow to 25g, but were screened for disease when staff noticed “huge variation” in size, with some weighing just 2g.

Tests later confirmed the presence of infections hypodermal and hematopoietic necrosis virus (IHHNV), which causes deformations and mass mortalities. The findings triggered the destruction of “all animals” at the production centre and a chemical decontamination process.

Marine Scotland Science was brought in when IHHNV was reported. Inspectors visited the prawn farm in mid-July to find staff “in the process of culling all stocks at the production unit”.

The inspection report tells how “43,000 shrimp remain on site from the initial 350,000 that were imported”, with mortality rate during transport from Texas is “estimated at 50%” and more dying on site.

Marine Scotland Science noted that the farm was to be restocked using animals remaining in the hatchery at one third of capacity, pending further checks.

In June, Great British Prawns revealed ambitions to open further facilities across the UK. McEuen said: “Most prawns have travelled 6000 miles to reach a UK consumer, with worldwide demand continuing to grow.

“We aim to meet growing UK consumer demand for regional and local food production with the reassurance of outstanding husbandry, provenance and sustainability.”

Commenting on the incident, anti-fish farming campaigner Don Staniford, director of Scottish Salmon Watch, said: “Importing foreign fish – be it shrimp from Texas or salmon eggs from Norway – is a recipe for ruin. Scotland should surely focus on producing healthy, locally sourced fish products from the wild.”

Responding to The National after we revealed the story, McEuen said: “In order to start our farm, we had to import our initial stock, which would then enable us to build up a breeding stock for the future.

"The virus was a blow for us but it isn’t an unusual disease. Our tight and controlled biosecurity has meant that we’ve been able to contain this virus easily – it’s a closed system so there is no risk to anything outside the farm. Our farm is a world–first with truly cutting edge processes and technology and we’re confident that we’re now back on track and will be ready to harvest the first clear water, clean energy king prawns by the end of this year.

"Going forward, we’ll focus on stock bred on our farm, using green energy and very little waste. The ideal conditions we have created for our prawns will actually mean that we won’t have to use the vaccines and antibiotics that other prawn farms across the world use.”