It's been a foodie destination on Scotland's west-coast tourist trail since the 1980s, but was losing money at an alarming rate.

Now the Loch Fyne Oyster Bar in Argyll is to have a multi-million-pound upgrade – and the Herald can exclusively reveal Roy Brett, Scotland's top seafood chef, is its new culinary director.

All staff, including head chef Martin Furlong, will be retained.

Mr Brett, 43, chef-proprietor of the seafood restaurant Ondine, off Edinburgh's Royal Mile, will oversee a complete overhaul of the food operation at Cairndow on the banks of Loch Fyne – which began as an oyster farm in 1978 and became a restaurant in 1988.

It moved into employee- ownership after its founder Johnny Noble's death in 2003, and was sold to Scottish Seafood Investments (SSI) in February this year in a seven-figure deal, following a £1.6 million operating loss in 2011.

The existing Loch Fyne Oyster's management team will remain, under a new chairman, SSI director Campbell Shirlaw.

Designing a new kitchen, a larger restaurant with enhanced views to the famous Loch, a kitchen garden and boutique hotel in the grounds of the oyster bar, are all part of Mr Brett's remit, along with modernising the seafood menu and, in time, establishing a Loch Fyne cook school. Work is expected to commence in the autumn.

Mr Brett will also be involved in the aquaculture side of the business – the investment from SSI is primarily aimed at growing Loch Fyne Oysters' capacity of salmon, oysters, mussels, sea urchins and seaweed in Loch Fyne, and increasing export trade to half of its overall sales within five years.

SSI is a joint venture, launched in 2011, with the Scottish Salmon Company (SSC) and private equity firm Northern Link. At the moment, SSC produces 24,000 tonnes of farmed salmon every year, and hopes to increase that to 44,000 tonnes. Earlier this year, it announced plans to open 10 new farms along the west coast. New oyster and mussel beds will be established in these waters.

Mr Brett has worked with Mark Hix at London's Le Caprice and with celebrity chef Rick Stein in Cornwall, as well as Malmaison and Dakota in Scotland before opening Ondine in 2009.

Ondine, where he will continue to work, was the first Scottish seafood restaurant to be certified by the Marine Stewardship Council by only serving fish from sustainable sources.

He told The Herald: "The Loch Fyne brand is the flagship Scottish seafood product. Having admired and sourced my seafood from Loch Fyne Oysters as a chef for over 20 years, there's no other place I'd like to have my second restaurant than here. In your lifetime you only get certain opportunities and this is one of them.

"I feel lucky to be involved in aquaculture, to learn more about how seafood is produced, and to work with Martin and the rest of the staff to create a new buzz at Loch Fyne."

Bruce Davidson, managing director of Loch Fyne Oyster Bar, said: "In many ways Loch Fyne Oysters is a sleeping giant. This is a really exciting stage of our ongoing evolution.

"Roy Brett has the experience and vision to take the business forward."

The Loch Fyne Oyster Bar at Cairndow is a separate operation from Loch Fyne Restaurants, which has 44 outlets throughout the UK – although it is Loch Fyne Oyster's biggest customer.