Salmo Salar (the Atlantic salmon) is an extraordinary creature. Capable of living in both fresh and sea waters, and able to navigate across thousands of miles with pin-point accuracy back to the very gravel bed in which it spawned, it’s a fish that has fed man since the days of the Picts, and just one example of the rich seafood heritage of the North Highlands.

However, stocks of wild salmon are now limited and strictly controlled, while the farmed salmon raised in local lochs and bays have become an important employer and international export.

Of course, modern aquaculture is not without its critics, with some believing it has no place, except as an on-land closed system. Clearly, with consumers becoming increasingly ethically astute in their purchasing, no salmon farmer worth their salt ignores the sustainability and environmental impacts of working in some of the most pristine waters on earth.

Loch Duart salmon is a case in point. Employing around 55 people, with a history going back to 1999, they hit the headlines when their salmon was served at the royal wedding of Kate and William in 2011.

Producing 5,600 tonnes of fish a year, it is no boutique operation, but then is easily dwarfed by the larger Norwegian-owned operations elsewhere that churn out the bulk of Scotland’s 160,000 tonnes of fish annually.

On the important subject of sustainability, Loch Duart’s Sales Director Andy Bing points to the eight separate sets of regulations from different bodies that Loch Duart aspires to meet. Among the many practices and disciplines which he believes make a significant contribution is leaving a fish farm fallow for a year, after the two years it takes to raise a fish to harvest size. Theoretically, this allows the debris from the fish and its feeding to dissipate and the ocean floor to recover. Working with the Scottish Environmental Protection Agency (SEPA), Loch Duart has modified this practice where and when it has proved not to work.

‘I think aquaculture realises that to have a long-term future, we have to continually look for improvements in sustainability,’ he asserts, speaking from Loch Duart’s Badcall Salmon House HQ near Scourie, a building ironically built by the Duke of Northumberland as part of a 19th-century wild salmon netting station.

For another North Highlands fish supplier, Keltic Seafare, the challenge is a different one: bringing the wild harvest from the ocean floor off the northwest coast of Scotland to the tables of some of the world’s most revered restaurants in London, Paris or Madrid, in under 24 hours.

This 20-year-old company was begun by a renowned scallop diver and a sales partner, at first focussing on scallops alone, but now taking in creel-caught lobster, langoustine and crab.

The race to table begins with a fleet of a dozen vans trawling up and down the coast, awaiting the post-noon landing of up to 75 small boats bringing their catch ashore at harbours and quays both huge and tiny. It’s a complicated logistical operation, heavily weather dependent.

Consolidated on Skye, the catch is brought to Dingwall for packing and rapid despatch to destinations far and wide. Passengers on the overnight sleeper train to London might be interested to know that they are sharing transport with hundreds of wriggling langoustine and briny lobsters.

The good news (though local seafood lovers prefer to keep it secret) is that it’s possible to intercept some of the world’s finest shellfish by visiting Keltic Seafare’s new building in Dingwall. Place your order in person and, a day later, you could be eating exactly what they savour at places like the Savoy Grill or Gordon Ramsay’s Petrus. Incidentally, if you’re not in the area, and a Michelin-starred meal is out of your price range, then a mail-order delivery can be organised via the Keltic Seafare website.

Another rather more earthy string to the Keltic Seafare bow is the addition of wild girolles and chanterelles, picked by local foragers, usually in June and July. These are much in demand by local chefs early in the season – and possibly with those locals and visitors with a taste for the exceptional too.