Looking over the sea to Skye

Two hundred years ago, Scotland's rivers were full of salmon, and smoked salmon was the crofter's winter food store. When wild salmon became scarce it was considered a luxury food, and today, if you buy salmon, it's almost certainly from a fish farm.

Fish farming

A fish farm should be sheltered from storm waves, but in water at least 30ft (9m) deep so that fish droppings don't poison the fish. There should be a vigorous tidal flow to carry oxygen-rich water into the pens, no pollution and the water should be cool, but should not freeze. In other words, it should be in a Scottish sea loch. Scotland's farms now produce salmon with a fish-counter value of one billion pounds each year, they employ 8,500 people and produce 160,000 tonnes of fish a year, enough to give every Briton a 4oz (100g) steak every week.

Fish farming is a tough life. Mending a net that's 3ft (90cm) underwater is not comfortable when the water is still, and it invariably isn't, because the day when it's blowing half a gale is the very day the nets break. Hauling the cages out of the water for cleaning is the toughest job of all – seaweed grows on fish farms just as it does on the shoreline, and after two years it starts to hinder the flow of water. And a single storm, or even a passing whale, can tear the nets and lose the work of two years.

Mass catering

During its first 40 years, fish farming tried to produce as much as possible, as cheaply as possible. Salmon were stocked like battery hens and fed a high-fat diet. Antibiotics keep them alive if not altogether healthy, and dyes give their flesh the pink colour. One result has been pollution from their droppings poisoning nearby shellfish beds. Fish farms act as reservoirs of disease, in particular of the parasitic sea-lice. There are many reasons for the decline of the wild salmon and infection from fish farms is one of them. Scottish fish farming has now reached the point where it has to clean up its act. A recent development is the organic fish farm, where the fish are stocked less densely and are fed a more natural diet. Fish pens are circular because the salmon prefer to swim round and round. If they were put in a square enclosure, the corners would be wasted. More importantly, the fish would hit the sides, and this would damage their scales.

A track runs out of the car park, signed for Ardintoul and Totaig. It descends gently through two gates, then goes up through a third into a plantation. With high power lines ahead and above, the track forks. Take the left-hand one, downhill, passing a waymarker post. The track runs between the feet of a tall pylon and then diminishes to a path as it climbs to contour through a birch wood. It dips in and out of a tiny stream gorge, then gently descends towards the shore. On the other side of Loch Alsh, the white houses of Balmacara are directly ahead.

At the shoreline, the track disappears into an open field strip. Follow the short grass next to the shingle beach, passing a salmon farm just offshore. Soon after this you reach walled fields, backed by a small crag with birches. Keep along the shore, outside the field walls, and sometimes taking to the stripy schist shingle, towards a square brick building on the point ahead. Opposite the end of the birch crag, you come to a wide break in the wall. Here a track that's simply a pair of green ruts runs directly inland through a grey gate to meet a gravel track. Turn left, away from the abandoned former farm. You pass the ruin of Ardintoul house to the shoreline.

The track runs along the shoreline, then turns inland to climb the hill behind. The steeper uphill sections are tarred. Below on the left, the Allt na Dalach runs into Loch Alsh, with, at low tide, a clear example of a gravel spit where river debris runs into tidal water. The track enters plantations, crosses a stream and bends right to complete its climb to the Bealach Luachrach. Here you may see traces of recent peat workings on the left.

The energetic can make a diversion on to Glas Bheinn – a tough little hill, but a fine viewpoint. The grading and timing given for this walk don't take account of this side-trip. From a big turning circle at the road's high point, turn right up a wet tree gap to reach open hillside. Follow the remains of an old fence up the first rise. Where it bends right, continue straight uphill to the summit, returning by the same route. The old fence makes a useful guide back into the tree gap. Continue downhill from Point 4 on the unsurfaced road, which reaches the tarred public road a mile (1.6km) north of Glenelg village. Grassy shoreline, then the road, leads back to the ferry pier.