COUNTRYSIDE NOTES OCTOBER 2018 SALMON
Wherever there are rocky rivers in Britain wild salmon might possibly be found but it is Scotland that is most famed for its salmon fishing. Eating the ‘king of fish’ was the prerogative of the rich until the early 1970s when rearing salmon in captivity became feasible. There are now 250 fish farms round the west coast of Scotland and the Western Isles annually producing around 177,000 tonnes of salmon of which 60% is eaten by British consumers. It is an expanding industry and salmon is Scotland’s single biggest food export worth £660million and providing work for 1,500 people. Farmed salmon are reared until they are two to three years old in large cages sited in sheltered sea lochs. Environmentalists are concerned this is having an adverse effect on our declining wild salmon population which need to pass through these lochs to reach the rivers in which they spawn. Intensively farmed captive salmon pose a number of serious health risks to migrating salmon. They are often infected with large numbers of parasitic lice. Harmful chemicals are frequently used to remove these although keeping small fish that feed on sea lice within the cages or bathing the salmon in warm water to remove the pests are alternative treatments. Further threats are pollution from the excrement of caged salmon and the fact that many escape, an estimated 300,000 in 2016, which interbreed with wild salmon the progeny of which do not possess the natural instincts needed to survive. The whole life cycle of wild salmon is incredible. A hen fish has the ability to lay 5,000 eggs which are immediately fertilised by the male. These hatch in early spring and the miniscule creatures are known as alevins. As they begin to develop they become fry and at two to four years old are known as parr. At this stage, in late spring or autumn, they head out to sea and are called smolts. After spending at least one year as grilse out in the Atlantic, the few that have survived return to breed in the same river in which they hatched. After spawning both the males and females (kelts) are exhausted and most die. The Latin name for salmon is ‘salmo salar’ which translated means salmon the leaper. They have the miraculous ability to return to the same shallow, gravel-bottomed area of the river, several miles from the sea, where they hatched and which they identify by sense of smell. These are in fast flowing rocky rivers and the salmon’s tenacity in negotiating obstacles, sometimes leaping more than 10ft up steep, rocky inclines, is nothing short of amazing. They need to wait for sufficient water in the river before they can do this; heavy rain after a dry spell stimulates them into action. Autumn is generally the best time to see them leaping. Because stocks of wild salmon are in decline salmon fisheries now have a catch and release policy. For true sportsmen the pleasure is in the catching of a salmon not in the eating!