Salmon farming started in Norway in the 70s as an extension of normal agriculture, and a farmer would get a licence for one pen that would be placed in the sea as close as possible to the farm. Originally fish farms in Norway were not this large. In Norway, where fish farming is big business, a farm might have eight or 10 pens, which would hold more fish than the wild Atlantic salmon population of the entire world. Even in these packed pens, there is open water as well as crowded areas. But fish generally don’t mind a crowd, believing there is safety in numbers. The pen is large enough for about 200,000 fish – as some opponents point out, packed in tightly. The pen needs to be placed in deep water because it cannot rest on the bottom and should have more than 30 metres of swiftly moving ocean current rushing under it. A visitor looking closely might see a few salmon leaping, because salmon always leap.īut passersby see very little because most of the farm – other than a few tubes to a feeder, the top rim of a fish pen that goes down some 50 metres (164ft), and usually a barge – is below the surface of the water. Invisible from across the loch are a million salmon below. They might see an unobtrusive area with metal poles sticking about a metre out of the water and perhaps some netting over the top of floating wooden walkways it doesn’t look like much. But fish farming currently creates as many problems as it solves.Ī tourist viewing the dramatic sheer mountain fjords of Norway and the island-strewn mouths of the rivers or passing the lochs of Scotland might easily never notice the presence of fish farms. One way to make the sea productive is fish farming. This is clearly not going to be accomplished with wild fish, already struggling under the effects of climate change. The FAO believes that we cannot afford to plough up more land for agriculture and we need to derive more protein from the sea. There is a growing realisation, greatly promoted by the United Nations Food and Agriculture Organization (FAO), that we have to start producing much more protein to sustain a growing world population. For Atlantic salmon, the situation is even more desperate. In 2005, a group of scientists studying the survival prognosis for Pacific salmon concluded that 23% of all salmon stocks in the world were at moderate or high risk of complete extinction. This is partly because it is central to the “food web” (now that we understand the importance of biodiversity and the interdependence of species, this term has replaced the more familiar “food chain”) and partly because of a complicated life cycle that depends on both marine and inland habitat. Complex as the problem of survival is for most fish, few species are faced with as many difficulties as salmon. Our greatest assaults on the environment are visible in salmon. Most of what we do on land ends up impacting the ocean, but with salmon we are able to see that connection more clearly. That is because anadromous fish – fish that live part of their life in freshwater lakes and rivers and part of it in the sea – offer a clear connection between marine and terrestrial ecology. The salmon, though it belongs only to the northern hemisphere, has always been a kind of barometer for the planet’s health.
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