Salmon – it’s complicated, but fascinating

Being currently in British Columbia, Canada, salmon is everywhere both in the natural environment and in the food culture.  This got me thinking about the salmon we get in the UK.  As most people know salmon is a great source of protein, vitamins, minerals and omega fatty acids.  These fatty acids are thought to be especially good for our hearts, joints and brains.  We are encouraged to eat 1-2 portions (1 portion is 140g)  of oily fish, including salmon per week.  One 130g portion of fresh salmon has 280 cals, 31g of protein and 17g of fat. (Carbs & Cals).

Nutritional information of fresh salmon.

Nutritional information of fresh salmon.

Salmon used to be a rare and expensive treat.  Then in the 70’s Norway and the UK started intensive farming and the cost significantly reduced.  A bit like meat, it became more affordable so people ate it more often.   Now it can be bought relatively cheaply, but like meat this comes at a cost.

What are the issues?

Within the standard Scottish loch salmon farm pollution from the concentrated amounts of fish waste, uneaten food, colouring treatment and anti-lice treatments can build up at the bottom of the loch, affecting the growth of marine plants and animals.  The Salmon & Trout Association reported that a number of loch sea beds were contaminated with anti lice treatment chemicals above the recommended safe levels. They were also concerned that sea lice from the farms are getting into the the wild population.

Farmers have a huge incentive to include pigmentation (colouring) in with the salmon’s food as the pinker the salmon flesh the more money the fish will sell for.  In the wild the different breeds of salmon are different colours due to the contents of their natural diet. It would seem only 50% of Scottish salmon are now fed artificial colours to alter the colour of their flesh, the rest are fed a natural version of ground up crustations, and they are not allowed to be fed GM soya.

The varied colours of wild salmon.

The varied colours of wild salmon.

Overcrowding can cause disease, injures and stress in Atlantic Salmon.  The maximum stocking density can be as much as 22kg per m3 of seawater,  15g per m3 is the RSPCA recommended standard where as the organic system seems to be only 10kg per m3.  This is also the ideal amount recommended by Compassion in World Farming.

Farmed salmon escaping into the wild is also a huge environmental issue.  In 2009 the Atlantic Salmon Trust reported that over 133,000 salmon escaped!  Farmed Atlantic salmon are genetically different to the wild Atlantic salmon, there have been 400 different species identified in Scotland alone. Cross breeding and the dilution of the wild species is a very real threat.  The escapees carry sea lice into the wild population and compete with them for food.  Within the farms the sea lice are becoming resistant to treatments, which is concerning.  Unlike Norway the baby farmed fish are raised in freshwater pens within the migratory system of the wild salmon, as opposed to closed systems, and this seems to cause issues with the wild salmons natural behaviour.

So are the MSC certified salmon farms the answer?

The MSC Fisheries Standard is based on three principles:

1. Sustainable fish stocks

2. Minimising environmental impact

3.Effective management

This is not just a UK certification, but a world wide standard.  Essentially if your fish does not have this logo then it is unlikely to have come from a fishery or farm meeting these standards.   You can check the stock levels of your favourite fish at the Good Fish Guide.

What about organic salmon farming?

Organic salmon are farmed far off shore away from industrial pollutants, land farm run off and the risk of them polluting the surroundings.  Also away from the concentrations of wild migrating salmon.  The feed is as natural as possible and without colourings.  The low stocking density of only 10kg per sq metre helps them to need less chemicals and the waste products have less of an impact on the surrounding environment.

So like meat I will be eating less salmon, but having sustainable wild or farmed organic.  When eating out if the salmon is not certified I always assume that it is the non-sustainable kind and choose something else.

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