There’s nothing new in the world

Luckily, age has not dimmed my memory yet, so I can remember the first discussions about serious commercial RAS (recirculating aquaculture systems) farming of salmon. I thought then it was a bad idea, and I have found no reason over the decades since to think any differently. Perhaps, though, it has become time to actually detail a bit more why I think it to be a red herring.

So let me break it down into sections. Recirculation is a complex business in any situation but the simplest is undoubtedly freshwater. Here the “only” issues are pH, oxygen, carbon dioxide and excretion products. When I say only I hope the irony is clear. These matters are complex to deal with when you are trying to manage a vulnerable fish. Of course some have had considerable success in freshwater but I would suggest that this is mostly because the production tonnage is small generally.

Seawater comes with a very different set of issues. Like a lot of things analysed by modern science, there was an assumption that seawater was a set of dissolved salts well-mixed and relatively stable. Science as we know it tends to like to break complex systems into single components and then reconstruct them assuming that this will work the same. History shows that too often this is a simplistic view. Interaction between components of a complex system often creates a different effect to the effect of those individual components added together.

The next issue in production is the volume involved. To grow a significant weight of fish, particularly salmon, requires a very large amount of water or a significantly fast turnover of water. Both require highly complex systems managed by complex computer systems with inputs and maintenance by human beings. This tends to end up with a lot of fish dying or being very stressed.

Also, the stocking levels required for any reasonable form of economic return are very high. Every time I have been involved in such discussions, the numbers required have been too high for comfort. One case needed 4.5kg average at harvest, with a sub 1 FCR and a stocking density of 80kg/m3.

This creates the next problem: to make the system pay, every tank has to be full as much of the time as possible. For farms at sea you can factor in a period when the pens are empty, to allow for poor performance and time for the fish to grow. If you have fish waiting to go into a tank and the fish in the tank have grown poorly then you have to harvest.

Lastly, the market for these fish needs to be looked at carefully. The only reason for the production of these fish is because activists have put pressure on the industry for supposed environmental impact. At no time has the impact of these campaigns affected the growth of the fish farming market. At times it affected the price but rarely significantly and rarely for long.

The only place it has had an effect is with governments. I remember the time when the organic market took off and went from 0 to 1% of product sold in an extremely short time. We were told that this was the future of food production and we should all get ready for the change. In fact it tailed off pretty quickly and has settled down into a steady production and supply.

So, when you take a product that is grown in buildings with an easy comparison to a feed lot for cattle, it will be hard to market unless the environmentalists will fund your market campaign – and they won’t. Even if all of salmon farming moved onshore, I would like to bet you that the environmental groups would still attack it. After all, they have to earn their money somehow.

Finally if you are of the rather mad, risk-taking persuasion and you need to virtue signal yourself to bankruptcy by creating a RAS farm, then may I suggest that you find another fish to do it with. Why not try John Dory or Dover sole, which at least command a high price? A small RAS farm could make enough money from a small tonnage.

People have said to me a few times, after buying a salmon farm when ISA (infectious salmon anaemia) was rife and the price was awful, that I was rather mad and seemed to want to take risks with the little money I had. I cannot argue with that sentiment but I am not mad enough to try RAS… yet! Maybe I will be persuaded one day.