The jury is still out on closed-containment salmon farms

I have closely followed the debate about open-net pen aquaculture within the pages of The Telegram and would like to offer a view from the other side of the Atlantic.

There are people like Leo White calling for aquaculture reform in Scotland, too (“LETTER: Open-net pen aquaculture is a failed technology,” The Telegram, Aug. 3).

They make similar claims to White but mainly do so from behind a computer screen. They are extremely reluctant to meet face to face in case they lose their argument.

In Scotland, it is suggested that aquaculture has trashed the marine environment but when asked to show where such devastation has occurred, there is total silence. Yet, the debate continues simply because they besiege the media and politicians with claims that are so often repeated that they must be true.

The reality is that if all the salmon pens in Scotland were placed together, they would take up an area of two 18-hole golf courses. The insignificance of such an area can be demonstrated by looking at the home of golf, St. Andrews on a webbased map. St. Andrews golf club has five courses in total but if scale of the map is pulled back to increasingly show a bigger area of Scotland, the land covered by the golf courses disappears swiftly from view.

If this is compared to the seas of off the west coast, it is quickly apparent that salmon pens take up just a dot in the seas.

It is true that waste is generated by the salmon. Critics such as White refer to it as sewage, suggesting that it is akin to human waste.

It is not. It is relatively benign but what is more important is that there are at least 3.5 trillion fish that also live in the world’s oceans that defecate continually into the water. It is a natural cycle.

Of course, salmon waste does accumulate under the pens, but it tends to be in the footprint of the pen and hence is a tiny area. Salmon pens are designed to be moved and the seabed does recover.

Unfortunately, salmon farms do sometimes need to treat their fish, but the products used are all fully licensed and have been assessed for quality, efficacy and safety and use in the marine environment. They are also administered under veterinary care.

Although White doesn’t mention it, the salmon industry is regularly accused of depleting the world’s oceans of wild fish for feed. Interestingly, critics never refer to the amount of wild fish used to feed pigs and chickens and even more critically, the 2.8 million tonnes of wild fish that is fed to pet cats.

At least salmon naturally eat other fish in the wild.

In Scotland, the biggest debate over fish framing relates to the disappearance of wild fish.

Anglers claim that salmon farms have decimated stocks of wild salmon and sea trout, even though stocks are also in decline in areas where there are no salmon farms. Sea trout catches were in decline on Scotland’s west coast for 30 years before salmon farming arrived, yet it is salmon farming that is judged to be the cause.

Like other critics, the angler’s refuse to debate the issue face to face so the debate rages on.

Finally, White states that there are closed-containment farms operating in Poland and Denmark which show the way forward. The fact is none are producing large quantities of salmon on a regular basis profitably.

Closed farms may not suffer sea lice, but they do suffer other disease issues, and these can wipe out a whole farm in the blink of an eye because when things go wrong in closed containment they go wrong very quickly.

It is correct, that there are new farms with planned high levels of production popping up all over the place but whilst their promoters might be able to persuade investors to part with their money in the hope of making big bucks, the jury is still firmly out.