Saving Loch Torridon

Fishy business

After a dook in the sea in the west Highlands last week, a neighbour led me over to her car to show me a water-filled jar with a chunk of something that looked a bit like coral in the bottom. She lifted it up to the light and turned it around. “Can you see? It is covered with filamentous algae’. 

Sue Whiting with the maerl sample

The jar held a sample of maerl, a pink coralline algae that carpets the seabed in tidal reaches protected from big waves. Maerl beds are important because they contain airy pockets where wild fish lay their eggs, and are nurseries for juvenile fish.  

About a third of all the maerl beds in northern Europe are around the west coast of Scotland and the Hebrides. The whole spread of it is sometimes called Scotland’s barrier reef. Maerl takes thousands of years to form and grows at just one millimetre a year. It is precious stuff. Unfortunately, the specimen I was looking at was being slowly choked by a fast-growing species.

This sample was captured from Loch Torridon, where the maerl was last officially surveyed 24 years ago. Now local residents have formed a group to monitor its health themselves, because they fear it is under pressure from years of fish farm waste, probably combined with warming water temperatures. 

Maerl Friends of Loch Torridon estimates that the daily volume of shit going into Loch Torridon from all three farms together is about the same as the city of Stirling. That’s a big dump.  Plus urine. And salmon are carnivorous animals. Their waste is very nutrient-dense. It contains carbon and nitrogen as well as ammonia and phosphorous. It is likely changing the balance of the ecosystem and encouraging the filamentous algae to overgrow the maerl. 

Loch Torridon has three fish farms but it is the largest which is causing most concern. It is situated behind a peninsula, which makes it harder for the tide to clear out its waste. It has been there for more than forty years and for all that time, fish faeces and urine have been pouring directly into the loch. It probably would not get planning permission now - back then in the early days of the industry there was an untested assumption that all the fish shit and fish pee would wash out with the tide ‘every 11 days’.

The largest fish farm is behind a peninsula

But now we know much more about the hydrodynamics of the loch - it is a complex system where the fish farm waste drifts slowly across the loch and settles on the seabed. We also know more about the link between salmon farming and the overgrowth of algae. 

Regulation is much stronger for new fish farms - as it should be. Similar operations on land like intensive chicken farming are not allowed to throw their waste into the environment. But why is this stricter oversight not being applied to the existing fish farm in Loch Torridon?  

One afternoon, a day or two after the conversation on the seashore and the disturbing look at the choked maerl, I decided to go and take a closer look at the fish farm and I drove round. Frustratingly it kept coming into view as I navigated hairpin bends and then vanishing again below the horizon. I made a couple of false starts, going along paths that fizzled out in thickets. 

On one of these, I saw a sign half hidden by ferns saying ‘marine laboratory’. At the end of a muddy lane, I found a biologist in a portacabin called Jim. Jim couldn’t comment on the maerl but he unlocked a long-abandoned visitor centre that pre-dated Covid and talked to me about salmon. 

The Atlantic salmon is born in the freshwater rivers and burns, it is at first territorial, finding a patch of shade under a tree or in some rocks which it will defend.  Each subspecies is minutely adapted to the conditions of a particular area. After a year or two, in the spring, they go through a physiological change that fits them to live at sea - they smolt. They change colouring, now camouflaged from below by a silvery belly making it hard to see them from below against the sky, and from above by a dappled pattern. That is called countershading. They become able to excrete salt and stay hydrated in seawater. 

The changing appearance of salmon

While at sea, salmon live in shoals. After one year or two, they return to their original pools to spawn. For females, egg-production is incredibly energy intensive - they don’t eat at all for months. They lay eggs and bury them in the gravel, releasing pheromones which attract the males. The males have by this time developed hooked jaws which they use to fight for the privilege of fertilising the eggs. Most of them die. But unlike the American salmon, a proportion generally survives. The most indefatigable females (about 30%) and the most dominant males (about 5%) return to the sea and they can spawn three times, living to 10 or 12.

Escapes of farm fish - which are Norwegian and later-maturing - interfere with local adaptations. And there is something happening at sea which means that fewer salmon return, and those that do are often too small to spawn. They are now endangered. 

I thanked Jim for all the information and went on my way - ‘I haven’t told you a fraction of it’ he said. Perhaps one reason that the marine environment seems less effectively regulated than the land is because we know far too little about it. Out of sight, out of mind.

By early evening, I was hovering at what seemed to be a dead end when a muddy SUV came past and continued down a dirt track which I had not noticed. I followed a few minutes later. The SUV was parked outside a grey warehouse building. There was no sign of its driver. I could see a path winding across a meadow on the top of a cliff path, and thought I would be able to see the fish farm from there. 

Watching the fish farm

I found my way to a promontory overlooking it and sat watching a flock of gulls circle the fish cages and the endless, futile leaping of the salmon. It was a depressing sight. The king of fish has been brought very low. Some argue it would be better to farm vegetarian fish that naturally live in shoals. A blue boat sat among the pens, with a series of plastic feeding tubes stretching out from it. But there was no sign of any employees at that time. 

One defence of salmon farming is that it provides much-needed jobs in rural areas. But fish farms are increasingly automated. MOWI which owns this farm and many others, has 250 employees in Scotland. Of these, 120 work in the area loosely defined as ‘operations’, which includes managerial posts. There are probably fewer than 100 jobs in the rural Highlands. 

As dusk fell, the scene changed and so did my mood. I heard a crack behind me like someone stepping on a stick and I jumped. MOWI, which used to be known as ‘Marine Harvest”, is owned by multi-billionaire John Fredrikson. Born in Oslo, Fredrikson was once taken to court by Norwegian authorities for endangering the lives of his employees by ignoring safety rules. Now he is a naturalised Cypriot, although he lives in a mansion in Chelsea.

The kayak campaigner Don Staniford and all of his associates have been barred under a permanent injunction from going near MOWI farms. I once spoke to Staniford on the phone, does that make me an associate? The possibility would probably get me arrested - and perhaps a few months in police cells waiting for a date in overcrowded courts. And there are all kinds of other rumours… I decided to go back to the car, by now feeling a little nervous. As I neared the road, I could hear the sound of a saw which set my teeth on edge. As I passed the warehouse a masked man cutting wood with a chainsaw raised a hand in a cheery wave.

You have been watching far too many movies, I told myself as I drove home. But I think the idea of being one person or one of a small group of people up against the might of the fish farm industry is a bit intimidating. 

It should be up to the government, acting on behalf of all of us, to protect the maerl beds of Loch Torridon. They are in a stronger position to stand up to the rich and powerful and all the marketing and muddying of the water that money can buy. The problem is not going to solve itself. And the time to act is now. Once the maerl has been choked to death it will be too late to save it. 

Torridon fish farm, photo Rob Bruce