
SAVING THE SEA STARTS HERE: HOW INTENSIVE FISH FARMING IS UNDERMINING THE OCEANS
The Truth About Salmon, Seabirds, and Sustainability

Early summer on Scotland’s most northerly island of Unst, Shetland. Gannets, fulmars and puffins patrolled the cliffs, their calls echoing over slopes dotted with sea pinks. But beneath this vibrant scene lay a troubling truth: seabird breeding failures have coincided with the presence of industrial fishing trawlers offshore.
It was thirty years ago when I first discovered that the phrase, ‘there’s plenty more fish in the sea’ couldn’t be trusted. That fish in the sea is finite. And that carry on as we are, seabirds won’t be the only ones facing trouble.
There has been welcome progress since then, not least the Scottish Government’s recent ban on sandeel fishing in all Scottish waters, including the Scottish part of the North Sea. The decision was made to protect marine biodiversity and align with national and international commitments to environmental protection.
However, the backdrop is that human activity continues to steadily drain the life out of the ocean. We are plundering the seas faster than the fish can replicate.
Global warning
At the recent UN Ocean Conference in Nice, a statistical ‘catch of the day’ was showcased: that more than a third of the world’s fish are harvested unsustainably. Pushed beyond their biological limits. More than one-third of all sharks and rays are now at risk of extinction because of overfishing.
In 1883, the British scientist, Thomas Huxley notoriously declared that “all the great sea fisheries are inexhaustible” and that “nothing we do seriously affects the numbers of fish”.
More than a century on and it has become abundantly clear he was wrong.
The damage done by overfishing goes beyond the marine environment. Billions rely on fish for protein, and fishing provides livelihoods for millions of people around the world.

False solution
As wild fish stocks dwindle, fish farming is often touted as the solution. But far from easing the burden on our oceans, it may be compounding the crisis.
Farming of carnivorous fish species like the salmon farming found along the west coast, Highlands, and Northern Isles of Scotland, is wrongly seen as a solution to declining wild fish populations.
That’s because vast quantities of fish are being caught from the wild simply to feed farmed fish in what is a wasteful process – a single farmed salmon takes about 350 wild fish to produce.
Pulling the plug
By continuing to feed wild-caught fish to farmed fish, we are taking away an essential layer in the food chain, thereby undermining the future for the oceans.
Today, about a fifth of the world’s fish catch is used as animal feed, being fed to farmed chickens, pigs, and fish.
Anchovies, sardines, and herring are the main species targeted by the industry, with supplies often sourced from as far off as South America and Africa.
These wild fish tend to be the foundation of the marine ecosystem, providing the food for puffins and other seabirds, as well as feeding the bigger fish that we like to put on our plate.
Worldwide, the fish used in this way would be enough to provide a billion more people with a dietary supply of fish. Leaving them in the ocean would take huge pressure off hard-pressed fish stocks.
In Scotland, the industry has grown from just a couple of sites about fifty years ago to more than two hundred fish farms today.
Salmon farming has been described as Scotland’s ‘new oil’, but like petrochemicals in the context of climate change, it’s seriously in need of an urgent rethink.
The Scottish fish-farming industry feeds as much wild-caught fish to its salmon as is eaten by the entire UK population.
Intensively farming what are essentially wild fish species like salmon also raises serious animal welfare concerns.
Salmon are farmed in large sea cages anchored along the coast, with each fish having the equivalent of a single bathtub of water.
Yet, these are natural ocean wanderers.
Which is why huge shoals of farmed salmon swim in incessant circles, showing behaviour reminiscent of caged tigers pacing their enclosures out of frustration.

Fallen crown
Like the environmental impact, welfare conditions for farmed fish are often out of sight, out of mind. Hidden below the depths.
However, investigations from time to time bring home what life can really be like for these incarcerated ‘king of fish’.
One such example in recent years was by a diver who took to the icy waters off the west coast of Scotland, the Isle of Skye and Shetland, to uncover salmon farming’s hidden side.
Farmed salmon were found with diseased and swollen gills. One swam in a bit of a daze, with eyes missing and sockets red raw. Some had chunks out of their bodies and gaping wounds, while others had seaweed growing from their injuries, as if they were rotting alive.
Living oceans
Industrial fish farming often causes serious concern for animal welfare and is central to a ravenous fishmeal industry.
The true impact on iconic wildlife and the ecosystem we all depend upon, is only just coming to light. Some companies involved are starting to make changes, but much more needs to be done.
Consumers can help by buying wild fish from sustainable stocks, preferably line caught. If buying farmed fish, then ensure that it comes from a certified organic supplier.
We still have time to act – but only just. As oceanographer Sylvia Earle warns, “there is still time, but not a lot.” The choices we make now will determine whether future generations inherit thriving seas – or empty ones.
Note: This is a version of an article first published in The Scotsman on Friday 27th June
Main Image Credit: Compassion in World Farming