Get the facts

Atlantic salmon have declined by 70% in Scottish rivers since 2000. Industrial salmon farming is one of the causes linked to this decline.

Salmon farming in Scotland has grown exponentially since the 1970s. In 2021, the Scottish salmon industry produced just over 205,000 tonnes of Atlantic salmon; this is expected to double in the coming years, with an aim of producing 400,000 tonnes per year by 2030.

Copyright Corin Smith


The overview

Often touted as an environmentally-friendly alternative to other forms of protein, in reality industrial salmon farming wreaks havoc on the surrounding environment; has severe costs for the planet in terms of resources and carbon use; and facilitates the immense suffering of millions of fish.

These issues apply to all types of farmed salmon, whether they are certified, so-called ‘organic’, sold fresh or smoked. Certification labels are no guarantee for sustainability – breaches of their standards are frequently ignored, and almost never result in a loss of accreditation for the farm.

Off The Table - salmon return graph
Decline in the estimated number of salmon returning to the Scottish coast. Data are taken from the International Council for the Exploration of the Seas Working Group on North Atlantic Salmon.

Environmental

Open-net salmon farms compromise the integrity of the marine and freshwater ecosystems of Scotland.

Salmon farms are plagued by parasitic sea lice, which disperse from farms and infect wild salmon and sea trout, sometimes with fatal consequences.

Chemicals used on salmon farms are lethal to other types of sea life – in particular lobsters, crabs and prawns

In 2021 the Scottish salmon farming industry used 8.9 tonnes of antibiotics – the only livestock industry to report increasing usage trends

Scottish salmon farms dump untreated waste, including fish faeces, into surrounding waters

Combined, Scottish salmon farms produce the same amount of waste as half of the Scottish human population.

Off The Table - salmon farm
Copyright Corin Smith
Off The Table - salmon in a net

Sustainability

The production of salmon comes at a significant price for the planet.

Farmed salmon are carnivorous fish; they are fed on a diet containing wild-caught fish, soy and a pigment called Astaxanthin to colour the fillets.

It takes much more than 1kg of wild fish to produce 1kg of farmed Scottish salmon

90% of these wild fish, such as anchovies, mackerel and sardines, could be eaten directly

Many of these wild fish are sourced globally from low-income countries, which is problematic for food security and the industry’s carbon footprint

The industry is increasingly using so-called ‘cleaner fish’ such as wrasse to treat sea lice infestations. These fish are often taken from ecosystems across the UK, and killed at the end of the production cycle. They are also carnivorous, so also require feed.

Off The Table - Lice damaged salmon (photo: Corin Smith)
Copyright Corin Smith

Welfare

Salmon farming is a form of intensive farming, with immense welfare issues.

On average, over 25% of Scottish farmed salmon die before harvest. This would not be tolerated in other types of farming

In 2022, the Scottish industry reported over 16.5 million farmed salmon died prematurely

As average sea temperatures rise, so too do potentially fatal conditions and diseases that damage the fish’s gills, effectively suffocating them

Treatments for sea lice are polluting, brutal and cruel – and in some cases ineffective

The farms act as a breeding ground for parasitic sea lice, which graze on salmon skin and mucus

Hundreds of thousands of wrasse are taken from the wild and caged with the farmed salmon every year. Millions of these ‘cleaner fish’ die, or are culled at the end of the production cycle.

Eating Atlantic salmon from open net salmon farms is the wrong choice for our health and the health of our environment. Responsible consumers should avoid these inhumanely, unsustainably raised fish.

Douglas Frantz and Catherine Collins
Authors of Salmon Wars