For years, the advice has been simple: eat less red meat, eat more fish. It’s lighter, cleaner, better for your heart, better for the planet. But once you factor in welfare, environmental damage and sheer scale, it starts to look like one of the most ethically complicated food choices.
In recent months alone, the cracks have started to show. New figures revealed that almost 36 million fish died in aquaculture cages in three years, with regulations being ignored at over 75 per cent of sites surveyed. In the UK, there is concern that industrial trawlers are still fishing in supposedly protected waters. Once framed as a “better” option to meat or poultry, fish is now more likely to be described as at “breaking point” or on the “brink of disaster”.
To be clear, the health case for fish is real. The British Nutrition Foundation (BNF) says official recommendations of two portions a week date back to a 2004 report which found significant health benefits, particularly reducing risk of cardiovascular disease and benefits for maternal health. Fish is rich in protein, iodine, vitamin B12 and selenium, while oily fish provides omega-3 fatty acids and vitamin D. Average UK consumption sits at around one portion a week, with oily fish intake particularly low.
But the BNF acknowledges that this guidance comes with caveats: “There are likely to be population health benefits of increasing fish intakes, but this needs to be balanced with sustainability concerns.” The question, according to Kerry Lyne of the Marine Conservation Society, is not ‘fish or meat’ but understanding where the fish is from, how it is caught or farmed and the species.
Some seafood can have a lower environmental impact than meat, but that comparison tends to focus on climate. Bottom trawling can remove up to a quarter of seabed life in a single pass and releases an estimated 370 million tonnes of carbon dioxide each year. Farmed salmon can generate higher emissions than chicken and relies on feed made from wild fish. In the UK, just five species – salmon, cod, haddock, tuna and prawns – account for roughly 80 per cent of seafood consumption.
Even protected areas are showing signs of strain. Nearly 40 per cent of England’s seas are designated as protected marine areas, yet between 2020 and 2024, more than 1.3 million tonnes of fish were still caught within them. In the case of North East Atlantic mackerel, scientists recommended a 70 per cent reduction in catches; governments agreed to cut just 48 per cent. Earlier this year, Waitrose became the first UK retailer to suspend sales of mackerel, long considered one of the more sustainable options.
