Hake is widely considered the most sustainable fish in the UK due to its quick recovery, healthy stocks, and high, well-managed fishing standards, notes the NFFO and Marine Conservation Society. Other excellent, highly sustainable options for UK consumers include Cornish sardines, mackerel, mussels, and pollack.
Also a chip shop favourite, haddock is generally a sustainable wild-caught option. However haddock often swim in the same areas as cod, meaning haddock fisheries may catch both species.
Oily fish – such as salmon and sardines – is also particularly high in long-chain omega-3 fatty acids, which can help to keep your heart healthy. Most of us should have more fish in our diet, including more oily fish. There is different advice for women who are pregnant or breastfeeding, and children and babies.
Wild-caught seafood with the blue fish tick can be traced back to a certified sustainable fishery. We conduct DNA testing to ensure this works, so you can be sure the fish you're buying is what it says it is. There are many sustainable fish species to eat.
Generally, it's best to buy local. Not only does this support your local fishers, but it has a smaller carbon footprint and is often cheaper, too. Plus, it's easier to find out exactly where your fish came from and… How was it caught?
All of our farmed fish is third-party certified, and our other wild caught fish is sourced from low-risk areas or suppliers working towards achieving a responsible and sustainable fishery certification. When you see the blue MSC ecolabel, you can be sure that the seafood you're buying is sustainable.
Choose fish and shellfish that are lower in mercury such as salmon, trout, tilapia, cod, sole, sardines, shrimp, oysters, and other shellfish. For the most health benefits, choose fatty fish such as salmon, trout, herring, chub mackerel, and sardines. o These fish have healthy omega-3 fatty acids.
For example, U.S. Atlantic wild-caught black sea bass are currently not at risk of overfishing and are in abundance, according to 2025 data from Atlantic State Marine Fisheries Commission. Eat this instead: You can get the same texture and feel with U.S. hook-and-line–caught haddock.
Cheap alternatives to cod that offer a similar mild, flaky whitefish experience include Pollock, Tilapia, Pangasius (Basa), Whiting, and Coley (Saithe), all great for frying, baking, or in stews, providing similar textures without the higher cost of cod.
Cornwall, Sussex, and North Western Inshore Fisheries Conservation Authorities (IFCAs) all enforce local bylaws to prohibit landing of black bream below 23 cm. This effectively protects female bream and gives them a chance to spawn, meaning bream from these areas are amongst the most sustainable in the UK.
For non-farmed fish in the UK, look for wild-caught options like mackerel, sardines, herring, hake, coley, and sustainable cod or haddock, often certified by the Marine Stewardship Council (MSC), with suppliers like Leap Wild Fish, Eversfield Organic, and The Fish Society offering choices like wild salmon, Dover sole, and shellfish, ensuring healthier choices with less fat and contaminants than many farmed varieties.
We use close to 50,000 tonnes of seafood (whole weight) annually with approximately 52% wild caught and the remainder farmed. Our aim is to ensure that all wild-caught and farmed seafood and aquafeed, including M&S Scottish salmon, Organic Salmon and trout, come from the most responsibly managed sources.
The unhealthiest fish to eat are typically large, predatory species high in mercury like Shark, Swordfish, King Mackerel, Tilefish (from the Gulf of Mexico), and Marlin, which are harmful to developing brains and nervous systems, especially for pregnant women, children, and the elderly, while others like Farmed Tilapia or imported Catfish raise concerns about contaminants and antibiotics, and some popular options like certain Tuna and Chilean Sea Bass also have high mercury or sustainability issues.
*Redfish (Family: Trachichthyidae) are unclean. *Ricefish are small fish, typically sold for aquariums, and are not commonly eaten. *Rockfish (Myliobatis Goodei), Rockfish (Genus: Acanthoclinus), Grouper (Subfamily: Epinephelinae), Scorpionfish (Genus: Scorpaenidae), and Stonefish (Genus: Synanceia) are unclean.
Bluefin tuna are heavily overfished, and most experts agree that without prompt intervention, the slow-growing, slow-maturing species will become extinct.
Avoid: Take a pass on this red-rated seafood for now. Red-rated seafood is caught or farmed in ways that have a high risk of causing significant harm to the environment.
Farmed fish will also a lot more fatty marbling in its flesh (those wavy white lines) since they aren't fighting against upstream currents like wild ones. In general, Miller says, any time you spot fillets that look too uniform and perfect in color, they're most likely farmed.
