Sustainable seafood: what fish can I eat?

If your supermarket, fishmonger or restaurant does not have a good policy on sourcing sustainable seafood, you will need to do the hard work yourself. Asking questions about your seafood sends a clear message to supermarkets and restaurants that people do care where their seafood comes from.

Is there something I haven't tried before?


Many stocks of the popular whitefish such as cod or plaice are in bad shape - there may be plenty on the shelves, but there are not many left in the sea. Try something new - ask staff at the fish counter for a good alternative to your usual choice. Some supermarkets are promoting these alternatives each month - look out for these options. If consumers reduce consumption and broaden their tastes, then the pressure on popular species can be reduced.

What about oily fish such as mackerel, sardine or herring?


Stocks of these fish around the UK have improved, and they tend to be caught by less destructive fishing methods.

Where is it from?


Choose seafood that has been sourced from small local UK fisheries. There are a number of reasons for this:

  • Local fishermen who are using or developing more sustainable methods need your support. Fish sourced from the waters of the south-west UK generally tend to be less depleted than those caught in the North Sea.
  • Climate change is already having a major impact on the marine environment - transporting seafood around the world is only adding to this problem.
  • Fish from the other side of the world may be taken from poorer communities that rely on fish as their main source of protein - you have many other choices.

How was it caught?


Choose line-caught fish wherever possible. Line-caught fish from small-scale fisheries don't have the bycatch or stock-depletion problems that are associated with trawling with massive nets. Line-caught fish also tend to be of better quality than trawled or netted fish. The line-caught sea bass and mackerel fisheries in SW England are a good option.

Not all lines are good however. If you must eat tuna, then go for skipjack or yellowfin caught by rod-and-line. Avoid tuna caught by long-lines unless you are sure that the lines have been specially adapted to avoid catching threatened species such as seabirds, sharks and turtles.

For shellfish, choose hand-gathered scallops, winkles, clams, oysters or mussels rather than dredged ones, and pot-caught crabs, langoustines (scampi), and lobsters.

Be wary of farmed fish


Aquaculture is often promoted as being the solution to sustainable fisheries, and has undergone a massive growth over the last 50 years. Unfortunately, with the exception of some shellfish farms and freshwater fish reared in ponds, most aquaculture exacerbates the pressures placed on over-exploited marine ecosystems. In particular:

  • Wild caught fish are used for fishmeal and fish oil to feed farmed stocks. It takes over three tonnes of wild fish to produce one tonne of salmon.
  • Industrial fishing for smaller fish like sandeels and anchovies for use in fishmeal has caused massive disruption to marine food webs. It has almost certainly led to the decline in numbers of cod, seals and seabirds in the North Sea.
  • Disease spreads easily from farmed to wild populations, further depleting wild stocks.
  • Water and surrounding ecosystems are polluted by chemicals, antibiotics and vaccines used to control diseases in intensively farmed fish.
  • Many aquaculture practices are associated with poor human rights records, including loss of land and access to fishing grounds and poor employee rights.

Which supermarkets are best?


Currently Waitrose, Marks & Spencer and the Co-op have good sustainable aquaculture polices in place and are working to improve the sustainability of their farmed seafood, particularly Waitrose.

Buy Organic or Freedom Food-certified seafood

Fish or shellfish farms that have organic certification have the highest environmental standards in the aquaculture industry. The main organic certifier, the Soil Association, is raising its standards to ensure that any wild-caught fish used in farmed fish feed is minimized and sourced sustainably. 

Freedom Food standards developed by the RSPCA for farmed fish are also good. Although the standards are primarily welfare-based, the better environment which they provide for the fish not only produces healthier fish, but also reduces the impact on the marine environment around the farm.

Buy herbivorous fish


Fish like carp, tilapia, and barramundi are herbivores - they eat plants and don't need to be feed with fishmeal. In the UK these fish tend to be farmed in enclosed ponds and have a lower impact on the surrounding environment.

Find out more about best practice in aquaculture from these farms:

  • Purely Organic - a small-scale family farm producing Organic certified rainbow and brown trout
  • Salmac - Organic and Freedom Food certified salmon

More questions about sustainable seafood? Read our FAQs.

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