Shoal of Tuna in the Mediterranean Sea Guido Montaldo

How to buy the Big Five: cod, haddock, salmon, tuna and prawns

2 minute read

80% of the seafood we eat in the UK is made up of just five species: cod, haddock, salmon, tuna and prawns. Ideally we should eat a wider variety of sustainably caught fish, but if you're keen to stick with the familiar – or nothing else is available – here's what you need to know.


Cod is one of the UK's favourite fish, often found in fish and chips dinners. It's a cold-water fish that is generally wild-caught rather than farmed. UK stocks are doing very badly as a result of overfishing, but stocks from Iceland are healthy and are currently at sustainable levels. Atlantic cod is available all year round but it's most abundant in autumn and winter.

Best choice

  • Atlantic cod from North East Arctic, Iceland or Norway
  • Pacific cod from Bering Sea
  • MSC-certified cod

What to avoid

  • Atlantic cod from UK seas
  • North Sea cod
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Atlantic cod


Also a chip shop favourite, haddock is generally a wild-caught sustainable option. However some stocks are running low and haddock often swim in the same areas as cod, meaning haddock fisheries may catch both species. You can protect juvenile fish by only buying fish that are larger than 30cm and avoiding buying fresh fish during the main breeding season of March and April.

Best choice

  • Haddock from the North Sea
  • Haddock from Scotland, Iceland or Norway
  • MSC-certified haddock

What to avoid

  • Small fish, less than 30cm
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Popular for its tasty, pink flesh packed full of omega-3 fatty acids, salmon is a versatile fish that can be wild-caught (oceans, lakes and rivers) or farmed. Both methods have some issues. Atlantic salmon is struggling in the wild and numbers are dangerously low. Some farming methods are very intensive, leading to environmental problems. Farmed salmon also have to be fed large quantities of wild-caught fish, which may not be sustainably sourced. Most of the salmon found in UK supermarkets will be Atlantic salmon farmed mainly in Scotland.

Best choice

  • Pink, red or keta salmon
  • Wild-caught Pacific sockeye salmon
  • Wild-caught Alaskan salmon
  • MSC-certified wild-caught salmon
  • Organic, Freedom Food or ASC-certified farmed salmon

What to avoid

  • Wild-caught Atlantic salmon
  • Uncertified farmed salmon
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Pink salmon


Tuna are a top predator that can grow up to 3m long and weigh as much as a horse! All the tuna we eat is wild-caught from the ocean. There are lots of different species and some are more sustainable than others. All bluefin tuna are either endangered or vulnerable. Skipjack and albacore (commonly used in tinned tuna) are usually the best choices but it depends on fishing methods. Some tuna are caught by gillnet which can be 10km long and trap all sorts of other species, including dolphins, sharks, turtles and seabirds. A 'dolphin safe' label unfortunately means very little.

Best choice

  • Sustainably caught skipjack tuna
  • Sustainably caught Pacific albacore tuna
  • Sustainably caught North Atlantic albacore
  • Tuna caught by pole-and-line, handline or troll fishing
  • MSC-certified tuna

What to avoid

  • All bluefin tuna
  • Yellowfin tuna from the Indian Ocean
  • Tuna caught by gillnet or drift net
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Skipjack tuna


Sourced from all over the world, prawns can be sustainable, depending on what species they are, where they're caught and whether they're wild or farmed. Generally small, cold-water prawns (often found in sandwiches and prawn cocktails) are the best option. King or tiger prawns from the tropics are often farmed very intensively and in ways that can seriously damage local communities and the environment. Some Asian prawn fisheries use bottom trawls – an industrial fishing method that scoops up everything in its path and damages the sea floor.

Best choice

  • Wild cold-water prawns smaller than a 20p coin
  • Northern prawns from Northeast Arctic, Canada or Greenland
  • Prawns labelled Organic or ASC-certified
  • Creel-caught Scottish langoustines (also known as Dublin Bay prawns or scampi)

What to avoid

  • Prawns caught using bottom trawl (otter)
  • Uncertified king and tiger prawns farmed in Indonesia, Vietnam and India
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Northern prawn

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