British fish: which should you buy if you want to eat sustainably? | Food & drink industry

British diners were this week warned off buying a dozen new types of seafood – including dover sole – from the Irish Sea due to depleted fish populations. They joined the growing “red” or “avoid” list in the Good Fish Guide, which aims to help consumers make ocean-friendly choices.

The guide, compiled by the Marine Conservation Society (MCS), provides environmental ratings using a traffic light system. But of the 337 wild fisheries around the British Isles, only 13% have a green rating while 25% are red. So what do you need to know to make sustainable fish choices?

What has happened?

In the autumn update, 117 seafood ratings were reviewed by the MCS, leading to 53 changes with 19 moving down the sustainability scale. Of these, a dozen “regrettably received red ratings”.

Those downgraded to red include: pollack caught in the Channel and Celtic Seas; beam-trawled plaice from the eastern Channel; dover sole from the Irish Sea; prawns from the North Sea and sea bass from the west of Scotland. There was a modicum of good news with North Sea and Channel mullet and North Sea sprat moving up to amber, resulting in a net increase of eight on the red list.

How can I make sure the fish I eat is sustainable?

A good place to start is on the Good Fish Guide website (it can also be downloaded on to your phone) so you can check a fish rating when you are planning a meal or actually in the supermarket. “We always recommend people look for ‘what, where and how’ on labels,” says Good Fish Guide manager Charlotte Coombes. “If that’s there you’ve got enough information to get a rating.”

Alternatively look for the Marine Stewardship Council’s (MSC) blue tick on wild-caught fish and seafood (or the Aquaculture Stewardship Council’s (ASC) green logo on farmed products). The label is the “simplest way for the consumer to know that they can eat the seafood without having to worry about whether or not it is sustainable”, says George Clark, the MSC’s UK & Ireland programme director. This applies to everything from tinned tuna, fresh sardines or cod on the fish counter or on fish finger packs.

Now I know what to look for, what fish should I buy?

The reality is fish lovers tend to eat the same things over and over, with 80% of the seafood eaten in the UK made up of the “big five”: cod, haddock, salmon, tuna and prawns. This puts a lot of pressure on a handful of wild stocks and, while there are some sustainable sources, experts have come up with some sustainable swaps. In place of cod it suggests European hake which has the same meaty texture. Instead of haddock, buy North Sea plaice. If it has to be tuna, buy skipjack or albacore caught by pole & line (or give sardines a whirl).

Everyone tells me to eat more oily fish, such as salmon, is that OK?

Avoid wild-caught Atlantic salmon which is on the red list. Instead, buy Pacific (pink, red or keta) caught in Alaska, organic or ASC-certified Scottish salmon. “Anything that relies on rivers as well as the sea, like salmon and eels, is really under pressure,” says Coombs. Easy-to-cook salmon regularly tops polls as the nation’s favourite fish and while it’s not easy to replace its orange-pink flesh, any firm white fish such as hake or haddock can be cooked in a similar way. Another option is farmed rainbow trout. Just stick to the same thickness and type of fillet in the recipe.

What about prawns, are there any good options?

Prawns can be sustainable, depending on the species, where and how they were caught or farmed, so again check the information on the packet. Arctic northern prawns (or shrimp), for example, with a green rating are the best option whereas North Sea ones have just joined the red list. For king and tiger prawns look for eco-labels, including organic or ASC, and avoid buying uncertified ones from places like Indonesia, Vietnam and India.

Does this mean I should stop going to the fish ‘n chip shop?

No, you can still go out for fish and chips. Andrew Crook, who speaks for the industry as the president of the National Federation of Fish Friers, suggests customers ask shop owners about their policy but insists the industry is focused on sustainable sourcing. “Without cod and haddock there won’t be any fish shops so it is in our interest to have well-managed fisheries,” he says, adding that the majority of cod and haddock is coming from the Barents Sea or around Iceland. “We’d always encourage people to be a bit more adventurous, there’s a lot of hake that comes into the UK that is caught by the domestic fleet.”

Is sea bass totally off the menu these days?

No it’s not, but the guide advice is to buy the farmed fish. In 2015, sea bass was in “real trouble”, says Coombs. “They were quite concerned about stocks and brought in emergency management measures and it has been recovering. We’re a still bit worried about wild sea bass as stocks are not where they should be. Going for the farmed option takes the pressure off the wild population while it’s still recovering.”

Is farmed or wild fish better from an environmental point of view?

Neither. Both systems have good options and really unsustainable ones. Wild capture fisheries can be harmful to the seabed and result in unwanted bycatch, while aquaculture can affect the environment through pollution from chemicals, escaped fish and disease. For farmed fish customers should seek out the ASC or “RSPCA-assured” labels for peace of mind. Waitrose, for example, says its “responsible seafood” policy considers issues pertinent to each system, with catch method most relevant for wild fish, while responsible sourcing of feed applies to farmed.

Should I just buy Omega 3 pills instead? Where does that fish oil come from?

Swallowing a golden-coloured fish oil supplement is often touted as a way of getting a health-boosting shot of omega-3 nutrients every day without having to eat any fish. While some fish oil is made from cod, mackerel or sardines, most of its comes from Peruvian anchovetas, a type of anchovy, with the Guardian reporting concerns about overfishing and environmental damage caused by the industry. There are, however, a growing number of supplements badged as containing sustainable fish oil on the shelves of specialist stores like Holland & Barrett as well as in the supermarket, with Tesco and Morrisons offering them in their own brand ranges.