Good Fish Guide: Shoppers urged to branch out from cod, tuna, salmon and prawns - for more sustainable seafood

An ocean protection charity is urging Brits to diversify the types of seafood they eat, with the country’s hunger for the ‘big five’ putting increasing pressure on wild populations.

The Marine Conservation Society has released its updated Good Fish Guide on Wednesday (3 April), which highlights seafood species under strain using a traffic light system; with ‘green’ fish the most environmentally-friendly choice, amber fish being okay but needing some improvements, and red indicating fish to avoid. Covering seafood sold or produced in the UK, the guide covers both farmed and wild caught species - and recommends more sustainable alternatives.

Good Fish Guide manager Charlotte Coombes said that most of the seafood eaten in the UK was made up of just a few different species, known as the ‘big five’: cod, haddock, salmon, tuna and prawns. However, this put a lot of pressure on a handful of wild stocks, she said, and risked driving unsustainable fishing and farming practices to meet the high demand for these species.

“Every fish species plays a unique role in the marine food web. By diversifying our consumption, we reduce the pressure on vulnerable ecosystems and help to support local fishers and producers,” she continued. “Not only are there lots of like-for-like options out there, but exploring lesser-known species introduces us to new culinary experiences, enriching our palates while lessening the strain on overexploited favourites.”

While it is possible to source ‘big five’ species like prawns or tuna sustainably, the Marine Conservation Society has come up with a list of sustainable seafood swaps for shoppers wanting to try a new, locally-caught alternative. Here are its tips for both buying more environmentally friendly fish, and what you can replace them with:

The Marine Conservation Society’s top sustainable seafood swaps

Cod to hake

The UK’s cod stocks have been low in recent decades due to a combination of overfishing and warming waters, the Marine Conservation Society said.

However, some Good Fish Guide ratings for cod have improved this spring, thanks to signs populations in the North Sea are beginning to recover - following new restrictions in 2019 which reduced fishing pressure. “Nonetheless, it’s early days and more needs to be done to get fishing down to sustainable levels,” the charity said.

Consumers were most likely to see Icelandic or Arctic cod for sale in the UK, and while this could be a green-rated choice, sustainability varied depending on how and where it was caught. If this information is available on the packaging, you can search how sustainable the cod you’re buying is using the Good Fish Guide (linked above).

The Marine Conservation Society also recommended swapping cod for hake, wild-caught in UK seas. “Similar to cod, hake has a meaty and flaky texture. This white fish can be swapped like-for-like in any recipe, and it’s great pan fried or in a stew. Thanks to good management and beneficial environmental conditions, hake from the UK is an environmentally friendly choice.”

Haddock to coley

The Marine Conservation Society’s Good Fish Guide listed wild-caught haddock as a generally sustainable option. However, there was a risk of cod getting accidentally caught in nets from haddock fisheries, it warned, as they often swam together.

The charity recommended swapping haddock for saithe, also known as coley, from the North Sea. “Coley is a white fish, closely related to haddock, but with a stronger flavour and meatier texture. Stocks of this species are booming, and it makes for a great sustainable swap from the local chip shop and can often be found frozen in supermarkets – perfect for a fish pie.”

Salmon to trout

According to the Marine Conservation Society, salmon is the single most popular fish eaten in the UK. But because of this popularity, numbers of wild-caught Atlantic salmon have fallen dangerously low, and it now has a ‘red’ rating on the charity’s Good Fish Guide.

Most UK supermarkets sell farmed Atlantic salmon, or wild-caught Pacific salmon. But once again, sustainability varied depending on how and where they were caught or farmed.

For a simple swap, the Marine Conservation Society suggested buying UK freshwater farmed rainbow trout instead. “A close relative of salmon, trout is similar in texture with a slightly stronger flavour. It’s widely available in supermarkets across the UK, both in fillets and smoked, and can be swapped in recipes like-for-like with salmon.”

Tuna to anchovies (or sardines)

Most of the tuna eaten in the UK was wild-caught from the ocean, where ratings ranged from green to red. This depended on the species and fishing methods - with skipjack or albacore tuna caught by either pole and line or troll - found to be the most sustainable options. You can often find information about the species and method in the ingredients list or on the bottom of the tin, which you can look up in the Good Fish Guide.

The charity recommended swapping tuna for anchovies caught in the Bay of Biscay, or MSC-certified sardines from Cornwall. “Much like tuna, anchovies and sardines are oily, fatty fishes packed full of omega-3 and nutrients. Available in tins and jars, they make for a healthy and convenient addition to your pantry and are a great replacement for tuna in a pasta sauce or salad.”

But it warned there were some red-rated options for these species too, and it urged shoppers to make sure to check the label for where the fish was caught, “and avoid sardines form the Bay of Biscay and anchovies from Portuguese waters”.

Prawns to mussels

Prawns for sale in Britain can be sourced from all over the world, but the charity’s Good Fish Guide said it was possible for them to be sustainable. But this sustainability was “greatly influenced” by what species they were - such as king, tiger or cold water prawns - and how and where they were caught or farmed. The Marine Conservation Society recommended looking out for eco-labels like organic, MSC or ASC on your prawns - which were often the most environmentally friendly choices.

For an alternative, it suggested swapping prawns for UK rope-grown mussels. These mussels are usually grown using low-impact methods, harvested by hand, and get all the food they need from the sea around them, the charity said, making them one of the most sustainable and ocean-friendly seafood options.

Mussels are also packed full of protein and nutrients and can be swapped in for prawns in most recipes, it said, from pasta dishes to Thai curries.

Trying a plant-based option

As part of NationalWorld’s vegan review series, I recently tried Future Farm’s completely plant-based ‘future tuna’ - and can vouch for it making a great tuna mayo sandwich. It’s also packed with protein and has added Omega-3 fatty acids, like its meaty counterpart. You can read the full review here.

Plant-based meats have come a long way in recent years, and there are alternatives to a bunch of different kinds of seafood readily available at supermarkets. Trying one out can be a good way to steer clear of some of the other environmental concerns surrounding the fishing industry too - including carbon emissions and plastic waste from the global fishing industry - depending on how it was produced.