Covering seafood sold or produced in the UK, the the Marine Conservation Society’s Good Fish Guide shows consumers and businesses which seafood options are the most environmentally friendly by using a simple traffic light system depending on where and how a species is caught or farmed. Green is the best choice, amber is OK but improvements are needed, and red indicates fish to avoid.  

Every rating on the Good Fish Guide is carefully researched and rigorously reviewed, ensuring the guide is accurate, transparent and credible. After the charity has researched and drafted a set of ratings updates, these are sent out to consultation, where scientists, fishermen and businesses review the proposed updates and provide extra information. When the consultation has closed, any feedback is considered. The ratings are then finalised and published – these launches happen twice a year in April and October.  

The charity creates one rating for each species farmed by a specific method in a specific area. Four different factors are rated to achieve an overall rating: fish feed, environmental impact, fish welfare, and management. For wild-caught seafood one rating is given for each fishery. A fishery is a species of fish or shellfish from a specific area caught in a specific way. There are three main things assessed here: stock status, management, and capture (or fishing) method impacts.

Most of the seafood consumed in the UK is made up of just a few different species, known as the big five: cod, haddock, salmon, tuna and prawns. This puts a lot of pressure on a handful of wild stocks and creates demand that drives unsustainable fishing and farming practices.  

Charlotte Coombes, Good Fish Guide Manager, said: “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. 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.” 

As an example, the updated ratings suggest swapping cod for hake as UK cod stocks have been low in recent decades due to overfishing and warming waters. Some Good Fish Guide cod ratings this spring have seen improvements thanks to signs that populations in the North Sea are beginning to recover. This follows a series of restrictions since 2019 that have reduced fishing pressure – showing what can happen when managers respond to scientific evidence. Nonetheless, it’s early days and more needs to be done to get fishing down to sustainable levels. You’re most likely to see Icelandic or Arctic cod on sale in the UK, and while this can be a green-rated choice, sustainability varies depending on how and where it was caught. The Marine Conservation Society recommends 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, according to the Good Fish Guide. 

The Marine Conservation Society further recommends swapping prawns for UK rope-grown mussels. These mussels are a seafood superhero, grown using low-impact methods, harvested by hand and they get all the food they need from the sea around them. This makes them one of the most sustainable and ocean-friendly seafood options. 

Salmon is the single most popular fish consumed in the UK. However, because of this popularity, numbers of wild-caught Atlantic salmon have fallen dangerously low, and it is red-rated on the charity’s Good Fish Guide. Most UK supermarkets sell farmed Atlantic salmon, or wild-caught Pacific salmon. Sustainability varies depending on where and how they’re caught or farmed. 

For a simple swap, the Marine Conservation Society suggests 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.   

Furthermore, the Good Fish Guide suggests swapping tuna for anchovies or sardines as the majority of the tuna consumers eat in the UK is wild-caught from the ocean, and ratings range from green to red. The charity recommends 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. 

While the Marine Conservation Society’s Good Fish Guide lists wild-caught haddock as a generally sustainable option, there is a risk of cod getting accidentally caught in nets from haddock fisheries as they often swim together. The charity therefore recommends swapping haddock for saithe, also known as coley, from the North Sea. 

More information on the Marine Conservation Society’s Good Fish Guide can be found on the charity’s website. 

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