The sustainability of fish can vary significantly depending on how and where it has been caught or farmed. Many single species are caught or farmed in a variety of ways and this range shows that, within a species, some sources may be more sustainable than others.

To find out specific ratings, click on the 'Show options for this fish' button under the image of the fish.

'Best choices' are rated 1 and 2 (green), 'Fish to Avoid' are rated 5 (red). Ratings 3 and 4 mean 'Think' (yellow and amber), as there are better rated alternatives.

Fish that are under review are shown with a question mark icon and no rating.

This system has been developed by the Marine Conservation Society to help consumers and businesses choose the most environmentally sustainable fish.

Seafood sources indicated as, 'To be assessed', are those that have not yet been assessed and assigned a rating or are undergoing a period of review. These include sources previously rated by MCS for which the rating has lapsed, due to changes in the market or MCS priorities and resources. Given that these sources are not fully assessed, the profile should not be used to infer the current sustainability of the fishery or farmed species.

If you are interested in the sustainability of this seafood source, please let us know by emailing ratings@mcsuk.org

Rating 1 (light green) is associated with the most sustainably produced seafood.

Fish to Eat are rated 1 and 2, Fish to Avoid are rated 5. Ratings 3 and 4 mean don’t eat too often.

This system has been developed by the Marine Conservation Society to help consumers choose the most environmentally sustainable fish.

Rating 2 (pale green) is still a good choice, although some aspects of its production or management could be improved

Fish to Eat are rated 1 and 2, Fish to Avoid are rated 5. Ratings 3 and 4 mean don’t eat too often.

This system has been developed by the Marine Conservation Society to help consumers choose the most environmentally sustainable fish.

Rating 3 (yellow) based on available information; these species should probably not be considered sustainable at this time. Areas requiring improvement in the current production may be significant. Eat only occasionally and check www.goodfishguide.org for specific details.

Fish to Eat are rated 1 and 2, Fish to Avoid are rated 5. Ratings 3 and 4 mean don’t eat too often.

This system has been developed by the Marine Conservation Society to help consumers choose the most environmentally sustainable fish.

Rating 4 (orange) should not be considered sustainable, and the fish is likely to have significant environmental issues associated with its production. While it may be from a deteriorating fishery, it may be one which has improved from a 5 rating, and positive steps are being taken. However, MCS would not usually recommend choosing this fish.

Fish to Eat are rated 1 and 2, Fish to Avoid are rated 5. Ratings 3 and 4 mean don’t eat too often.

This system has been developed by the Marine Conservation Society to help consumers choose the most environmentally sustainable fish.

'Red improver' ratings are assigned to seafood sources which have been assessed and rated 5 (red) due to significant environmental concerns with one or more aspects of their management, capture or production, yet credible efforts to improve these issues have been agreed through a Fisheries or Aquaculture Improvement Project – a FIP or an AIP - and work is underway. Such projects are normally publicly listed at www.fisheryprogress.org. MCS wants to encourage environmental improvements in fisheries and fish farms, and so does not recommend avoiding these sources, as we normally do for seafood rated 5 (red rated).

'Best choice' fish are rated 1 and 2, Fish to Avoid are rated 5.

This system has been developed by the Marine Conservation Society to help businesses and consumers choose the most environmentally sustainable fish.

Rating 5 (red) is associated with fish to be avoided on the basis that all or most of the criteria for sustainablilty have not been met.

Fish to Eat are rated 1 and 2, Fish to Avoid are rated 5. Ratings 3 and 4 mean don’t eat too often.

This system has been developed by the Marine Conservation Society to help consumers choose the most environmentally sustainable fish.