Fish ratings

Each of the fish included on the MCS websites have been given a rating to enable you to quickly identify species that are considered to be sustainably produced, and those species which are not. Where a species is considered as being:

• vulnerable to exploitation and/or assessed by the World Conservation Union (IUCN) as threatened
• from overfished stocks and/or stocks where data is deficient
• from poorly managed or unregulated fisheries
• caught using methods which are detrimental to other marine species and habitat

then they are more likely to have a higher score, and therefore a poorer rating, e.g. 4 or 5.

Conversely, those species from well managed, healthy stocks, which are harvested or produced in ways which have less impact on the environment or non-target species, or are from fisheries or aquaculture systems that are certified as environmentally responsible, are more likely to have a lower score, and therefore a higher rating, i.e. 1 or 2.

A species whose production method or management still needs to improve for them to be considered sustainable is likely to obtain an intermediate rating, i.e. 3.

The ratings appear in a traffic light-type format as indicated:

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

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

 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.fishonline.org for specific details.

 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 one which has improved from a 5 rating, and positive steps are being taken. However, MCS would not usually recommend choosing this fish. Follow developments for these species at www.fishonline.org

 Rating 5 (red) is associated with fish to be avoided on the basis that all or most of the above bullet points apply.

Fish to Eat are Rated 1 and 2 and Fish to Avoid are Rated 5

The rating system has been developed by the Marine Conservation Society as advice for choosing the most environmentally sustainable fish.

You can read more about our ratings system for wild fisheries in the Wild-Capture Methodology Handbook.