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 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.
Read how MCS determines the ratings of each fish