In the UK the Marine Conservation Society has issued this guideline on mackerel:
We’ve updated the environmental sustainability ratings on our Good Fish Guide in line with the latest scientific advice.
We reviewed 186 environmental ratings for seafood, with 20 seafood ratings moving to the ‘Fish to Avoid’ list and only 15 seafood ratings joining the green-rated, ‘Best Choice’ list with this season’s ratings update. Unfortunately, Northeast Atlantic mackerel has moved on to the amber list, having been on the charity’s green list since before 2011.
Populations of mackerel in the past have been large enough to withstand fishing, however, in recent years the population has been in steady decline.
An amber rating means that improvements are needed – in this case, better management to end overfishing of the stock.
Mackerel is caught by various states, including Norway, Iceland, the UK, and the EU. Currently, these countries are not working together to tackle overfishing of the species.
Everyone involved generally agrees that scientific limits should not be exceeded, but they don’t agree on how to divide the catches between themselves. Consequently, quotas have been higher than scientifically recommended limits since 2009, exceeding them by as much as 80% in some years.
In October 2021, the main fishing states again agreed that total mackerel catches in 2022 should not exceed the scientific advice, but not how the catches should be divided. The combined catch limits set by all countries for 2022 exceeded advice by 42%.
Read the whole recommendation here.