As someone who is interested in this topic (we eat a lot of fish) but not an expert, is this correct? ie as follows:
The most popular fish in the UK are cod and haddock, and these are the ones being affected by the shared waters with France.
There are many fisheries off our south and west coasts which aren't affected by the new agreement. Hake is caught there (similar to cod and haddock) and as someone said, mackerel, and other healthier oily fish.
Wicked Little Letters? (funny film of a long-forgotten case)