Some are - seems herring has made come back 'cause we don't eat it any more.Are you just stupid .......you don't think the EU are after fishing in our internationally recognised waters ....Wake up man.
I mentioned shell fish not what you bought from a fish and chip shop. We don't eat as much of that as we could either.
I typical UK fish and chip shop eater is pretty hooked on cod but due to shortages may decide to eat haddock which is also rather overfished. Decent sized plaice are a thing of the past. Plenty of dabs about in places but rather small and don't keep that well so not commercially fished. Skate - once popular, rays - same, Pollock that's what some cod may turn out to be.
The UK market generally in this area just isn't big enough to justify lots of modern trawlers so the foreigner fish for many of them instead also paying UK fees.