I have never seen a spear fisherman in the UK. I guess they must exist as the gear is in a couple of shops I use, and a couple of people I have had on a boat talked about having freaked out some other club by spear fishing.
Other than the culturally objections I think the sort of fish and the typical viz would make it a bit pointless. If you want something to eat then a line works well. Many wrecks are used by sea anglers. I have a fine collection of fishing weights....
People commonly take lobsters, crabs and sometimes flat fish. Obviously size matters, in some places there are other licensing concerns including the odd no take zone.
In Ireland you cannot take lobsters on scuba, you see many more and much larger ones there.
"Hunting, fishing and shooting" is a class term here. None of those activities is considered cool, although apparently angling is the biggest participation sport in the country.