There's no way mackerel are unsustainable, unqualified. Maybe not at present net-dragging prices, but I've been mackereling a couple of times, with crab lines

There's no way mackerel are unsustainable, unqualified. Maybe not at present net-dragging prices, but I've been mackereling a couple of times, with crab lines trailing off the back (while we headed to a deeper spot for rod fishing), absolute easiest fishing imaginable, it doesn't qualify as sport. Some 'bycatch', but only other edibles like swordfish. And of course fishing like that you can set them free if not desired anyway. Depending on season I can't really imagine it could be much more expensive. Afaict the only reason there isn't more commercial action from small boats is the competition from big trawlers. If you eat mackerel at an independent restaurant in a coastal town on the UK I think there's a good chance it's a local catch by a local fisherman. They're just not going to get the bigger contracts, nor pieces of them when they can be filled in total by a bigger operation.