From January through October of this year, and most especially through the Canadian lockdown, I helped operate a "corner store" concept for my company --4000 sq feet of grocery attached to a pharmacy in the Oakridge shopping mall. An unwelcome legacy of the old Oakridge store was a queue of items that had gone out of stock just before the old store shut off automatic replenishment. Unless we manually removed them from outgoing orders, we got a very eclectic set of items, again and again.
Yes, they included an item identified as kippered herring, although as far as I can tell it's not quite the same preparation as the kippered herring that comes in cans. These particular kippered herrings had to be stored frozen and cooked before eating. I bought a couple and they were . . okay. Products of the Scottish herring fishery, they are Relevant to events of today, as fishing rights come up under Brexit. Foreigners fish some fishing grounds in British waters, and it is perhaps a matter of urgency that they be made to stop. Because of conservation. Or jobs. The fact that the British are great fishers but terrible seafood enthusiasts is a very interesting subtext to the discussion, and perhaps a historical question of some significance.
Getting back to the fish I ate (not a normal part of my diet, either), Alison Mary Locker explains that these short-life preservation techniques came into vogue in Nineteenth Century London because the fish would last long enough to be distributed by costermonger, but didn't ask too much in the way of cooking equipment and time. She's probably not the only historian to explain such things, but, in comparison with agrarian history, there's a bit of shortage of fishing/salt industry historians. In spite of that, there's been some movement in the field in the last few decades, perhaps not entirely synthesised yet. (I keep finding references to Kurlansky's Salt in academic monographs. Surely if there was something less popular, it would be cited instead?)