Are we actually much more cruel to fish than to other animals that we slaughter?

We suffocate them to kill them when we pull them from the sea. That's quite mean. Few people would advocate the humanity of killing a cow in the same way.

Fair enough. How much more would it cost / how much more would one have to pay for humanely slaughtered tuna and salmon, I wonder? Would there be a market? After all, we have certified-organic, fair trade, halal and kosher....

Just to call out - halal and kosher are _less_ humane than simply killing an animal in the usual industrial way

Or freeze them live into a block of ice.

Are you aware of how cows are actually killed?

I am. It's not very nice. Arguably nicer than suffocating though.

shrimp welfare is a real thing people argue for...

Citation.... not _needed_, but just morbid curiousity

> vegetarians still happily eat fish

I've not met any vegetarians in at least twenty years that eat fish.

This does not sound like any of the several vegetarians I know. Is it a cultural difference?

In Scandinavia in particular, there’s a tendency of pescatarians to refer to themselves as vegetarian for social convenience, but that hasn’t changed the definition of “vegetarian”.

> vegetarians still happily eat fish

Please look up what a vegetarian is.