I know this will vary a lot based on where you live, but here in Denmark you can get sushi with a lot of our local smaller fish. Mackerel, herring and smelt are

I know this will vary a lot based on where you live, but here in Denmark you can get sushi with a lot of our local smaller fish. Mackerel, herring and smelt are quite popular. I think a lot of it is because "sustainability" as a "brand" is just good market value here, but it's also just as good as salmon or tuna. Very few places actually use farmed salmon, though I'm not sure the Alaskan salmon are really that much better than Norwegian farmed salmon from a sustainability point of view.