I'm not directly responding to your comment but some of the best sushi chefs use fish that was frozen. And this says all sushi served in the US has to be freezed to kill any bacteria-
For those that don't click through, the only exception is tuna. It lives deep enough in the ocean and is clean enough to get around the "must be frozen" rule.
https://mobile.nytimes.com/2004/04/08/nyregion/sushi-fresh-f...