Not necessarily that close. I know a guy who catches tuna in the Atlantic. Goes out with a rod, and catches about one per month. When he catches one, he immediately calls it in and heads to port. When he gets to port there's some Japanese guys waiting for him, they assess the fish, buy it for a significant amount of money, put it on ice and it's put onto a plane bound for Tokyo.

So for high end sushi, it's possible for to be on someone's plate in Tokyo about 20 hours after being caught in the Atlantic. Of course if it were Tokyo, time zones would make it weird to say "this morning" because of the dateline. But it wouldn't be too much of a stretch to say a fish caught in the Atlantic in the morning that's on someone's plate about 20 hours later was caught "this morning" and the chef may not be all that worried about the timezone dateline stuff.