I haven’t heard of any problem there.
The fresh salmon goes by plane over the pole while frozen whole salmon is mostly shipped in containers via R’dam.
Other seafood, like mackerel, capelin etc. is usually shipped by reefer vessels, either via Suez Canal.
(The NWP or NSR when that is possible) Maybe now via Panama Canal (??)
My understanding is that Japanese preferences are based upon taste, fat content, and wild fish that are free from farmed fish parasites, diseases, and antibiotics, etc.
I am very surprised that none of the TV analysts/talking heads have mentioned this yet. It seems almost too easy for the PLAN /Russians, really. $10K (maybe $20K?) drone or a crude ballistic missile gets knocked down by a million dollar SM2 guided in by high tech DDGs…Intel bonanza for a potential enemy.