It has to do with direct cost of production - so long as labor in Asia plus transportation costs is less than labor costs in the US, there's a buck to be made. Things like the pollution and CO2 that come from 12K miles over water are externalities.

Agreed that it's absurd, but there aren't a lot of people in CA who are willing to dress seafood for a wage that matches the combined transport / Asian labor cost.

I suspect the wage would have to be under CA's minimum - so the producers are stuck for as long as those of us who cook seafood are unwilling to buy it in 'as caught' condition.

That said, the cost of transport is going up, and China has pretty much run out of super cheap labor (no more people straight off the farm) so the producers might move to a closer pool of inexpensive labor (maybe Latin America?). We'd still be getting twice-frozen seafood, but the journey would be shorter.