I have a close relative who has been part of fishing industry and his first question was why so many people on a longliner? 
A pole and line boat (Aku) boat yes but a longliner? 20 crew for a 79' vessel? Groceries alone would consume way to much space ( even if it is just rice, onions and by catch) 
The whole foriegn crew issue is bogus and invisible corporate welfare that punishes US workers by allowing underpaid, abuse, workers to undercut US workers who would never become whistle blowers on violations of environmental, regulatory, reporting crimes.
Before some one fakes a concern about what obeying the law and hiring workers to US standards would do to the price of fish remember these vessels get whatever the market will bear and any surplus is just pocketed by corporation. So any savings is never seen by consumer it is just cream skimmed off the top.