Just to play the Devil's advocate I wonder what the cost of comercial production would be if you included all the transportation and maintanece facilities cold storages etc. Most of the stuies I have seen supplied by sportfish advocates usually go no further than ex vessel pricing (amount paid to the fisherman). This would be akin to adding up only the rod and reel and one set of terminal tackle to the sport angler for that one fish he or she caught. As opposed to sleds driftboats 4 wheel wonders depth finders on and on.
All of these are discretionary purchases and if there were no fishing at all the money would show up in the economy somewhere else. However if you have a bussiness that competes for these discretionary funds you should ,I guess, come up with lots of numbers to support your bussiness or lifestyle.