Not really a monopoly, but yeah, what he said. I, however, am in favor of more "farm" raised fish and less wild caught. Really don't think the death of the LFS has any impact on that though. It's not like any LFS is importing anything.
If you care about the community you live in, spend your money at businesses owned by people that live in that community. They will, in turn, do the same. If you don't give a flying-F, then Wal-Mart it all the way.
All that said, there were a pile of shady and stupid LFS's that got run out of business by PetSmart/Co. It's a shame that the ones that contine to survive are the ones that are good at math/advertising/and running a business...rather than the ones that were knowing a thing about the stuff they sold.