On a more national level should those from the Northeast only eat striped bass, fluke, porgy?West coasters can only eat yellowtail, corvina, rockfish? No wild king or sockeye salmon for us east coast folks? Those from Mich. can only eat bass, walleye, perch, and pike? Much like fruits, vegtables, meats, cheeses (okay I am a little overextending here), I think there are some things that I appreciate from other parts of the world that I may not be able to get here easily or at all.
I will tell you, many people, even those in the culinary world have somewhat of a limited knowledge of the fish species. I am a strange person in that I am crazy about it because I fish quite a bit for fun all across the world and have a little background on marine fisheries science. There are subtle differences even within species within the same family. Here in the southeast our "glory" fish are mostly grouper and snapper. 99% of the popluation could not tell the difference from red snapper, vermillion, mutton, cubera, or mangrove snapper but to some people there is a difference (taste, fat content, flake, etc)....enough so that some people will pay more for it.
Another example is scamp grouper but most of you will never see it because there is no demand for it since most people think grouper is grouper. I will tell you that it is hoarded by those locals and the few regional chefs who can appreciate the fact that the flesh is of much high quality than the other available grouper. Another one is yellowedge grouper (which I am beginning to see labled as such in some places). Unfortunately, when word gets out people only want that fish and you get overfishing and mislabeling. Monkfish and triggerfish are both delightful but there was little demand so they were cheap and underfished here in the US until more recently they have become overfished in some parts. The New Orleans chef Paul Prudomme(sp) made redfish trendy with his blackened redfish dish and that fish needed federal protection after decimation from severe overfishing that came abruptly when demand came up. It was considered trashfish by many before then. Cobia is another fish to which I think there is no real sub. The list of such fish goes on and on.
Marketing plays a huge role in the fish that we know about and what people are willing to pay for and eat. There is not enough red snapper to go around so much of it is not even really red snapper but other species and you know what..... most people could not even tell the difference. Especially since the preferred presentation of market fish are in the form of fillets deception is common in the industry. Of course if all the fish sold as red snapper was really red snapper that would pretty much destroy that fishery (it happened to swordfish). Interestingly, one of my charter capts. asked if he could take some of our catch home for dinner. He left the red snappers and took home the mangrove snapper.
Sorry for the long post I just wanted to explain some viewpoints.......