fivecandles, the "natural" argument was brought up by the vegetarian side, not by the meat-eaters; they are just responding
as it so happens, some of my relatives still live in places where hunting and fishing are natural parts of the economy, and most vegetables will not grow; you don't have to go to Greenland to find countryside which is simply not suitable for raising crops
Welsh mountainsides are another example
I think being a vegetarian is a perfectly valid choice
but I see why the people at home need to be fishermen; it's harder to be a farmer if you happen to live on a granite rock
the important thing is that they must now become sustainable fishermen or their livelihood will be gone very shortly
and any meat farming needs to be drastically reduced and restricted to those areas which are naturally suited to it- i.e. not the Amazonian rainforest, as is currently happening
and that means that most of us, here, in urban settings, will need to eat less meat and fish
in fact, what I think we will have to do if we want to save the planet is getting used to the idea of eating less varied food, trying to stay more local
my ancestors may have had a dull time on their boiled spuds and salted herrings
but heck! they were sustainable