Any Vegetarians/Vegans here?

[The Grand Nudger]

There's no doubt that if we start messing with food production, we'll have to solve problems of nutrient distribution as well as that of calorie distribution. However, the fluid nature of the oceans means that you won't deplete nutrients in the same way that you would on land-locked farms

Unfortunately, and for the very same reasons, we lose control of a system like that. We have to maintain control, because we don;t want to expend the resources to allow the ocean to -do what it does- it would have to -do what we want it to do-....before it's a viable place for ag. Open water fish farms are already grappling with this (unsuccessfully).

Hmmmm. Why are we producing grains that aren't fit for human consumption? Could it be-- subsidies and tarriffs?

Actually, no. We're producing grain that's unfit because we can, and because it's often the best or most economical use of the land. Our hard drive into grain since 1940 or so left us with a bunch of cultivars that are monstrous in terms of biological competitiveness and hardiness, but not so useful as food - until we feed it to livestock (possible use as a fuel source, but that has issues too..I don;t want to compete with my car for water directly).

(the subsidies and tariffs are now, largely, centered around post production applications - for which grain finds itself almost uniquely suitable. They're stable, just like meat.)