I agree this seems like a meritable solution. But I think this also bears quite close resemblance to how the taxi and medallion system sprung up in many cities, ultimately corrupted by the economic value of being in this exclusive club.

The problem is that mostly we don't farm ocean life - we just hunt it, on an industrial scale.

More than half of the seafood consumed globally is farmed:

http://www.nmfs.noaa.gov/aquaculture/faqs/faq_aq_101.html

Hmm, thanks - that's much higher than I thought. Still, leaves 50% hunted though, which is very high.

If 50% of the animal protein that we eat was hunted instead of farmed, we'd eat the last elephant, tiger, chimp, giraffe, etc... by Friday.