We face much different challenges in the agricultural food sector than we do in the fishing sector. Why is this? Land and crops are privately owned and operated by profit maximizing firms while the oceans and their fishy inhabitants are unowned or publicly owned. Nobody has an incentive to increase the supply of fish or decrease fishing yields.
We should allow firms to breed and patent various, subtly different varieties of fish and give them the exclusive right to breed, grow, plant and harvest that particular DNA strand. Then, allow open and limitless fishing to occur but allow the firms to charge fisherman a price per pound caught. Firms are incentivized to increase supply while fisherman are incentivized to economize on consumption. Potentially increasing global fish populations while increasing the yield of fishing vessels.
A global enforcement body could be created as a trade group or an arm of the WTO or UN which raises funds for enforcement.
Just thinking out loud.