The problem with most of the oceans is that once outside the 200-mile coastal zone, there is no governing authority. It's every ship for themselves. And poaching is a serious problem a lot of places that do have a legal authority, but not much money to spend on enforcement. So the alternative would have to be economic; tariffs, import bans, trade sanctions, etc. to get countries to police and control their own fleets and coasts.
I have a fishing trip planned off Gulf Shores, AL next month...Does this mean I can’t go???
The tragedy of the commons. Perhaps the solution lies in bidding out the right to fish up to legislated limits, with the proceeds funding enforcement. This might drive up the cost of seafood, albeit to its true market level.