like I was saying, many people would like us to abandon this large source of protein even though sustainable fisheries are possible.

Look at the fisheries in New Zealand or Alaska for examples of very well managed fisheries.

In many developing countries it's not a tragedy of the commons problem, it's a structure/stability problem. How can you ever have managed fisheries without political stability, or with stability but rampant corruption?

How can you have political stability without economic stability and food? It's a chicken and an egg problem.