The most successful people change with the times. In this case some kind of fish farming is your best bet for long term sustainability. Just like foresters plan

The most successful people change with the times. In this case some kind of fish farming is your best bet for long term sustainability. Just like foresters plant trees, or hunters are involved in wildlife conservation efforts. Obviously they don't always do that, but to assume you can simply run things the same exact way as your ancestors is foolish.