COMMENT Doubts are mounting over whether scientific tagging can truly predict when stocks are being overfished. "There is no realistic way of knowing when the point of unsustainable fishing has been reached. It is certainly not a point that anyone should want to reach," says Laurentia Laracy, studying the Papua New Guinea tuna industry for his MA. Good point. So far, the best scientific estimates have not stopped massive overfishing in every region outside the Pacific, with corresponding loss of nutrients, jobs and businesses because of poor management.