The difference is us. In a world sensitive to every nuance of use and consumption, fishes, like the sea in which most of them swim, are the new frontier. As the queer theorist and Sydney-based academic Elisabeth Probyn notes in her new book, Eating the Ocean (Duke University Press), our modern sensitivities — and the middle-class-driven search for ethically-sourced food — have resulted in a remorseless expansion. We are eating twice the amount of fish now that we were eating in the 1960s; the same period has seen a 50 per cent fall in fish populations.