Man's efforts to manage marine resources have so far proved conspicuously unsuccessful. The prime cause is human greed, which we rationalise as a scientific concept and call achieving ‘maximum sustainable yield’, in the arrogant belief that we know how to achieve it. But, says the author, we do not know; we do not even know how to manage ourselves. He believes that one path man should explore is the scientific study of communication between individuals of a species – he suggests dolphins or whales – as a pointer to the possibility of communication between animals and humans. Such studies might, he thinks, help humans to shed their present arrogance and save us from the consequences of our destructive behaviour.