This evaluation of some of the developments in ocean culture and catch, probable, possible, or conceivable, is underscored by description of oceanographic methods and instruments--the Nansen bottle, the Pinger, the Piston Core Sampler. He deplores the exploitation of resources such as the whale, makes a case for aquaculture: ""Clearly man must do in the sea what he has done on the land: he must engage in marine animal husbandry."" Man now draws 60 million metric tons of fish from the sea, could extend his catch, using methods from net to electrofishing. He could extend as well his use of fish products: fish meal, now fed mainly to animals, moved up on the food chain; fermented fish, FPC (Fish Protein Concentrate). And with the land becoming increasingly over-populated, Mr. Bardach forecasts floating cities on the water that covers 70.8% of the globe. The author of Downstream has written another fluent, informative book.