This is the sequel to the World of Plankton, the first part of Sir Alister Hardy's great survey of life in the Open Sea. It in fact deals with everything in the sea that depends on plankton.
Once more it is the work of an enthusiast, written with the same lucidity and the same delightful style, both informal and informative, that was so highly praised when Part One was published. Indeed, to quote the Manchester Guardian, 'the author is a complete master of his subject and no comparable book has been published in this generation'.

In addition to writing of the marine fish of our waters as living creatures taking their part in the general community of the sea, Sir Alister also deals with the fisheries as part of that general natural history. He deals with the animals on the sea bed, so important in supplying food for the bottom living fish, and with fish parasites. Whales and reptiles come within the book's scope, and there is a sketch of the development of fisheries research. The book ends with a discussion of the future development in the fisheries as a result of advances in technology and research.

As in Part One, the 16 pages of remarkable colour illustrations are all from the author's own paintings and the 68 black and white photographs are mainly by Douglas P. Wilson.