PREFACE 



The present publication is a considerably amended and supplemented version 

 of the second edition of my book The Fauna and Biological Productivity of the 

 Sea, published in 1947. A large amount of new research has been gathered 

 during the last fourteen years. Some bodies of water have considerably 

 changed their hydrographical and biological aspect during that time. 



I have found it necessary to add a section on 'The Far Eastern Seas', which 

 was not included in the Russian edition. An Introduction has also been added. 

 Since I did not wish to make any considerable increase in the size of the book 

 I have shortened the sections on the Northern and Southern seas. Some illus- 

 trations have also been omitted. 



I set myself the task of collecting in this book the results of research carried 

 out in seas adjacent to the frontiers of the u.s.s.R., and only in the section 'The 

 Far Eastern Seas, have I gone beyond the boundaries of the u.s.s.R. in order 

 to give a summary of the results of Soviet deep-water explorations in the 

 Pacific Ocean. 



In the Russian edition of my book many problems of marine biology are 

 included in the first volume and are not discussed in further detail in the 

 second. These problems include, for instance, the conception of the biosphere, 

 biological productivity, the problem of brackish-water environment, bio- 

 geographical zonation, the practical significance of marine organisms, the 

 problems of acclimatization, and others. All these problems had to be ex- 

 cluded, the more so because of the addition of the large new section. 



Unfortunately I have also been unable to include in the book a more de- 

 tailed exposition of comprehensive and numerous monographic studies on 

 individual groups of marine organisms, or of the large number of works on 

 the ecology and biology of individual forms. These works form an abundant 

 literature in Russian. 



I have thought it essential to give a short physico-geographical introduction 

 to the description of each sea. Although a zoologist, I have considered it 

 expedient to include some botanical data, in order to give a more complete 

 biological picture. 



The land mass of Europe and Asia is distinguished from other land masses in 

 that its shores are almost entirely bordered by coastal seas. This is particularly 

 true of the Soviet Union ; the south eastern coast of Kamchatka and the Kuril 

 Islands alone being washed by ocean waters. It is not surprising that these 

 coastal seas have been the subject of many different and complex marine 

 research studies, and in particular the Azov, Caspian, Barents and Black 

 Seas have been systematically explored. Equal attention has been given to the 

 study of plankton, benthos and fish. 



This book has a strongly quantitative approach. There are quantitative 

 studies of the feeding habits of fish ; similar investigations of the distribution 

 of flora and fauna throughout the seasons make it possible for general con- 

 clusions about biological productivity to be drawn. 



The author has taken part in many expeditions to both the northern and 

 the southern seas and has devoted fourteen years to the study of the Far 



