INTRODUCTION 



1 he first portion of this work has given an account of the present-day condition 

 of the fisheries in the countries bordering on the North Sea. At the same time, the 

 sources of information general as well as statistical have been displayed, and the actual 

 information which the statistics of each country yield has been subjected to a preliminary 

 critical review. Some notion has been given thereby of the value of existing statistics, 

 and the way has been cleared for the general summary which has to bring the principal 

 data together. 



The importance of this general summary must be evident to all who have had 

 occasion to search for statistical data with regard to fisheries. What is, however, of equal 

 importance in the present instance, is the manner in which such a summary is made. 

 On the one hand, there is an enormous mass of statistical data in widely varying degrees 

 of accuracy, and on the other, there is a number of theories and ideas just as difficult 

 to coordinate as the data. The data may be summarised in almost any order; of far 

 more vital importance is the rank or value given to the various factors, which have at 

 one time or another been taken to indicate overfishing and decrease of fish. 



It has been maintained, for example, that statistics of the average catch per boat 

 were alone sufficient to prove the existence of overfishing and coming exhaustion of the 

 fisheries'. The point was overlooked here, that the average catch, whether per day or 

 per annum, is but a minor factor, depending entirely for its worth on the total catch 

 and total amount of fishing. 



Again, the practical problem of overfishing has been unnecessarily connected with 

 the problem of decrease of fish. In a recent paper ^, Dr. Petersen of Denmark has 

 based his discussion of overfishing on the assumption, that a decrease of fish has been 

 shown to have taken place. Further on in the same essay, however, he indicates that 

 overfishing can be conceived as occurring, even when the numbers of fish are increasing 

 (1. c, p. 590, note). In an earlier paper^ also, he had shown the converse truth, namely, 

 that a decrease of fish was not necessarily overfishing. In later pages it will be shown, 

 that overfishing may occur even when the quantities of fish remain practically stationary. 



1 Garstang, W., «The Impoverishment of the Sea>; Jour. Mar. Biol. Ass. vol. VI. igoo. The author 

 has now withdrawn from the position he took up in that work (see Evidence on the Sea Fisheries 

 Bill (H. L.), 1904. p. 115). 



2 Petersen, C. G. Joh.: '<What is Overfishing ^ ; Jour. Mar. Ass., vol. VI. 1903. 

 ^ Beretning fra den danske biologiske Station I. 1890— (91). 



