— XIII — HOEK-INTRODUCTORY 



The problem of the so-called overfishing. Concerning the great eco- The problem ot 



* overfishing 



nomical importance of the second main question whose treatment was undertaken 

 by the international investigations, but few words are necessary. The sea-fisheries 

 in most of the countries bordering on the North Sea developed to an important 

 industry during the foregoing century, and in many this development still contin- 

 ues. The production of the sea is enormous: is it sufficiently great, however, to 

 satisfy the demands upon it? and if well-grounded doubts concerning this arise, is 

 it not time to recommend the consideration of how the productivity can by pro- 

 tection be eventually increased? 



Huxley was of the belief in his day, that the productivity of the sea was 

 so great, that man's influence on its wealth was scarcely worthy of regard by 

 comparison. The experience of the past 25 years has shown, however, for the 

 North Sea and for certain species, that man's influence is not by any means so 

 harmless. It is the resident species in the North Sea, the so-called 'stand-fish', 

 which specially come into regard here, and amongst these, more especiall}--, the 

 flat-fishes (Pleuronectidae), which live on the bottom and are well suited to the 

 trawl-fishery. Amongst the round fishes, the haddock may be added to these. 

 When the enormous development of the trawl-fishery in the North Sea is taken 

 into consideration^ there can be no wonder, that it is specially these fishes and 

 not the migratory fishes occasionally visiting this sea, which give rise to the view 

 that the so-called overfishing is taking place. 



Is there overfishing in the North Sea? This is indeed the first question ''^ °^<^''f"''""g 



... - taking place? 



which must be settled, and to answer which, the International Council appointed 

 a special committee at its first meeting (Copenhagen, July 1902). From the begin- 

 ning, overfishing was understood to be too severe fishing, and this meant that 

 more fish or better qualities of fish were taken away than the natural produc- 

 tion could regularly replace. If overfishing is taking place, then, consequently, 

 the catch gradually becomes smaller, quantitatively or qualitatively. Since other 

 circumstances, however (unfavourable physical conditions, for example) may 

 possibly cause a similar decrease in the catches, occasionally at least, and a not 

 unimportant fluctuation may thus arise in the fisheries, it is only a decrease 

 extending over a long period of years that can be taken as final evidence of the 

 occurrence of overfishing. 



It had therefore to be investigated first of all, if the catch of the principal evidence from 



^ ' 1 • J r ^" catch 



fishes of the North Sea really displayed such a decrease over a long period of 

 years. By catch is intended total catch and not the average catch per day or per 

 fishing vessel. If the number of vessels fishing on a certain region changes or 

 increases, or if the number of fishing days increases, owing, for example, to the 

 more general use of steam power, it is then very possible, that the average catch 

 per day or per vessel will decrease without any diminution in the productivity. 

 On the other hand, the total catch may be used with certainty for the answering 

 of the question, whether overfishing is taking place; certainly, it is conceivable, 

 that the total catch may decrease because fishing has been carried on during fewer 

 days and with fewer vessels, and it is not excluded, that this may have occurred for 



