— 55 — 



certainly the case on commencement of more intensive fishing, then necessarily, as can 

 be shown, the number of males will show a greater decrease than that of the females 

 (since the larger males are, to begin with, fewer and older than females ot equal size) 

 and not only this, the point of intersection of the male and female curves of frequency 

 will fall to a lower length. 



The fishing grounds of the White Sea, or rather, the Barents Sea, have only been 

 fished by trawlers since 1905, and yielded in the beginning, as also now, relatively 

 (i. e., per unit of fishing power) great quantities of very large plaice. The measure- 

 ments which up to now have been carried out with these plaice are unfortunately only 

 few in number, only a little over 11,000; they show the following composition of 

 the catches. 



Table 10. Composition of measured plaice from the Barents Sea. 



We see, that far more large plaice are landed from the Barents Sea than even 

 from the Iceland waters; whereas the Iceland plaice show 50^/0 over 35 cm. we have 

 here no less than 89% of this size. It must, however, be born in mind, that in the 

 Barents Sea, as in the case of Iceland, small plaice are also to be found, and must be 

 found, in quantities, since the Barents Sea is a separate plaice region for itself, and moreover 

 with distinct local racial character. The most prominent racial characteristic of the 

 Barents Sea plaice is, that it is an extremely slow-growing race; i. e., the fish are 

 considerably older than North Sea or Iceland plaice of equal size. According to the deter- 

 minations of age by the bones, which have been carried out in Germany, the Barents 

 Sea plaice, for instance of 40 cm. long, are already on an average 15 to 20 years old, 

 while North Sea and Iceland fish of the same size are on an average only 6 years 

 old. Plaice from the Barents Sea over 50 cm. long are almost invariably more than 

 20 years old and some of the fish examined had reached an age of from 45 to 50. 

 In the North Sea and Iceland waters, plaice of 50 cm. are fish of 8 years old and up- 

 wards; the olde.st of the North Sea plaice examined were from 30 to 33 years old. 



The plaice from the Barents sea resemble, in this racial characteristic of slower 

 growth, to a remarkable degree the fish of the Baltic, and especially the eastern Baltic: 

 there also we find plaice of 40 cm. at an age of 20 years or more. A strong point of 

 difference between the Baltic and the Barents Sea lies however in the fact that in the 

 Baltic the utmost limit of growth is probably attained at a length of 40 cm., with an 

 age of 20 years, no plaice being found beyond this, whereas in the Barents Sea the 

 plaice reach fiilly 30 cm. more in length and 30 years more in age. 



