— 20 — 



i. e., those under 25 cm., which amount in number to about one-third of the total 

 quantity of all the landings, no less than J"] ^jo are taken from the three areas As, B3 

 and B-i. Of the large plaice (over 35 cm. long) which make up about 10 "/o of the 

 total number of fish in the EngHsh landings, nearly three fourths are drawn from 

 Areas B3, Ca, Ci, D and E and only about one-fourth from the southern areas Cs, 

 B3, B4 and A."!. This varying composition of the landings from the different areas is 

 also entirely in agreement with the general law of distribution of the plaice in the 

 North Sea, according to which the size and age of the plaice in a given district of the 

 North Sea are inversely proportional to the density of their occurrence, and directly 

 proportional to the distance of the ground from the coast, and its depth. Fig. 3 here 

 appended gives a clear view, in chart form, of the relative quantities of undersized 

 plaice (under 25 cm.) and large plaice (over 35 cm.) in the landings from the various 

 parts of the North Sea. 



The areas can be divided into three groups, according to the size of the plaice 

 and the composition of the landings. 



1. The four areas Ai, Bi, Bz and C-.i form, (with Ai), the southern, most landward 

 plaice zone of the North Sea. From here are drawn the greatest quantity, in number 

 and weight, viz., yearly about 15 million kg. and 75 million fish, of an average weight 

 of 200 gr. The value of greatest density of the plaice measured is from 24 to 25 cm. 

 the median from 24 to 26 cm. More than one-third of all the plaice (37 to 55 %) are 

 under 25 cm. long and can tlius be designated as "tmdersized" plaice, more than two- 

 thirds [ôj to 95 Vo) are under 29 cm. and can be called "smair plaice. The "large" 

 plaice, i. e., those over 35 cm. long, amount to less than 8 "/o (7 to i "/")■ the very 

 largest and oldest, i. e., over 50 cm. long, (mostly over 10 years old) less than i "/o. 

 This zone is thus the district of small and undersized plaice. As shown by the scientific 

 catches, great quantities of plaice are caught here, which, falling below the legal or 

 practically accepted size-limit of 18 cm., are thrown away, and never reach the market. 

 This then, is the region, where the useless destruction of enormous quantities of young, 

 immature, undersized plaice, is continually carried on. 



2. The two areas Bi atid d form the medium plaice zone of the North Sea. 

 Although in point of space almost as large as the first, this zone yields annually only 

 about 9 million kg. and only 29 million fish, these being however, for the most part larger 

 plaice, with an average weight of about 300 gr. The greatest density of the plaice 

 lies from 26 to 28 cm., the median from 28 to 29 cm. Only about one-fifth of all the 

 plaice are under 25 cm. long, and scarcely half under 29 cm. Large plaice, i. e. over 

 35 cm. make up about 10 to 20%; very large and old, over 50 cm. about i to 2 "/o. 

 The useless destruction of small, unmarketable plaice is here extremely restricted, and 

 occurs only in certain parts of B3. The question of protective measures here therefore, 

 no longer applies. 



J. The areas Ci, B\, D\, D% and E form the extreme northern plaice zone of 

 the North Sea. In point of extent about as large as the first two combined, this zone 

 is represented in the landings with an annual yield of only 4 million kg. and 5 million 

 fish; these being, however, large plaice with an average weight of about 800 gr. The 

 number of undersized plaice (under 25 cm.) here amounts to oui)' o to 6V0; that of 

 the "small"' (under 29 cm.) at the outside three tenths of the total. The "large" plaice 



