WHAT IS OVER-FISHING? 593 



A suitable size limit will be able, in some cases, (1) to augment the 

 average size of the II and especially of the III Groups ; (2) to increase 

 the numbers of the III Group, and thereby the number of eggs. 



A low size limit may be without any effect at all, while a too high 

 limit may cause an excessive number of " P " to die out or to be eaten 

 before they are fished. I imagine the best size limit will be found in 

 the neighbourhood of the upper part of the II Group, or perhaps in the 

 lowest part of the III Group, since the " P " at this point is growing 

 fast, and increases its value four to five times in one year's growth, and 

 since the " P " at this size obtains the highest price per kilo which on 

 the whole is paid for this species of fish at any size. 



The North Sea is, with regard to the " P," a well-limited area from a 

 biological point of view, but this is not so from all fishermen's points of 

 view. The interests of the shore-fishing vessels are not the same as of 

 the sea-going ; and over-fishing is, perhaps, not carried out in all parts 

 of the North Sea, but only in tliis area taken as a whole. I feel 

 inclined to think that the decrease of the total yearly catch of " P " is 

 essentially due to reduction of the III Group, and, consequently, that 

 the process of over-fishing takes place in the areas inhabited by the 

 fishes of this group, viz. in the open sea. If the shore-fishing vessels do 

 not affect the yield of the large open areas in the North Sea by killing 

 the young "P" on the shore, they should still be left in peace; but if 

 they are now interfering with greater interests, it may be necessary 

 that they, at least to some degree, should give way to the interests of 

 the commonwealth. 



It has been proposed by means of artificial hatching, and by artificial 

 fertilisation of eggs, to increase the stock of "P." At present we know, 

 however, that this remedy can only meet one kind of over-fishing. It 

 has also been suggested to fix a size limit simply from a biological point 

 of view, viz. one which should allow fish to spawn once before being 

 caught. This also does not deal with more than one part of the 

 problem ; but we have to consider all parts of the problem at the same 

 time as far as we are able. Which of these parts is the most essential 

 can only be ascertained through experience. Artificial hatching would, 

 e.g. probably in the Lim Fjord, be of no consequence because the water 

 is so dirty. I also consider all natural hatching here impossible for the 

 " P." In this place a new stock of " P " can only be produced every 

 year by immigration from the North Sea. We know, however, that 

 this immigration does not reach all parts of the fjord to the extent that 

 is desirable, so we help it artificially by transplanting. Such trans- 

 plantation would, I think, also be useful in larger seas, e.g. in the 

 North Sea. It would be a profit to the whole stock if multitudes of 

 small " P " were taken from the overcrowded shallow grounds where 



