592 WHAT IS OVER-FISHING ? 



named fish may then increase its stock and take its food in areas where 

 the "P" was formerly the dominant lish. This only means that the 

 equilibrium of nature has been disturbed by man. We may in many 

 cases expect other organisms to augment the disturbance by retarding 

 the rate of growth of the " P " and by augmenting its mortality, but 

 this has nothing immediately to do with over-fishing. 



How is it possible to recognise in nature which of the four kinds of 

 over-fishing we have to deal with in a particular case ? 



We suppose the " P " to be the most important fish in the North Sea, 

 and the fishing on the whole to be based upon it. We know that the 

 value of the total catch is going down year by year, and that the prices 

 per kilo of the various sizes have been constant or perhaps rising. We 

 know still further that the average size of " P " in the market has gone 

 down. We know the " P " of Group I to be living close to the shore 

 in shallow water, while Group II is living at greater depths, and 

 Group III in the greatest depths of the North Sea, We, furthermore, 

 are acquainted with the facts that no accumulated stock of " P " exists 

 here, that the weight of a II Group " P " on an average is one-quarter 

 kilo, and the price of each fish ten ore (three halfpence), while the " P " 

 of the relatively scarce III Group has a weight of one-half kilo, and 

 the price of it is forty ore (sixpence). 



Perhaps we shall never be able to prove in a purely scientific and 

 statistical manner, without experiments by preventive laws, which 

 kind of over-fishing, as set forth in II, III, and IV, actually has 

 damaged the stock of the " P " most seriously in the North Sea — 

 whether over-fishing of the mature III " P," relative destruction of the 

 immature II " P," or the destruction of the I Group. However, we 

 cannot ignore the fact that over-fishing is taking place, and that we 

 must do something if the fisherman is not to starve and the North Sea 

 become a barren " P " fishing ground. What must be done ? We must 

 do something that at the same time will help us in all the three kinds 

 of over-fishing. The remedy may be a suitable size limit for saleable 

 " P." If the size limit be sufficiently high, it will, in the markets as 

 well as in the sea, augment the average length of the " P," and, there- 

 fore, the number of eggs. It must be high enough to prevent saleable 

 fish of too small a size being admitted to the market. It must further 

 be provided that shrimp-trawling does not destroy too many young 

 " P," as we have perhaps here an essential factor in the problem of 

 over-fishing. In applying this method, all three kinds of over-fishing 

 will be dealt with at the same time. 



How to legislate here I do not wish to discuss, nor shall I propose 

 any particular size limit, since the most economical size limit can only 

 be shown by investigations all over the North Sea. 



