The average density during the period 1933-35 ought to be 70a » 

 When calculated we found 69,5, a very minor difference o Finally 

 the value 40a, corresponding with a fishing standard of 60 percent, 

 was alMost reached in 1938 and far surpassed in 1939o This, too, is 

 in agreement with the condition as it was actually observedo 



Therefore, the North Sea is not able to deliver more than about 

 390 million kilograms of bottom fish per yearo One may catch larger 

 amounts than the optimxan catch and will be able to continue to do 

 this for several years, but the stock will decline in such a way that 

 a moment soon will appear where regardless of the increased energy 

 of the fishery the catches will decrease, and the decline will be 

 very fast because of the smaller production capacity of the stock* 



When a good stock is present in an accessible sea, and when there 

 is enough demand for fish, a fishery will develop in that sea which 

 will continue to increase in intensityo Not only will more fishermen 

 appear, but the fishermen vdll try to compensate for the decline of 

 the catch-per-unit-of-time, following the decline in strength of the 

 stock by fishing, by increasing the efficienpy of their fishing methods. 

 An abatement of the fishing intensity will ofecur again only when fish- 

 ing is no longer profitable. In that case, the largest and most ex- 

 pensive fishing operations will be the first to disappear, but the 

 state of overfishing will have already been exceeded. 



If it is desired to prevent the passing of the critical point, 

 then an unlimited increasing of the fishing intensity must be 

 prevented. The most practical way to accomplish this is by limiting 

 the quantity of ships fishing that area and, once this has been accom- 

 plished, by forbidding any increase in the catching power of the gear 

 in use. Increasing the efficiency of the industry may then take place 

 only by limiting the quantity of energy used per fish-weightj for 

 instance, by increasing the engine utility or improvement of the methods 

 to locate fisho 



The approximate 390 million kilogram bottom fish which the North 

 Sea can deliver each year will be landed by small vessels, which catch 

 chiefly flatfish, and by large trawlers Irhose catch consists chiefly 

 of haddock and cod. About 15 percent of the catch consists of 

 flatfish, the rest is roundfisho 



The average yearly capacity of the different ship types should be 

 calculated (this could be made even easier if types were standardized). 

 Then the total number of steam trawlers which may be allowed can be 

 adjusted to the available quantity of flatfish and roundfish. Finally, 

 since several countries take part in the North Sea fishery, it will 

 have to be established how many ships will be apportioned to each 

 country. Such a quota system is undoubtedly a serious breaking with 

 the traditional freedom of the seas, but it is the only sufficient 

 way to prevent overfishing and to assure a continuous flourishing of 

 the fishing industry. 



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