However, in the absence of experiments with this type of ship, it 

 cannot be said with certaintyo An important part of their income 

 comes from the sole catches, and it is not unlikely that with cod 

 ends of more than 8 centimeter mesh width, they would lose sole of 

 16-30 centimeter. Generally sole of such size bring good prices, 

 often not much less than larger sole. There is no doubt that, with 

 wider cod ends, they would lose more whi tinge This would be of 

 little importance to the total amount of their returns since whiting 

 brings a very low price » It is to be expected that the loss of 

 whiting will be very well compensated by better catches, as a result 

 of the increase of density of the stock by the preservation of young 

 fish with the wide-meshed netso A serious objection against the 

 reduced catch of whiting, however, is the fact that the whiting in 

 normal times is so little in demand that it actually may be looked 

 upon as a sort of weedo The food consumed by the whiting could be 

 eaten by more valuable fish and, therefore, it is objectionable to 

 give the whiting an unlimited opportunity to increase itself o 



If one wants to be certain that the regulation (to use nets of 

 notb less than 80 millimeters) will not be by-passed, then one has to 

 set the minimum size for haddock at a length whereby three-quarters 

 of those which enter the net are caught. This means a minimum size 

 of 27 centimeters (see fig. 5A)» 



The size of 27 centimeters is absolutely necessary to prevent the 

 by-passing of the mesh-width regulations. As with eveiy minimxim size, 

 it has the disadvantage that some fish will have to be thrown back 

 into the sea. Included therein are fish which in the past had a 

 fairly good value. Therefore, we have to ask ourselves if this waste 

 is balanced by the advantages of the regulations. 



A series of tabulations has been made in table 12 to estimate 

 the price of 1,000 haddock while fishing with 1) nets with cod-end 

 meshes of 5 l/2 centimeter and 2) nets with a minimum mesh width 

 of 8 centimeters. In the first case, a minimtmi size of 21 centimeters 

 would be in effect. Before the war practically no haddock were brought 

 in below this size. In the second case, all haddock below 27 

 centimeters were taken to be valueless. 



In table 12a, the rate of growth has been taken as it was during 

 the period 1926-33, when cod-end meshes of 55 millimeters were prin- 

 cipally used (Raitt, 1939). It is calculated that 40 percent-per-year 

 of the haddock present were caught and with the aid of the selection 

 curve in figure 3a, it was tabulated how many fish of each age group 

 remained in the net (column 5). The natural mortality everywhere is 

 taken at 10^. The prices are the average prices during the period 

 1933-38 



61 



