LATER STAGES OF GADOIDS 



Upper decile corresponds to 

 a size of about lOO centi- 

 metres, or rather more. On 

 Smith Banl<, however, the 

 figure is smaller, and falls 

 to 65 centimetres at the 

 outer edge of the Bank; in 

 the shallow waters within 

 Burghead Bay we find the 

 upper decile at 52 centi- 

 metres; in other words, 

 here only 10% of the fish 

 are above that compara- 

 tively small size. Again, 

 it seems worth while to 

 give a chart of the upper 

 quartiles (fig. 30), or the 

 sizes above which lie 25 %, 

 and below which lie 75 % 

 of the total catch. These 

 figures are particularly strik- 

 ing in the contrast which 



Fig. 19. Upper deciles for the Cod of the Moray Firth. 



Fig, 30. Upper quartiles for the Cod of the Moray Firth. 



they indicate between the 

 shallow and the deeper sta- 

 tions. 



In the next place, fi- 

 gure 31, shows the average 

 catch per hour of Cod at 

 all stations in the Moray 

 Firth. The figures are 

 somewhat irregular, and 

 are all markedly small 

 in comparison with those 

 from the Firth of Forth 

 (figure 23). The largest 

 number are on and to the 

 east of Smith's Bank, in 

 the Dornoch Firth, and in 

 the deeper parts of Burg- 

 head Bay. 



Lastly, in figure 32, 

 we show the proportion 

 of Cod to the total catch 

 4 



