— 21 



I.ATI'.H STAC.I'IS OF GADOIDS 



The largest catches are at Stations I and VI, where we have respectively 82 and 97 fish 

 per hour. 



The last chart of this series, figure 24, shows the proportion of Cod by number in 

 the total catch of all fish. The numbers are again smallest at the outermost stations, 

 and largest on the stations close to Inchkeith. In this case it is necessary to consider 

 the other species of fish to discover how the relative proportions of the Cod are in- 

 fluenced thereby. In Table IV these figures are shown for the Firth of Forth, and 

 again in Table V for the Moray Firth. As regards the Firth of Forth, we see that 

 on the outermost grounds it is the comparatively large quantities of Haddock which 

 tend to reduce the percentage proportion of Cod, while on the contrary the Had- 

 dock is much less plentiful than the Cod in the neighbourhood of Inchkeith. Many 

 other points which are brought out by this Table the reader may easily discern for himself. 



As regards St. Andrews and Carnoustie Bays, the quantity of Cod caught therein 

 has not been very great; and we find in both ^ 

 regions so marked a seasonal difference that 

 it is not convenient to bring together the total 

 catches, irrespective of season, as has been 

 done in the case of the Firth of Forth sta- 

 tions. Both in St. Andrews Bay and Car- 

 noustie Bay Cod are comparatively scarce in 

 summer-time. The median sizes at the different 

 seasons are given in a supplementary Table 

 from which it will be seen that the largest 

 Cod are certainly present in the winter-months. 



A similar phenomenon exists in the Firth 

 of Forth, though not to so great an extent. 

 It requires further investigation, but in a few 

 cases I have taken month by month the ave- 

 rage median size of the fish, and attempted 



to draw a smoothed curve through them. The result is shown below and in fig. 25 for 

 Station II (North Bay); the monthly means are apparently irregular enough, but when 

 smoothed by the process of averaging in sets of three, they give us a very fairly regular 

 curve, in which the smallest average size is seen to correspond to the month of August 

 and the largest sizes to the months of November to January. In St. Andrews and Car- 

 noustie Bays the same seasonal difference is still more conspicuous. 



Median sizes of Cod, in centimetres, at Station II. Firth of Forth. (Smoothed numb, in brackets.) 

 Jan. 40-8 (40-4) May 28-0 (33-0) Sept. 23-6 (29-5) 

 Feb. 30-5 (37-5) June 36-0 (30-5) Oct. 39-0 (31-9) 

 Mar. 41-2 (35-6) July 27-5 (29-8) Nov. 33-0 (40-7) 

 Apr. 35-0 (34-7) Aug. 26-0 (25-7) Dec. 50'0 (41-3) 



The same in Carnoustie Bay. 

 Jan.— Mar. 70-0 

 April— June 54-0 

 July— Sept. 29-0 

 Oct.— Dec. 56-5 



20L 



Fis 



n m w YYiwrnjuxjiMi 



25. The median sizes of Cod from month to 

 month, in the North Bav, Firth of Forth. 



