35 



Another point which is not without interest with regard to 

 these northern shoals is that whereas the third year growth of 

 fish with four winter rings is chiefly under 25, 26 and 27 cm., the 

 third year growth of fish with six winter rings is, for a considerable 

 number of fish, under 23 and 24 cm. Whilst these smaller grown 

 fish may come from the younger slow growing fish of the northern 

 area, their numbers for the north coast of Sutherland and the 

 Shetlands probably point to their origin further west and south 

 respectively. Fish with a similar growth up to the third year 

 can be found in the samples of the east coast as far south as North 

 Shields and even Scarborough. 



The condition of the gonads of the herrings from the trawled 

 samples of North Shields suggested the possibility of these fish 

 joining the Yarmouth shoals for the purpose of spawning. With 

 the object of comparing the growth of the fish from the two areas 

 the table on the following page has been prepared. It will be seen 

 that there is a difference between the first year growth, the Yar- 

 mouth shoals containing a large number of fish with a compara- 

 tively small first year growth. Further the Yarmouth herrings by 

 the end of the sixth year have reached a growth equal to that of 

 the North Shields trawled herrings. From the number of samples 

 examined from these trawled herrings and the fish seen as landed 

 on North Shields Fish Quay, the shoals fished by the trawlers 

 have been considered for some years now as autumn spawners. 

 The Yarmouth shoals do not spawn until later in the year. 



If the difference in grow^th, as observed between the spring and 

 autumn spa^vners of Stornoway and the Shetlands, exists between 

 other shoals having a difference in spawning times, it would appear 

 that the difference in spawning time between the trawled and 

 Yarmouth shoals accounts for the comparatively quicker growth 

 of the latter with increasing age. 



The material available does not allow of a detailed examina- 

 tion of the data from the standpoint of age, maturity and growth, 

 and a comparison being made in this way between the two shoals. 

 It is thought, however, that the general view of the difference 

 in growth, as shown above, is sufficient to indicate a difference 

 between the two shoals, and that the samples examined give no 

 support to the trawled shoals joining the Yarmouth shoals for 

 spawning purposes. It is thought also that growth after maturity 



