AND DECENNIAL SUMMARY. 181 



manner altered by the closure. Further, while there is a 

 tendency to an increase in the warmer months, the differen- 

 tiation of the colder from the warmer months is less pronounced 

 in this group than in the bony fishes. The numbers, however, 

 were so small as to make it hazardous to rely on them. The 

 notion that young skate probably frequent rocky ground and 

 are thus free from injury by the trawl is unlikely. They occur 

 on the smooth ground where their parents live, as in the case 

 of the thornback in St Andrews Bay. 



Special attention was drawn in the Trawling Report of 

 1884 to the necessity for observing the increase in the size of 

 inshore flat fishes during the experiments after closure of a 

 bay^ It was commonly believed and generally stated by 

 fishermen that the flat fishes (pleuronectids) in open sandy 

 bays had been reduced in size by trawling, that is, all the 

 larger forms had been swept off. There were reasons, however, 

 in 1884 for desiring further information on this point, and hence 

 it was one to which the attention of the Fishery Board in 

 carrying out the experiments was specially directed. One of 

 these reasons was that in the deeper offshore water only adult 

 plaice had as a rule been found, whereas in St Andrews Bay and 

 similar regions an immense number of plaice of small size 

 occurred. Even at that time (1884) an attempt was made to 

 locate the several sizes of plaice and other flat fishes by 

 trawling in parallel lines from the region beyond low-water 

 mark outward. The remarkable uniformity of the saleable 

 plaice (7 — 13 inches) procured in such a bay as that of 

 St Andrews was another fact which suggested the true ex- 

 planation, viz., that the eggs, larval and post-larval plaice 

 sought the shore, and that the older plaice as they grew large 

 sought the deeper waters. Year after year since that date and 

 the closure the same size of saleable plaice from St Andrews Bay 

 has uniformly been obtained, showing that the original view 

 was correct, and that little alteration of any note had occurred 

 from the interference of man by the closure. 



In the summary in the 14th Annual Report it is stated 

 that from a " calculation of the average size of the individuals 



1 Op. cit. p. 379. 



