SEA FISHERIES 145 



(1) We have firmly established what had been 

 anticipated from previous but more limited ob- 

 servations that the young fry of plaice are reared 

 only in the shallowest fringe of coastal waters, 

 and in far greater numbers along the continental 

 than along the English side of the North Sea. 



(2) We have located important spawning 

 grounds in the most southern bight of the North 

 Sea, have traced the special migrations of both 

 sexes to these grounds on the advent of the 

 spawning season, and have watched the course 

 of their return migration to the feeding grounds 

 in spring. 



(3) We have determined the distribution of 

 the various sizes of plaice over a large part of 

 the North Sea, and can give clear indications 

 of the sizes which may be taken in different areas 

 at different seasons of the year, together with 

 the relative frequency of the various classes in 

 each area. 



(4) We have determined the rate of growth 

 of plaice from year to year, can now give a close 

 approximation to their weight and length at all 

 ages, and can follow the steady off-shore migra- 

 tions of each yearly group during the years of 

 adolescence. 



K 



