Year-Class Analysis 



455 



3 4 5 6 7 8 9 10 1112 13 14 1516 17 18 19 20 21 



Fig. 12.13. Age composition of catch of Norwegian herring {Chtpea harengus) in 



each of the indicated years, showing the predominance of a few good year-classes. 



( Russell and Yonge, 1928, Copyright, Frederick Warne after Lea. ) 



