- 400 



1951 



1953 



1955 



1957 1959 1961 



YEAR CLASS 



1963 



1965 



1967 



Figure 31— Total weight, by age and year-class, of catches of Atlantic menhaden, 

 1951-68. 



sampling crews visit a number of these tribu- 

 taries and estimate tlie abundance of juvenile 

 menhaden on the basis of catches in a surface 

 trawl hauled between two boats. Relative 

 abundance estimates are also made from aerial 

 surveys later in the fall to corroborate these 

 earlier findings. Although the relative abun- 

 dance estimates have been made since 1962, 

 more extensive coverage of the myriad of 

 tributaries along the Atlantic coast has been 

 achieved only in recent years; sampling tech- 

 niques also have improved markedly over 

 earlier years. 



These estimates of abundance of juvenile 

 menhaden are the first indication of the 

 strength of the year class. Consequently, they 

 are of vital importance to the fishing industry 

 and would be important in any management 

 plan for the resource. The relation between the 

 index of juvenile menhaden abundance, based 

 on the catch per 5-minute towing of a surface 

 trawl in a number of related and comparable 

 streams along the Atlantic coasts, and the total 

 catch from the year classes in the purse seine 

 fishery, is shown in Figure 32. The indices for 

 the 1962 and 1963 year classes obviously were 



Figure 32.— Relation between relative index of juvenile 

 abundance and total catch of Atlantic menhaden by 

 year-class, 1962-68. 



17 



