to over 8,000 SVLD in the early 1960's. A 

 large portion of this increased fishing effort 

 occurred in the Chesapeake Bay fishery, which 

 catches mainly immature, age-1 and age-2 fish. 

 The dominant role that the 1958 year class 

 played in the catches through the early 1960's 

 can better be seen from Figure 29, where the 

 annual catches by age are shown. 



Figure 29.— Number of Atlantic menhaden of ages 0-4+ 

 caught in the purse seine fishery, 1955-68 (black 

 areas show 1958 year-class). 



To see the true effect of the 1958 year class 

 on the annual catches, the numbers of each age 

 group caught annually should be weighted by 

 the average weight of the fish to give the catch 

 in weight. This has been done in Figure 30. 

 Thus, in 1959, the age-1 fish from the 1958 

 year class contributed more weight to the catch 

 than any other age group. Again, as 2-year-old 

 fish in 1960, 3-year-olds in 1961 and 4-year- 

 olds in 1962, this yeEir class contributed more 

 weight to the annual catch for any given age 

 than any other year class during this period. 

 This can be seen a little easier in Figure 31 

 where the catch by weight is grouped by age of 

 fish and year class. When the 1958 year class 

 virtually disappeared from the catch in 1963 

 and there were no subsequent strong year 

 classes, it is not surprising that the landings 

 declined. 



Thus, in the early 1960's the Atlantic 

 menhaden resource was in the predicament of 

 high levels of fishing effort, magnified by 

 improved efficiency of the fishery (Henry, 

 1968), coupled with the lack of any strong 



Figure 30.— Total weight, by age, of catch of Atlantic 

 menhaden, 1955-68. (Shaded areas show 1951 year- 

 class; black— 1958 year-class). 



year classes. The decline in the fishery for older 

 fish and the increased dependency on younger 

 fish was inevitable. The decline in the catches 

 would have been even greater except for the 

 increased size of fish and increased fishing 

 effort in Chesapeake Bay. 



Recruitment Predictions 



Of major importance to the proper manage- 

 ment of any fishery is the ability to estimate 

 the strength of the year class, before it enters 

 the fishery. One phase of the Atlantic men- 

 haden research program has been a project to 

 estimate the relative strength of the incoming 

 year class by sampling in various estuaries along 

 the Atlantic coast (Reintjes, 1969). During the 

 summer, and before seaward migration, 



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