20 



1 — I — I — I — I — I — I — I — I — I — I — I — r 



SOUTH ATLANTIC AREA 



I .0 



T — \ — I — I — r 



N= 2,021 



N" 3,099 



CHESAPEAKE BAY AREA 



MIDDLE ATLANTIC AREA 



N«2,I32 



N« 1,800 



NORTH ATLANTIC AREA 



NORTH CAROLINA 

 FALL FISHERY 



1 — I — I I I — I — \ — I — I — rn — I I in I rn~ 



50 100 150 200 260 300 350 400 490 500 550 600 650 700 750 800 850 900 950 



BODY WEIGHT (G.) 



Figure 8. --Weight frequency of samples from purse seine catches of Atlantic manhaden, 1958 



fall fishery. Compared with the previous 

 season, mean lengths and weights of certain 

 age groups increased, while others decreased. 

 In all areas, age-1 fish (1957 year class) were 

 longer than those in the previous two year 

 classes and, except for those in the Middle and 

 North Atlantic Areas, were heavier. Mean 

 lengths of age-2 fish in the summer fishery, 

 on the other hand, were the shortest in the 

 past four seasons, but mean weights were 

 variable. Mean lengths and weights of older 

 age groups also were more variable in 1958, 

 but generally greater than those in previous 

 seasons. 



DISCUSSION 



Before discussing the 1958 fishery, it is 

 pertinent here to examine several hypotheses 



regarding the migrations and population struc- 

 ture of Atlantic menhaden developed from the 

 pattern of age and size distribution during 

 successive fishing seasons. These are: (1) 

 Atlantic menhaden undertake an annual, north- 

 south, cyclic migration; (2) there are at 

 least two recognizable subpopulations, and 

 during the summer, one is distributed from 

 Cape Hatteras, N. C, northward and the other, 

 south of that location; (3) year classes which 

 are represented in the summer fishery north 

 of Cape Hatteras are represented in the same 

 proportion in the North Carolina fall fishery; 

 and (4) the same length-age groups return 

 in spring to those localities occupied during 

 the previous autumn. 



That the fish migrate seasonally is generally 

 accepted, but whether the stocks in all areas 



16 



