TABLE 10. --Mean length (in millimeters) of major age groups in end- 



of -season catches (October) of Atlantic menhaden, by area, and 



in the North Carolina fall fishery, 1955-58 



farthest northward at the beginning of each 

 successive summer season. 



Further evidence of mixing between seasons 

 is provided by the increased proportion of 

 successive age groups in each more northerly 

 area and a decrease in the proportion of older 

 fish in adjacent southerly areas at the beginning 

 of the summer fishery. This pattern is most 

 striking in the Chesapeake Bay and Middle 

 Atlantic Areas. The lengths of age-2 fish in 

 the South Atlantic Area at the beginning of the 

 summer fishery most closely resembled those 

 of age-1 fish caught in that area in the pre- 

 vious September or October. That fish in the 

 South Atlantic Area apparently furnished few 

 recruits to the Middle Atlantic stock is obvious 

 from the nearly complete separation of the 

 length-age curves for the two areas, but the 

 extent to which they may have participated in 

 the north-south migration of stocks north of 



Cape Hatteras cannot be determined from the 

 data presented. It is probable that the fish 

 which occupied North Carolina waters prior to 

 the appearance of the larger fish in November 

 also migrated southward, for an influx of fish 

 into northern Florida waters in late October and 

 November, similar in length-age to those 

 caught in North Carolina waters just prior 

 to the disappearance of the summer stock in 

 September or early October, was sufficiently 

 great in some years to permit operation of a 

 plant located at Fernandina Beach (see p. 3 and 

 June and Reintjes, 1959). It thus would appear 

 that the summer stock in the South Atlantic 

 Area does not mix to any great extent with 

 those farther northward. 



The foregoing hypothesis of a cyclic north- 

 south migration (with mixing taking place be- 

 tween seasons) of two major population com- 

 ponents, one occurring north of Cape Hatteras 



20 



