increase in growth of the fish and to show the 

 interrelation between the various fishing areas. 

 Admittedly some of the analyses contained in 

 this report require additional study and I hope 

 my discussions will stimulate this effort by 

 other investigators. 



GENERAL BIOLOGY AND STRUCTURE OF 

 THE ATLANTIC MENHADEN POPULATION 



Menhaden have a rather complicated life 

 history. Although menhaden spawn in oceanic 

 waters (Sutherland, 1963), the larvae enter 

 estuaries and spend several months in the 

 tributary streams reaching almost to fresh 

 water (Fig. 3). Whether some larvae remain in 

 the ocean is not known. During this period in 

 the tributary streams they metamorphose from 

 larvae into juveniles. Then, in late summer the 

 juveniles leave the tributaries and return to the 

 bays, sounds, and eventually the ocean. 



In the ocean, Atlantic menhaden undertake 

 rather extensive migrations— generally north- 

 ward in the spring and summer and southward 

 in the fall. Furthermore, as menhaden grow 



older they tend to migrate farther northward 

 each year so during the summer fishery you 

 generally have older fish to the north and 

 younger fish to the south. Throughout the 

 summer the fish generally are in water less than 

 20 fathoms deep and are in great concentra- 

 tions in localities with extensive estuarine 

 drainage systems, such as Chesapeake Bay. 

 Most of the menhaden in Chesapeake Bay are 

 reported to inhabit the bay throughout the 

 year while they are immature 1 and 2 year old 

 fish. When they reach maturity at the end of 

 that third season of growth— as 2+ fish (Higham 

 and Nicholson, 1964)— they leave the bay and 

 enter into the migrations and fisheries along 

 the coast. 



Age of Fish 



Since 1955, the Bureau of Commercial 

 Fisheries, and now the National Marine Fish- 

 eries Service, have regularly sampled the com- 

 mercial menhaden landings to obtain informa- 

 tion on the sex, age, and size composition of 

 the Atlantic menhaden resource. The pro- 

 cedures and results of the sampling were 



TRANSFORMING PREJUVENILE 



OCEAN 



ESTUARY 



\ 



ADVANCED LARVA 



INTfRMEOIATE LARVA 



\ 



WEEK OLD LARVA 



\ 



YOLK SAC LARVA 



/ 



— O 



FERTILIZED ECG 



SPAWNING ADULTS 



Figure 3.— Life cycle of Atlantic menhaden. 



