SUBPOPULATIONS OF THE STRIPED BASS ROCCUS 

 SAXATILIS (WALBAUM), IN TRIBUTARIES OF 

 CHESAPEAKE BAY!/ 



By 



2/ 



Edward C . Raney-' 



INTRODUCTION 



The striped bass, Roccus saxatilis 

 (Walbaum), is widely distributed along the At- 

 lantic coast from the St . Lawrence River to the 

 northern part of the St. Johns River, Florida, 

 and in the Gulf of Mexico from west Florida to 

 tributaries of Lake Pontchartrain, Louisiana. 

 Throughout its range it spawns in fresh water. 

 In southern tributaries of Chesapeake Bay, 

 Tresselt (1952) reported that its eggs were de- 

 posited in fresh water usually within 25 miles 

 of brackish water . The time of spawning varies 

 with latitude and local temperature conditions; 

 in the tributaries of Chesapeake Bay most 

 spawning occurs in late April and May . 



(1937 and 1941) demonstrated that the bulk of 

 the migrating schools which pass northward 

 along the coast in spring and southward in the 

 fall was largely of Chesapeake Bay origin . An 

 immense year class was produced in the Chesa- 

 peake Bay area in 1934 from one of the smallest 

 spawning populations then on record. This year 

 class produced large catches in Chesapeake Bay 

 and coastal fishery in 1936 and 1937. Fortunately, 

 this was followed by frequent successful year 

 classes and the present numbers of striped bass 

 remain high. Other populations are important 

 locally like that found in the Hudson River; this 

 population is a separate race (Raney and de 

 Sylva, 1953) and has a different migratory pat- 

 tern (Raney, Woolcott, and Mehring, 1954). 



In the Gulf of Mexico and at both extremes 

 of the range along the Atlantic Coast it is more 

 of a freshwater species and rarely undertakes 

 coastal migrations. In southeastern United 

 States it is icnown to move upstream as much as 

 100 miles to spawn and at least one population, 

 that of the Santee -Cooper reservoirs of South 

 Carolina, has been shown by Scruggs and Fuller 

 (1955) to be maintained at a high level without 

 returning to brackish or salt water. The biology 

 of the striped bass has been reviewed by Raney 

 (1952). 



The largest numbers of striped bass are 

 found in Chesapeake Bay and its many large 

 tributaries. The classic studies of Merriman 

 17 This study was supported by the U .S . Fish 

 and Wildlife Service as part of the Atlantic 

 States Cooperative Striped Bass Program of the 

 Atlantic States Marine Fisheries Commission 

 for which the author serves as coordinator. 

 William S. Woolcott, who assisted in this study 

 when a graduate student at Cornell University, 

 was a recipient of a Sport Fishing Institute 

 Fellowship Award, 1953-54. 



Optimum conditions for striped bass pro- 

 duction exist within the Chesapeake Bay region. 

 The many large rivers serve as breeding and 

 nursery grounds and Chesapeake Bay, with an 

 abundance of forage fishes, is an excellent feed- 

 ing area for juveniles and adults . Tagging 

 experiments by Pearson (1938) and tagging and 

 meristic studies by Vladykov and Wallace (1938 

 and 1952) suggested that different subpopulations 

 exist within the Chesapeake Bay region. Raney 

 and de Sylva (1953) produced further evidence, 

 based on relatively few specimens, of subpopula - 

 tion differences in the Chesapeake Bay area. 

 Studies of numerous samples of young of several 

 additional year classes from most of the large 

 and productively important Bay tributaries have 

 shown differences which are interpreted as in- 

 dicating the presence of several subpopulations 

 within the Bay. The results reported here are 

 based largely on fin ray counts. Where morpho- 

 logical differences have not yet been shown, the 

 2/ Fishery Research Biologist, U.S. Fish and 

 Wildlife Service and Professor of Zoology and 

 Fishery Biology, Cornell University, 

 Ithaca, New York. 



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