FISHERY BULLETIN: VOL, 76. NO. 2 



SUMMARY AND CONCLUSIONS 



A study was conducted to identify the origin of 

 striped bass collected in the Atlantic coastal 

 fishery and estimate the relative contribution of 

 major stocks to the fishery. Quadratic discrimi- 

 nant analysis was applied to values of five mor- 

 phological characters obtained from Hudson, 

 Chesapeake, and Roanoke spawning-stock speci- 

 mens to determine functions which best separated 

 the stocks. Correct-classification percentages of 

 76.8, 67.7, 85.9'7f were obtained for the Hudson, 

 Chesapeake, and Roanoke spawning stocks, re- 

 spectively, resulting in an overall correct clas- 

 sification of 74. 47c of the specimens. 



A simulation study was conducted to investi- 

 gate the bias in as-classified, iterative, and ad- 

 justed estimates of relative contribution due to 

 misclassification error inherent in the discrimi- 

 nant functions. Results indicated that iterative 

 estimates may best approximate the true con- 

 tribution of the Hudson stock in oceanic collec- 

 tions. 



A stratified sampling design was used during 

 six 2-mo periods in 1975 to collect representative 

 samples of striped bass in the Atlantic coastal 

 fishery from southern Maine to Cape Hatteras. 

 This provided estimates of stock composition by 

 stratum throughout the year. 



Oceanic samples were classified by discriminant 

 functions and as-classified, iterative, and revised 

 estimates of relative contribution of the major 

 stocks were obtained. Mean iterative estimates of 

 relative contribution for 1975 are 6.59c Hudson, 

 90.87c Chesapeake, and 2.7% Roanoke stocks. 

 Iterative estimates of Hudson contribution for 

 legal-sized striped bass exceeded 207c only in 

 western Long Island Sound and the New York 

 Bight during certain months. In collections from 

 Western Long Island Sound and the New York 

 Bight, iterative estimates of the percentage of 

 sublegal-sized fish classified into the Hudson stock 

 were at least 807c during the May through October 

 periods. For Hudson River collections of overwin- 

 tering striped bass, an iterative estimate of 97.4% 

 Hudson stock was obtained. 



The occurrence of a dominant year class was 

 noted. Approximately 52% of the legal-sized 

 specimens collected in the 1975 oceanic sampling 

 program were from the 1970 year class, and 77% of 

 these were classified as Chesapeake in origin. 



Major conclusions drawn from the study are: 1) 

 the Chesapeake stock is the major contributor to 



the Atlantic coastal striped bass fishery from 

 southern Maine to Cape Hatteras; 2) the 

 Chesapeake stock is also the major contributor of 

 legal-sized striped bass in the vicinity of the Hud- 

 son River (western Long Island Sound and the 

 New York Bight); 3) sublegal-sized striped bass 

 collected in the vicinity of western Long Island 

 Sound and the New York Bight are predominantly 

 of Hudson origin; and 4l striped bass overwinter- 

 ing in the Hudson River are predominantly of 

 Hudson origin. 



ACKNOWLEDGMENTS 



We acknowledge Thurman L. Grove who in- 

 itiated the study and was instrumental in its suc- 

 cessful completion, and George A. Roth who 

 helped gather and process the data and aided in 

 report writing. We also thank Eddie Baldocchi, 

 Dana Grass, Michael Locke, Edwin Manter, 

 Ronald McGratten, Thomas Orvosh, Martin Ot- 

 ter, and Donald Strout for their help in gathering 

 and processing the data; John Bennett and 

 Leanna Pristash for their work in computer pro- 

 gramming; and Dennis DuBose for his help with 

 the Schuermann and Curry methodology. This 

 study was carried out under contract to Consoli- 

 dated Edison Company of New York, Inc., as part 

 of the Hudson River Ecological Survey. 



LITERATURE CITED 



ALPERIN, I. M. 



1966. Dispersal, migration and origins of striped bass from 

 Great South Bay, Long Island. N.Y. Fish Game J. 

 13:79-112. 

 AMOS. M. H., R. E. ANAS. AND R. E. PEARSON 



1963. Use of a discriminant function in the morphological 

 separation of Asian and North American races of pink 

 salmon, Oncorhynchus gorbuscha (Walbaum). Int. 

 North Pac. Fish. Comm., Bull. 11:73-100. 

 ANAS. R. E., AND S. MURAL 



1969. Use of scale characters and a discriminant function 

 for classifying sockey salmon (Oncorhynchus nerka) by 

 continent of origin. Int. North Pac. Fish. Comm., Bull. 

 26:157-192. 

 ANDERSON, T. W. 



1958. An introduction to multivariate statistical anal- 

 ysis. John Wiley & Sons, N.Y., 374 p. 

 CHAPOTON. R. B., AND J. E. SYKES 



1961. Atlantic coast migration of large striped bass as 

 evidenced by fisheries and tagging. Trans. Am. Fish. Soc. 

 90:13-20. 

 CHITTENDEN, M. E., jR. 



1971. Status of the striped bass, Morone saxatilis, in the 

 Delaware River. Chesapeake Sci. 12:131-136. 



344 



