CONTENTS 



Page 



Introduction 169 



Commercial production of yellowtail 170 



Price trends 170 



Landin gs 170 



Producing areas 171 



M igrations 175 



Yellowtail stocks 183 



The southern New England stock 184 



Landings 184 



Length composition of the catch 185 



Length-weight relation 192 



Calculating numbers of fish landed 195 



Catch per unit of effort 195 



Age determination 198 



Rate of growth 202 



Age composition of the landings 206 



Survival, mortality, and availability 210 



Immediate fishing mortality 210 



Mortality from tag returns in successive years 210 



Mortality and apparent abundance of age groups 212 



Reproduction 215 



Age and length at maturity 215 



Spawning season . 216 



Distribution of eggs and larvae 217 



Faunal changes on the yellowtail grounds 228 



Effects of the fishery on yellowtail stocks, 1942-49 230 



Management of the yellowtail flounder 231 



Conclusions 232 



Summary 233 



Literature cited : 235 



Appendix 237 



A. Sources of data on landings of yellowtail, 1940-49 237 



B. Methods of estimating catch by statistical subarea 238 



C. Length frequencies of yellowtail by statistical subarea, quarter, and sex, 

 1941-47 239 



D. Length and age frequencies of yellowtail from the southern New England 

 stock, by quarter and sex, 1942-47 246 



E. Yellowtail larvae taken in 1932 256 



F. Probit analysis 266 



III 



