CONTENTS 



Page 



Introduction 1 



Apparent abundance 1 



Long-term trends in catch-per-unit-of-effort 3 



Deviations from the long-term trend 5 



Spatial statistics 8 



Interpretation 8 



Periodicities and trends 10 



Effort 11 



Catch and catch-per-unit-of-effort 12 



Average location 15 



Apparent movement 20 



Migratory route 23 



Size distribution 25 



Size distributions, growth rate, and the time interval between the mid- 

 dates of the various fisheries 25 



Correlation between apparent abundances for the pole-and-line fishery 



and for the longline fishery 26 



Tagging data 26 



Discussion and evaluation of present understanding 28 



Decline in apparent abundance.^ 28 



Spatial statistics 29 



The environment and anomalies in catch-per-unit-of-effort and spatial 



statistics 30 



Migratory route 32 



Evolution of migratory pattern 32 



Possible genetic effects of fishing 34 



Summary remarks 35 



Acknowledgments 36 



Literature cited 36 



