724 



Fishery Bulletin 94(4). 1996 



are not obvious and are not consistent with many 

 claims that have been based on much less extensive, 

 and less systematic, analyses. If a population is "man- 

 aged" such that spawner abundance is reduced to 

 low levels, the manager should not be surprised to 

 observe the smallest recruitment ever recorded. 



Are our results of practical importance for the 

 management offish populations? We believe the an- 

 swer is clearly "yes." The simple observation that 

 recruitment is generally lower at lower spawner 

 abundances implies that recruitment overfishing is 

 a pervasive problem among heavily exploited fish 

 populations. The collapse of many of the fish stocks 

 in the world, e.g. cod in eastern Canada (Myers et 

 al., in press), can be at least partially blamed on re- 

 duced recruitment associated with reduction in 

 spawner abundance. 



We conclude that fish populations should be man- 

 aged so as to maintain sufficient spawner abundance 

 to yield high recruitment. Recruitment overfishing 

 appears to be a common problem. 



Acknowledgments 



We thank the hundreds of assessment biologists 

 whose hard work made this meta-analysis possible. 

 We thank J. Hoenig, J. Hutchings, G. Mertz, N. 

 Shackell, and W. Warren for advice and are grateful 

 for financial assistance from the Northern Cod Sci- 

 ence program. 



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