Clardy et at: Relative contribution of Scomberomorus cava/la stocks to winter fisheries off South Florida 
159 
was not the case in winter 2002-03. Zone 1 and zone 
3 in particular showed reductions of 35% and 45%, 
respectively, in the contribution of Atlantic females in 
2002-03. It is unclear why Atlantic females were esti- 
mated not to have contributed as significantly to land- 
ings in these zones. Differences in classification accura- 
cies between summer 2001 and summer 2002 females 
may have affected landings contribution estimates, but 
discriminant function classification accuracies differed 
by only 7% between years. The reduced contribution of 
Atlantic females in winter 2002-03 most likely reflects 
temporal variability in stock mixing. 
Overall, results of this study provide further evi- 
dence that the U.S. Atlantic king mackerel stock con- 
tributes a certain, and perhaps a significant, per- 
centage of landings taken in the management-defined 
winter mixing zone off south Florida. Based on our 
results, fisheries managers should consider adopting 
some form of a gradient approach in attributing south 
Florida winter landings to GOM and Atlantic stocks. 
An alternative, and perhaps more easily defended, 
management approach may be to assign 50% of win- 
ter mixing zone landings to the Atlantic stock in the 
absence of annual estimates of stock-specific landing 
contributions. 
Acknowledgments 
This study was supported by the Marine Fisheries 
Initiative (MARFIN) Program (contract number: 
NA17FF2013). The authors thank C. Newton, J. Lehrter, 
