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Fishery Bulletin 102(1) 



Table 4 



Examples of the effect of timing on expected catch rates 

 of species in the South Pacific yellowfin tuna fishery. The 

 expected catch rates (number per 1000 hooks I are pre- 

 dicted from the soak-time coefficient for each species for a 

 longline operation with a soak time of 12 hours. The differ- 

 ent catch rates are for longline segments exposed to nei- 

 ther the dawn or dusk period, for dawn only, and for dawn 

 and dusk periods. LN = long-nosed; SN = short-nosed. 



For a few species (e.g. tiger shark) the poor correlation may 

 have been a function of small sample sizes and the wide 

 confidence intervals of the estimates. For other species the 

 estimates were well determined, yet poorly correlated, 

 e.g. the coefficient for short-nosed lancetfish was 0.09 



(CI ±0.05) in the Western Pacific distant fishery compared 

 to 0.01 (CI ±0.04) in the Western Pacific bigeye tuna fishery. 

 Therefore, we urge caution in applying our estimates to the 

 same species in longline fisheries in other areas. 



