510 



Fishery Bulletin 103(3) 



A High sampling-effort area 



1-Jan-01 16-Jan-01 31-Jan-01 15-Feb-01 2-Mar-01 17-Mar-01 1-Apr-01 16-Apr-01 1-May-01 



1-Jan-01 16-Jan-01 31-Jan-01 15-Feb-01 2-Mar-01 17-Mar-01 1-Apr-01 16-Apr-01 1-May-01 



' C South of survey area 



35 



0.0 

 1-Jan-01 



x2KJ^5cJ^bfe. 



4.000 

 3,500 

 3.000 

 2.500 

 2.000 

 1,500 

 1.000 

 500 



16-Jan-01 31-Jan-01 15-Feb-01 2-Mar-01 17-Mar-01 1-Apr-01 16-Apr-01 1-May-01 



Figure 5 



Daily average catch per unit effort (CPUE on left y-axis) for the observed Pacific cod (Gadus 

 macrocephalus) fishery by gear (see legend for units) and area (Fig. 1) from 1 January-30 April 

 2001 in the southeastern Bering Sea. Estimated cumulative catch (t) of cod by all gear types 

 by area is also shown (right y-axis). 



(slopes) in all cases were negative and significantly 

 different from zero. Collectively, these results strongly 

 indicate that cod fishery CPUE was negatively corre- 

 lated with cumulative catch. Initial biomass estimates 

 (B ) from the four regressions were similar and ranged 

 between 14,119 and 14,806 t, with 95% confidence in- 



tervals ranging from approximately 9000 to 25,000 t. 

 Use of different fishery catch levels (20%, 40%, 60% 

 cod in each haul) had little effect on the initial biomass 

 estimate but changed the estimate of q, which increased 

 directly with the threshold proportion of cod in each 

 haul (Table 5 and Fig. 7). 



