212 



Fishery Bulletin 103(1) 



578 



576 



57.4 - 



57.2 



152 8 



152 4 



152 

 Longitude (°W) 



151.6 



151.2 



Figure 3 



Geographic distribution of standardized catches (no. of individuals/m 3 ) 

 of age-0 walleye pollock iTheragra chalcogramma) collected in trawl 

 hauls conducted near Kodiak Island during 5-18 September 1993. 



dates in comparison to fish from the shelf (8 May). In- 

 terestingly, the hatching dates of the cohort of small in- 

 dividuals from Ugak Bay and inner Kiliuda Bay ranged 

 from June to July. 



Mean otolith increment width varied with area. It 

 was not necessary to include fish length as a covariate 

 (Table 2). For the 1-5 d precatch period, the large mean 

 increment width associated with fish from Chiniak Bay 

 (0.036-mm band width) was different from the means of 



Chiniak Bay 

 Ugak Bay 

 Kiliuda Bay 

 Shelf 



30 40 50 60 70 80 90 100 110 120 

 Standard length (mm) 



Figure 4 



Size composition (mm SL) of age-0 walleye pollock (Thcr- 

 agra chalcogramma) by area from samples collected 

 near Kodiak Island, 5-18 September 1993. 



each other area (Table 4). The only other difference was 

 between the Kiliuda Bay (0.026 mm) and shelf (0.030 

 mm) areas. The only difference for the 6-10 d precatch 

 period was again between the Kiliuda Bay (0.029 mm) 

 and shelf (0.036 mm) areas. 



No area effect on gut content weight (GCW) was de- 

 tected (Table 2). There was, however, a significant fish 

 length effect (Fig. 5C), and this was incorporated in the 

 final model (Table 3). After adjusting for length, area- 

 specific mean GCW agreed in rank with area-specific 

 fish weight (Table 4). 



Differences in taxonomic composition of age-0 pollock 

 diets resulted in a good separation of samples by area 

 (Fig. 7A, ANOSIM, K = 0.533, P=0.001). Each pair-wise 

 comparison of areas resulted in a significant difference 

 (P<0.05) (the one sample of small fish from Kiliuda 

 Bay, and two samples from the shelf of fish with empty 

 stomachs were omitted from the ANOSIM). The diet of 

 fish from Ugak Bay and Kiliuda Bay were mostly crab 

 larvae or copepods, depending on fish size (Table 5A). 

 Over the shelf, fish diets comprised mostly euphausiids 

 (74%). In contrast, fish from Chiniak Bay had a much 

 more varied diet; no single prey category exceeded 40% 

 of the items per stomach. Note the correspondence be- 

 tween the number of prey per fish (Table 5A) and mean 

 gut-content weight (Table 4); both were lowest for fish 

 from the shelf. 



Differences in taxonomic composition also resulted in 

 separation of the plankton samples by area (Fig. 7B, 

 ANOSIM, i? = 0.886, P=0.001). Pair-wise comparisons 

 indicated a difference between Chiniak Bay and the 

 shelf (fl = 0.813, P=0.029). Ugak Bay was not included 

 in the comparisons because only one sample was avail- 



