Figure l. — Stations near Kodiak Is- 

 land. Alaska, where Pacific cod were 

 collected by pots and trawls during 

 summers of 1973-75. 







... • ^ .. .. . . 



<J ••:/ 



• Pol Stations 



* Trawl Stations 



Crab occurrences were dominated by juvenile C. 

 bairdi. Snow crabs were the single most fre- 

 quently occurring food species found in Pacific cod 

 stomachs and occurred in nearly 40% of the cod 

 (Table 2t. The average number of snow crabs oc- 

 curring in cod feeding on snow crabs was 3.3 and 

 they ranged from 1.8 to 70 mm carapace width^ 

 (Hilsingeretal.^); 78*^ were between 7 and 23 mm. 

 Up to 32 crabs were found in a single cod stomach. 



Chionoecetes bairdi had become important in 

 the Alaskan and world markets with landings for 

 Kodiak increasing from 50.3 t in 1967 to 12,400 t 

 in 1976 (North Pacific Fishery Management 

 CounciF). Since juvenile snow crabs are a major 

 item in the diet of the Pacific cod, reduction of cod 

 stocks by the anticipated new bottomfish fishery 

 should improve the chances for survival of young 

 crabs. Enhanced recruitment of snow crabs to 

 fishable stocks might result from such improved 

 survival. 



^Females mature at about 72 mm carapace width (Hilsinger et 

 al. see footnote 6) and males at about 110 mm carapace width 

 (BrowTi and Powell 1972). 



''Hilsinger, J. R., W. E. Donaldson, and R. T. 

 Cooney. 1975. The Alaska snow crab, Chionoecetes bairdi, 

 size and growth. Unpubl. manuscr., 38 p. Univ. Alaska Sea 

 Grant Rep. No. 75-12 (Inst. Mar. Sci. Rep. No. 75-6). 



'Fishery Management Plan and environmental impact state- 

 ment for the tanner crab off Alaska. Sept. 23, 1977. Unpubl. 



Pandalid and crangonid shrimps were impor- 

 tant in the diet of the Pacific cod in the Kodiak 

 area, a region where both groups are abundant in 

 species and numbers (Ronholt 1963; Barr 1970; 

 Feder and Jewett^). 



Anonyx nugax may be the principal amphipod. 

 Amphipods which were occasionally preserved 

 from the stomach contents as well as from the 

 perforated bait cans in the crab pots were later 

 identified as A. nugax. Because of attraction to the 

 bait, the occurrence of amphipods in stomachs of 

 the pot-caught cod was probably artificially high. 



Occurrence of food organisms in trawl-caught 

 cod, in decreasing order was also fishes, crabs, 

 shrimps, and amphipods (Table 3). The most com- 

 mon fishes wereA. hexapterus, T. chalcogramma. 

 and flatfishes. The most frequently consumed crab 

 was C. bairdi. Shrimps were primarily Cran- 

 gonidae. 



Wilcoxon's paired-sample test indicated no sig- 

 nificant difference (a = 0.05) among food groups 

 from cod caught by the two methods, or between 

 sexes (Table 4). No sex differences were found in 



manuscr., 346 p., prepared by the North Pac. Fish. Manage. 

 Counc. 



«Feder, H. M., and S. C. Jewett. 1977. The distribution, 

 abundance, and diversity of the epifauna of two bays ( Alitak and 

 Ugaki of Kodiak Island, Alaska. Inst. Mar. Sci. [Univ. Alaska] 

 Rep. R77-3, 74 p. 



701 



