Shima et a\ Spatial distribution of Theragra chalcogiamma in the Gulf of Alaska 



313 



I4(}l) 

 12(HI 

 KKK) 

 «IK) 

 600 

 400 

 2(I<1 

 



B 



It 



Int 



l(K)-2(X) :00-30() .iOO-5«) 



Bottom depth (m) 



0-20 20-40 40-60 



Distance from land (nmi) 



1400 -, £) 

 1200 - 



JllljJni 



JnJni 



Year 



Sliuma^'in Chinknt 



Geograptiic region 



Figure 4 



Tfie number of stations at which walleye pollock occurred by physical characteristic; (A) bottom depth (ml; (B) distance from 

 land inmi); (C) year; and (D) geographic region. 



pollock density was parsed into bins and plotted (Fig. 8). 

 The same trend seen in the adults was also seen with the 

 juvenile pollock. As the years progressed, there was an in- 

 crease in the proportion of stations that had low-density 



(<1000 fish/kni-) concentrations of all juvenile age groups 

 of pollock. For age-0 and age-1 pollock, there was about a 

 tenfold difference in the proportion of stations with low- 

 density concentrations after 1987 (Fig. 8 ). Age-2 pollock 



