574 



Fishery Bulletin 100(3) 



Rajidae (skates) Somniosus pacifiais 



''■'•^■' 



tz 



hkillotus villosiis 



Tludcichilns /)iiLifuii\ 



Sliumagin Cliinkof Kodiak \akutalSoiitheast Shumagin Chirikot Kodiak ^^akulal SniulKasi 



Micros toinus pacijkiis (jlyphKepludus zachinis 



Depth (111) Shumagin Chirikof Kodiak 'I'akutatSoutheast Shuma gin Chinkof Kodiak Yakutat Southeast 

 '- ' 1 * . iiii i !i » i .» ii »m I ' , , 1 



-l-l- 



-l-l- 

 ++ 



Atheresthes s!omiii.s Sehustcs alutiis 



Shumagin Chirikol Kodiak YakutatSoutheast Shumamn Chinkof Kodiak ^'akutat Southeast 



Figure 10 



Changes in CPUE-where-present and frequency of occurrence (FO) by depth stratum and area for 

 eight species that increased significantly over time. Significant changes at the b"i level are indicated 

 by '+' or '-'. Changes that were significant at the Y7t level are indicated by '++' or '-'. Areas-depth 

 strata where a species was not caught in any of the five survey years are shaded. Significance was 

 tested by using generalized linear models including gear effects (see text). 



Therefore, the alongshore trends may be partly due to 

 differences in the distribution of sampling depth between 

 the eastern and western GOA resulting from differences 

 in topography. Nevertheless, we do not believe that the 

 magnitude of correlations (Table 3) presents a serious 

 problem for the general patterns that were observed for 

 CPUE, diversity, and species composition. 



Alongshore patterns in CPUE (Figs. 5 and 6) indicate 

 a higher biomass of demersal fishes in the western GOA, 

 particularly in the Kodiak Island area. If the higher bio- 



mass is related to the availability of food, this pattern may 

 reflect higher benthic productivity in the Kodiak Island 

 region. There are several pieces of evidence that suggest a 

 higher productivity in this region. First, there is a higher 

 benthic biomass and productivity of infaunal organisms 

 on the Chirikof and Kodiak shelf compared with the 

 Yakutat and Southeast areas (Semenov, 1965, as cited in 

 Feder and Jewett, 1986). Second, enhanced primary pro- 

 ductivity in the western GOA is evident in estimates from 

 coastsl zone color scanner (CZCS) data and from more 



