Stem et al : Fish-habitat associations at edge of Oregon continental shelf 



545 



The second axis, which described 20% of the varia- 

 tion of relative fish abundance, presented an additional 

 independent pattern of variation among stations (Table 

 2, Fig. 3). This axis primarily contrasted transects at 

 stations 1 and 3 (shallow rock ridge) with transects 

 from all other stations. As in the first axis, transects 

 within stations along the second axis were heterogen- 

 eous; that is, the relative abundances of the fishes seen 

 varied among transects. Station 1 transects were 

 relatively homogeneous compared with transects at 

 stations 2, 3, and 6, which varied considerably. Variable 

 loadings indicated that this axis represented variation 



in the relative abundance of kelp greenlings and 

 lingcod, which were abundant on bank tops, versus 

 thornyhead and sharpchin rockfish, zoarcids, thread- 

 fin sculpin, and dover, rex, and slender sole, which were 

 abundant at other stations. 



Fish-habitat associations 



Of the 49 possible combinations of bottom type (7x7 

 types), 27 were encountered. Cluster analysis indicated 

 that habitat types had varying degrees of similarity in 

 fish assemblages (Fig. 4). Mud had the most distinct 



