Brodeur et al.: Distribution, growth, condition, origin, and associations of juvenile salmonids 



39 



June 



100 



Information remaining (%) 

 75 50 25 

 H 1 1 1 H 



Coho 



Chinook (a) 



Wolfeel 



Chinook (j) 



Lmgcod 



Steelhead 



Sablefish 



Market squid 



Whitebait smelt 



Pacific herring 



Surf smelt 



Darkblotched rockfish — , 

 Yellowtail rockfish — T~ 

 Rex sole — 

 Speckled sanddab — 



i 



August 



100 



r- 



Information remaining (%) 

 75 50 25 



H 1 1 1 h 



i 



Coho (a) 



Coho (j) 



Chinook (a) 



Chinook (j) 



Surf smelt 



Steelhead 



Medusafish 



Pacific saury 



Wolfeel 



Osmeriid (j) 



Blue shark 



Northern anchovy 



Rex sole 



Chub mackerel 



Pacific sardine 



Jack mackerel 



Figure 6 



Cluster species groupings by cruise. The dashed lines indicate the cutoff levels for each 

 cluster group. See Table 1 for scientific names. 



i> 



ing steelhead were classified within the same grouping that 

 included several pelagic juvenile taxa, including wolf-eel, 

 lingcod, and sablefish (Fig. 61. Two other clusters that were 

 not associated with juvenile salmon included a southern 

 inshore group consisting of market squid. Pacific herring, 

 and two species of smelt and an offshore northern group 

 consisting primarily of juvenile rockfish and rex sole. For 

 the August cruise, all salmonid juveniles and adults again 

 clustered together in one large group with surf smelt and 

 medusafish ( Fig. 6 ). The remaining three groups were much 

 smaller and consisted primarily of offshore pelagic species. 

 Cluster analysis of stations based on species assem- 

 blages, and subsequent examination of the cutoff level us- 

 ing MRPP, resulted in three groupings from both sample 

 periods (Fig. 7). MRPP revealed strong within-group 

 agreement for all levels (P<0.0001); however, delineation 

 at three groups was based on maintaining lower percent in- 

 formation remaining (<30%) and still having a meaningful 



level of resolution. There was some measure of geographic 

 separation among the three groups (Fig. 7). In June, group 

 A was predominantly inshore and mostly in the southern 

 half of the sampling area, group B was found mainly in 

 the middle shelf region and was more northern, and group 

 C was found predominantly offshore. In August, group A 

 consisted of only three stations, all south of Cape Blanco, 

 whereas groups B and C both spanned the entire shelf and 

 offshore region and had no particular north-south affin- 

 ity (Fig. 7). ISA of the groups from both sampling periods 

 showed that only groups A and C had indicator species 

 (Tables 6 and 7), whereas the intermediate groups had 

 none. 



Ordination analyses and environmental correlates 



NMS ordination of the June sampling period (Fig. 8A) 

 revealed most of the variance in the data: axes 1 and 



