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Fishery Bulletin 100(3) 



of the environmental variables had significant loadings 

 (Table 6); however, it would appear to reflect some level of 

 biological richness. 



PCS accounted for 13% of the variance in the data set 

 (Table 6), whereas PC4 was responsible for only 7%. The 

 significant loadings on the environmental variables of 

 the former contrasted the biota on hard substrata of high 

 relief (boulder and reefs) with the biota of low relief areas 

 (Table 6). PC4 contrasted (much of) the biota with the sub- 

 strata, although few of the environmental variables had 

 significant loadings (Table 6). 



Selection of environmental features 



The observed associations between nekton and the bio- 

 physical environment were often due to active selection. 

 In the north only hake selected subsets of the available 

 environment based on major substratum type (and its 

 associated biota) (Table 7). This species avoided the rocky 

 extremes, but otherwise showed a pattern of distribution 

 that resembled that of the samples (Fig. 3A). Although 

 false jacopever and hake selected opposite environments 

 based on the broken or unbroken nature of the rock debris 

 (PC2), it would appear that hakes again tended to avoid 

 the extremes (Fig. 3, B and C). The other environmental 

 PCs were not significantly selected for by any species. 



Although interpretation of the results generated from 

 the northern data set is confounded by the (mixed) nature 

 of the samples (see Table 1), the same problems did not 

 hamper the data from the south. In the south, six species 

 of demersal nekton selected subsets of the available envi- 

 ronment based on the identified axes (Table 7). Hake, goby, 

 sole, and dragonet all appeared to select their environments 

 on the basis of general physical features (PCI). As in the 

 northern area, hake did not show a strong selection for axis 

 extremes (e.g. Fig. 4A), which in itself could mean that hake 

 did not favor very rocky or sandy areas. Dragonets and sole 



