13. 



then used to assess faunal similarities between depths and 

 various locations. This method basically measures and groups 

 the samples by the degree of faunal overlap, in terms of 

 species composition. The results are presented in cluster- 

 diagram form, with the taxa responsible for the grouping 

 identified. 



The other method used to identify patterns of community 

 similarity and species distribution was rotated principal 

 components analysis. Each camera run was divided into con- 

 secutive 100 meter depth intervals. All species seen, and 

 their abundances, within a depth interval were combined into 

 a composite sample. After elimination of 100-meter depth 

 intervals in which fewer than 50 m'^ were viewed, 15 3 composite 

 samples were retained; 48 in Baltimore Canyon; 59 in Oceanog- 

 rapher Canyon and 46 in Lydonia Canyon. Of 155 recognizable 

 taxa possibly occurring in the study area 65 were encountered. 

 This resulted in a data matrix of 153 samples and 65 taxa. 

 Ten categories or taxa were dropped from the quantitative 

 analysis because they either provided no consistent faunal 

 information, such as burrows, or because they occurred in 

 such high concentrations that they were impossible to count 

 and tended to obscure the distribution patterns of less 

 abundant forms. In the latter case, the distribution of these 

 taxa was considered separately. 



Distributional patterns of faunal assemblages were studied 



