23. 



canyons is similarly low. 



Comparisons of the field data with the results of faunal 

 density during the historical survey indicate that both 

 follow the same general trend (Fig. B-2, Appendix A), with one 

 notable exception. The densities in the middle depth region 

 (600-1600 meters) were somewhat higher in the historical 

 survey. This discrepancy in absolute values may be due to 

 the low angle of the "Cheep Tow" camera with respect to the 

 bottom magnifying errors in the estimates of area viewed. 

 Another factor explaining this difference could be that less 

 coverage of hard substrates was obtained during the field 

 program and such areas tend to support more abundant fauna. 



Faunal components 



Previous work has shown that the relative abundance of 

 faunal components changes with depth (Haedrick, Rowe and 

 Polloni, 1975; Grassle et al. , 1975; Appendix A). Generally, 

 the faunal assemblages of shallow-water regions are composed 

 of a variety of taxonomic groups and trophic types. The high 

 concentration of particulate nutrients on the shelf and upper 

 slope support a variety of organisms. The faunal assemblage 

 of mid-slope depths is dominated by demersal fish, such as 

 eels and rattails, and the red crab Gevyon quinquedens , 

 These organisms are large mobile predators and scavengers, 

 with the ability to cover large areas in their search for food. 

 This reflects the lower nutrient flux in the middle depth 



