A-i 



yield densities in order of magnitude greater than those 

 obtained from trawls (Haedrich, Rowe and Polloni, 1975). 

 This is probably due to the fact that the more mobile 

 components of the epifauna can readily avoid the net. 

 Additionally, the uncertainty of the actual configuration 

 of the net with respect to the bottom is a problem that 

 excludes trawling as a valid quantitative sampling 

 technique. 



The main disadvantage of using submersible photographs 

 to determine abundance of epibenthic organisms is that the 

 fixed camera is at a low angle with respect to the bottom. 

 This allows the camera to cover a large area, but also 

 results in amplification of errors in estimates of the area 

 observed. Thus, any deviation of elevation above the bottom 

 can substantially alter the size of the field of view. In 

 such instances estimates of the area viewed can be made in 

 relation to the size of organisms and various topographic 

 features. 



METHODS 



Slide Examination and Species Recognition 



The photographs reviewed from the ALVIN consisted mainly 

 of color slides taken with an externally mounted camera. 

 These were augmented by transcripts of the observers' comments 

 whenever they were available. To calculate abundances of the 



