9. 



has major disadvantages, namely avoidance by many of the mobile 

 or burrowing organisms and poor recovery of fragile soft- 

 bodied organisms. Another problem encountered while dredging 

 was clogging with sediment. This latter problem was somewhat 

 alleviated toward the end of the second cruise by removing 

 the weight usually attached to the front of the dredge. This 

 resulted in the dredge skimming the bottom rather than biting 

 into it and thus allowing retrieval of more organisms. The 

 "voucher" specimens aided in identification of some of the taxa 

 observed on the photographs. 



METHODS 

 Slide examination and species recognition 



Estimates of the number of square meters viewed were made 

 to calculate abundances of the faunal constituents. The method 

 consisted of constructing and photographing a grid of 1 m^ 

 quadrants. The photograph of this grid was then projected onto 

 a screen and traced. A correction factor of 2/3 was then 

 applied to compensate for the refractive index of sea water. 

 One major problem of the camera system on "Cheep Tow" is that 

 the camera is oriented at a low angle with respect to the 

 bottom. This results in each photograph covering a large 

 area of the sea floor, but has the disadvantage of amplifying 

 errors in estimates of the area viewed if the sled is tilted 

 or off the bottom. Thus, any deviation from horizontal, or 



