72. 



is a large deeply incised canyon with steep walls and is 

 located off Georges Bank. The canyon walls and flanks consist 

 of a fine-grained substrate with extensive exposures of 

 rock and consolidated clay, while the walls along the thalweg 

 consist mainly of rock outcrops. Large talus blocks are 

 corranon in the axis of Oceanographer Canyon and numerous glacial 

 erratics are found on the east flank. The extensive exposure 

 of outcrops and numerous glacial erratics indicate that this 

 canyon is an area of contemporary erosion. The heterogeneity 

 of this canyon is high and this is reflected in the fauna, with 

 corals and sponges comprising a substantial proportion of the 

 fauna. As a result the dominant fauna found in Oceanographer 

 Canyon differs substantially from that commonly found on the 

 slope. 



(1) Faunal density is moderately low throughout most 

 of the depths surveyed in this canyon (400-1600 m) . 

 Between 1700 and 1800 meters faunal density is 

 quite high due to the presence of the ubiquitous 

 ophiurid Ophiomusium lymani, 



(2) The major faunal constituents of the middle depth 

 range (400 to 1100 m.) are shrimp and sponges. 

 Corals are also quite common in this depth range. 

 Below 1100 meters corals, shrimp and sponges again 

 are common constituents of the fauna. Other dominant 



