A-21, 



and Polloni, ]975). The environmental heterogeneity and 

 increased nutrient flux would allow canyons to support a 

 greater variety of species and trophic types. As a result, 

 canyons tended to have higher concentrations of corals. A 

 notable exception to this was Hudson Canyon which was pre- 

 dominated by fish and crustaceans, and followed the more 

 general trend seen on the slope. This may well be due to 

 the scarcity of outcrop within its axis. 



Norfolk Canyon is the only mid-Atlantic canyon in which 

 there is deeper dive coverage. Figure C4 shows the major 

 faunal components seen during dive transects in the axis of 

 this canyon. Dive 808 covered the depth range from 1050 to 

 1250 meters. All depths within this dive were dominated by 

 the quill worm Hyalinoec-ia artifex. The corals which com- 

 prised a minor component of the fauna were the solitary horn 

 coral Desmophyllum oristagalli and a white gorgonian 

 Aaanthogorgia armata, both of which require a hard substrate. 

 Dive 809 covered the axis from 1200 to 1550 meters. A 

 variety of tropic types were found in this interval. Gevyon 

 quinquedens dominated the first 50-meter depth interval. A 

 species of the burrowing cerianthid anemone dominated from 

 1250 to 1450 meters, fish dominated from 1500 to 1550 meters, 

 while two soft corals Anthomastus grandif torus and a species 

 of Pennatula dominated the last interval. During dive 810 

 deeper in the canyon axis the same two soft corals, A. gvandi- 

 florus and Pennatula sp. , dominated between 2150 and 2350 

 meters. 



