A-54 



The results have identified canyons as unique habitats, 

 particularly for corals and other filter-feeding organisms. 

 It should be noted that these organisms can be considered as 

 potential environmental "indicators". As filter-feeders 

 they are directly tied to water column characteristics for 

 their nutrients. Thus, any development of resources on the 

 OCS that alters the characteristics of the water (i.e. 

 drilling increasing the amount of suspended particles or oil 

 spills decreasing the primary productivity) could potentially 

 increase coral mortality. Once coral communities, in a 

 specific area, have been located and identified they can be 

 revisited and used as "indicators" of environmental 

 disturbance. 



SUMMARY 



For the historical coral report all available submers- 

 ible dives on the mid- and north-Atlantic continental margin 

 were reviewed. Particular emphasis was placed on the canyons 

 found within this area. The depths studied ranged from 100 

 to 3200 meters. 



1. Corals were found at all depths within the study 

 area. Particularly high concentrations and more diverse 

 assemblages were found in the northern canyons. Several of 

 the species exhibited emergence with increasing latitude 

 while others did not. 



