A-5 



Corals are an important constituent of the fauna found 

 in canyons. Many of the coral species, though not all of 

 them, are restricted to hard substrates, such as outcrop and 

 glacial erratics. Additionally, they are suspension feeders 

 relying on the higher current activity for their nutrition. 

 Thus, resource development that alters the characteristics 

 of the water column in the vicinity of canyons might be det- 

 rimental to the coral communities. These characteristics 

 make corals good "indicator organisms" for assessing 

 potential environmental deterioration. 



DATA SET 



The data set for this report consists of information 

 collected from previous ALVIN and DIAPHUS dives. This was 

 accomplished by analyzing color slides taken of the seafloor 

 during the dives. Additionally, the data was augmented by 

 reviewing photographs obtained from camera lowerings within 

 the study area. The study area encompassed the region be- 

 tween Cape Hatteras and Georges Bank from a depth of 100 to 

 3200 meters. All available submersible dives within this 

 region were surveyed for the historical report. 



Table I lists the location and depth of the dives 

 viewed that had adequate picture quality and coverage for 

 systematic review and analysis of the slides. Table II lists 

 the location and maximum depth of dives that had very poor 



