4. 



Canyon is a mid-Atlantic canyon and is thought to be largely 

 inactive (Keller and Shepard, 1978) . This would indicate 

 that it is a site of high net deposition, being characterized 

 by a high sedimentation rate and predominantly silty substrate 

 with little exposed outcrop. In contrast, Oceanographer and 

 Lydonia Canyons, located off Georges Bank, are sites of active 

 erosion (Ryan et al. , 1978) . The low net deposition allows 

 exposure of massive rock outcrops, as well as numerous talus 

 blocks in their axes and glacial erratics on their walls. As 

 a result of these physical differences it would be expected 

 that corals and other filter- feeders would be a less important 

 component of the fauna in Baltimore Canyon when compared to 

 that of Oceanographer or Lydonia Canyons. 



A study of canyon faunal assemblages is important in 

 assessing the consequences of resource development for a 

 variety of reasons. Their faunal communities are composed of 

 a variety of trophic types with a particularly high proportion 

 of filter- feeders. Of the various trophic types filter- 

 feeders would probably be affected the most by activities that 

 change the characteristics of the water column. Additionally, 

 since canyons have been implicated in funneling nutrients 

 from the shelf to the deeper regions of the continental margin, 

 a thorough study of canyon habitats is important in assessing 

 the possible farther ranging impact of resource development. 



