Composition and Distribution of Macrobenthic Invertebrate Fauna 



17 



of which the Virginian subprovince extends from Cape 

 Cod southward to Cape Hatteras (Ekman, 1953; 

 Hedgpeth, 1957). Although these views postulated the 

 highly visible physical features of Cape Cod and Cape 

 Hatteras as the boundaries between these provinces (a 

 credible hypothesis topographically and hydrographi- 

 cally), no definitive consensus of opinion among bio- 

 geographers of the period prevailed as to the precise 

 placement of the boundaries in the Northwest Atlantic. 

 Indeed, the plethora of varying definitions and terms 

 led to a rather confusing semantic problem that exists 

 to this dav. Further, these views resulted from studies 

 based almost solely on biological and physical data 

 from inshore or nearshore areas. 



Hazel (1970) reviewed the historical development of 

 faunal provinces for North America and Europe based 

 on the work of 17 authors from 1838 to 1966 and noted 

 that during that period essentially three biogeographic 

 schemes evolved to characterize the Northwest Atlantic 

 down to Cape Hatteras: 1 ) Cape Cod acts as a boundary 

 between the cold temperate Nova Scotian or Boreal 

 Province to the north, and the warm temperate Virgin- 



ian subprovince to the south, with Cape Hatteras form- 

 ing the boundary between the Virginian and Carolin- 

 ian subprovinces, which together formed the Trans- 

 Atlantic Province down to present day Cape Kennedy; 

 2) a region of overlap or transition, lacking a unique 

 fauna of its own (low endemism) with no provincial 

 status, between the Nova Scotian and Carolinian Prov- 

 inces; and 3) A cold temperate Boreal Province extend- 

 ing from Newfoundland to Cape Hatteras. 



Although more recent biogeographic studies, based 

 mostly on offshore fauna within the region, such as 

 those of Bousfield (1960), Coomans (1962), Schopf 

 (1968b), Franz (1970), Hazel ( 1970), Bousfield (1973), 

 Franz (1975), Bowen et al. (1979), Kinner (1978), 

 Watling (1979), Franz and Merrill (1980a, 1980b), and 

 Franz et al. (1981) have expressed concern over the 

 boundary's existence and have attempted to resolve the 

 semantic problem of terminology through revision and 

 simplification, they have not, for the most part, signifi- 

 cantly altered the three biogeographic concepts of ear- 

 lier workers. These recent works, however, have pro- 

 vided some new insights concerning the placement of 



Figure 10 



Distribution of minimum reported bottom water temperatures (in degrees Celsius) in the study area. 



