OVERHOLTZ and TYLER: DEMERSAL FISH ASSEMBLAGES 



, GULF OF MAINE DEEP 



■^Nj: X NORTHEAST 

 SHALLOW --V \ PEAK 



INTERMEDIATE 



SLOPE AND CANYON 



FALL 1963 



Figure 3.— Georges Bank assemblages for three autumn surveys 

 1963, 1970, 1976. 



43<= 



42° - 



41° - 



40° 

 43° 



42° - 



4r 



40' 



71' 



70' 



69' 



68' 



67' 



66' 



Figure 4.— Sample pooled station distributions for the Slope and 

 Canyon assemblage, spring 1968-73 (top panel) and the Shallow 

 assemblage, autumn 1963-67. 



Data for all cruises were pooled by season and 

 used to generate composite maps of general assem- 

 blage areas, for the spring and autumn (Fig. 5). The 

 Slope and Canyon assemblage appears to encompass 

 a similar area regardless of season, while some of 

 the other assemblages changed slightly. The Shallow 

 assemblage covered most of Georges Bank in the 

 spring (Fig. 5) and was slightly smaller in the fall 

 (Fig. 5). The Intermediate assemblage is somewhat 

 larger in the fall (Fig. 5), suggesting a migration of 

 the species in this area to shallower water as the year 

 progresses. Assemblages in the spring appear to 

 follow depth contours resulting in the elongate shape 

 of the groups at this time (Fig. 5). The Northeast 

 Peak Interior (NPI) and Northeast Peak-Gulf of 

 Maine Deep (NP-GM Deep) assemblages show 

 definite seasonal spatial changes when compared 

 with the Gulf of Maine Deep (GM Deep) and North- 

 east Peak assemblages in the fall (Fig. 5). The 

 general shape and location of the fall assemblages 

 suggests that a different set of oceanographic and 

 biological forcing factors are important in deter- 



511 



