Composition and Distribution of Macrobenthic Invertebrate Fauna 



127 



GRAMS 

 PER SQUARE METER 



BIVALVIA 



Figure 117 



Geographic distribution ol Bivalvia: A — number of specimens per square meter of 

 bottom; B — biomass in grams per square meter oi bottom. 



of Maine, on the Southern New England Shelf, and 

 along the continental slope south of Georges Bank and 

 Nova Scotia. 



Bivalves ranked above all other benthic animals in 

 terms of weight. Average biomass ranged as high as 

 3,162 g/m'-' in some 20-minute unit areas. High biomass 

 values of bivalves occurred over broad expanses of both 

 the inshore and offshore sections of the Southern New 



England continental shelf, in Great South Channel, on 

 the southern half of Georges Bank, and in coastal areas 

 of the Gulf of Maine. 



Within the six standard geographic areas bivalves were 

 most numerous (212 to 276 specimens/m 2 , respectively) 

 on the Southern New England shelf and in the Gulf of 

 Maine (Table 6; Fig. 118). Densities were moderate in all 

 other areas including Georges Slope and Southern New 



