140 



120 



60-' 



40 



20 



0° 



l?S^ 



PACIFIC OCEAN 



40 



Figure 6. The distribution of Crassostrea virginica is indicated by the shaded 

 line. Note the distribution of the other major North American species, Ostrea 

 Turida, shown by the solid line on the west coast (adapted from Ahmed 1975) . 



19 



