Theoretical Distributions Based on Negative Binomial Models 

 n=500 



Expected distribution- Jeffreys Ledge 

 Expected distribution- Fippenies Ledge 



1>^^?r<T^, 



s s s s s 



' I ' 2 ' 3 '4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 >I8 

 Scallops/Photograph 



Figure 5. Illustration of the negative binomial model for number of scallops 

 per photograph on Jeffreys ledge and Fippennies Ledge. Actual 

 population density is much higher on Fippennies than on Jeffreys 

 ledges as indicated by the much less truncated distribution in the 

 above illustration. 



«.2 



c </> 



to 



<v 



1.8 



1.4 



o ^ 



1.2- 



1.0— * 



2q 



4q. 



>l= contagious 



I = random 

 <l= regular 



Quadrat Size (q = 0.33 m ) 



Figure 6. Plot of Morisita's index of dispersion for three different size 

 photographic quadrats from the highest scallop density region on 

 Fippennies Ledge. A value >1 indicates a contagious distribution 

 while a value = 1 indicates ? a random distribution. The smallest 

 quadrat size examined (0.33m ) was statistically indistinguishable 

 from a random distribution. 



253 



