PACJ'JC MURING 



DO l°78 



Po.,,1 I 



Inter 

 stats 

 Bridge 



Tongue ,0 | 

 Po.nt 5 o [ 



Tan, , 

 Po.nl 



Inter 

 s tale 

 Bridge 



Tongue 

 Po.nt 



n» IftJs^.w- 



kSf 



n-68 



10 12 If 16 18 20 22 24 

 FORK IF.NGTH IN cm 



Figure 2. Length frequency and food habits of Pacific herring captured at 

 four estuarine hydraulic scour sites during two surveys. The 

 IRI diagram for this and the following four figures shows 

 numerical percent of food organisms above the horizontal line, 

 the percent weight below the horizontal line, and width of the 

 box represents the percent frequency of occurrence of the item 

 in stomachs (see enlarged diagram below) . 



Index of Relative Importance (IRI) 

 numerical value determination 

 (N + W)F = IRI. 



100 



50 



50 



tool 







PERCENT 

 NUMBER 



PERCENT 

 WEIGHT 



50 100 



PERCENT FREQUENC, 

 OF OCCURRENCE 



443 



